Coded Error Performance Analysis for RSMA Over Nakagami- m Fading With Transceiver Hardware Impairments

Transceiver hardware impairments (THI) significantly affect the performance of communication systems, necessitating their analysis for realistic performance evaluation and robust system design. Furthermore, integrating channel coding is imperative for enhancing error resilience under diverse fading environments. However, the joint impact of THI and channel coding on error performance in downlink rate-splitting multiple access (RSMA) systems remains unexplored. This paper investigates the impact of THI on the symbol error rate (SER) and explores the effectiveness of block codes in mitigating these impacts in RSMA systems. More precisely, a detailed analysis of the constellation-based SER is conducted for a multi-user RSMA setup, considering both transmitter and receiver hardware impairments with perfect and imperfect detection events of the common stream. Moreover, closed-form expressions for the coded average SER (ASER) are derived under both zero and non-zero THI for multi-user RSMA systems over Nakagami-mfading with varying shape parameters in single-input single-output (SISO) scenarios. This study also presents asymptotic ASER expressions with diversity order analysis under both zero and non-zero THI. The accuracy of these derived ASER expressions is verified through Monte Carlo simulations. Furthermore, the SISO analytical framework is extended to the multiple-input multiple-output scenario, with comparative evaluations against the SISO scenario to demonstrate the practical applicability of the proposed coded RSMA system.