不对称放大转发双向中继功率分配及中继位置选择

摘要

该文研究基于放大转发中继的不对称双向中继系统容量问题.首先,在瑞利衰落信道环境下,从双向通信的角度,通过理论分析得出其中断概率精确表达式和渐进表达式.理论分析发现节点发射功率和源节点目标速率共同决定系统中断概率,并且在大多数业务下系统中断性能仅取决于单向链路,而与另一链路无关.基于此,以优化系统中断性能为目标,提出一种基于业务知识的节点功率分配算法和中继位置选择算法.数值仿真实验结果表明,通过功率分配和中继位置选择可以显著提高不对称放大转发双向中继系统的中断性能.%The capacity issue of asymmetric two-way amplify-and-forward relaying is investigated. First, exact and asymptotic outage probabilities of the network scenario under investigation are derived over Rayleigh fading channels. Then, it is found that the system outage probability is determined by the terminals' average transmission powers and the traffics that the system operates. For most of the traffics, the overall system outage probability depends only on the one-way channel. Following this analysis, novel power allocation and relay location algorithms are proposed, both of which are based on the traffic-knowledge of operating networks. The simulation results show that the outage performance is significantly improved when the proposed algorithms are applied.