信道估计误差与同道干扰下的双向中继系统性能分析

Performance Analysis of Two-Way AF Relaying with Channel Estimation Error and Cochannel Interference

分别在瑞利衰落环境和瑞利-莱斯混合衰落环境下,研究了双向中继系统在同时受到信道估计误差和同道干扰影响下的中断概率性能。首先,给出了系统模型以及系统协议;然后,基于得到的接收端信干噪比表达式,分别推导了双向中继系统在单一瑞利衰落环境和瑞利-莱斯混合衰落环境下的中断概率表达式;最后,分析了双向中继系统受信道估计误差和同道干扰影响时的最佳中继位置选择,并得出了最佳中继位置的闭式表达式。数值仿真验证了所推导的中断概率表达式以及最佳中继位置表达式的正确性,揭示了信道估计误差和同道干扰对系统性能的影响,表明当信道估计质量阶数小于1时性能将明显下降,当衰落因子增大时性能将得到提高。

Different wireless channels may experience different kinds of channel fading due to the com‐plexity of practical situations exposed to the impact of channel estimation error and cochannel interfer‐ence .To coincide with the practical scenarios ,the outage performance of the two‐way relaying system is investigated under the Rayleigh fading environment and Rayleigh‐Rice mixed fading environment ,respec‐tively .First ,the system model and the system protocol are presented .Then ,based on the expression of the signal‐to‐interference‐plus‐noise ratio at the receiver , the closed‐form expressions for the outage probabilities are derived for Rayleigh fading environment and Rayleigh‐Rice mixed fading environment , respectively .Finally ,the optimum relay position selection is discussed considering the channel estimation error and the co‐channel interference in the two‐way relaying system ,and the closed‐form expression for the optimum relay position is derived .Simulation results verify the correctness of the outage probability and the optimum relay position analysis ,and reveal that channel estimation error and the co‐channel in‐terference have great impact on the system performance .Furthermore ,the performance declines visibly when the channel estimation quality order is less than 1 ,and becomes better when the fading coefficient increases .