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.