tailieunhanh - Báo cáo hóa học: " Research Article Link-Adaptive Distributed Coding for Multisource Cooperation"

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 Link-Adaptive Distributed Coding for Multisource Cooperation | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 352796 12 pages doi 2008 352796 Research Article Link-Adaptive Distributed Coding for Multisource Cooperation Alfonso Cano Tairan Wang Alejandro Ribeiro and Georgios B. Giannakis Department of Electrical and Computer Engineering University of Minnesota 200 Union Street Minneapolis MN 55455 USA Correspondence should be addressed to Georgios B. Giannakis georgios@ Received 14 May 2007 Accepted 7 September 2007 Recommended by Keith Q. T. Zhang Combining multisource cooperation and link-adaptive regenerative techniques a novel protocol is developed capable of achieving diversity order up to the number of cooperating users and large coding gains. The approach relies on a two-phase protocol. In Phase 1 cooperating sources exchange information-bearing blocks while in Phase 2 they transmit reencoded versions of the original blocks. Different from existing approaches participation in the second phase does not require correct decoding of Phase 1 packets. This allows relaying of soft information to the destination thus increasing coding gains while retaining diversity properties. For any reencoding function the diversity order is expressed as a function of the rank properties of the distributed coding strategy employed. This result is analogous to the diversity properties of colocated multi-antenna systems. Particular cases include repetition coding distributed complex field coding DCFC distributed space-time coding and distributed error-control coding. Rate diversity complexity and synchronization issues are elaborated. DCFC emerges as an attractive choice because it offers high-rate full spatial diversity and relaxed synchronization requirements. Simulations confirm analytically established assessments. Copyright 2008 Alfonso Cano et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use .