中文摘要：

研究了半双工系统协同多用户接入协议中的用户节点协同工作方式以及基站的多用户信号检测和处理方式.提出了基于网络编码的协同多用户接入协议,由中继节点对各用户节点发送的信号进行网络编码传输,基站端对接收到的所有用户节点和中继节点传输的信号进行联合迭代网络译码,进而恢复出所有用户的信息.理论分析和仿真结果表明,通过网络编码系统的处理不仅能获得分集增益,同时还能获得编码增益,显著地提高了系统的性能.另外,编码的码长可变使得用户数目的扩展方便,且对于不同的用户数可保持相同的编码码率.

英文摘要：

Processing algorithm for the base station in a cooperative multiple access （CMA） protocol of a half duplex system and a network coding based on cooperative multiple access （NCCMA） protocol are proposed. Cooperation scheme among several user nodes and the multiple users＇ signal detection are addressed. The data from all user nodes are network coded and transmitted by the relay node. The information data of all user nodes are extracted first by joint iterative network decoding in the pro posed protocol. The theoretical analysis and simulation results demonstrate that the NCCMA achieves coding gain as well as diversity gain which greatly improve the system performance. The code length is variable, thus it is convenient to change the user number and fix the code rate for diverse user.