非对称调制的双向全双工车载通信BER性能分析

BER performance analysis of asymmetric modulation for two-way full-duplex vehicular communication system

在车载通信系统中,全双工中继技术可满足车联网的低时延需求以及缓解频谱资源短缺问题。然而,实际车载通信应用中不同信源车辆发送的信息相互独立,节点调制方式往往不对称。这种非对称传输会加剧全双工模式残余自干扰造成的译码错误。针对这一问题,提出一种非对称调制的全双工通信方法,该方法引入网络编码联合调制的解码转发方式解决了非对称调制带来的误码率增大的问题。此外,分析了全双工残余自干扰随功率动态变化情况下的优化约束条件,得到最优功率分配区间。数值分析结果证明:在不同功率区间内,所提方法都可找到最优功率比例,使得系统端到端误比特性能最优。

In vehicular communication system,the full-duplex relay technology can meet the requirement of low delay and alleviate the shortage of spectrum resources.However,the information transmitted by the source vehicle is independent of each other in the vehicular communication scenario,and the node modulation is usually asymmetric.In this case,the asymmetric transmission increases the decoding error in a full-duplex transceiver with the residual self-interference.A full-duplex strategy with asymmetric modulation is presented to solve this problem,where the network coding with decode-forward and joint-modulation is utilized to reduce the end-to-end bit error rate caused by asymmetric modulation.The optimal constraint conditions for power variation are analyzed under the effect of residual self-interference,and the corresponding optimal power allocation intervals are obtained.Numerical simulations show that the proposed method can be used to find the optimal power ratio and the end-to-end bit error rate(BER)performance is optimal within a given power interval.