车载双向AF协作通信系统的中断性能分析

摘要

In vehicular communication system,two-way cooperative communication can improve system performance.However,vehicle mobile communication will cause the two-way link correlation and thus reduce the system outage performance.To solve the problem,a vehicular communication system model of two-way link correlation is presented,where the correlation coefficient is used to describe two-way link correlation and the system outage performance analysis is also simplified.Furthermore,a closed-form expression for the outage probability with AF cooperation mode is derived,and the optimal power allocation under the certain outage probability is gotten.Numerical results show that the correlation coefficient has more influences on outage performance than that of the power allocation coefficient.Moreover,compared with the optimal power allocation in one-way AF relay system,the total power with the correlation coefficient power allocation can be reduced about 4 dB.%在车载通信系统中采用双向中继协作通信可以提升系统性能.然而,车辆移动造成的链路相关性会增大车载双向中继协作通信系统的中断概率.针对这个问题,建立了车载双向链路相关性系统模型,用相关系数描述车辆移动造成的双向链路特性,简化了系统中断性能分析.同时,在中继采用AF方式下得到系统中断性能的闭式解,且中断概率一定时,求得最优功率分配方案.数值分析表明,相关系数比功率分配系数对中断性能影响的幅度更大,相比传统单向AF中继协作通信系统的最优功率分配方案,最多可以节省4 dB的总功率.