Hybrid Precoding for Multi-user Massive MIMO Systems Based on Equivalent Channel

Abstract Utilizing millimeter-wave (mmWave) band with massive MIMO architecture is deemed as an available paradigm for the future 6G wireless systems to cater the increasing demands in communication rates, in which hybrid precoding is a promising solution to reduce hardware cost and power consumption while maintains almost the same spectrum efficiency. In this paper, for multi-user massive MIMO systems, a new hybrid precoding scheme is presented based on the concept of equivalent channel by designing the analog precoder at the transmitter and the analog combiner at the receiver jointly. Specifically, after the optimal analog precoder/combiner for each user has been derived based on the equivalent channel of the individual sub-channel via exploiting the singular value decomposition (SVD) technique, the total baseband digital precoding is implemented with the block diagonalization method to suppress inter-user interference. In this way, not only high spectrum efficiency can be achieved, but also the computational complexity to realize hybrid precoding is decreased. To further verify the superior performance of the proposed hybrid precoding, simulation results are presented with different parameter settings.