Large-Scale MIMO Transmitters for CR-NOMA in Fixed Physical Space: The Effect of Realistic System Impairments Using Stochastic Geometry

Abstract

Hardware impairments (HWI) are imperfections in hardware components that diminish wireless communication performance. Unlike Geometric-based Stochastic Models (GBSMs), existing works on the impact of HWI on cooperative-relay (CR) Non-Orthogonal Multiple Access (NOMA) systems employ the Correlated-based Stochastic Model (CBSM), which does not capture realistic propagation mechanisms. Moreover, studies on CR-NOMA with large antenna transmitters (LATs) using CBSM and GBSM have attracted little attention in academia. We consider this as a computational issue. Although considerable work has been done, there is still a significant knowledge gap about how HWI and imperfect successive interference cancellation affect far-users in CR-NOMA with the LAT system. In this study, the LAT is considered a cylindrical array, and parameters such as delay spread, angle of arrival, and departure are incorporated to achieve a CR-NOMA-GBSM system with amplify-and-forward (AF) or decode-and-forward (DF) relaying schemes. To reduce computing demands, we offer a novel concept of using the physical dimensions of the array to derive the location vector of the antenna element. Using Monte Carlo simulation, near and far users� BER performances deteriorate for AF and DF at 15 dB and 5 dB or below, respectively. As far-users can receive comparable performances as near-users for both AF and DF in terms of achievable rates, this demonstrates the potential rewards of CR-NOMA with LAT. � 2024 The Authors.