基于网络编码的协作HARQ协议

该文基于网络编码技术提出了一种新的协作HARQ协议。在中继节点的协助下两个用户与基站进行通信。中继节点响应基站的重传请求，对两用户的增加冗余帧采用物理层网络编码即信号重叠调制技术进行处理，然后发送至基站。基站对接收信号采用多用户联合检测以及联合软判决译码。在平坦瑞利衰落信道下，该网络编码协作HARQ协议较传统的非协作HARQ协议可获得较大的性能改善，其性能接近没有采用网络编码的协作HARQ协议，且需要较少的硬件和带宽资源。

Cooperative Hybrid-ARQ Protocol Based on Network Coding

A novel cooperative Hybrid-ARQ protocol is presented on the basis of network coding. Two users communicate with the base station with the assistance of a relay node. Relay node responds the repeat request and processes two users’ incremental redundancy frames with physical-layer network coding, i.e. signal superposition modulation, before transmitting to the base station. Multi-user joint detection and joint soft decision decoding are adopted at the base station. Compared with traditional Hybrid-ARQ protocol, the proposed cooperative Hybrid-ARQ protocol can achieve better performance on flat Rayleigh fading channel, and approximates the performance of cooperative Hybrid-ARQ protocol without network coding with fewer hardware and bandwidth resources.