A universal hybrid precoding scheme for massive MIMO communications

Based on an analog radio frequency (RF) network, hybrid precoding (HPC) for massive MIMO can achieve very high spectral efficiencies with moderate hardware cost and power consumption. Despite the extensive research efforts in recent years, the practioners are still looking for HPCs that are efficient and easy-to-implement. In this paper, we present a new method termed as the universal hybrid precoding (UHP), which is nearly optimal, computationally efficient, and applicable to various types of RF network (thus, the name universal): the components of the network can be phase shifters (with finite or infinite resolutions), switches, or their combinations; the topology of the network can be fully-connected or partially-connected. Besides the standard UHP, we also propose a simplified version termed as sUHP to trade a negligible performance loss for much reduced computational complexity. The analysis shows that the computational complexity of the proposed UHP/sUHP is one to two orders of magnitude lower than the state-of-the-art methods. Simulation results verify the (near-)optimality of the proposed UHP scheme for various forms of the analog networks.