Near-Optimal Hybrid Precoding Analysis in 5G mmWave massive MIMO Systems with Large Antenna Arrays

Abstract

Millimeter-wave (mmWave) communication is most likely to appear as a aspiring technology in the upcoming generation of cellular communication (5G). To confront several challenges (e.g., system complexity, energy consumption etc.), hybrid precoding is largely investigated in mmWave massive MIMO systems due to its low energy consuming nature and reduced system complexity. Most prior works have focused on two types of hybrid precoding structures: (i) fully-connected structure which requiring a massive amount of phase-shifters (PS), (ii) sub-connected structure where comparatively less number of PS is needed; both structures considering only mmWave channel. In this paper, the downlink communication of a mmWave massive MIMO system in considered and the achievable sum-rate of a hybrid precoding (sub-connected) based on successive interference cancellation (SIC) is analyzed in both mmWave channel as well as in different wireless channels. Results demonstrate that the SIC-based scheme achieves nearoptimum sum-rate in different wireless channels and mmWave channel as well regardless of the fact that it utilizes a small number of phase-shifters compared to other architectures and performs even better in the conventional wireless channels than in mmWave channel. Results also indicate that the sum-rate is even more near to optimal when the user antennas and RF chains are sufficiently increased.