Enhanced turbo network coding with additional error protection by hybrid iterative decoding

In this paper, an enhanced turbo network coding scheme is proposed for the multiple access relay channel. The system is suitable for a relay assisted cooperative uplink from two mobile stations to one base station. In addition to the existing joint channel-network coding, the new design further exploits the symbol de-mapping soft information, which enables the base station perform a hybrid iterative decoding to improve the reliability. Moreover, it provides extra error protection over the relay link so that cooperative scenarios are extended to more conditions. Finally, a comparative study between the proposed scheme and the former one is conducted. Simulation result indicates that under a deteriorated relay condition, an up to 6 dB gain is achieved by the new model.