Performance Analysis of MIMO MRC Systems With Feedback Delay and Channel Estimation Error

In this paper, we investigate the performance of a multiple-input–multiple-output (MIMO) maximal ratio combining (MRC) system with feedback delay and channel estimation error. By taking these practical imperfect factors into account, we first formulate the system model and derive the moment-generating function of the output signal-to-noise ratio (SNR), which serves as the basis for further system performance analysis. Then, we compute the probability density function (pdf) and the cumulative distribution function (cdf) of the output SNR. Furthermore, we derive the analytical expressions of the exact and approximate average symbol error rates (SERs) of the MIMO MRC system, which are used to investigate the performance loss in terms of the array gain and diversity order. Finally, computer simulations are conducted to show the efficacy of the analytical results and the effect of feedback delay and channel estimation error on the system performance.