信道估计误差对MIMO系统信道容量的影响

In order to study the impact of channel estimation error on the channel capacity of a Multiple Input Multiple Output (MIMO) system, a novel method is proposed to explore the channel capacity under correlated Rayleigh fading. The system model is constructed based on the channel estimation error at the receiver side. And using the properties of Wishart distribution, the lower bound on the channel capacity is derived when the MIMO channel is full rank. And then a method is proposed to select the optimum set of transmit antennas based on the lower bound on the mean channel capacity. The proposed method based only on the fading correlation and not the instantaneous channel realization. And also its computational complexity is low and tends to be realized. The simulation results show that the channel capacity of MIMO system is sensitive to the channel estimation error. The channel capacity is maximized when the signal-to-noise increases to a certain point. Antenna selection of transmitter can increase the channel capacity of MIMO system by about 1bit/s in a flat fading environment with rank deficient channel.