The Experts below are selected from a list of 51510 Experts worldwide ranked by ideXlab platform
S.h. Mneney - One of the best experts on this subject based on the ideXlab platform.
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Turbo Decoding of Super-Orthogonal Space-Time Trellis Codes in Rayleigh Fading Channels
Wireless Personal Communications, 2006Co-Authors: J.n. Pillai, S.h. MneneyAbstract:Space-time trellis codes have shown to provide a good performance in Rayleigh Fading channels. Recently Super-orthogonal space-time trellis codes have shown to outperform these codes, and also provide a systematic design method to maximize diversity and coding gain in quasi-static Rayleigh Fading channels. We investigate the performance of these new codes in rapid Rayleigh Fading channels and further propose two concatenated versions of these codes. We further investigate the effect of imperfect channel state information on one of the concatenated versions. Some simulation results of the various concatenated schemes in quasi-static and rapid Rayleigh Fading channels are presented.
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Concatenated Super-Orthogonal Space-Time Trellis Codes in Rayleigh Fading Channels
EUROCON 2005 - The International Conference on "Computer as a Tool", 2005Co-Authors: J.n. Pillai, S.h. MneneyAbstract:Space-time trellis codes have shown to provide a good performance in Rayleigh Fading channels. Super-orthogonal space-time trellis codes have shown to outperform these codes, and also provide a systematic design method to maximize diversity and coding gain in quasi-static Rayleigh Fading channels. We investigate the performance of these new codes in rapid Rayleigh Fading channels and further propose a concatenated version of these codes. Some simulation results of the various concatenated schemes in quasi-static and rapid Rayleigh Fading are presented
Guan Yun-feng - One of the best experts on this subject based on the ideXlab platform.
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New Method for Generation of Multiple Uncorrelated Rayleigh Fading Waveforms
Computer Simulation, 2009Co-Authors: Guan Yun-fengAbstract:An improved Simulation model of Rayleigh Fading Channels was proposed for the generation of multiple uncorrelated Rayleigh Fading waveforms. First, the simulation models of flat Rayleigh Fading channel were divided based on sum-of-sinusoids into four categories by a uniform framework, depending on whether the parameter sets (amplitudes, phases, or Doppler frequencies) were fixed or random in simulation trials. Furthermore, the mechanisms of the multipath radio propagation show that the Fading phenomenon is a primary result of time variations in phases, and three methods were summarized altogether to define the specific initial phases for each category of the simulation models. For comparison purposes, the second-order statistics of different kinds of simulation models were proposed. Finally, a useful simulator based on Class III for generation of multiple independent Rayleigh Fading waveforms was achieved, which outperformed the other techniques in terms of its accuracy and convergence rate.
Thomas Kesselheim - One of the best experts on this subject based on the ideXlab platform.
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Scheduling in Wireless Networks with Rayleigh-Fading Interference
IEEE Transactions on Mobile Computing, 2015Co-Authors: Johannes Dams, Martin Hoefer, Thomas KesselheimAbstract:We study approximation algorithms for optimization of wireless spectrum access with $n$ communication requests when interference conditions are given by the Rayleigh-Fading model. This model extends the deterministic interference model based on the signal-to-interference-plus-noise ratio (SINR) using stochastic propagation to address Fading effects observed in reality. We consider worst-case approximation guarantees for the two standard problems of capacity maximization and latency minimization. Our main result is a generic reduction of Rayleigh Fading to the deterministic non-Fading model. It allows to apply existing algorithms for the non-Fading model in the Rayleigh-Fading scenario while losing only a factor of $O(\log ^\ast\, n)$ in the approximation guarantee. This way, we obtain the first approximation guarantees for Rayleigh Fading and, more fundamentally, show that non-trivial stochastic Fading effects can be successfully handled using existing and future techniques for the non-Fading model. We generalize these results in two ways. First, the same results apply for capacity maximization with variable data rates, when links obtain (non-binary) utility depending on the achieved SINR. Second, for binary utilities, we use a more detailed argument to obtain similar results even for distributed and game-theoretic approaches. Our analytical treatment is supported by simulations illustrating the performance of regret learning and, more generally, the relationship between both models.
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SPAA - Scheduling in wireless networks with Rayleigh-Fading interference
Proceedinbgs of the 24th ACM symposium on Parallelism in algorithms and architectures - SPAA '12, 2012Co-Authors: Johannes Dams, Martin Hoefer, Thomas KesselheimAbstract:We study algorithms for wireless spectrum access of $n$ communication requests when interference conditions are given by the Rayleigh-Fading model. This model extends the recently popular deterministic interference model based on the signal-to-interference-plus-noise ratio (SINR) using stochastic propagation to address Fading effects observed in reality. We consider worst-case approximation guarantees for the two standard problems of capacity maximization (maximize the expected number of successful transmissions in a single slot) and latency minimization (minimize the expected number of slots until all transmissions were successful). Our main result is a generic reduction of Rayleigh Fading to the deterministic SINR model. It allows to apply existing algorithms for the non-Fading model in the Rayleigh-Fading scenario while losing only a factor of O(logast n) in the approximation guarantee. This way, we obtain the first approximation guarantees for Rayleigh Fading and, more fundamentally, show that non-trivial stochastic Fading effects can be successfully handled using existing and future techniques for the non-Fading model. Using a more detailed argument, a similar result applies even for distributed and game-theoretic capacity maximization approaches. For example, it allows to show that regret learning yields an O(log* n)-approximation with uniform power assignments. Our analytical treatment is supported by simulations illustrating the performance of regret learning and, more generally, the relationship between both models.
J.n. Pillai - One of the best experts on this subject based on the ideXlab platform.
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Turbo Decoding of Super-Orthogonal Space-Time Trellis Codes in Rayleigh Fading Channels
Wireless Personal Communications, 2006Co-Authors: J.n. Pillai, S.h. MneneyAbstract:Space-time trellis codes have shown to provide a good performance in Rayleigh Fading channels. Recently Super-orthogonal space-time trellis codes have shown to outperform these codes, and also provide a systematic design method to maximize diversity and coding gain in quasi-static Rayleigh Fading channels. We investigate the performance of these new codes in rapid Rayleigh Fading channels and further propose two concatenated versions of these codes. We further investigate the effect of imperfect channel state information on one of the concatenated versions. Some simulation results of the various concatenated schemes in quasi-static and rapid Rayleigh Fading channels are presented.
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Concatenated Super-Orthogonal Space-Time Trellis Codes in Rayleigh Fading Channels
EUROCON 2005 - The International Conference on "Computer as a Tool", 2005Co-Authors: J.n. Pillai, S.h. MneneyAbstract:Space-time trellis codes have shown to provide a good performance in Rayleigh Fading channels. Super-orthogonal space-time trellis codes have shown to outperform these codes, and also provide a systematic design method to maximize diversity and coding gain in quasi-static Rayleigh Fading channels. We investigate the performance of these new codes in rapid Rayleigh Fading channels and further propose a concatenated version of these codes. Some simulation results of the various concatenated schemes in quasi-static and rapid Rayleigh Fading are presented
T Sunaga - One of the best experts on this subject based on the ideXlab platform.
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Rayleigh Fading compensation for qam in land mobile radio communications
IEEE Transactions on Vehicular Technology, 1993Co-Authors: S Sampei, T SunagaAbstract:A pilot symbol-aided Rayleigh Fading compensation is investigated for M-ary quadrature amplitude modulation (QAM) to achieve highly spectrally efficient land mobile communication systems. The optimum parameters for Fading compensation, bit error rate (BER) performance against E/sub b//N/sub 0/ (energy per bit to the noise power spectrum density), adjacent channel interference, and cochannel interference for 16-QAM, 64-QAM, and 256-QAM, and the spectral efficiencies for these modulation schemes in Rayleigh Fading environments are investigated by computer simulation. To further verify the effect of pilot symbol-aided Fading compensation from a a practical point of view, a 16-QAM modem is implemented, laboratory experiments are executed, and the impact of the dynamic range limitation due to the resolution of the analog-to-digital (A/D) converters is evaluated, along with the imperfection of the analog circuits. It is demonstrated by computer simulation and laboratory experiments that the pilot symbol-aided Fading compensation can sufficiently compensate for fast varying Rayleigh Fading, and 16-QAM gives the highest spectral efficiency in the case of cellular systems. >
