中文摘要：

双向中继信道（TWRC）传输模型中,用户通过中继与基站构成的上下行链路进行传输,采用现有的时分方案时,传输时隙数与用户数成正比,并可联合物理层网络编码消除自身信号的干扰;在用户数增多的情况下,不仅增大传输系统复杂度,而且降低了数据传输速率.针对此问题,提出物理层网络编码联合预编码方案,仅利用2个时隙便可完成信息传输,在不影响传输速率的同时,还可提高复用增益且避免了同信道干扰.从中断概率和遍历容量两个角度对这2种方案进行性能分析和比较,结果表明网络编码联合预编码方案在高信噪比情况下,性能更优,且随着用户数的增加,系统性能会得到进一步提高.

英文摘要：

In the two-way relay channel transmission model,the user transmits data through the uplink and downlink composed of relay and base station.When using existing time-division scheme,the number of transmission time slots is proportional to the number of users,and the interference from self signals can be eliminated by combining physical layer network coding;when the number of users is increasing,it not only increases the complexity of transmission systems,but also reduces the data transfer rate.To solve this problem,this paper proposes a scheme that combines physical layer network coding and precoding,using only two time slots to complete information exchange,without affecting the transmission rate.In addition,it improves the multiplexing gain and avoids co-channel interference.The performance of these two schemes was analyzed and compared from two perspectives of outage probability and ergodic capacity.The results show that in the case of high SNR,the joint network coding and precoding scheme performs better,and with the increasing number of users,the system performance will be further enhanced.