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Optimization and comparison of continuous and discontinuous Current Source Drivers for MHz boost PFC converters | A Current Source Gate Driver Achieving Switching Loss Savings and Gate Energy Recovery at 1-MHz | Plane-based Surface Regularization for Urban 3D Reconstruction | eng_Latn | 13,200 |
what kind of converter for croatia | One Wonpro Non-Grounded plug adapter for Croatia. One Basic Grounded plug adapter for Croatia (other outlet configuration if needed) One Basic Non-Grounded plug adapter for Croatia (other outlet configuration if needed) One Black Travel Velvet Carrying Pouch with Drawstring closure Large 4 wide x 5 inches. | The flyback converter is used in both AC/DC and DC/DC conversion with galvanic isolation between the input and any outputs. The flyback converter is a buck-boost converter with the inductor split to form a transformer, so that the voltage ratios are multiplied with an additional advantage of isolation.he flyback converter is used in both AC/DC and DC/DC conversion with galvanic isolation between the input and any outputs. The flyback converter is a buck-boost converter with the inductor split to form a transformer, so that the voltage ratios are multiplied with an additional advantage of isolation. | eng_Latn | 13,201 |
Supporting change request assignment in open source development | Predicting fault incidence using software change history | Double-Deck Buck-Boost Converter With Soft Switching Operation | eng_Latn | 13,202 |
EXTERIOR: using a dual-VM based external shell for guest-OS introspection, configuration, and recovery | CloudVisor: retrofitting protection of virtual machines in multi-tenant cloud with nested virtualization | Single inductor three-level boost bridgeless PFC rectifier with nature voltage clamp | eng_Latn | 13,203 |
americas conference on information systems ( amcis ) december 2002 e - commerce adoption in developing countries . | Online banking: a field study of drivers, development challenges, and expectations | A Novel Phase-Shift Control of Semibridgeless Active Rectifier for Wireless Power Transfer | eng_Latn | 13,204 |
Three-Phase Three-Level DC/DC Converter for High Input Voltage and High Power Applications-Adopting Symmetrical Duty Cycle Control | Three-Phase (LC)(L)-Type Series-Resonant Converter with Capacitive Output Filter | Is open innovation the way forward for big pharma? | eng_Latn | 13,205 |
A Switched-Inductor Integrated Voltage Regulator With Nonlinear Feedback and Network-on-Chip Load in 45 nm SOI | A fully-integrated switched-capacitor 2∶1 voltage converter with regulation capability and 90% efficiency at 2.3A/mm2 | Representativeness revisited: Attribute substitution in intuitive judgment | eng_Latn | 13,206 |
Analysis and Design of Energy Regenerative Snubber for Transformer Isolated Converters | RC-RCD clamp circuit for ringing losses reduction in a flyback converter | object - based selective materialization for efficient implementation of spatial data cubes . | eng_Latn | 13,207 |
A Full Soft-Switching ZVZCS Flyback Converter Using an Active Auxiliary Cell | Transformer-Coupled Multiport ZVS Bidirectional DC–DC Converter With Wide Input Range | IMPACT OF CAPITAL STRUCTURE ON THE FINANCIAL PERFORMANCE OF NIGERIAN FIRMS | eng_Latn | 13,208 |
Evaluating React Native and Progressive Web App development using ISO 25010 | Survey, comparison and evaluation of cross platform mobile application development tools | High-Frequency Transformer Isolated Bidirectional DC–DC Converter Modules With High Efficiency Over Wide Load Range for 20 kVA Solid-State Transformer | kor_Hang | 13,209 |
Optimal Power Flow by Black Hole Optimization Algorithm | A new optimizer using particle swarm theory | Soft-Switching Zeta–Flyback Converter With a Buck–Boost Type of Active Clamp | eng_Latn | 13,210 |
Fundamentals Of Multiaccess Optical Fiber Networks | Effects of collisions in optical CDMA networks | Attention Network Test reveals alerting network dysfunction in multiple sclerosis | kor_Hang | 13,211 |
Joint Power and Rate Assignment for Downlink Throughput Maximization in Multi-Cell CDMA | This paper presents a full analytical characterization of the optimal joint downlink rate and power assignment for maximal total system throughput in a multi cell CDMA network. The paper has three main contributions. First, we provide an explicit and exact characterization of the structure of the optimal rate and power assignment: in a network with N base transmitter stations (BTSs) either all mobiles have maximum rate, or in k BTSs all mobiles have maximum rate and the other BTSs transmit at maximum power, or N-1 stations transmit at maximum power. Second, we give a characterization of the optimal rate assignment in each cell. Third, we give an exact algorithm for solving the rate and power assignment problem and a fast and accurate heuristic algorithm for power and rate assignment to achieve maximal downlink throughput in a multi cell CDMA system. | The invention discloses an MVB device status word transmission method based on load balance. Before bus resource allocation, all cyclic loads in a whole macrocycle are calculated according to allocation of application ports, calculation results are sequenced from small to large, and roll poling of a device status word is inserted in a low-load cycle in a single cycle according to the sequencing result. The method has the advantages that the principle is simple, network loads can be optimized, and correctness and stability of device state display are guaranteed. | eng_Latn | 13,212 |
A Bit Allocation Algorithm for MB-OFDM UWB with Spectral Mask Constraint | Optimal discrete bit loading for multicarrier modulation systems | Iterative overlap QRM-MLBD for single-carrier MIMO transmission without CP insertion | eng_Latn | 13,213 |
Generation of Orthogonal Logistic Map Sequences for Application in Wireless Channel and Implementation using a Multiplierless Technique | A New Optimal Design Method of Arbitrary Limited Period Spreading Sequences Based on Logistic Mapping | Orthogonal Experiment Analysis of Mechanical Thermal Conductivity on Multi-Component Fillers | eng_Latn | 13,214 |
A power assignment mechanism for OFDM-based underwater acoustic communication system | OFDM-based micro-signal communication method for the spherical amphibious underwater vehicle | Reducing the peak-to-average power ratio of OFDM | eng_Latn | 13,215 |
Performance of Adaptive Modulation Scheme for Adaptive Minimum Symbol Error Rate Beamforming Receiver | Planning Optimization of the Distributed Antenna System in High-Speed Railway Communication Network Based on Improved Cuckoo Search | Aldosterone Is Not Associated With Metabolic and Microvascular Insulin Sensitivity in Abdominally Obese Men | eng_Latn | 13,216 |
Development of a Software GNSS/RNSS Receiver with Carrier-Phase Output | RINEX: The Receiver Independent Exchange Format Version 2.11 | Completely Stale Transmitter Channel State Information is Still Very Useful | eng_Latn | 13,217 |
Multi-level EDT to Reduce Scan Channels in SoC Designs | EDT channel bandwidth management in SoC designs with pattern-independent test access mechanism | Completely Stale Transmitter Channel State Information is Still Very Useful | eng_Latn | 13,218 |
4/spl times/40 Gb/s, 75-km WDM transmission over conventional fiber using a broadband fiber grating | 16 x 10 Gb/s WDM transmission over 840-km SMF using eleven broad-band chirped fiber gratings | 16 x 10 Gb/s WDM transmission over 840-km SMF using eleven broad-band chirped fiber gratings | eng_Latn | 13,219 |
A 10-Gb/s burst-mode limiting amplifier using a two-stage active feedback circuit | A Burst-Mode 3R Receiver for 10-Gbit/s PON Systems With High Sensitivity, Wide Dynamic Range, and Fast Response | Completely Stale Transmitter Channel State Information is Still Very Useful | eng_Latn | 13,220 |
The measurement uncertainty challenge for the future technological nodes production and development | 3D-AFM tip to tip variations and impact on measurement performances | Completely Stale Transmitter Channel State Information is Still Very Useful | eng_Latn | 13,221 |
Iterative Overlap TD-QRM-ML Block Signal Detection for Single-Carrier Transmission without CP Insertion | Iterative overlap QRM-MLBD for single-carrier MIMO transmission without CP insertion | Therapeutic blockade of CD54 attenuates pulmonary barrier damage in T cell-induced acute lung injury | eng_Latn | 13,222 |
Increase of Reverse Link Capacity of the 3G CDMA Network by Mobile Transmit Diversity | The diversity gain and the reverse link capacity gain on the CDMA network from the mobiles with transmit diversity | The diversity gain and the reverse link capacity gain on the CDMA network from the mobiles with transmit diversity | eng_Latn | 13,223 |
RZ-DPSK Modulation Signal Generation using Only One Mach-Zehnder Modulator for 48 × 40 Gbit/s Ultra Long Haul DWDM Transmission | Performance Comparison of SSMF and UltraWave Fibers for Ultra-Long-Haul 40-Gb/s WDM Transmission | ERK-MAPK signaling opposes Rho-kinase to promote endothelial cell survival and sprouting during angiogenesis | eng_Latn | 13,224 |
Sideband-Separating SIS Mixer at 100GHz Band for Astronomical Observation | Plug-In Cryogenic System for Cartridge-Type SIS Receivers | Link adaptation in LTE-A uplink with Turbo SIC receivers and imperfect channel estimation | kor_Hang | 13,225 |
Iterative Receiver for MIMO-OFDM Systems with Joint ICI Cancellation and Channel Estimation | Optimal training design for MIMO OFDM systems in mobile wireless channels | No-Guard-Interval Coherent Optical OFDM for 100-Gb/s Long-Haul WDM Transmission | eng_Latn | 13,226 |
A second-generation 40/43-Gb/s CDR/DEMUX and MUX chipset in a 120-GHz-f/sub T/ SiGe technology is presented. While consuming 3.4-W, the fully-integrated CDR/DEMUX provides an electrical sensitivity of less than 40-mVpp at a BER of 10/sup -12/, the MUX consumes 2.3-W. Additionally, the integration of the chipset as a 3R-regenerator on a ceramic is demonstrated. | In this paper, a fully integrated 40-Gb/s clock and data recovery (CDR) IC with additional 1:4 demultiplexer (DEMUX) functionality is presented. The IC is implemented in a state-of-the-art production SiGe process. Its phase-locked-loop-based architecture with bang-bang-type phase detector (PD) provides maximum robustness. To the authors' best knowledge, it is the first 40-Gb/s CDR IC fabricated in a SiGe heterojunction bipolar technology (HBT). The measurement results demonstrate an input sensitivity of 42-mV single-ended data input swing at a bit-error rate (BER) of 10/sup -10/. As demonstrated in optical transmission experiments with the IC embedded in a 40-Gb/s link, the CDR/DEMUX shows complete functionality as a single-chip-receiver IC. A BER of 10/sup -10/ requires an optical signal-to-noise ratio of 23.3 dB. | In this paper, a fully integrated 40-Gb/s clock and data recovery (CDR) IC with additional 1:4 demultiplexer (DEMUX) functionality is presented. The IC is implemented in a state-of-the-art production SiGe process. Its phase-locked-loop-based architecture with bang-bang-type phase detector (PD) provides maximum robustness. To the authors' best knowledge, it is the first 40-Gb/s CDR IC fabricated in a SiGe heterojunction bipolar technology (HBT). The measurement results demonstrate an input sensitivity of 42-mV single-ended data input swing at a bit-error rate (BER) of 10/sup -10/. As demonstrated in optical transmission experiments with the IC embedded in a 40-Gb/s link, the CDR/DEMUX shows complete functionality as a single-chip-receiver IC. A BER of 10/sup -10/ requires an optical signal-to-noise ratio of 23.3 dB. | eng_Latn | 13,227 |
Filter-bank Multicarrier Modulation (FBMC) is a 5G waveform candidate with improved spectral efficiency and out-of-band emissions performance compared to OFDM. To address the challenge of designing flexible hardware infrastructures for future wireless communications, this paper presents a dynamically reconfigurable FPGA-based Frequency Spreading FBMC (FS-FBMC) baseband modulator. Based on a detailed modulator datapath analysis, the proposed architecture combines static multi-mode modules with dynamic partial reconfiguration (DPR) to achieve a flexible and evolvable system. Results show that our design is resource-efficient, due to hardware virtualization. Moreover, low-latency reconfiguration of static multi-mode modules combined with ICAP overclocking results in sub-millisecond reconfiguration times which are viable in the context of flexible communication systems, such as Cognitive Radios. | Scenarios envisaged for mobile communication systems beyond 2020 imply that future applications and services will impose highly diverse requirements on the system design. To appropriately respond to these requirements while ensuring an efficient usage of available spectrum and system resources, the air interface of 5G system is expected to provide much more flexibility compared to today's systems. Filterbank based multi-carrier (FBMC) may be considered a potential enabler for that purpose, as it provides excellent waveform properties with additional degrees of freedom for the system design, thanks to the use of prototype filters that may be adjusted to meet desired system constraints. This paper elaborates on the challenges that still need to be solved to render FBMC an eligible candidate as fundamental technology for 5G mobile radio and presents some first approaches towards practical solutions. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,228 |
A phaser-based processing technique was adopted in an UWB over fiber system employing SOA. The target is to simultaneously reduce the ASE noise impact and nonlinear effects inherent to optical amplification. Experimental results prove the effectiveness of chirping in terms of cross correlation and bit error rate. | The recent FCC frequency allocation for UWB has generated a lot of interest in UWB technologies. There is 7,500 MHz of spectrum for unlicensed use. The main limitations are provided by the low-power spectral density and by the fact that the transmit signal must occupy at least 500 MHz at whole times. IEEE 802.15.3a is being developed for high-bit-rate PAN applications, and UWB is the most promising technology to support the stringent requirements: 110, 200, and 480 Mb/s. Two UWB multiband systems, frequency hopping and Spectral Keying, have been described in this article. Both systems meet the stringent requirements provided by IEEE 802.15. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,229 |
In this paper we give an overview over the nonlinear impairments arising in passive optical networks (PON) and show different approaches to compensate for them before and after the transmission. | A nonlinear electrical equalization technique is proposed to improve the performance in optical duobinary modulation system. We show that more than 1000 ps/nm dispersion tolerance improvement and comparable performance to MLSE equalizer can be achieved. (2 pages) | By using the advantages of symmetry, a novel architecture of orthogonal frequency division multiplexing passive optical network (OFDM-PON) is proposed. It can not only achieve flexible protections but also provide the function of adding users conveniently. By utilizing the characteristics of ring based optical access network, the network keeps strong survivability against the fibers' failures. Based on a novel remote node (RN) with symmetrical structure and an expansible optical network unit (ONU), the network can add new ONUs easily. Simulation and analysis show that it can achieve perfect performance. Furthermore, the system also has low BER (bit error rate) and SER (signal error rate) for the different kind of signals, besides the system can adapt a variety of working modes. | eng_Latn | 13,230 |
The GLOBALSTAR System, is a Low Earth Orbit (LEO) satellite-based mobile communications system that is interoperable with the current and future Public Land Mobile Network (PLMN). The GLOBALSTAR System concept is based upon technological advancement in two key areas: (1) the advancement in LEO satellite technology; (2) the advancement in cellular telephone technology, including the commercial application of Code Division Multiple Access (CDMA) technologies.. The GLOBALSTAR System uses elements of CDMA, Frequency Division Multiple Access (FDMA), and Time Division Multiple Access (TDMA) technology, combining with satellite Multiple Beam Antenna ( M U ) technology, to arrive at one of the most efficient modulation and multiple access system ever proposed for a satellite communications system. The technology used in GLOBALSTAR exploits the following techniques in obtaining high spectral efficiency and affordable cost per channel, with minimum coordination among different systems: CDMA with power control Voice activity factor Spot beam satellite antenna for frequency reuse Weighted satellite antenna gain Multiple satellite coverage Soft handoff The GLOBALSTAR System design has the flexibility to use several frequency bands, which may be authorized by the Federal Communications Commission (FCC) and other international regulatory authorities. | The performance of a direct sequence spread spectrum CDMA communication system in an actual land mobile satellite channel is experimentally evaluated. Field test results using the ETS-V satellite in urban and suburban environments at L-band frequency show that this land mobile satellite channel of 3 MHz bandwidth can be seen as a non-frequency selective Rician fading channel as well as a shadowing channel. The bit error performance can be estimated using signal power measurements as if they were narrow band modulation signals. Based on the experimental results of the ETS-V, a prototype system for the personal satellite communication is proposed and field tests are planned on the S-band frequency using the ETS-VI satellite which will be launched in August 1994. > | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 13,231 |
100-Mbit/s fiber-optic transmitter and receiver modules using a 1.3-μm light-emitting diode (LED)-p-i-n combination are developed for computer-link applications. The use of a dc-balanced coding scheme is desirable in such applications from the viewpoint of improving the transient response of the system. A modified duobinary class-II coding scheme is applied as a transmission code. Four monolithic integrated circuits, that is, a preamplifier, an automatic-gain-controlled (AGC) amplifier, regenerator, and LED driver, are developed and confirmed to be useful for realizing highly reliable compact modules. These modules are tested using a standard graded-index fiber. An allowable span loss of 12.4 dB is achieved at an error rate of 10-12. The degradation due to the data pattern transients from 1/12 to 11/12 is negligibly small. Total power consumption of modules is a 1.4-W/module pair with a 5-V single power supply. | A modified version of pulse position modulation (PPM), asynchronous digital pulse interval modulation (PIM), is examined. The modulation scheme strengthens the viability of using LEDs as sources on a single mode fiber system, by allowing an increase in the peak power coupled into the fiber. First, an overview of the PIM code is provided. This is then followed by a detailed description of the 3B17P PIM code, which was implemented in an experimental 90-Mb/s communication system. Experimental results of the system's bit error rate (BER) versus the average received power were obtained for both the PIM and NRZ code over a coaxial cable link. The results are compared and discussed. The PIM code has a power advantage of up to 3.5 dB over the NRZ binary code. At a constant peak received power, the effect of the threshold level on the BER is similar for both codes at a high SNR. At a low SNR, there appears to be an optimal threshold level that depends on the duty cycle of the received code. > | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 13,232 |
Various PSK modulations as well as minimum shift keying (MSK) have achieved great improvements in the signal-to-noise ratio by utilising the nonredundant error correction (NEC) technique. The cost for this improvement is neither an increase in bandwidth nor an increase in transmission power, but some extra complexity in the receiver. The receiver is only equipped with a bank of differential detectors and a simple error detection/correction circuit, whose complexity depends on the correction capability that the transmit-receive system must have. Here, it is proved that it is possible to differentially detect correlative, nonsymmetric continuous-phase frequency modulations such as tamed frequency modulation (TFM) with NEC receivers. TFM has not been used as much as MSK until now owing to its generation difficulties, but its main advantages of constant envelope and of very high spectrum efficiency make it a perfect candidate to work upon. Hence, TFM is first contaminated with additive white Gaussian noise and is subsequently detected through a single-error-correcting NEC receiver. Both the theoretical analysis and the computer simulations show that substantial error probability reduction is achieved over differentially detected TFM systems. | We study the use a continuous phase modulation (CPM) system providing mobile data service with ::: QPSK transmission for a telemedicine system. The results of using an I/Q modulation and CPM schemes with ::: their BER performance are compared. The system provides direct symbol-by-symbol detection with no special ::: decoding mechanism necessary. We have compared the performance in bit error rate (BER) with coherent ::: detection of CPM and I/Q modulation. The scheme offers high bandwidth and power efficiency making it ::: particularly suitable for telemedicine applications. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,233 |
100 Gbps wireless – data link layer VHDL implementation | Improved turbo product coding dedicated for 100 Gbps wireless terahertz communication | V2V Radio Channel Performance Based on Measurements in Ramp Scenarios at 5.9 GHz | eng_Latn | 13,234 |
Fiber dispersion effect on subcarrier label detection in suppressed carrier systems | Chromatic dispersion in fiber-optic microwave and millimeter-wave links | High-speed running performance is largely unaffected by hypoxic reductions in aerobic power | eng_Latn | 13,235 |
FPGA Design and Performance Evaluation of a Pulse-Based Echo Canceller for DVB-T/H | An Upper Bound on the Probability of Instability of a DVB-T/H Repeater with a Digital Echo Canceller | Completely Stale Transmitter Channel State Information is Still Very Useful | eng_Latn | 13,236 |
A non-binary LDPC Code in WBAN: Patterned data transmission | Near Shannon limit performance of low density parity check codes | Design space of flexible multigigabit LDPC decoders | eng_Latn | 13,237 |
Design of an efficient uplink time alignment module for Long Term Evolution | Synchronization Techniques for Orthogonal Frequency Division Multiple Access (OFDMA): A Tutorial Review | Completely Stale Transmitter Channel State Information is Still Very Useful | eng_Latn | 13,238 |
Iterative Frequency Domain Equalization for OFDM Over Doubly Selective Channels | A space-frequency parallel ICI cancellation technique for OFDM systems | SNARE Function Is Not Involved in Early Endosome Docking | eng_Latn | 13,239 |
A multiple access scheme for the uplink of broadband wireless systems | Scheduling Based on Maximum PF Selection with Contiguity Constraint for SC-FDMA in LTE Uplink | Mdm2 promotes the rapid degradation of p53 | eng_Latn | 13,240 |
Enhanced performance of single-input multiple-output visible light communication system utilizing space diversity technology | Efficiency droop effects of GaN-based light-emitting diodes on the performance of code division multiple access visible-light communication system | Continuous Finite-Time Output Regulation for Disturbed Systems Under Mismatching Condition | eng_Latn | 13,241 |
New constructions of optimal frequency hopping sequences with new parameters | Two classes of near-optimal frequency-hopping sequence sets with prime-power period | An utter refutation of the ‘Fundamental Theorem of the HapMap’ | eng_Latn | 13,242 |
Multiple Antenna Enhancements for a High Rate CDMA Packet Data System | Layered space-time architecture for wireless communication in a fading environment when using multi-element antennas | Unenhanced multidetector computed tomography findings in acute central pulmonary embolism | kor_Hang | 13,243 |
Research of Low Power Design Strategy Based on IEEE 1801 Unified Power Format | Low-power Design of Digital Integrated Circuit Based on UPF Standard | White Paper Advanced Modulation Formats for Ultra-Dense Wavelength Division Multiplexing | eng_Latn | 13,244 |
Low-noise optical receiver front-end using narrow-bandwidth TIA and cascaded linear equalizer | An 82-m 9 Gb/s PAM4 FSO-POF-UWOC Convergent System | On the Fundamental Limits of Recovering Tree Sparse Vectors From Noisy Linear Measurements | eng_Latn | 13,245 |
Adaptive Resource Allocation and Scheduling for the Delay Limited OFDM Systems | Adaptive resource allocation and its scheduling for good tradeoff between power consumption and latency in OFDMA based wireless distributed computing system | No-Guard-Interval Coherent Optical OFDM for 100-Gb/s Long-Haul WDM Transmission | eng_Latn | 13,246 |
SPACE COMMUNICATIONS PROTOCOLS FOR FUTURE OPTICAL SATELLITE-DOWNLINKS | Optical technologies for terabit/s-throughput feeder link | Completely Stale Transmitter Channel State Information is Still Very Useful | yue_Hant | 13,247 |
Low-Level Multimedia Synchronization Algorithms on Broadband Networks | Communication support for multiple QoS requirements | Design space of flexible multigigabit LDPC decoders | eng_Latn | 13,248 |
A clock recovery algorithm for software defined radios and performance analysis over a frequency nonselective fading channel | Digital Communication Receivers: Synchronization, Channel Estimation, and Signal Processing: Digital E-BK | All-optical clock recovery from NRZ signal through preprocessing by single narrow-band filter | eng_Latn | 13,249 |
Improvement in the Spectral Efficiency Achieved in OCDMA using 1-Dimensional OOCs | Performance enhancement of optical code-division multiple-access systems using transposed modified Walsh code | On the impossibility of informationally efficient markets | eng_Latn | 13,250 |
A physical-layer encryption scheme is proposed and experimentally demonstrated in orthogonal frequency division multiplexing passive optical network (OFDM-PON). In the proposed multifold encryption scheme, quadratic-amplitude modulation (QAM) symbols are scrambled and distributed onto the complex plane independently. The dynamic parameters of constellation shifting are generated by a 3-D hyper digital chaos, in which a key space of ~10162 is created to enhance the security level of OFDM data encryption during transmission. An encrypted data transmission of 9.4-Gb/s, 16-QAM optical OFDM signals is successfully demonstrated over 20-km standard single-mode fiber. | We propose and demonstrate a physical-layer encryption algorithm against chosen-plaintext attacks (CPAs) in optical orthogonal frequency-division multiplexing (OOFDM) transmission, where the cyphertexts are dynamically generated for the first time by incorporating the random feature of the input data. The multiple-fold encryption algorithm consists of chaotic subcarrier allocation scrambling in time/frequency domains, chaotic phase rotation of subcarriers, as well as chaotic training sequence, which creates a total huge key space of $10^{194}$ by using a 4-D hyperdigital chaos. The transmission of 8.9-Gb/s 16-QAM encrypted OOFDM data is demonstrated over 20-km standard single-mode fiber. The proposed encryption scheme provides excellent confidentiality of OOFDM transmission against the brute-force attacks and CPAs. | The oxidative polymorphism of debrisoquine (DBQ) has been determined in 89 patients with colo-rectal cancer and in 556 normal control subjects. Four patients and 34 controls, with a metabolic ratio >12.6, were classified as poor metabolisers of DBQ (n.s.). | eng_Latn | 13,251 |
There has been an emerging interest in non-coherent ultrawideband (UWB) communications, mainly due to their low-complexity and low-power consumption. Due to the large transmission bandwidth, UWB systems need to coexist and contend with many narrowband communication systems. As a result, the presence of narrowband interference (NBI) severely degrades the system performance. In this paper, we consider transmitted reference signaling and analyze its bit error probability in a multipath fading channel when NBI is present. In particular, we consider the case of multiple NBI, where the interfering nodes are scattered according to a spatial Poisson process. Our framework is simple enough to allow a tractable analysis and provide valuable insights to the design of practical UWB systems. | In this paper, studies are performed and techniques are proposed for interference mitigation in Transmitted Reference ultra wideband (TR-UWB) system. The best method for suppressing and reducing the mutual interference is without modifying interfering systems. The coexistence of multisystem is given by: (a) Interference reduction from UWB systems to other narrowband (single and multiple) and wideband systems. (b) Interference reduction from other narrowband (single and multiple) and wideband systems to UWB systems. The TR-UWB signal using AcR based multi-resolution technique is used to avoid its interference to other wireless systems. By using a notch filter the reverse interference is alleviated at frontend of UWB receiver which is having much smaller bandwidth as Gaussian pulse-shaped multi-resolution environment. The BER performance of AcR receiver and modified TR-UWB receiver are investigated on AWGN and IEEE 802.15.3a UWB channel models. We show that for a modified TR-UWB receiver operating at low to medium SNR’s, the system performance increases as the single NBI are perfectly suppressed, while at high SNR’s the system still performs satisfactorily in presence of multiple narrowband and wideband interference using modified receiver structure in NLOS channel environment. | Cardiac surgical procedures typically use cardiopulmo nary bypass (CPB), a technique that diverts blood from the heart and lungs, where it is oxygenated and pumped back into the circulation. CPB is associated with significant pathophysiologic changes leading to an increased bleeding risk. Bleeding during CPB occurs for multiple reasons; the primary reason is the expo sure of blood to the material components of the CPB system, with intense systemic coagulation and platelet, fibrinolytic, and endothelial activation. To counteract the coagulation activation, extremely high levels of heparin anticoagulation are required to prevent sys temic thrombosis. Thrombin generation through tissue factor pathway activation is now thought to be the predominant mechanism of coagulation activation in CPB. The stimulus for tissue factor exposure to blood is thought to be a systemic activation of tissue factor on monocytes and endothelial cells caused by comple ment activation by the CPB materials and circulating inflammator... | eng_Latn | 13,252 |
The process margins of an emitter-base self-alignment structure were analyzed using two-dimensional simulations and experiments. The margins were obtained quantitatively in terms of ECL propagation delay time. It was found that the margin for emitter opening overetching was very large when the intrinsic base impurity was introduced before base sidewall formation. Misalignment of the emitter opening and the base opening was also analyzed. It was found that an alignment error of less than 0.2 mu m, which is within the misalignment margin of currently available steppers, does not lead to serious problems. > | A simple method for determining both the emitter and the base series resistances of bipolar transistors from the measured I - V characteristics is described. The method is based on the observation that deviation of the base current from the ideal \exp (qV_{BE}/kT) behavior at high currents can be attributed solely and relatively simply to series resistances. Series resistances determined by this method are given for sample high-speed digital bipolar transistors. | The effect of land cover is incorporated in the radio propagation prediction algorithm of Q-Rap. It is implemented by optimizing both the effective height of the land cover, hence affecting obstruction-loss calculations, and by adding terms to the basic transmission loss algorithm. A complete set of separate coefficients to these terms is determined for each land cover type. The optimization method improves the standard deviation of the error from 9.6 to 6.3 dB for measurements and predictions done at 390 MHz. This is an improvement of 3.3 dB over the original model that comprises the free-space loss equation with obstruction loss calculations for multiple knife edges. At this frequency, the correlation coefficient between the measured and predicted values improved from 79.5% to 85.6%. At 2145 MHz, the optimization method improves the standard deviation of the error from 16.2 to 8.6 dB, as well as the correlation coefficient between the measurements and predicted values from 56.2% to 70.5%. The use of the correlation coefficient between the measured and predicted signal values, in addition to the standard deviation of the error and mean error as criteria to be used when evaluating propagation prediction models, is also proposed in this paper. A basis for best practices in tuning propagation prediction algorithms in radio planning tools using semi-empirical models is presented. | eng_Latn | 13,253 |
In satellite multiple access communications a variety of measures exist with which to compare the performance of the various competing schemes. However, the results of these comparisons can be misleading. In particular, when comparing VSAT schemes which typically have a very large potential user population and a relatively small number of simultaneously active users, then traffic statistics must be included if the comparison is to have any relevance. A performance measure is introduced that takes into account the arrival statistics of the active users. This measure, termed the normalised throughput is then used to compare the performance of two schemes. The first scheme, FCMA, is a multiple access scheme proposed by the authors for application in VSAT networks. This new scheme uses signatures composed of discrete frequency elements, with well defined mathematical properties to M-ary modulate the data and simultaneously permit access to the channel resource. FCMA is suited to VSAT applications in which a small number of active users are randomly selected from a much larger potential user population. The second scheme, VFHMA, is a frequency hop satellite multiple access scheme, proposed by Viterbi (1978) and generally regarded as a benchmark against which the performance of competing schemes is measured. The comparison demonstrates that FCMA gives superior performance to VFHMA, for the range of parameters given and that both schemes outperform the traditional Aloha and Slotted Aloha channel access techniques. > | Time-hopping and frequency-hopping multiple-access (TH/FHMA) packet communication systems are proposed and investigated. In TH/FHMA communication systems, a message packet is encoded into several subpackets via a Reed-Solomon error correcting code. The subpackets are transmitted over the channel using time-hopping and frequency-hopping patterns. It is assumed that the channel is noiseless and the side information is perfect so that all subpacket collisions can be correctly detected. Slot-synchronous and totally asynchronous TH/FHMA systems are analyzed in detail, and they are shown to have excellent throughputs at small packet erasure rates. Various time-hopping techniques which significantly reduce the multiple-access interference are developed. > | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,254 |
We propose a novel optical double-sideband modulation technique with dispersion pre-compensation and free of dispersion-induced RF power fading and dispersion-induced phase shifting problems. Theoretical analysis and system simulations are carried out to evaluate this scheme. | We demonstrate that a nonlinearly chirped fiber Bragg grating can compensate RF power degradation in subcarrier-multiplexed (SCM) systems that is caused by fiber dispersion. Our all-optical technique provides tunable dispersion that compensates for multiple SCM channels simultaneously. We achieve RF-power-fading compensation for two SCM/BPSK 156-Mb/s channels in which the fading is reduced from 15 and 6 dB, respectively, to <0.5 dB for each channel. | A technique for measuring the accumulated dispersion affecting a digital optical signal without recovering the baseband was developed and experimentally demonstrated. This technique allows measurement of the accumulated dispersion independently of the data origin and transport history. The technique employs an amplitude-modulated double-sideband subcarrier applied to the signal at the transmitter and monitored at an arbitrary point in a link or network using a novel suppressed-sideband optical-tap technique. The phase difference between the upper and lower sidebands of the subcarrier signal is measured and used to compute the dispersion. A combined coarse and fine measurement realizes high accuracy and large dynamic-range dispersion monitoring. | eng_Latn | 13,255 |
This paper presented an enhanced of SINR based on serving and neighboring path loss to mitigate co-channel interference by using DSSS technique in LTE-Wi-Fi network. The proposed technique is the continuity from the earlier work which enhanced the DSSS with new coefficient: chip rate coefficient and radius fraction coefficient. The earlier works only consider its serving BS for path losses values. In this paper, an enhance DSSS technique is proposed which considers path losses for both serving and its neighbouring base stations in the network. The purpose of the proposed technique is to improve the signal-interference-to-noise ratio (SINR) value at UEs. The proposed technique applied delta path loss which is the path loss difference between the serving and the neighbours BSs. As the results, the SINR at MUE using the proposed technique gives better SINR around 66%∼72% improvements. On the other hand, the SINR at WUE using the proposed technique also gives better SINR around 155%∼170% improvements. | The deployment of modern mobile systems has faced severe challenges due to the current spectrum scarcity. The situation has been further worsened by the development of different wireless technologies and standards that can be used in the same frequency band. Furthermore, the usage of smaller cells (e.g. pico, femto and wireless LAN), coexistence among heterogeneous networks (including amongst different wireless technologies such as LTE and Wi-Fi deployed in the same frequency band) has been a big field of research in the academy and industry. In this paper, we provide a performance evaluation of coexistence between LTE and Wi-Fi systems and show some of the challenges faced by the different technologies. We focus on a simulator-based system- level analysis in order to assess the network performance in an office scenario. Simulation results show that LTE system performance is slightly affected by coexistence whereas Wi-Fi is significantly impacted by LTE transmissions. In coexistence, the Wi-Fi channel is most often blocked by LTE interference, making the Wi-Fi nodes to stay on the LISTEN mode more than 96% of the time. This reflects directly on the Wi-Fi user throughput, that decreases from 70% to ≈100% depending on the scenario. Finally, some of the main issues that limit the LTE/Wi-Fi coexistence and some pointers on the mutual interference management of both the systems are provided. | The catalytic removal of nitrogen oxides (NOx) from lean-burn exhaust emissions is one of the major challenges in environmental catalysis. Among the NOx emission control technologies, NOx storage/reduction (NSR) is currently regarded as one of the most practical technologies for lean-burn gasoline and diesel vehicles. This review gives a comprehensive overview of NSR technology, including the NSR reaction mechanisms, degradation mechanisms and NSR catalyst developments. The NSR reaction and degradation mechanisms will be addressed based on a typical NSR catalyst such as Pt/BaO/Al2O3, along with the concurrent new NSR catalyst developments for enhancing the NSR performance and alleviating their sulfur poisoning and thermal degradation. | eng_Latn | 13,256 |
The use of IP technology for delivering voice services is growing rapidly across all type of networks (fixed and wireless). One of the impairment factors that IP networks exhibit which affects the quality of voice services is packet loss. Different types of networks will have different packet loss characteristics, with most being susceptible to bursty loss, which can be significantly detrimental to voice quality. As part of the evolution of codec technologies, Enhanced Voice Services (EVS) has been introduced by 3GPP in order to provide higher speech and audio qualities at lower bitrates and higher resilience to packet loss compared with previous communication codecs. In this paper, a method has been developed for characterising and comparing the performance of codecs under different bursty packet loss characteristics. It has been used to compare the performance of EVS with AMR-WB and G.722. EVS has been tested with and without its partial redundancy mode, known as Channel-Aware (CA) mode. All codecs have been tested using a range of different packet loss profiles (PLPs) with loss rate values reaching 20% and mean burst length values going up to 10 packets. It was found that EVS with and without CA performs better than AMR-WB and G.722 for almost all the tested PLPs. | EVS, the newly standardized 3GPP Codec for Enhanced Voice Services (EVS) was developed for mobile services such as VoLTE, where error resilience is highly essential. The presented paper outlines all aspects of the advances brought during the EVS development on packet loss concealment, by presenting a high level description of all technical features present in the final standardized codec. Coupled with jitter buffer management, the EVS codec provides robustness against late or lost packets. The advantages of the new EVS codec over reference codecs are further discussed based on listening test results. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,257 |
We propose and numerically evaluate a novel sub-band processing architecture for computational complexity reduction of the perturbation-based nonlinear compensator. The complexity is reduced by a factor of 12.4 in 3000-km transmission with 0.1 dB penalty. | Digital nonlinear compensation techniques have been thought to be keys to realize further spectrally efficient optical fiber communication systems. The most critical issue of the digital nonlinear compensation algorithms has been their computational complexity, or gate count of digital signal processing circuit. Among several approaches, digital nonlinear compensation algorithms based on perturbation analysis are attractive in terms of the hardware efficiency because the algorithms can compensate the accumulated nonlinear noise over all transmission spans with only one stage. In this paper, we discuss three approaches to sophisticate the perturbation nonlinear compensation. First, we illustrate a perturbation-based post-equalization method to improve the robustness to transceiver device imperfections. We next propose and numerically evaluate a symbol degeneration method to extend the perturbation nonlinear compensation methods to higher-order QAM without increasing the computational complexity. Finally, we discuss a sub-band processing of perturbation nonlinear compensation for further computational complexity reduction. By combining the perturbation method with Nyquist frequency division multiplexing, the computational complexity of perturbation calculation is reduced by a factor of more than 10 for 3000-km single-channel transmission of 128 Gbit/s dualpolarization QPSK with only 0.1 dB performance degradation. | Digital nonlinear compensation techniques have been thought to be keys to realize further spectrally efficient optical fiber communication systems. The most critical issue of the digital nonlinear compensation algorithms has been their computational complexity, or gate count of digital signal processing circuit. Among several approaches, digital nonlinear compensation algorithms based on perturbation analysis are attractive in terms of the hardware efficiency because the algorithms can compensate the accumulated nonlinear noise over all transmission spans with only one stage. In this paper, we discuss three approaches to sophisticate the perturbation nonlinear compensation. First, we illustrate a perturbation-based post-equalization method to improve the robustness to transceiver device imperfections. We next propose and numerically evaluate a symbol degeneration method to extend the perturbation nonlinear compensation methods to higher-order QAM without increasing the computational complexity. Finally, we discuss a sub-band processing of perturbation nonlinear compensation for further computational complexity reduction. By combining the perturbation method with Nyquist frequency division multiplexing, the computational complexity of perturbation calculation is reduced by a factor of more than 10 for 3000-km single-channel transmission of 128 Gbit/s dualpolarization QPSK with only 0.1 dB performance degradation. | eng_Latn | 13,258 |
Evaluation of the candidates for the next generation cellular wireless standards is currently going on widely. One critical aspect in the standardisation process is the definition of terrestrial physical layer interface. The physical layer principles along with resource allocation mechanism on medium access control (MAC) together define how well the physical layer resources can be utilised. The prototyping environment presented in this paper has been built to analyse and validate effectiveness of the different design choices. As an example, the case considered is wideband time division multiple access (W-TDMA) based air interface developed in the EU ACTS AC090 FRAMES project. | An evaluation of several multiple access schemes against UMTS criteria has been carried out within the European FRAMES project. Based on this comprehensive evaluation, a harmonised radio interface termed FRAMES multiple access (FMA) has been designed consisting of two operating modes: a wideband TDMA mode with and without spreading (FMA1), and a wideband CDMA mode (FMA2). This paper describes the FMA1 radio access system proposal. The FMA2 proposal is described in Ovesjo et al. | An intuitive derivation of symplectic concepts in mechanics and field theory.- Nonrelativistic particle dynamics.- Field theory.- Examples. | eng_Latn | 13,259 |
Persistent median artery (PMA) thrombosis is a rare cause of carpal tunnel syndrome (CTS) with only a few cases reported in the literature. The bifid median nerve (BMN) is often associated with PMA and may be a factor in the development of CTS. There is a paucity of information in the literature on the management options for CTS secondary to PMA thrombosis. This paper presents two cases of CTS with associated PMA thrombosis and BMN and offers a discussion on diagnostic and management options. | Purpose: To determine the prevalence of aberrant or unexpected anatomic structures within one surgeon's elective experience of carpal tunnel releases and their association with pathologic compression. Methods: A total of 31 anomalies of median nerve, muscle, and tendon, median artery persistence, and ulnar nerve were documented in 30 hands during the course of 526 elective carpal tunnel releases in one surgeon's practice. The data collected were reviewed retrospectively. All carpal tunnel releases were performed open, exposing the median nerve from the palmar arch to the proximal wrist crease. Anomalies were categorized into those involving the median nerve and its motor and sensory branches, the ulnar nerve, a persistent median artery, and anomalies of muscle/tendon units traversing the carpal tunnel area. Results: Seven hands were noted to have aberrant muscle/tendon variations within the carpal tunnel region (1.3%). Anomalies of the median nerve or its palmar cutaneous or motor branches were observed in 5 hands (1.0%). An anomaly of the ulnar nerve with an aberrant branch crossing the carpal tunnel incision occurred in one hand. A persistent median artery (≥1 mm) was noted in 18 hands (3.4%). One hand had 2 anomalies present. One anomaly was high bifurcation of the median nerve and the second anomaly was an anomalous muscle to the long finger superficialis. Conclusions: The specific anatomic variations described may be anticipated and more readily recognized by hand surgeons during such open surgery, thus increasing the efficacy and safety of this common procedure. | We summarize the enabling technologies for photonics-assisted broadband millimeter-wave (mm-wave) communication, which is a promising candidate for the enhanced mobile broadband (eMBB) communications, one of the three main typical application scenarios of 5G wireless networks. These enabling technologies, mainly focusing on the improvement of the system structure, include broadband mm-wave signal generation with simple and cost-effective schemes, multiple-input multiple-output architecture with polarization-multiplexing optical mm-wave signal, advanced multilevel modulation, optical or electrical multicarrier modulation, antenna polarization multiplexing and the employment of the high-gain mm-wave antenna, multi-band multiplexing, and broadband mm-wave signal detection. We also review the advanced digital signal processing (DSP) for heterodyne coherent detection, which can be applied into the photonics-assisted mm-wave communication systems, to further enhance the system performance for a given system structure and certain available devices. Based on these enabling technologies and advanced DSP, we have realized over 1 Tb/s wireless signal transmission at D-band and over 2.5 km wireless transmission with a bit rate up to 54 Gb/s at W-band. Our work verifies the photonics-assisted broadband mm-wave communication can meet the high-data-rate demand of eMBB. | eng_Latn | 13,260 |
In this work we report a comprehensive experimental study targeting the dimensioning of the next-generation multicore-fibre (MCF) optical fronthaul employing space-division multiplexing (SDM). This fronthaul is capable of simultaneous provision of multiple radio-access technologies (multi-RATs) with advanced multi-antenna MIMO capabilities per RAT. The different parameters required for fronthaul dimensioning are evaluated considering state-of-the-art 4G LTE-Advanced altogether other legacy wireless standards in operation nowadays. In particular, the modulation characteristics, the antenna quality requirements (in terms of EVM, phase error or rho) and the signal-to-noise ratio (SNR) thresholds are evaluated employing fully-standard cellular signals transmitted on a multicore fibre (MCF) fronthaul. The study includes bi-directional signal transmission and multi-antenna MIMO multiplexing. The MCF optical fronthaul is evaluated with a multiplexed transmission of 2G, 3G, 3.9G and 4G MIMO signals in radio-over-multicore-fibre (RoMCF) employing a commercially available four-core MCF. The SNR requirements at the transmitter antenna are obtained for each cellular signal considering GSM, EDGE, EGPRS2-A, cdma2000 1xEV-DO, UMTS HSPA+ and LTE-Advanced standards. LTE-Advanced single-antenna and two-antenna systems implementing 2 × 2 MIMO transmission can be accomplished with SNR levels over 25 dB. In the case of LTE-Advanced 4 × 4 MIMO multiplexing over four cores of MCF media, 32 dB SNR is needed to achieve almost four times provided bitrate per user. | This paper describes and experimentally validates different multi-antenna system applications supported by a multicore fiber (MCF) optical fronthaul. The MCF fronthaul enables the simultaneous transmission of different optical data streams at the same wavelength by the spatial multiplexing of multiple-input multiple-output (MIMO) signals. In addition, the MCF enables simultaneous radio beamforming by transmitting the same optical data signal with different phase or time delays to each antenna element. Both MIMO and beamforming capabilities are required for 5G multi-antenna systems. Experimental demonstrations of $4 \times 4$ MIMO transmission and multi-beam $4 \times 1$ beamforming using a commercially available 4-core fiber are reported in this work. Optical beam-steering in 5G is achieved using a Si 3 N 4 photonic chip based on optical ring resonators (ORRs) that enables the continuous and centralized tuning of the time delay applied to each antenna element. | MLL1 regulates circadian promoters by depositing H3K4 trimethyl marks, whose levels are also modulated by the NAD+-dependent deacetylase SIRT1. SIRT1 is now shown to promote circadian deacetylation of MLL1, thus affecting MLL1's methyltransferase activity. | eng_Latn | 13,261 |
Optical code-division multiple access (OCDMA) for high-speed multimedia transmission is proposed and its performance is investigated. The proposed system introduces time hopping to vary transmission bit rate and power control to control transmission signal performance, which allows various signals with different desired rate and performance. An expression for the bit error rate (BER) of the proposed system is derived and numerical results are shown. An optical power selector (OPS) coupled with a hard limiter are also proposed to improve system performance. The OPS is a device to transmit the instantaneous maximum optical power among input signals. The OPS combined with the optical hard limiter reduces the interference from simultaneous users which results in an improved BER. BER is theoretically derived and numerical results for some parameters are shown. We show that the proposed system significantly improves BER and is an attractive scheme for future multimedia networks. | In this study, a distributed power control algorithm is proposed for Dynamic Frequency Hopping Optical-CDMA (DFH-OCDMA) system. In general, the DFH-OCDMA can support higher number of simultaneous users compared to other OCDMA techniques. However, the performance of such system degrades significantly as the received power does lower than its minimum threshold. This may obviously occur in a DFH-OCDMA network with near-far problem which consist of different fiber lengths among the users, that resulting to unequal power attenuation. The power misdistribution among simultaneous active users at the star coupler would degrade the Bit Error Rate (BER) performance for users whose transmitting signals with longer fiber lengths. In order to solve these problems, we propose an adaptive distributed power control technique for DFH-OCDMA to satisfy the target Signal to Noise Ratio (SNR) for all users. Taking into account the noise effects of Multiple Access Interference (MAI), Phase Induced Intensity Noise (PIIN) and shot noise, the system can support 100% of users with power control as compared to 33% without power control when the initial transmitted power was −1dBm with 30 simultaneous users. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,262 |
A non-orthogonal waveform transmission (NOWT) technique with convolutional multiplexing signalling (CMS) is introduced and analyzed, which can improve the data rate and spectrum efficiency of the wireless communication system. By narrowing the time interval of pulse shaping filter and overlapping parallel data branches together, the technique can obtain preferable gains compared with Nyquist signalling in the band-limited Gaussian channel, as well as frequency selective fading channel. The technique decreases E b /N 0 threshold distinctly compared with M-QAM technique, which can be used in the power efficient communications. It's proved that Nyquist signaling is not the optimal transmission criterion, and capacity of NOWT technique outperforms that of Nyquist system. | Preface 1. Introduction to digital communication 2. Coding for discrete sources 3. Quantization 4. Source and channel waveforms 5. Vector spaces and signal space 6. Channels, modulation, and demodulation 7. Random processes and noise 8. Detection, coding and decoding 9. Wireless digital communication. | Purpose ::: Is onset of symptoms in AV nodal re-entrant tachycardia (AVNRT) and accessory pathway-mediated re-entrant tachycardia (AVRT) patients gender-specific? | eng_Latn | 13,263 |
In telecommunication, Intersymbol interference (ISI) is caused by multipath propagation. The bandlimited frequency selective time dispersive channel distorts the transmitted signal, causing successive symbols to blur together. Therefore, the main objective of designing the transmitter and receiver is to minimize the effects of intersymbol interference, and thereby deliver the digital data to its destination with the smallest error rate possible. In this paper Adaptive Equalization technique is used to combat intersymbol interference. The proposed model is synthesized with ISE, simulated with Modelsim and implemented on Virtex2 based xc2v1500–5bg575 target device. The result shows that proposed model has the advantages of reduction in ISI using simple and less computational complex LMS algorithm along with enhanced performance in terms of speed, cost and area with existing results. | This paper presents the adaptive filters algorithms for removing noise from the Electrocardiogram to receive noise less pure embryo signals. Filtering ECG signals requires a filter which can automatically adapt according to changing input and noise. Adaptive filtering has been used to reduce the noise from the desired ECG signals by using LMS algorithm. Other algorithms like NLMS and RLS can also be used but LMS gives least MMSE amongst them so it can be used where accuracy is required. The measures of performance contains the optimization between the rate of convergence and MMSE by the help of MATLAB. The experimental results have shown that for small values of step size the rate of convergence increases. | Broadband wireless communication systems are currently in a rapid evolutionary phase in terms of development of various technologies, development of various applications, deployment of various services and generation of many important standards in the field. Ever increasing demand on various services justifies the need for the transmission of data at the highest possible data rates. The multipath and fading characteristics of the wireless channels result in various impairments and distortions, the most important of those being the Inter-Symbol Interference (ISI) especially at relatively high data rates. Among the various possible solutions to mitigate ISI, the adaptive equalizer remains one of the most attractive solutions, particularly the algorithms requiring minimal or no training sequence and at the same time are computationally efficient. This paper presents a novel neural networks based architecture for channel equalizers that require only order of 20–40 training symbols to converge to the optimum solution and at the same time is computationally efficient. | eng_Latn | 13,264 |
The question of the number of permeability measurements that are required to estimate the mean permeability of a reservoir interval is not generally considered during reservoir evaluation. Permeability sampling is traditionally carried out with core plugs (1.0-1.5 inch or 2.5-3.8 cm cylindrical samples) at a spacing of about 1 foot or 0.3 m. This spacing has evolved from considerations of practicality, cost and the need for core conservation, and takes little account of the underlying rock variability. | An integrated outcrop and subsurface study of permeability variations in the San Andres formation demonstrates the extreme heterogeneity present in this economically important carbonate horizon. Permeability measurements were made with a field permeameter and were compared to subsurface core data. Geostatistical techniques were used to predict variability and scales of spatial correlation. Measured permeability showed substantial variability within units arranged in three correlation scales. Outcrop permeability data exhibited no marked permeability anisotropy in predicted spatial correlation length. Several scales of spatial variability have been observed in an outcrop section, with subsurface results in agreement. | Wireless transmission over 15Gb/s data rate is reported using space diversity MIMO. Multi-diversity planar antennas are designed and fabricated to transmit and receive the radio frequency signal simultaneously in 2 radiation diversities. Reliable 15Gb/s indoor data transmission over 5m distance is demonstrated in the super high frequency band (SHF) of 11.6GHz to 20.4GHz. Low BER is achieved with 2×2 MIMO space time block coded OFDM modulation. | eng_Latn | 13,265 |
Confidentiality performance is analyzed in detail for a 2-D incoherent optical code-division multiple access (OCDMA) system, especially a multi-user two-code-keying wavelength- hopping time-spreading (WHTS) code system. The WHTS system's robustness against brute-force attacks is discussed. Other than brute-force attacks, several practical approaches are proposed to compromise the WHTS system. The effectiveness of these practical approaches is theoretically analyzed and an experimental demonstration is provided. Possible approaches to improve WHTS system's confidentiality are proposed and discussed. | We demonstrate all-optical wavelength and time code conversion for O-CDMA networks at 2.5-Gbit/s with 10-Gchip/s. Difference-frequency generation provides wavelength-shifting and fiber-Bragg gratings introduce cyclic time-shifts to the incoming code, generating a new time/wavelength code with less than 0.7-dB power penalty. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,266 |
Mobile WiMAX is a 3rd generation broadband wireless technology that enables the convergence of mobile and fixed broadband networks through a wide area radio-access. Since January 2007, the IEEE 802.16 working group has been developing a new amendment the IEEE 802.16 standard i.e. IEEE 802.16 m as an advanced air interface to meet the requirements of ITU-R/IMT-Advanced for 4G systems. The mobile WiMAX air interface adopts orthogonal frequency division multiple access (OFDMA) as multiple access technique for its uplink and downlink to improve signal performance affected by multipath distortion. All OFDMA based networks, including mobile WiMAX, experience the problem of high peak-to-average power ratio (PAPR). This paper presents a discrete-sine-transform precoding technique based random-interleaved OFDMA (RI-OFDMA) uplink system for PAPR reduction in mobile WiMAX. The PAPR of proposed system is analyzed with root-raised-cosine pulse shaping filter to keep out of band radiation low and to fulfill the spectrum mask requirements. Simulation results show that, the proposed system has low PAPR compared to the Hadamard transform precoded RI-OFDMA uplink systems and the conventional RI-OFDMA uplink systems. | Orthogonal frequency division multiplexing (OFDM) is an emerging technology in wireless communication system. It is a multi-carrier transmission and suggested for 4G network. It has advantages like efficient deal with multi-path propagation, robust against ICI and efficient use of bandwidth. But major disadvantage in the OFDM system is peak to average power ratio (PAPR), which reduces efficiency of the HPA used at transmitter and increase complexity of analogue to digital converter (ADC) and digital to analogue converter (DAC). Different techniques have been proposed for reduction of PAPR like clipping and filtering, coding scheme, SLM (selective mapping), PTS (partial transmit sequence) and precoding techniques but none of them give acceptable results. In this paper, PAPR reduction techniques have been discussed. Their working efficiency against PAPR, advantages and disadvantages will also be discussed. Peak to average power ratio is the ratio of square of maximum power of signal to square of average power of signal. Different techniques give different results but precoding technique show very good results in PAPR reduction process. Hybrid technique also gives acceptable results with very low complexity in PAPR reduction. | ABSTRACTUNC-45A is an ubiquitously expressed protein highly conserved throughout evolution. Most of what we currently know about UNC-45A pertains to its role as a regulator of the actomyosin system... | eng_Latn | 13,267 |
We develop a simulation platform for investigating the impact of component mismatch, caused by wavelength and/or time misalignments in the optical encoders/decoders or misbalance in the photodetectors, on the bit error rate (BER) system performance of 2D wavelength-time bipolar OCDMA systems | A new fast optical time-spreading/frequency hopping differential code division multiple access system with prime/optical orthogonal codes is proposed. The performance of a multiple Bragg grating fiber is analyzed. By assigning two orthogonal codes for one user and using these two codes to encode "1" and "0," respectively, differential detection can be adopted. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,268 |
In this paper, the authors briefly discussed some of the main benefits and challenges for Radio over Fiber technology when applied to 60 GHz wireless communication. In general, the benefits that RoF technology offers to low-frequency picocellular systems also apply to 60 GHz RoF systems. However, the hardware requirements for 60 GHz RoF systems are more stringent. We have shown that channel uniformity is an issue for 60 GHz RoF systems due to the wide channel bandwidth. We have demonstrated that linear feed-forward equalization may be used to reduce the distortion induced by channel ripples. Finally, we have experimentally demonstrated an optical I/Q direct launch transmitter at 60 GHz, and used it to generate 7 Gbps data on a single carrier - representing three times higher efficiency than simple ASK modulation. | A 60-GHz point-to-multipoint wireless access link with data rate of 156 Mb/s incorporating 60-GHz transceiver modules and full-duplex fiber-optic millimeter-wave transmission is developed for short-range applications such as indoor wireless local area networks and intelligent transport systems. For compact system configuration, a small-size millimeter-wave transceiver module with planar antennas is developed. The transceiver module is based on broadband planar integration and packaging of millimeter-wave circuits. The RF output power is +10 dBm and the measured 3-dB antenna beamwidth is 30/spl deg/. The total size of the developed 60-GHz transceiver module, except input and output connectors, is 50 mm /spl times/ 75 mm /spl times/ 35 mm. A point-to-point full duplex fiber-optic configuration is extended to the scheme with multiple access points (APs) by using a tree coupler and a dense wavelength division multiplexing multiplexer. The AP has a simple configuration without frequency conversion. The bit error rate and packet error rate performances of the 60-GHz fiber-radio access link are evaluated. Furthermore, the effect of the extension to the scheme with multiple APs is investigated. | Coherent optical modems have been implemented that provide low cost 40 Gb/s connections over any optical line that can support 10 Gb/s transmission. CMOS signal processing allows performance substantially independent of PMD and optical dispersion. | eng_Latn | 13,269 |
Silicon photonics has enormous potential for ultrahigh-capacity coherent optical transceivers. We demonstrate an in-phase and quadrature (IQ) modulator using silicon photonic traveling-wave modulators optimized for higher order quadrature amplitude modulation (QAM). Its optical and RF characteristics are studied thoroughly in simulation and experiment. We propose a system-orientated approach to optimization of the silicon photonic IQ modulator, which minimizes modulator-induced power penalty in a QAM transmission link. We examine the tradeoff between modulation efficiency and bandwidth for the optimal combination of modulator length and bias voltage to maximize the clear distance between adjacent constellation points. This optimum depends on baud rate and modulation format, as well as achievable driving voltage swing. Measured results confirm our prediction using the proposed methodology. Without precompensating bandwidth limitation of the modulator, net data rates up to 232 Gb/s (70 Gbaud 16-QAM) on single polarization are captured, indicating great potential for 400+ Gb/s dual-polarization transmission. | Codesign and integration of optical modulators and CMOS drivers is crucial for high-speed silicon photonic (SiP) transmitters to reach their full potential for low-cost, low-power electronic-photonic integrated systems. We present a CMOS-driven SiP multi-level optical transmitter implemented using a commercially available lateral p-n junction process. It uses a Mach-Zehnder modulator (MZM) segmented to increase speed and to lower the required power on a per segment basis to a level achievable with CMOS. A multi-channel driver is designed and implemented in 130 nm RF CMOS, providing a swing of 4 V in a push-pull configuration at 20 Gbaud. Binary data at the CMOS input is manipulated via digital logic to produce the proper per-segment drive signals to generate a four-level pulse-amplitude modulation optical signal. Multi-level modulation is achieved using only binary signals as input (DAC-less). Cosimulation of the optical and electrical circuits shows good agreement with experiment. Reliable transmission is achieved without post-compensation at 28 Gb/s, and at 38 Gb/s when using post-compensation. | The oxidative polymorphism of debrisoquine (DBQ) has been determined in 89 patients with colo-rectal cancer and in 556 normal control subjects. Four patients and 34 controls, with a metabolic ratio >12.6, were classified as poor metabolisers of DBQ (n.s.). | eng_Latn | 13,270 |
Fourth Generation (4G) wireless communication systems support current and emergent multimedia services such as mobile TV, social networks and gaming, high-definition TV, video teleconferencing, and messaging services. These systems feature the All-over-IP concept and boast improved quality of service. Several important R&D activities are currently under way in the field of wireless communications for 4G systems, but the coverage is widespread in the literature. Transmission Techniques for 4G Systems presents a compilation of the latest developments in the field of wireless communications for 4G systems, including evolved Multimedia Broadcast and Multicast Service (eMBMS). Topics include: Transmission schemes suitable for future broadband wireless systems Advances in transmission techniques and receiver design to support emergent wireless needs for 4G requirements Multiple-Input Multiple-Output (MIMO), base station cooperation, macro-diversity, and inter-cell interference cancellation Multihop relay techniques, hierarchical constellations, and multi-resolution techniques Advances using block transmission techniques for different propagation and multi-user environments System-level evaluation of 4G using different transmission techniques Exploring the key requirements of emergent services, this volume provides fundamentals and theory along with transmission and detection techniques and schemes transversal to many digital communication systemsincluding wireless, cellular, and satellite. If youre interested in or involved with 4G multimedia systems, this is the book you need on the latest R&D wireless activities so you can plan, design, and develop prototypes and future systems. | The concept of cooperative Multiple-Input-Multiple-Output (MIMO), also referred to as network MIMO, or as Coordinated Multi-Point Transmission (CoMP), was standardized in 3GPP Release 11. The goal of CoMP is to improve the coverage of high data rates and cell-edge throughput, and also to increase system throughput. In this paper we analyze only the latter scenario, using system level simulations in accordance with 3GPP guidelines. It is shown that the use of joint coordinated multipoint transmission achieves additional throughput gains. However, the gains depend on the scheduling type. This paper also indicates that the criterion of fairness is an important parameter when the number of users is high. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,271 |
In a TDM-PON system to be used for Mobile Fronthaul (MFH), uplink transmission latency is an important problem, so we proposed the cooperative resources control system and report its effect in reducing latency in a 10G-EPON system for MFH. | The 5G-induced paradigm shift from traditional macro-cell networks towards ultra-dense deployment of small cells, imposes stringent bandwidth and latency requirements in the underlying network infrastructure. While state of the art TDM-PON e.g. 10G-EPON, have already transformed the fronthaul networks from circuit switched point-to-point links into packet based architectures of shared point-to-multipoint links, the 5G Ethernet-based fronthaul brings new requirements in terms of latency for an inherently bursty traffic. This is expected to promote the deployment of a whole new class of optical devices that can perform with burst-mode traffic while realizing routing functionalities at a low-latency and energy envelope, avoiding in this way the latency burden associated with a complete optoelectronic Ethernet routing process and acting as a fast optical gateway for ultra-low latency requiring signals. Wavelength conversion can offer a reliable option for ultra-fast routing in access and fronthaul networks, provided, however, that it can at the same time offer both packet power-level equalization to account for differences in optical path losses and comply with the typical, in optical fronthauling, NRZ format. In this paper, we demonstrate an optical Burst-Mode Wavelength Converter using a Differentially-Biased SOA-MZI that operates in the deeply saturated regime to provide optical output power equalization for different input signal powers. The device has been experimentally validated for 10Gb/s NRZ optical packets, providing error-free operation for an input packet peak-power dynamic range of more than 9dB. | This letter proposes and experimentally demonstrates a secure orthogonal frequency-division-multiplexing passive optical network (OFDM-PON) based on the chaos scrambling in the OFDM frequency domain. The Logistic map is adopted for the chaos mapping. The chaos scrambling algorithm can dynamically allocate the scrambling matrices for different OFDM frames according to the initial condition, which enhance the confidentiality of the physical layer. It achieves a secure transmission at physical layer in OFDM-PON for data encryption. The experiment successfully transmits 8.37-Gb/s OFDM data with Logistic mapped chaos scrambling over 25-km single-mode fiber (SMF), and the results indicate the robustness against eavesdropping. | eng_Latn | 13,272 |
This presentation discussed the issues, technologies, and spectrum implications of broadcast technologies for mobile TV. The presentation aims to address such broadcasting dilemmas as limited battery capacity, limited processing power, and competing demands for antenna/silicon space. It also gives the advantages and disadvantages of the following technologies: DVB-H, DMB, and FLO. | Digital video broadcasting for handhelds (DVB-H) is a standard for broadcasting IP Datacast (IPDC) services to mobile handheld terminals. Based on the DVB-T standard, DVB-H adds new features such as time slicing, MPE-FEC, in-depth interleavers, mandatory cell id identifier, optional 4K-modulation mode and the use of 5 MHz bandwidth in addition to the usually used 6, 7, or 8 MHz raster. IPDC over DVB-H is proposed for ETSI to complement the DVB-H standard by combining IPDC and DVB-H in an end-to-end system. Handover in such unidirectional broadcasting networks is a novel issue. In the last few years since the birth of DVB-H technology, great attention has been given to the performance analysis of DVB-H mobile terminals. Handover is one of the main research topics for DVB-H in mobile scenarios. Better reception quality and greater power efficiency are considered to be the main targets of handover research for DVB-H. New algorithms for different handover stages in DVB-H have been the subject of recent research and are currently being studied. Further novel algorithms need to be designed to improve the mobile reception quality. This article provides a comprehensive survey of the handover algorithms in DVB-H. A systematic evaluation and categorization approach is proposed based on the problems the algorithms solve and the handover stages being focused on. Criteria are proposed and analyzed to facilitate designing better handover algorithms for DVB-H that have been identified from the research conducted by the authors. | According to the characteristics of glass defects, through analyzing the advantages and disadvantages of the traditional BP algorithm, an improved BP neural network recognition algorithm is applied to the glass defect classification and character recognition. Experimental results show that compared with traditional BP recognition algorithm, convergence speed of the algorithm is fast and the identification of false positives is low. | eng_Latn | 13,273 |
An efficient approach to revealing the propagation characteristics for broadband mobile services in the 5-GHz microwave band is to utilize the existing 2-GHz band propagation data accumulated by many researchers. This paper presents the height variation characteristics at 5.2-GHz compared with that at 2.2-GHz in a residential area based on experiments and theoretical analysis. Propagation measurements were carried out using the dual band antenna at 5.2-GHz and 2.2-GHz, and the measured results were compared. Furthermore, this paper compares the measured results with the calculated results using a two-dimensional (2D) ray-tracing approach based on geometric optics (GO) and the uniform geometrical theory of diffraction (UTD). | This paper reports on the interim beyond-3G (B3G) channel model developed by and used within the European WINNER project. The model is a comprehensive spatial channel model for 2 and 5 GHz frequency bands and supports bandwidths up to 100 MHz in three different outdoor environments. It further features time-evolution of system-level parameters for challenging advanced communication algorithms, as well as a reduced-variability tapped delay-line model for improved usability in calibration and comparison simulations. | An active double-balanced mixer for automotive applications in the 77 GHz range is presented. The circuit includes on-chip baluns both at the RF and the LO port. The mixer was designed and fabricated in a 200 GHz f/sub T/ SiGe:C bipolar technology. The chip was characterized by on-wafer measurements. At 77 GHz, the conversion gain of the mixer is 11.5 dB. The single sideband noise figure at 77 GHz is 15.8 dB. The input-referred 1 dB compression point at 75 GHz is -0.3 dBm. Measurements across the wafer verified that this mixer circuit is robust against wafer inhomogeneities. The size of the chip is 700/spl mu/m /spl times/ 900/spl mu/m. The circuit was designed for a supply voltage of 5.5 V and draws 75 mA. | eng_Latn | 13,274 |
A wideband-IF receiver architecture is described for use in mobile terminals capable of receiving multiple standards like GSM, UMTS, DECT, etc. The architecture uses a single down-conversion and digitizes the wanted signal at high intermediate frequencies. The wideband nature of the architecture ensures a great adaptability to various mobile standards. It denotes a step into the direction of a fully reconfigurable software radio due to the shift of the ADC to higher frequencies. The paper is focused on the realization of the analog part of the receiver. | A re-configurable, highly-integrated receiver architecture is described for use in 3/sup rd/-generation mobile handsets. It is intended for dual-mode UMTS and GSM operation but should be capable of operating in other modes such as CDMA2000. The receiver achieves its adaptability by using a single down-conversion approach to either a zero IF or a near-zero IF and then digitizing as much of the IF signal chain as possible. Notwithstanding its reconfigurability, system simulations indicate that the receiver should achieve state-of-the-art performance. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,275 |
With emerging multi-media wireless applications, there is a need for next-generation W-CDMA to be designed to support variable rate traffic. Several schemes have previously been proposed to support variable rate transmission, namely, variable spreading gain (VSG), multicode transmissions and fixed spreading gain (FSG). In this paper, a universal framework to evaluate and compare the various variable rate transmission schemes in terms of bit error rate (BER), power and required bandwidth is proposed. The framework also provides for the synthesis of the power assignment that delivers a specified BER to heterogeneous variable rate sources under each scheme. | This paper presents an approach to the evaluation of the reverse link capacity of a CDMA cellular voice system which employs power control and a variable rate vocoder based on voice activity. It is shown that the Erlang capacity of CDMA is many times that of conventional analog systems and several times that of other digital multiple access systems. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,276 |
The overlaying of a CDMA system on an existing narrowband system has been proposed and investigated in several publications. This topic is critical in many environments where new broadband systems are required to coexist with legacy narrowband systems. This paper is focused on minimisation of the performance degradation of the narrow-band system(s) caused by the CDMA one. Common background in most of this topic deals with notch-filtering of CDMA signals in transmitter to minimise its interference over the narrowband signal. However, this solution results in effective spreading codes longer that bit time, causing ISI within the CDMA system. The solution that is proposed in this contribution is the design of spreading codes that notch the CDMA power spectrum density (PSD) on specified bandwidth intervals where narrow-band signals are transmitted. To achieve this, spreading codes are selected from the orthogonal set of polynomials arising from digital prolate functions (DPF) which have property of energy concentration in specified intervals. Provided solution guarantees null interference in CDMA system with orthogonal codes, strictly located within the bit period. | Wireless communication has emerged as the most promising and one of the leading sectors of the telecommunications industry in the 21st century. To appreciate the expansion of the wireless sector, in 1990, there were only ten million cellular phone subscribers worldwide that frequently use first-generation technology. Today, there are more than one billion subscribers, and it is expected to increase to more than three billion subscribers during 2007-2010. Attempting to more efficiently use the limited frequency bands available for mobile communications, the idea of overlaying a code-division multiple-access (CDMA) system on an existing narrowband system has been proposed and explored. The basic idea of a CDMA overlay is to allow wideband CDMA waveforms to share a common spectrum with narrowband conventional waveforms to take advantage of the unexploited bandwidth available in the narrowband systems. Theoretically, the separation of CDMA and narrowband waveforms can be accomplished through notch filters. However, the filtering techniques are not sufficient for eliminating the multicross interference problem. In this paper, as a means of reducing the interference that cannot be eliminated by the use of filters, we have introduced a new proposal of an overlaid system in which we reduce the coverage area of the time-division multiple-access (TDMA) interference slots (slots inside the CDMA bandwidth are henceforth cited as cochannel slots). With this new strategy, we significantly reduce the effect of TDMA interference over the CDMA system. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 13,277 |
In this paper, the sampling frequency synchronization for OFDM systems is modeled as a frequency recovery loop, and how the noise component of the frequency recovery loop affects on the symbol synchronization is analyzed. Both the theoretical analyses and numeric simulation show the symbol synchronization is necessary for the coherent detection in an OFDM system because even small noise component in the frequency recovery loop will lead to large FFT window drift. | The concepts of an all digital phase-locked loop (DPLL), which contains a purely digital phase detector, loop filter and voltage-controlled oscillator, are explained. A second order DPLL is considered and analysed using the Z-transform technique. Implementation of the DPLL, based on the CMOS digital signal processor TMS 320C25, and the experimental results, are presented. Potential applications are also discussed. | In this paper, a review of various link adaptation techniques employed in the transmission of adaptive Orthogonal Frequency Division Multiplexing (OFDM) is presented. Significant research effort in coded OFDM and adaptive modulation based on second moment adaptation are simulated and presented. Results show that coded OFDM performs at least 5 dB better in terms of signal to noise ratio (SNR) requirements as compared to uncoded system in any QAM modulation. Results on second moment adaptation show that, for adaptation up to 4 bits per symbols, second moment adaptation is about 3 dB more superior than adaptation by mean channel SNR. Other related issues are discussed to formulate future research direction in an effort to achieve higher throughput, lower bit error rate and better overall system performance. rd generation (3G) mobile system introduced in some of European countries and in Japan is not promising enough to provide such broadband multimedia services with its one carrier transmission system. So the challenge to provide high data rate over hostile mobile environment with limited spectrum and inter- symbol interference (caused by multipath fading) has led to the introduction of multi-carrier transmission system. This type of transmission system, namely Orthogonal Frequency Division Multiplexing (OFDM) has been identified as a potential candidate for the forth coming 4 th Generation (4G) broadband mobile communication system. This is because it is able to deliver rate data by splitting them into a number of lower rate streams that are transmitted simultaneously over a number of subcarriers (1). Besides it can also combat inter-symbol-interference commonly found in mobile communication system (2). OFDM was initially introduced in broadcasting system such as Digital Audio Broadcasting (DAB) and Digital Video Broadcasting (DVB) in Europe, IEEE 802.11 Wireless LAN, High-performance LAN (HIPER-LAN) type2, and Multimedia Mobile Access Communication (MMAC) for wireless LAN (3). These OFDM standards were designed for indoor environment with relatively short delay spreads. Many research efforts are now looking into possibility of utilizing OFDM in wider macrocellular-area that would provide multimedia-rich internet access to the user. An approach called link adaptation (LA) techniques has emerged as a tool to increase data rate and spectral efficiency (4). In this technique, modulation, coding rate, and/or other signal transmission parameters are dynamically adapted to the channel condition to increase the system performance in terms of Bit Error Rate (BER) and throughput (bps) in various conditions such as channel mismatch, Doppler spreads, fading, etc. The focus of this paper is to provide a review of these link adaptation techniques and also to develop research related to the implementation of OFDM transmission system. We identify the followings as techniques currently proposed by researchers in implementing OFDM system: • Adaptive modulation • Coded OFDM • Multi-antenna system | eng_Latn | 13,278 |
The Link-to-System (L2S) interface concept plays an important role in the evaluation of wireless communication systems in terms of System Level Simulation (SLS). The L2S interface is an abstraction model to predict the Link Level Simulation (LLS) performance and transfers the prediction criterion to the SLS. L2S interface is based on a number of mapping models that predict and abstract the link level performance. It is called Effective SINR Mapping (ESM) model, which plays a major role in the L2S interface. A number of L2S interface models have been analyzed for Single Input Single Output (SISO) based on Orthogonal Frequency Division Multiplexing (OFDM) for various wireless communication systems such as the 3GPP Long Term Evolution [1] and WiMAX systems [2]. This paper is extending the analysis of L2S interface based on Multiple Input Multiple Output (MIMO OFDM) based on LTE system. Several models have been considered for the investigation such as Exponential ESM model (EESM), Mutual Information ESM model (MIESM), Capacity ESM model (CESM), and Logarithmic ESM model (LESM). The analysis has covered various MIMO transmission mode of LTE such as Transmit Diversity (TxD) and Spatial Multiplexing (SM). It has considered the different physical layer configuration for different Modulation and Coding Schemes MCS (from 1 to 15) and different bandwidth transmission mode such 1.4 MHz, 10 MHz, and 20 MHz. The results show that MIESM and EESM give a very high accuracy. Particularly, for small transmission bandwidth mode such as 1.4 MHz, the MIESM model outperform EESM model and gives an error range between ±0.2 and ±0.6 dB for SM and between ±0.1 and ±0.9 dB for TxD. However, the results decrease for large transmission bandwidth, in particular, with high modulation and coding scheme. | Link to system interface methodology is a technique used in system level simulations to predict the receiver behavior using lookup tables under different channel conditions. This paper presents an improvement in link to system interfacing methodology for exponential effective signal to noise ratio mapping for a single input and single output transmission mode. It is proposed that the mean value of the receiver performance measure for different channels be used as reference instead of the performance of a single line of sight link. The results show a considerable improvement in the mean square error between the predicted and observed frame error rates at different signal to noise ratios. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 13,279 |
Using experimental mechanical method of moire analysis,strain field distributions of LY12CZ aluminum alloy welded joints under different conditions were investigated.The results show that moire stripes of conventional welded joint just before fracture are not only few and scattered but also uneven,and the stress mainly concentrates on the poor position welded toes during the tensioning process with the relatively poor mechanical properties of welded joints.When the method of welding with trailing peening is adopted,moire stripes of welded joint just before fracture are relatively thick and even due to the strengthening welded toes during the welding process,and fracture position transfers from the welded toes to weld,at the same time the mechanical properties of welded joints are improved greatly than conventional welding which can show that the technology of trailing peening is effective to strengthen welded joints of high strength aluminum alloy. | Build-up welding with trailing peening can achieve dispelling residual stress, meliorating the structure of welding and improving the fatigue life and quality of welding through peening welded seam and heat-affected zone (HAZ) timely along with welding. Some studies have proven that the peening performance depends greatly on the temperature of welded seam and HAZ. In this paper, a set of temperature measurement system was designed by integrate sensor technology, computer technology, data processing method and modeling technology. In order to achieve gathering electrical signal, calculating temperature field and forecasting peening location, the virtual instrument programming language Labwindows/CVI was adopted to program data acquisition and analysis in software and PC, high-speed data acquisition card model AMPCI-9111, voltage sensor model KV25A/P and current sensor KA200V were adopted in hardware. The process can be summarized as follows:i) gather voltage and current data of build-up welding; ii) set up temperature field model of build-up welding; iii) offer the reliable temperature parameter for confirming the best peening opportunity. The build-up test was conducted and the results indicate that the system can be used to simulate temperature field and forecast the peening location and opportunity accurately. | Despite the potential benefits of a maritime Internet of Things, a number of issues hinder its realization, including the need for wide area coverage and cost-effectiveness. Toward these needs, a model is first presented for uplink maritime radio communications that hierarchically employ Wi-Fi and cellular links for data transmission from marine user equipments (MUEs) on a ship to a cellular base station with distributed antennas (DAs) along a coastline. Then, the performances are evaluated given in terms of average data rate and outage probability in the hierarchical maritime radio networks. When evaluating the performances, heterogeneous channel characteristics of the hierarchical networks are taken into account in which Rayleigh fading is considered for the MUE-ship links, whereas shadowed-Rician fading is considered for the ship-DA links. Moreover, the effects due to various transmission errors that can be occurred at different communication layers are reflected in determining the quality of service (QoS) requirements of a ship. With the help of authors’ analysis, an antenna selection algorithm is proposed under which the minimum size of a service cloud can be found to support the QoS requirements of MUEs with a ship. The numerical evaluations demonstrate the validity of the proposed algorithm. | eng_Latn | 13,280 |
We experimentally demonstrate the 3×3 imaging multiple-input multiple-output (MIMO) visible light communication (VLC) system, using orthogonal frequency division multiplexing (OFDM) modulation and bit-loading, a total data rate > 800-Mbit/s over 1-m transmission is achieved without using blue-filter. | We report a visible-light wireless point-to-point communication link operating at 513 Mbit/s gross transmission rate (net Mbit/s). The bit-error ratio of the uncoded data was smaller than for an illumination level of lx. The link was based on a commercial thin-film high-power phosphorescent white LED, an avalanche photo diode, and off-line signal processing of discrete multitone signals. Quadrature-amplitude modulation, bit- and power-loading, as well as symmetrical clipping were successfully employed in pushing the gross transmission rate beyond 500 Mbit/s. Adaptation of the clipping level increased the data rate only by 2%, while simulations predicted an enhancement of 20%. Obstacles towards higher data rates as well as potential remedies are discussed. We predicted that data rates of over 1 Gbit/s can be achieved with the same setup and under the same experimental conditions if these obstacles are overcome. | Digital audio broadcasting offers the potential to give every radio in Europe the sound quality of a compact disc. To accomplish this, it requires a rugged method of transmission. The coded orthogonal frequency division multiplexing (COFDM) modulation system was developed to meet this need. The paper describes the reasons why a new modulation process was needed, and explains how the COFDM system has been optimised to meet the requirements. | eng_Latn | 13,281 |
Today's Metro networks are facing the challenge to transport different services like 2.5 Gbit/s and 10 Gbit/s SDH, Gigabit and 10G Ethernet, and different data formats at costs as low as possible. Particularly due to cost and associated performance reasons wavelength-division multiplex (WDM) transmission systems are an attractive candidate for the Metro area e.g. offering different services over different wavelengths. However, for cost-reduction it is mandatory to avoid expensive components like optical amplifiers (OAs) and dispersion compensating modules (DCMs) whenever possible. This leads to a limited extension of the transparent reach due to e.g. transmitter and receiver characteristics, fiber dispersion, and fiber nonlinearity. It is the object of this paper to investigate the potential of Metro WDM systems and to derive design guidelines without use of OAs and DCMs. Based on computer simulations different fiber infrastructures like Standard Single-Mode Fiber (SSMF, ITU-G.652), positive and negative dispersion Non-Zero Dispersion Shifted Fibers (NZDSF) are analyzed with respect to 2.5 Gbit/s and 10 Gbit/s data rate per channel with low-cost direct and chirp-free external modulation at both data rates. Non-Return-to-Zero- (NRZ-) intensity-modulation is assumed as standard modulation format. At 10 Gbit/s single channel transmission external modulation over pure SSMF results in transmission length of about 50km. Only for high-input powers fiber nonlinearity partly compensates the fiber dispersion and allows an increase in reach up to 90km. For WDM transmission the performance is limited by Self-Phase Modulation (SPM) and Cross-Phase Modulation (XPM) allowing 40x10 Gbit/s uncompensated low-cost transmission over 50km of existing SSMF. | Computer simulation is used to evaluate the chromatic dispersion limitations for both various coherent lightwave transmission systems and direct-detection on-off keying (OOK) systems. The results show that for a 2-dB dispersion penalty the maximum modulation rate ranges from 5 to 9 Gb/s for systems operating at 1.55 mu m with 15 ps/km-nm of chromatic dispersion and 100 km of fiber. The effect is less severe for OOK systems and most severe in coherent detection systems. Simulation results are in agreement with a available experimental data. > | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 13,282 |
In the Global Positioning System (GPS), code division multiple access (CDMA) signals are used. Because of the spectral characteristics of the CDMA signal, each particular type of interference (signals to be rejected) has a different effect on the quality of the received GPS satellite signals. In this paper, the effects of three types of interference are studied on the carrier-to-noise ratio (C/No) of the received GPS signal as an indicator of the quality of that signal; continuous wave (CW), pulse CW, and swept CW. For CW interference, it is analytically shown that the C/No of the signal can be calculated using a closed formula after the correlator in the receiver. This result is supported by calculating the C/No using the I and Q data from a software GPS receiver. For pulsed CW, a similar analysis is performed to characterize the effect of parameters such as pulse repetition period (PRP) and also duty cycle on the received signal quality. It is specifically shown that for equal interference power levels, in the cases where the PRP is far less than the pseudorandom noise code period, the signal degradation increases with increasing the duty cycle whereas it doesn't change when the two periods are equal or the PRP is far bigger than the code period. | This paper presents a precorrelation interference detection method based on statistical analysis in the time-frequency (TF) domain for global navigation satellite system signals. In particular, the short-time Fourier transform (STFT) is considered as the TF tool due to its linear property and low computational complexity. A goodness-of-fit (GoF) test is applied to each frequency slice in the spectrogram of the received signal, which approximately follows a chi-square distribution in the absence of interference. The expected probability density function (PDF) of the observed TF-domain samples can be computed based on an interference-free signal or the noise power estimate. Two versions of the proposed technique are presented: one based on the canonical STFT with the maximum overlap size, and the other based on the block-wise STFT using nonoverlapped samples. The canonical STFT-based method shows better detection capability at the expense of degraded false alarm performance caused by the PDF distortion in the canonical STFT samples. The block-wise STFT-based method alleviates the false alarm issue but slightly weakens the detection capability. Simulations show that the proposed canonical and block-wise STFT-based methods improve the detection performance for both narrow- and wideband interference in low jammer-to-noise ratio environments when compared with the existing GoF test applied to the time-domain samples. | Microwave devices with the Rollet parameter (k) less than one can always be made stable by resistive loading. In cases where noise figure or output power is at a premium, the performance of an amplifier can often be enhanced by using a design where k is less than unity thereby avoiding resistive loading. While a simultaneous conjugate match is impossible for such conditionally stable designs, single-sided matching can be achieved. Low-noise and power designs are examples where single-sided matching considerations naturally occur. With single-sided matching and 0 > | eng_Latn | 13,283 |
A Design of Double Broadband MIMO Antenna | The MIMO antenna applied to LTE mobile system should be miniaturization and can work in the current communication frequency band; isolation between each antenna unit also should be good so as to reduce loss of radio wave energy and improve the antenna performance of the MIMO system. This paper puts forward the design scheme of a broadband MIMO double antenna. And the design of antenna unit and debugging and related technical measures, such as bending antenna bracket, are both presented; the integration design of high isolation of ultra broadband MIMO antenna is realized on the plate with the volume of 100 × 52 × 0.8 mm3; antenna working bands are 698 MHz~960 MHz and 1710 MHz~2700 MHz; in the whole spectrum, the 10 dB of port isolation can be basically achieved; in low frequency band, the isolation degree of antenna port can reach 12 dB. | In order to reduce redundant forwarding nodes and transmission delay, this paper proposes a 2-hop neighbors table based broadcasting algorithm. The proposed algorithm introduces two conceptions which are in-degree of two hop neighbor nodes and out-degree of neighbor nodes. It can reduce the number of forwarding nodes and redundant forwarding that using the out-degree and in-degree of nodes chooses the forwarding nodes from neighbor nodes. The simulation results show that the proposed algorithm has lower ratio of forwarding and smaller transmission delay, the performance is good. | eng_Latn | 13,284 |
Distributed Beam Steering System Based on Embedded Computer and Ethernet | A distributed beam steering system based on a single board computer and Ethernet is introduced. Several single board computers become the core of the whole beam steering system and they communicate with the radar control computer through ethernet. | This work was supported by the UK Engineering and Physical Sciences Research Council (EPSRC) grant EP/K02924X/1. E.O.R. is supported by an EPSRC DTA studentship (University of Cambridge), and F.D.D. is supported by the Honorary Vice-Chancellor’s Award and a Qualcomm/DTA Studentship. | eng_Latn | 13,285 |
Comparison of Universal Fiber Against OM4 Fiber Transmission Using PAM4 at 50 Gb/s Over 152 m | The transmission characteristics of the universal fiber concept are shown and its performance is compared to standard OM4 fiber using a directly modulated VCSEL at 50 Gb/s using PAM4 modulation format. Results show almost identical performance up to a distance of 152 m without any digital signal processing. Coupling loss of less than 0.5 dB is achieved between VCSEL and universal fiber using free space optics, which is higher by only 0.2 dB compared to coupling into an OM4 fiber. | This paper describes the features and applications of ADAM5000TCP and ADAM5511 in control system of picosecond accelerator,and mainly recounts the skillful data processing of Kingview 6.5 used as upper-layer platform,including the linear form,database,file and bit operation.Actually experience indicates that the adoption has minimized the efforts and guaranteed the real-time character and practicability of control system. | eng_Latn | 13,286 |
Theoretical and practical investigation of error rates for digital f.m. | The bounds for the probability of error for f.s.k. systems using optimum detection are stated. The upper bound is obtained for other cases of interest using non-optimum detection. The theoretical results are presented together with past practical results and some new practical results for a wide-band digital f.m. system. | Tuning knobs are becoming common in analog and RF devices for postsilicon calibration for variation tolerance and compensation. This article presents a low-cost, hardware-iterative technique based on a steepest-descent-based gradient search algorithm and demonstrates its utility in performance tuning of a 2.4-GHz transmitter system. | eng_Latn | 13,287 |
StarDriver: an estimate of the bandwidth required to suppress the 2ω pe instability | We report the first calculations of the 2ω pe instability in an IFE-scale corona of a direct drive target being driven by a StarDriver-class laser. Using realistic plasma profiles (density, temperature, flow velocity and Z) taken from full hydrodynamic simulations of the capsule implosion, we propagate the StarDriver beamlets to the ¼ critical surface using ray-tracing. We then use that 'k-space' of laser modes in a model of the absolute 2ω pe instability in the inhomogeneous plasma at ¼ critical density. Our calculations indicate that 15–20 THz of bandwidth at 351 nm wavelength (about 2% bandwidth) significantly reduces or suppresses the absolute instability at most times in the drive pulse. A bandwidth of 35 THz suppresses it at all times in the drive pulse. We note that 2% bandwidth ~20 THz is achievable using laser gain media available today. | We investigate multirate multicarrier code-division multiple-access (MC-CDMA) downlink systems with multicode transmission. Specifically, we design a new linear equalizer that outperforms the minimum mean-squared error (MMSE) per-carrier equalizer, without requiring the spreading codes of the interfering users. The complexity of this new linear equalizer is similar to that of the MMSE per-user equalizer, which however needs the spreading codes of the interfering users. Simulation results validate the effectiveness of the proposed equalizer, especially when there are few interfering users. | eng_Latn | 13,288 |
Calculation of secondary cable losses and ampacity in the presence of harmonics | A simplified procedure for computing ohmic losses in secondary distribution cable systems by extending the Neher-McGrath model for 60 Hz losses is presented. Specifically, simplified formulae for evaluating ohmic losses due to harmonics are given. These results are subsequently used to compute the cable ampacity or the derating factor due to harmonics. The overall method is simple to follow and can be performed with a calculator. A typical example is given. > | Army tactic to expanding the mobile battlefield has created a demand for a highly mobile network centric communication system that provides peer-to-peer communications. To enable this network connectivity over satellite communications (SATCOM) requires a sophisticated scheduling mechanism of satellite resources. The challenge with this new method of satellite utilization is to maximize capacity by dynamically allocating just enough resources between user terminals. Various dynamic bandwidth allocation algorithms have been proposed to optimize ephemeral satellite links. But, ultimately, the determination of signal-to-noise and individual transmitter and receiver channel conditions must be accurately determined. This paper will identify the satellite link variables of a dynamic multi-frequency time division multiple access (MF-TDMA) system and the impact of these variables on determining the accuracy of the channel estimates | eng_Latn | 13,289 |
Land Mobile Satellite Propagation Channel Characterization Based on RF Measurements and Fish-Eye Images | This paper is focused on the characterization of a mobile Radio Frequency (RF) receiver environment. Based on fish-eye images acquired simultaneously with the RF signal, the detection of the sky, the vegetation and the close obstacles is performed. This optical environment characterization exhibits a strong correlation with the direct RF signal classification as recommended by the International Telecommunication Union (ITU). | This paper is concerned with wideband, multimedia packet switched wireless data networks. It considers the impact of a wireless access TDMA source queue on long range dependence (LRD) in traffic statistics. Simulation results show that traffic LRD is typically retained at the output of such queues. These results point to important implications for wireless network resource allocation and traffic management. | eng_Latn | 13,290 |
CK2 Is a C-Terminal IkappaB Kinase Responsible for NF-kappaB Activation during the UV Response. | NF-kappaB is activated in response to proinflammatory stimuli, infections, and physical stress. While activation of NF-kappaB by many stimuli depends on the IkappaB kinase (IKK) complex, which phosphorylates IkappaBs at N-terminal sites, the mechanism of NF-kappaB activation by ultraviolet (UV) radiation remained enigmatic, as it is IKK independent. We now show that UV-induced NF-kappaB activation depends on phosphorylation of IkappaBalpha at a cluster of C-terminal sites that are recognized by CK2 (formerly casein kinase II). Furthermore, CK2 activity toward IkappaB is UV inducible through a mechanism that depends on activation of p38 MAP kinase. Inhibition of this pathway prevents UV-induced IkappaBalpha degradation and increases UV-induced cell death. Thus, the p38-CK2-NF-kappaB axis is an important component of the mammalian UV response. | In this paper, we have designed an optimal detector for the space shift keying (SSK) receiver in the presence of the improper Gaussian noise (IGN) with multiple antennas mounted the transmitter and receiver nodes. We have analyzed this optimal detector by finding the error probability and comparing the performance of this receiver with the suboptimal one which uses the traditional maximum-likelihood (ML) detector to detect the IGN as if it is a proper Gaussian noise (PGN). The analytical expressions obtained can be used under general complex fading channels. The analytically derived results have been validated using the simulation, where it is demonstrated that the importance of using the optimal receiver, in addition to the importance of considering the IGN over the (PGN) at the receiver. | eng_Latn | 13,291 |
Reduced-Complexity Receiver for Free-Space Optical Communication over Orbital Angular Momentum Partial-Pattern Modes | This paper explores the effect of a partial-pattern receiver for transmitted orbital angular momentum (OAM) multimodes included in the Laguerre-Gaussian beam propagating under non-Kolomogorov weak-to-moderate turbulence on the achievable capacity and the error rates with introduced controlled parameters. We deduce the necessary conditions for reducing the receiver’s area to guarantee that the modes are decoupled when the area is reduced. Furthermore, we derive the conditions at which area reduction yields a performance gain over the complete-area reception. For that, some use cases are introduced and discussed and the basic building block for multibeam MIMO receivers with a reduced area is developed and analyzed. | In this paper, a modeling and simulation method for planar interdigitated ruthenium oxide MEMS supercapacitor was proposed based on the electrochemical reaction mechanism of supercapacitor. The study simulated the planar interdigitated ruthenium oxide MEMS super capacitor using Comsol software. The highly accurate charge and discharge curves of the super capacitor, electric potential distribution graph and the concentration distribution graph were got through simulation. The effects of two structure-parameters were discussed in the research. | eng_Latn | 13,292 |
PDB47 THE ASSOCIATION BETWEEN PATIENT-REPORTED DIABETES SYMPTOMS AND TOLERABILITY ISSUES OF ORAL ANTIDIABETIC AGENTS ON WORK AND LIFE PRODUCTIVITY | INTRODUCTION • It is currently estimated that 8% (23.6 M) of all Americans have diagnosed T2DM.1 The incidence and prevalence of T2DM are on the rise in the U.S. • Indirect costs of diabetes total $58 billion and include increased absenteeism and presenteeism (reduced productivity at work) among the employed, removal from the labor force as a result of disease-related disability and mortality, and reduced life productivity for those not in the labor force.2 • Although glycemic control has improved over time, a large proportion of patients with T2DM continue to have inadequate glucose control.3 • Several safety and tolerability issues are associated with OADs.3,4 • Diabetes symptoms and tolerability issues of existing treatments may affect work productivity, further contributing to the overall burden of T2DM. | The transmission performance of single-sideband alternate mark inversion return-to-zero (SSB-AMI-RZ) formats, with duty-cycles of 15%, 30% and 50%, in long-haul 40 Gbit/s/channel ultra dense WDM systems with 50 GHz of channel spacing is assessed through systematic numerical simulation. After optimizing the bandwidths and detuning of optical multiplexer and demultiplexer, the dispersion maps are optimized for each duty-cycle. From these, the tolerances to the in-line residual dispersion (IRD) and total residual dispersion (TRD), and the nonlinear thresholds (NLT) are assessed. It is shown that the different SSB-AMI-RZ formats have high tolerance to linear crosstalk, due to a - 20 dB bandwidth much smaller than the channel spacing, and similar tolerance to IRD. Numerical results indicate that the format with duty-cycle of 15% outperform the others because of its better tolerance to TRD and higher NLT. | yue_Hant | 13,293 |
APPLICATION OF NONLINEAR OPTIMISATION TECHNIQUE TO HULL FORM DESIGN BASED ON WAVE RESISTANCE THEORY | In the present study, SUMT is employed as the minimisation method for nonlinear optimisation problems. Two problems are discussed, one of which is to determine the best curve of sectional area under several side conditions for which the variational approach cannot be applied. The other problem is the improvement of given hull forms in order to reduce the wave resistance. | The fifth generation (5G) wireless network faces unprecedented massive concurrent random access requests in uplink (UL) contention-based (CB) transmission. In this paper, a non-orthogonal coded access (NOCA) UL transmission in combination with parallel interference cancellation (PIC) based reception scheme at base station is investigated. Non-orthonormal code generated by Zadoff-Chu (ZC) sequences is used to spread the data bits over orthogonal frequency division multiple (OFDM) symbols. It is shown through both link level and system level simulations that in dense urban scenario NOCA-PIC scheme is capable of working in highly overloaded system conditions. It can support more than 4 times concurrent random access number compared with OFDM based CB transmission. | yue_Hant | 13,294 |
IP-oriented QoS in next generation networks: application to wireless networks | The challenge of new communication architectures is to offer QoS in Internet networks. This paper investigates the QoS aspects in the NGN (Next Generation Networks), and especially in the wireless networks. Voice and video multimedia applications will be developed and used when QoS mechanisms will exist. Therefore new functions must be developed to guarantee performance, offer security, avoid jitter and to allow the respect of real-time constraints. | This paper addresses the problem of channel and propagation delay estimation in asynchronous DS/CDMA systems. We consider the uplink connection in DS/CDMA with long spreading codes. The MIMO stochastic gradient algorithm proposed in [6] is estimating a linear combination of the channel impulse responses and the propagation delays. This estimate suffices for the equalization purposes. The propagation delays are estimated with a simple matching scheme. | eng_Latn | 13,295 |
A Rice-lognormal terrestrial and satellite channel model | The paper describes a model for non-selective fading channels which is a combination of Rice and lognormal statistics, and is conceived for all types of environment, and both for terrestrial cellular and satellite personal communications. The model needs only three parameters to be completely specified. The model validity has been confirmed by comparisons with measurement data collected in the literature. For the satellite case, empirical formulae are derived for the model parameters to fit measured data over a wide range of elevation angles. In particular, the model is applied to macrocellular terrestrial channels and non-geostationary satellite channels. The paper derives expressions for the average bit error probability in the channel and provides some numerical results. > | AbstractRadar scatterometer observations at 17.2 GHz and 9.6 GHz were made of the snow cover in mid-latitude agricultural fields, using the University of Waterloo scatterometer, to determine the se... | eng_Latn | 13,296 |
A 3D-beamforming scheme for throughput optimization in Heterogeneous Network | Beamforming (BF) is an effective method to restrain interference in cellular communication systems. Steering beam direction in 3D space can improve useful signal power that user equipments (UEs) received and eliminate interference effectively. In this paper, we focus on how to choose 3D-BF angles of beam and propose a cooperative angle selecting scheme based on maximum signal to leakage plus noise ratio (SLNR) (CAS-MSLNR) to increase sum throughput of Heterogeneous Network (HetNet). In the proposed scheme, 3D-BF angles of every node in the same group node (GN) are chosen preliminarily by centralized coordination method to restrain intra-GN interference. Then, in each GN, the macro cell base station (MBS) adjusts the 3D-BF angles to maximize SLNR. Simulation result demonstrates that CAS-MSLNR 3D-BF outperforms 2D-BF and UE-specific 3D-BF in terms of sum throughput and cell-edge throughput. | This paper deals with the problem of optimal cooling of a multiphase, continuously cast vertical cylindrical metal ingot in order to improve the characteristics of the solid phase. For the purpose of determining the optimal values of heat removal, a direct extreme approach is applied based on calculating the gradient of the ingot quality criterion. The criterion includes the effect of thermal stresses and of the degree of dispersity of dendritic structure on the quality of the cooling ingot. | eng_Latn | 13,297 |
Deformation of Sr and Rb isotopes close to the N=Z line via β-decay studies using the total absorption technique | A study of the Gamow-Teller strength distributions B(GT) in the beta decay of 78 Sr and 76,78 Rb has been made using a total absorption spectrometer (TAS). Following the success in deducing the sign of the deformation for 76 Sr, a similar approach is adopted for 78 Sr based on a comparison of the measured B(GT) with quasiparticle random-phase approximation calculations. This work confirms its previously expected prolate deformation in the ground state. Conclusions about the structure of the odd-odd 76,78 Rb isotopes have been drawn based on their measured B(GT) distributions. | Due to their robustness and simple system configurations the Transmitted Reference (TR) modulation scheme and autocorrelation receiver are preferred candidates for the implementation of cheap Ultra WideBand (UWB) Impulse Radio (IR) systems. Unfortunately, the results of simulations and field tests performed on built UWB IR TR systems have shown a relatively poor noise performance. This noise performance results in such a bad receiver sensitivity that prevents the application of TR modulation and autocorrelation receivers in real applications. This contribution shows that the noise performance of UWB IR TR autocorrelation receiver can be improved considerably by reducing the energy capture time of the receiver. By matching the receiver parameters to that of the transmitted UWB pulse, an almost 8-dB improvement in receiver sensitivity has been achieved. | eng_Latn | 13,298 |
Microwave Photonics: Current challenges towards widespread application | Microwave Photonics, a symbiotic field of research that brings together the worlds of optics and radio frequency is currently facing several challenges in its transition from a niche to a truly widespread technology essential to support the ever-increasing values for speed, bandwidth, processing capability and dynamic range that will be required in next generation hybrid access networks. We outline these challenges, which are the subject of the contributions to this focus issue. | The problem of scaling down the size of the transmitting antenna of a solar power satellite is briefly discussed. It is shown that a multibeam Power Relay Satellite leads to smaller ground receiver stations which will improve the market penetration of power satellites. (WHK) | eng_Latn | 13,299 |
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