BER Reduction through Soft Information Relaying in Incremental Redundancy Cooperative Coded Schemes

In conventional incremental redundancy cooperative coding (IRCC) multiuser networks, if a user decodes its partnerpsilas data with error, it ignores sending incremental redundancy for its partner; thus, cooperation gain can not be achieved in such a case. In this paper, we propose a novel scheme that achieves cooperation gain even when relaying users decode their partnerpsilas data with error. This novel technique can be used to overcome the performance degradation caused by error-prone inter-user link. We study bit error rate (BER) performance of the proposed scheme in Nakagami fading channels. Simulation results show that the new scheme has superior performance compared to that of the conventional IRCC schemes and less than 0.3 dB inferior performance compared to that of full cooperative scheme with error-free inter-user link, at BER < 10^-3.