双向中继系统阀值速率影响分析

Impact Analysis of Threshold Rate on Two-Way Relaying System

为了更好地分析阀值速率不对称对实际双向中继系统性能的影响,提出了阀值速率比因子性能分析法.该方法首先根据2个方向阀值速率定义了阀值速率比因子,然后求出系统性能表达式作为阀值速率比因子的函数,并根据函数研究该因子对性能表达式的影响,从而得到阀值速率不对称对系统性能的影响.使用该方法对Nakagami-m衰落下的系统中断概率进行了研究,结果表明,信噪比一定时,阀值速率不对称将导致系统中断概率增大.仿真结果表明,当中继与终端Nak-agami-m衰落指数分别为1和1.2、信噪比为20 dB、阀值速率比因子从1增大到3时,系统的中断概率约增大了3%.

In order to analyze the impact of the asymmetric threshold rate on the performance of two-way relaying system more precisely, a method named performance analysis of ratio of threshold rate （RTR） is presented. The RTR is defined based on two directional threshold rates, then performance expressions are derived to obtain a function of RTR and the effect of the RTR on performance expressions is studied to obtain the effect of asymmetric threshold rate on the per formance of the system. The proposed method is used to analyze the outage probability in Nakagami-m fading channel, and the results show that the outage probability increases with RTR increasing when the ratio of signal to noise （SNR） is a constant. Simulation results show that the outage probability increases by about 3% when the fading parameter pertaining to each terminal pair-relay link is 1 and 1.2, respectively, SNR is 20 dB, and RTR increases from 1 to 3.