The Experts below are selected from a list of 55200 Experts worldwide ranked by ideXlab platform
Pla Uni - One of the best experts on this subject based on the ideXlab platform.
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A Novel Scheme for Space-Time Block Coding with Variable Transmit Diversity Gain in Time-Frequency-Shift Keying Systems
Journal of Electronics Information & Technology, 2007Co-Authors: Pla UniAbstract:A novel scheme for unitary space-time block coding with variable transmit Diversity Gain is proposed for TFSK (Time-Frequency-Shift Keying) systems. Each modulated TFSK symbol is divided into two orthogonal sub-symbols, and the new scheme is constructed by differently combining the sub-symbols with the different transmit Diversity Gain able to be achieved by noncoherent processing at the receivers. The results of computer simulation show that the new scheme has advantage of anti-flat-fading over Alamouti space-time block coding and space-time frequency-shift keying, and ST-TFSK systems with two Diversity Gain enjoy the superior coding rate and the inferior anti-fading performance to the ones with four Diversity Gain, which approve the theoretical analysis
Jiangzhou Wang - One of the best experts on this subject based on the ideXlab platform.
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Cooperative Performance and Diversity Gain of Wireless Relay Networks
IEEE Journal on Selected Areas in Communications, 2012Co-Authors: Shengbo Zhang, Xiang-gen Xia, Jiangzhou WangAbstract:In this paper, the error rate performance and Diversity Gain of amplify-and-forward (AF) wireless relay networks are studied. The distributed space-time block code (DSTBC) in a synchronous relay network with multiple relay nodes is considered. The distributed linear dispersion code is used at the relays. The symbol (or codeword) error rate is studied in terms of upper and lower bounds through rigorous derivations, and the Diversity Gain of the DSTBC is derived, for any number of relay nodes. As a corollary, a necessary and sufficient condition is obtained for achieving full cooperative Diversity. Arbitrary coding matrices at the relays, path loss and general linear power allocation are considered. Finally, the orthogonal frequency division multiplexing (OFDM)-based space-time transmission scheme in asynchronous cooperative networks is also discussed.
Hamid Jafarkhani - One of the best experts on this subject based on the ideXlab platform.
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Maximum-rate Transmission with Improved Diversity Gain for Interference Networks
arXiv: Information Theory, 2013Co-Authors: Hamid JafarkhaniAbstract:Interference alignment (IA) was shown effective for interference management to improve transmission rate in terms of the degree of freedom (DoF) Gain. On the other hand, orthogonal space-time block codes (STBCs) were widely used in point-to-point multi-antenna channels to enhance transmission reliability in terms of the Diversity Gain. In this paper, we connect these two ideas, i.e., IA and space-time block coding, to improve the designs of alignment precoders for multi-user networks. Specifically, we consider the use of Alamouti codes for IA because of its rate-one transmission and achievability of full Diversity in point-to-point systems. The Alamouti codes protect the desired link by introducing orthogonality between the two symbols in one Alamouti codeword, and create alignment at the interfering receiver. We show that the proposed alignment methods can maintain the maximum DoF Gain and improve the ergodic mutual information in the long-term regime, while increasing the Diversity Gain to 2 in the short-term regime. The presented examples of interference networks have two antennas at each node and include the two-user X channel, the interferring multi-access channel (IMAC), and the interferring broadcast channel (IBC).
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Maximum-Rate Transmission With Improved Diversity Gain for Interference Networks
IEEE Transactions on Information Theory, 2013Co-Authors: Hamid JafarkhaniAbstract:Interference alignment (IA) was shown to be effective for interference management in improving transmission rate in terms of the degree of freedom (DoF) Gain. On the other hand, orthogonal space-time block codes were widely used in point-to-point multiantenna channels to enhance transmission reliability in terms of the Diversity Gain. In this paper, we connect these two ideas, i.e., IA and space-time block coding, to improve the designs of alignment precoders for multiuser networks. Specifically, we consider the use of Alamouti codes for IA because of their rate-one transmission and achievability of full Diversity in point-to-point systems. The Alamouti codes protect the desired link by introducing orthogonality between the two symbols in one Alamouti codeword, and create alignment at the interfering receiver. We show that the proposed alignment methods can maintain the maximum DoF Gain and improve the ergodic mutual information in the long-term regime, while increasing the Diversity Gain to 2 in the short-term regime. The presented examples of interference networks have two antennas at each node and include the two-user X channel, the interfering multiaccess channel, and the interfering broadcast channel.
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Using Instantaneous Normalized Receive SNR for Diversity Gain Calculation
2010Co-Authors: Yindi Jing, Hamid JafarkhaniAbstract:We propose a technique to calculate the Diversity Gain for a vector channel when the noises have any nonsingular distribution and the fading coefficients have arbitrary distribution. This technique uses the serial expansion of the outage probability of the instantaneous normalized receive SNR to obtain the Diversity Gain. The approach is simpler than using the pairwise symbol error rate to analyze the Diversity Gain.
J H Winters - One of the best experts on this subject based on the ideXlab platform.
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the Diversity Gain of transmit Diversity in wireless systems with rayleigh fading
IEEE Transactions on Vehicular Technology, 1998Co-Authors: J H WintersAbstract:In this paper, we study the ability of transmit Diversity to provide Diversity benefit to a receiver in a Rayleigh fading environment. With transmit Diversity, multiple antennas transmit delayed versions of a signal to create frequency-selective fading at a single antenna at the receiver, which uses equalization to obtain Diversity Gain aGainst fading. We use Monte Carlo simulation to study transmit Diversity for the case of independent Rayleigh fading from each transmit antenna to the receive antenna and maximum likelihood sequence estimation for equalization at the receiver. Our results show that transmit Diversity with M transmit antennas provides a Diversity Gain within 0.1 dB of that with M receive antennas for any number of antennas. Thus, we can obtain the same Diversity benefit at the remotes and base stations using multiple base-station antennas only.
Zhang Min - One of the best experts on this subject based on the ideXlab platform.
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Study on Diversity Gain of Linear Block Code Under Rayleigh Channel
Computer Engineering, 2012Co-Authors: Zhang MinAbstract:The error performance of Additive White Gaussian Noise(AWGN) channel and Rayleigh fading channel is analyzed.Then the relation between Diversity Gain and communicating reliability over Rayleigh fading channel is studied.A formula of code error probability upper bound is derived for wireless communication system in which linear block code is applied.It shows the relation between Diversity Gain of linear block code through Rayleigh channel and its minimum hamming distance.Based on Monte Carlo method,the simulation is carried on this problem.A comparative analysis is made on the experimental and theoretical result,and results show that the Diversity Gain of linear block code under relay fading channel is equivalent to its minimum hamming distance.
