研究了频率非选择性瑞利衰落信道中的物理层网络编码系统容量问题。理论推导了基于解噪重传协议的系统容量,根据容量解析式给出了系统和容量最大化的2个条件表达式,提出了一种最大化系统和容量的自适应分集策略。在瑞利衰落信道环境下,通过理论分析给出所有中继链路特性均属于同一情况下的中断概率闭合解析式,同时也理论推导了一般放大重传和直接传输系统中断概率解析式。在此基础上,完成了数值仿真实验,结果表明所提策略的中断性能与非自适应系统、一般放大重传和直接传输系统相比有较大优势。
The capacity issue of a denoise-and-forward(DNF) protocol was focused on based PNC system of frequency non-selective Rayleigh fading channel.First,the total sum-rate of the system was derived.With the derived sum-rate expression,two policies maximizing the system sum-rate are proposed.On this basis,a novel adaptive diversity scheme was proposed.Closed-form expressions of the system outage probability with the new proposed scheme as well as the amplify-and-forward(AF) based PNC system and the conventional direct transmission were derived over frequency-nonselective Rayleigh fading channels.Simulation experiments are conducted and the results show that the outage performance of the system can be improved significantly compared to the AF based PNC system and the conventional direct transmission scheme.