Multi-objective resource allocation optimization for SWIPT in small-cell networks

Abstract

In this chapter we consider time switching (TS) simultaneous wireless information and power transfer (SWIPT) for a small-cell network consisting of multiple multi-antenna access points (APs) that serve multiple single antenna user equipments (UEs). In this scenario, we address the jointly optimized design of spatial precoding and TS ratios under a multi-objective optimization (MOO) framework. Our goal is to maximize a utility vector including the data rates and harvested energies of all UEs simultaneously. This problem is a non-convex rank-constrained MOO problem which is transformed into a non-convex semidefinite program using the weighted Chebyshev method. We propose an algorithm based on majorization-minimization approach to solve this problem. Numerical results are provided to demonstrate the performance of the proposed beamforming and TS algorithm in terms of harvested energy-data rate trade-off. The effect of different parameters on this trade-off is also investigated to get a general overview for the practical design of the network.