SER performance of MIMO full-duplex relay system with channel estimation errors and transceivers hardware impairments

In practice, traditional wireless communication systems are often affected by various negative factors such as channel estimation errors (CEE) and transceiver hardware impairments (THI). For in-band full-duplex (FD) communication systems, besides CEE and THI impacts, imperfect self-interference cancellation will significantly degrade the system performance because of residual self-interference (RSI). This paper aims to investigate the performance of a multiple-input multiple-output (MIMO) FD relay (FDR) system in realistic scenarios where the impacts of CEE, THI, and RSI are taken into account. We mathematically derive the exact closed-form expression of symbol error rate (SER) of the considered MIMO-FDR system and validate the derived expression by Monte-Carlo simulations. Numerical results indicate that the impacts of three imperfect factors (CEE, THI, and RSI) are remarkable. Specifically, with the considered values of CEE, THI, and RSI, the impact of CEE on the SER is most substantial. Additionally, compared with the ideal system (perfect channel estimations, transceiver hardware, and self-interference cancellation), the SER of the considered system is significantly higher and goes to the error floor fast. Therefore, it is crucial to apply all solutions for reducing the CEE, THI, and RSI in the considered MIMO-FDR system.