A Bandwidth-efficient Coded User-Cooperation Scheme for Flat Block Fading Channels

We propose a coded cooperation scheme based on turbo encoding/decoding, in which only newly generated parity bits of the partner are sent if the user successfully decodes its partner´s information in order to improve bandwidth efficiency. The proposed encoding structure introduces correlation between users´ data over multiple frames, which offers effectively longer codes and facilitates high-performance iterative multi-user decoding at the destination. Additionally, the iterative decoding over multiple frames can provide time diversity besides spatial diversity inherent in user-cooperation even for flat block fading channels. Simulation results show that the proposed scheme significantly outperforms direct transmission for the same transmit power and bandwidth efficiency.