Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Distributed Generalized Low-Density Codes for Multiple Relay Cooperative Communications | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2008 Article ID 852397 9 pages doi 2008 852397 Research Article Distributed Generalized Low-Density Codes for Multiple Relay Cooperative Communications Changcai Han and Weiling Wu Key Laboratory of Information Processing and Intelligent Technology Beijing University of Posts and Telecommunications Beijing 100876 China Correspondence should be addressed to Changcai Han cchan09@ Received 1 November 2007 Revised 17 March 2008 Accepted 9 July 2008 Recommended by Yonghui Li As a class of pseudorandom error correcting codes generalized low-density GLD codes exhibit excellent performance over both additive white Gaussian noise AWGN and Rayleigh fading channels. In this paper distributed GLD codes are proposed for multiple relay cooperative communications. Specifically using the partial error detecting and error correcting capabilities of the GLD code each relay node decodes and forwards some of the constituent codes of the GLD code to cooperatively form a distributed GLD code which can work effectively and keep a fixed overall code rate when the number of relay nodes varies. Also at relay nodes a progressive processing procedure is proposed to reduce the complexity and adapt to the source-relay channel variations. At the destination the soft information from different paths is combined for the GLD decoder thus diversity gain and coding gain are achieved simultaneously. Simulation results verify that distributed GLD codes with various number of relay nodes can obtain significant performance gains in quasistatic fading channels compared with the strategy without relays and the performance is further improved when more relays are employed. Copyright 2008 C. Han and W. Wu. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is
