研究了Nakagami信道中联合网络编码和双向协作中继选择的中断与平均误码率的性能,基于3个时隙的网络编码方案提出了一种最小化较差用户误码率的协作中继选择策略。在Nakagami信道下,从双向通信的角度,通过理论分析得出其中断概率和平均误码率的解析式和渐近式,同时推导了无协作中继选择时网络编码的中断概率和平均误码率解析式。通过理论分析发现,当Nakagami信道衰落参数降低时,联合网络编码的协作中继选择方案相对于无协作中继选择时的性能增益将逐渐升高。数值仿真实验结果表明,所提策略的平均误码率性能要显著高于无协作中继选择时的网络编码性能。
The outage probability and average BER (bit error ratio) of two-way relay system with network coding using relay selection were analyzed over Nakagami channels. The cooperative relay selection criterion of minimizing the worse user's BER was proposed based on three time slots network coding. The closed-form expressions of outage probability and average BER were derived through theoretical analysis from the point of two-way communication; meanwhile, the analytical expressions of outage probability and average BER of two-way relay system using network coding without cooperative relay selection were also obtained rigorously. By the analysis of two-way relay system without cooperative relay selection, it was found that the performance gains of the proposed scheme would increase gradually with the Naka- gami channel fading parameters decreasing. Simulation results verified the correctness of theoretical analysis and illus- trated that the performance of the proposed scheme can be improved significantly relative to the network coding without cooperative relay selection.