Joint information transmission design for intelligent reflecting surface aided system with discrete phase shifts

This paper studies the joint information transmission for an intelligent reflecting surface (IRS) aided single-input multiple-output (SIMO) communication system, where an IRS with discrete phase shifts aims to deliver its sensed information to the receiver, besides being a helper of the SIMO system. We first introduce the joint modulation strategy for delivering the information of the primary system and the IRS simultaneously. Specifically, the IRS modulates its information in both the received antenna index and the received signal phase; while the transmitter limits its signal phase in a small region to avoid aliasing. For the proposed strategy, we devise an IRS discrete phase shifts design to maximize the received signal power at the selected receive antenna. Then, we propose a receiver constellation design for the IRS’s and transmitter’s information to maximize the minimum Euclidean distance. Numerical results show that the proposed scheme is practical and competitive compared with several existing joint information transmission schemes.