Hybrid Precoding In Mmwave Mimo Broadcast Channels With Dynamic Subarrays And Finite-Alphabet Inputs

Hybrid precoding provides a tradeoff between spectral efficiency and power consumption in millimeter wave (mmWave) multiple-input multiple-output (MIMO) systems. In this paper, we investigate the partially-connected hybrid precoding design for mmWave MIMO broadcast channels with finite alphabet inputs. To enhance the spectral efficiency, a new algorithm is proposed to dynamically optimize the mapping strategy from radio frequency (RF) chains to transmit antennas such that the weighted sum of channel gains is maximized. Then we adopt the inexact alternating minimization method to design hybrid precoding matrices with given optimal mapping strategy and finite-alphabet inputs. Simulation results demonstrate the good performance of our proposed algorithm.