Abstract: An optimal power allocation scheme in energy harvesting based wireless networks was proposed aiming to maximize the effective capacity under the statistical delay-bounded Quality of Service (QoS). In particular, first, the effective capacity maximization problem was formulated for energy harvesting wireless networks. Next, the effective capacity maximization problem was sovled based on convex optimization theory. By analyzing the solution, the facts were obtained that when the QoS constraint is very loose, the optimal power allocation scheme converges to the water filling scheme; meanwhile, when the QoS constraint is very stringent, the optimal power allocation scheme converges to the channel inversion scheme. Then, the developed optimal power allocation scheme was theoretically analyzed by deriving the channel outage probability. Finally, the performance of the optimal power allocation scheme was tested. The experimental results show that the proposed scheme can obtain larger effective capacity than that existing works.

Key words: energy harvesting based wireless network, Quality of Service (QoS), effective capacity, power allocation, convex optimization

摘要： 针对能量收集无线网络中的服务质量（QoS）保障问题，提出了面向统计QoS的最优功率分配方案，从而最大化时延QoS约束下的有效容量。首先，构建能量收集无线网络的有效容量最大化问题。其次，利用凸优化理论求解出最优功率分配方案以及该方案下的最大有效容量，并得出了两种特例下的最优功率分配方案，即：当QoS需求非常松弛时，最优化功率分配方案收敛于注水策略；当QoS需求非常严格时，最优化功率分配方案收敛于信道反转策略。然后，求解了所提最优功率分配方案得到的信道中断概率。最后，通过仿真实验，检验了该最优功率分配方案的性能。实验结果表明，与现有策略相比，所提方案能够获得更大的有效容量。

关键词: 能量收集无线网络, 服务质量, 有效容量, 功率分配, 凸优化