针对无线携能通信(SWIPT)中的能量效率(EE)优化问题，考虑在满足一定通信服务质量和收集能量的条件下，通过一种基于时间反演(TR)的优化算法最大化系统的EE.首先，将TR引入SWIPT中构建新型的传输方案，并分析EE的闭合表达式.其次，对问题进行规划和分析，发现该优化问题是一个二元分式非凸规划问题，需要进行数学变换将其转化为凸优化问题.最后，通过Dinkelbach算法和CVX得到问题的解.仿真结果表明：解码噪声功率、最大发射功率及信噪比增大时，优化后的EE也会增大，且在满足约束条件时，基于TR的优化算法能够明显增大EE，提升系统性能.
Targeted at the problem of energy efficiency (EE) optimization in simultaneous wireless information and power transfer (SWIPT), this paper considers using an optimization algorithm based on time reversal (TR) to maximize the energy efficiency of the system under the condition of satisfying certain communication service quality and collecting energy. First, the time reversal is introduced into simultaneous wireless information and power transfer to construct a new transmission scheme, and the closed expression of energy efficiency is analyzed. Next, through analyzing and planning the problem, it is found that the optimization problem is a two-element fractional non-convex programming problem which needs to be transformed into a convex optimization problem by mathematical transformation. Finally, the solution of the problem is obtained by using the Dinkelbach algorithm and CVX. The simulation results show that the optimized energy efficiency will increase when the decoding noise power, the maximum transmission power, and the signal-to-noise ratio increase. The optimization algorithm based on time reversal can significantly increase the energy efficiency when the constraints are satisfied.
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