Adaptive User Cooperation with HARQ for the Uplink of a Turbo-Coded System

Coded cooperation has been proposed to increase the diversity or cell coverage in the uplink of a cellular network. In the method, a relay transmits incremental redundancy (IR) of the source´s codeword in cooperation stage. However, for a turbo coded system, IR is not always a best way especially when the first code segment is corrupted badly. Thus, we propose an adaptive cooperation method using different HARQ schemes by estimating the reliability of the first code segment. From simulation results, it is shown that the proposed method improves the performance irrespective of the SNR values of cooperating users.