Optimization of Harvesting Power and Information Quality by Multiple Objective Functions

Abstract

In this paper, the multiple objective function optimization for Simultaneous Wireless Information and Power Transfer (SWIPT) and Wireless Power Transfer (WPT) have been presented in the millimeter band. Three different objective functions for harvesting power (HP) and bit error rate (BER) are investigated. The real environment channel is calculated by shooting and bouncing ray/image techniques which include multi-path, fading effect and path-loss in the complex environment. Beamforming techniques are applied at the transmitter to focus the transmitter energy for reducing the multi-path effect and achieving good systems performance. The Self-Adaptive Dynamic Differential Evolution (SADDE) method is used to adjust the length of the feed line on each array element for maximum the objective. Numerical results show that single objective function can only achieve good performance for WPT node instead of SWIPT node. Moreover, the multiple objective function can meet the criterion both for WPT and SWIPT node. The multiple objective function can improve the BER to an acceptable level by only reducing about 9.2% harvesting power compared to the best harvesting power from the single objective function. Finally, the multiple optimization function can achieve the good information quality for SWIPT node, but also get good total harvesting power for WPT and SWIPT node.