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.

实际上，传统的无线通信系统通常受到各种负面因素的影响，例如信道估计误差（CEE）和收发器硬件损伤（THI）。对于带内全双工（FD）通信系统，除了CEE和THI影响外，不完善的自干扰消除还会由于残留的自干扰（RSI）而大大降低系统性能。本文旨在研究在考虑CEE，THI和RSI影响的现实情况下多输入多输出（MIMO）FD中继（FDR）系统的性能。我们以数学方式得出了所考虑的MIMO-FDR系统的符号错误率（SER）的精确封闭形式，并通过蒙特卡洛仿真验证了得出的结果。数值结果表明，三个不完善因素（CEE，THI和RSI）的影响非常显着。具体来说，考虑到CEE，THI和RSI的值，CEE对SER的影响最大。此外，与理想系统（完美的信道估计，收发器硬件和自干扰消除）相比，所考虑系统的SER明显更高，并且可以快速进入错误基底。因此，在考虑的MIMO-FDR系统中应用所有解决方案以降低CEE，THI和RSI至关重要。所考虑的系统的SER明显更高，并且可以快速进入错误基底。因此，在考虑的MIMO-FDR系统中应用所有解决方案以降低CEE，THI和RSI至关重要。所考虑的系统的SER明显更高，并且可以快速进入错误基底。因此，在考虑的MIMO-FDR系统中应用所有解决方案以降低CEE，THI和RSI至关重要。