A low complex method for performance improvement of wireless multiuser cooperative coding networks

User cooperation gain, in conventional incremental redundancy cooperative coding (IRCC) multiuser networks, is not achievable if cooperating user is unable to correctly decode its partner´s data. On the other hand, sending simple channel log likelihood ratio (CLLR) in the cases that relaying users are unable to decode their partner´s data, improves the bit error probability (BEP) performance of the system by achieving cooperative diversity gain, when the channel between two cooperating users is reliable. However, in adverse inter-user channel, exploiting channel reliability information is not appropriate. Simulation results show that the CLLR-based IRCC method has superior performance compared to that of the conventional IRCC method at high SNR and has inferior performance compared to that of conventional one at low SNR. Therefore, by combining two methods, we can achieve better performance in low as well as high SNR.