Optimal Relay Selection for Cache-aided Full-duplex SWIPT Systems with Maximal Throughput

Abstract

To optimize the throughput of the full-duplex simultaneous wireless information and power transfer(SWITP) cooperation system, a cooperative cache-aided full-duplex relay system model was constructed, and by using the idle energy access point (EAP) as the additional energy supplement of the relay node, an optimal relay selection strategy for cache-aided full duplex SWIPT systems was proposed to optimize the system throughput. The strategy established the problem model by jointly optimizing the parameters such as relay transmission power and power splitting factor, and transformed the original nonlinear mixed integer programming problem into a pair of coupled optimization problems through mathematical transformation. And then, using Lagrange function and Karush-Kuhn-Tucher(KKT) conditions to solve the internal optimization problem, the closed-form solution of power splitting factor and relay transmission power was obtained. Based on this result, the external optimization problem was solved to select the optimal relay for cooperative communication. Simulation experiments show that the proposed strategy is superior to other traditional cooperative relay communication systems, and it can bring significant system performance gain by using idle EAP and adding cache assisted relay configuration.