Wireless Information and power transfer assisted by reconfigurable intelligent surfaces

Abstract

In this work, we consider the design of a space division multiple access (SDMA) scheme where a set of energy harvesting users and a set of information decoding users receive energy and information, respectively, from a reconfigurable intelligent surface (RIS) assisted base station that replaces conventional repeaters. Based on precoding for SDMA and weight phases for the RIS used to model the BS signal, we propose optimization algorithms to optimize precoders at the BS and phase shifter coefficients of the IRS passive elements and obtain different trade-offs between information transfer and energy harvesting. The obtained results show that the use of a multiantenna base station and a RIS is very useful for simultaneous transmission of information and energy, permitting a reduction ofthe transmitted power and improving the performance in terms of the coverage area and harvested energy.