Low-Complexity Multiuser Hybrid Precoding and Combining for Frequency Selective Millimeter Wave Systems

One of the fundamental challenges in the design of millimeter wave communication systems is configuring the large antenna arrays. Finding optimal precoders and combiners fulfilling the hardware constraints imposed by hybrid MIMO architectures in frequency selective scenarios require high complexity solutions, because of the large number of filters to be designed. In this work, we propose a novel dictionary-free, low complexity algorithm to design suboptimal hybrid precoders and combiners suitable for both single-user and multiuser frequency-selective millimeter wave MIMO systems. We evaluate the proposed algorithm with both perfect and imperfect channel knowledge. Simulation results show the effectiveness of the proposed approach and its suitability for practical millimeter wave multi-user (MU) MIMO links.