协同通信系统中基于系统容量的功率分配研究

Power Allocation Based on System Capacity under Cooperative Communication Systems

对放大转发协同中继系统进行了容量分析,综合考虑源节点与中继节点以及各中继节点之间不同功率分配对系统容量的影响.基于中继信道强度的瓶颈效应,提出了一种使系统容量最大的优化功率分配方案,并得到了源节点功率Ps、中继节点总功率Pr、各个中继节点功率Pi的闭合表达式.仿真结果表明,相比传统的等功率分配,该方案使系统容量显著提高,特别是当信道信噪比较低时,提高比例超过90%;又因其复杂度低,该算法有很强的实用性.

Effects of different power allocation between the source node and all the relay nodes on the system capacity are taken into consideration in an amplify-and-forward cooperative communication system. An optimum power allocation algorithm based on bottleneck effect of relay channel strength to increase the system capacity is proposed. Furthermore, exact formulations of Ps, Pr and Pi are derived. The simulation shows that the algorithm proposed increases the system capacity significantly compared with the traditional equal power allocation algorithm, especially when the signal-to-noise ratio is low, and the increase ratio can be greater than 90%. Moreover, the scheme proposed is highly practicable, because of its low computational complexity.