A bandwidth-efficient cooperative relaying scheme with space-time block coding and iterative decoding

We propose a coded cooperative relaying scheme in which only newly generated parity bits of users are multiplexed, space-time block coded, and forwarded simultaneously by a multi-antenna relay to a common multi-antenna destination if the relay successfully decodes their information in order to improve bandwidth efficiency. Multiplexing introduces correlation between users' data, which offers effectively longer codes and facilitates high-performance iterative multi-user decoding at the destination. Additionally, space-time block coding makes bit-metrics calculation simple and increases spatial diversity of the received signal. Simulation results show that the proposed scheme significantly outperforms direct transmission under the same transmit power and bandwidth efficiency. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.