Title :
Capacity Theorems for the AWGN multi-way relay channel
Author :
Ong, Lawrence ; Kellett, Christopher M. ; Johnson, Sarah J.
Author_Institution :
Sch. of Electr. Eng. & Comput. Sci., Univ. of Newcastle, Newcastle, NSW, Australia
Abstract :
The L-user additive white Gaussian noise multi-way relay channel is considered, where multiple users exchange information through a single relay at a common rate. Existing coding strategies, i.e., complete-decode-forward and compress-forward are shown to be bounded away from the cut-set upper bound at high signal-to-noise ratios (SNR). It is known that the gap between the compress-forward rate and the capacity upper bound is a constant at high SNR, and that between the complete-decode-forward rate and the upper bound increases with SNR at high SNR. In this paper, a functional-decode-forward coding strategy is proposed. It is shown that for L ≥ 3, complete-decode-forward achieves the capacity when SNR ≤ 0 dB, and functional-decode-forward achieves the capacity when SNR ≥ 0 dB. For L = 2, functional-decode-forward achieves the capacity asymptotically as SNR increases.
Keywords :
AWGN channels; channel capacity; channel coding; AWGN multiway relay channel capacity theorems; L-user additive white Gaussian noise multiway relay channel; capacity upper bound; complete-decode-forward rate coding strategy; compress-forward rate coding strategy; cut-set upper bound; functional-decode-forward coding strategy; high signal-to-noise ratio; single relay; AWGN; Additive white noise; Broadcasting; Computer science; Decoding; Downlink; Gaussian noise; Relays; Signal to noise ratio; Upper bound;
Conference_Titel :
Information Theory Proceedings (ISIT), 2010 IEEE International Symposium on
Conference_Location :
Austin, TX
Print_ISBN :
978-1-4244-7890-3
Electronic_ISBN :
978-1-4244-7891-0
DOI :
10.1109/ISIT.2010.5513576