提出了一种相干型中继节点解调映射方案，适用于采用物理层网络编码的二进制频移键控(binary frequency shift keying, 2FSK)双向中继通信系统. 方案分两支路对叠加信号进行处理，然后对两路信号差值进行抽样判决，并对判决结果进行网络编码映射. 采用最大后验概率准则得到判决门限. 分析了采用该方案中继节点的
判决错误概率、系统误码率及吞吐率性能. 理论分析和仿真验证表明，采用该方法进行解调映射的物理层网络编码方案中继节点判决错误概率和系统误码率与传统方案和网络编码方案相近，系统吞吐率则高于两者.

A correlative demodulation and mapping scheme is proposed for the relay nodes in 2FSK two-way relay communication systems. The scheme ses superimposed signals with two branches, and samples the discrepancy to make a decision, which may be mapped to a binary bit. The decision thresholds are calculated according to the maximum posterior probability criterion. The relay nodes’ decision error probability and the bit error rate of the entire system are analyzed. Theoretical analysis and simulation results show that the relay nodes’ decision error probability and the system BER of the physical-layer network coding scheme using the proposed demodulation and mapping method are close to those of the traditional scheme and the network coding scheme, but the throughput is higher than the two.