多跳分集系统优化功率分配方案

Optimum power allocation for multi-hop diversity system

针对协同通信中广泛使用的等功率分配(EPA)方案性能往往不是最优问题,采用理论推导和仿真的方法找出了最优功率分配方案.推导了在高信噪比条件下解码转发(DF)多跳分集网络的中断概率近似表达式和分集度,选取此表达式为代价函数,提出一种适合于DF多跳分集系统的近似最优功率分配方案.仿真结果验证了理论分析的正确性,在DF多跳分集系统中采取此近似最优功率分配方案(AOPA)要优于等功率分配(EPA)方案.与等功率分配(EPA)方案相比,此近似最优功率分配方案(AOPA)能更有效地提高系统的性能.

For the problem that the performance of equal power allocation （EPA）scheme widely used in collaborative communication is not always the most optimized one, it is necessary tO find a reasonable power allocation scheme to improve system performance. An approximate outage probability formulation and diversity order were deduced in multi-hop decode-and-forward（DF） diversity system at high signal-to-noise ratio. And an approximately optimum power allocation was proposed by making use of the approximate outage probability formulation as cost function. The simulation results verify the correctness of the theoretical analysis, and the approximately optimtim power allocation outperforms the equal power allocation （EPA） in multi-hop diversity system employing decode-and- forward （DF） relaying. Comparing with equal power allocation （EPA）, this approximate optimal power allocation scheme can effectively improve the system performance.