A RIS Aided Channel Estimation Algorithm for MIMO Systems

Aiming at the problems of high hardware cost and energy consumption in millimeter wave large-scale multiple input multiple output (MIMO) communication system, the channel estimation problem of RIS aided quantized large-scale MIMO system is studied. We consider the RIS with continuous reflection phase shift and the optimization object of minimizing the transmit power of the base station, and take advantage of the angular domain sparsity of the millimeter wave channel. Then in the channel estimation of MIMO system, the power allocation is performed reasonably to optimize RIS integrated with the base station beamforming, and the equivalent channel estimation is adopted to replace the estimation of cascaded channels, to reduce the computational complexity. The simulation results show that the performance of the improved algorithm in this paper can achieve theoretical optimal performance under a certain signal-tonoise ratio, and it can effectively reduce the channel estimation pilot training and feedback overhead, which greatly improves the performance of the communication system.