Performance Analysis of an Index Modulation-Based Receive Diversity RIS-Assisted Wireless Communication System

In this letter, a system model for beyond 5G communication networks utilizing the potential of both index modulation and reconfigurable intelligent surface (RIS) based communication schemes is investigated. An analytical framework for the performance evaluation of the considered system which does not involve complicated phase distributions is developed. The performance of RIS-space-shift keying (RIS-SSK) and RIS-spatial modulation (RIS-SM) schemes using a greedy detector is analyzed, and novel closed-form expressions for the probability of erroneous receive antenna index detection are obtained. It is observed that for both RIS-SSK and RIS-SM, the derived performance metric: (a) decreases with increase in signal-to-noise ratio (SNR); (b) tends to saturate with increasing SNR as well as with decreasing SNR; and (c) decreases with increase in the number of RIS elements.