Hybrid precoding for mmWave massive MU-MIMO systems with overlapped subarray: A modified GLRAM approach

Mmillimeter-wave (mmWave) massive multiuser multiple-input multiple-output (MU-MIMO) system usually utilizes hybrid precoding to reduce complex hardware and high energy consumption. However, most hybrid precoding scheme consider the fully connected architecture, which may result in a significant loss of energy efficiency. In this paper, we propose a hybrid precoding scheme based on the overlapped subarray architecture (OSA), where the analog part of the MU-MIMO system is realized by a OSA network. Based on the OSA architecture, a modified generalized low rank approximation of matrices (GLRAM) based hybrid precoding scheme is designed to maximize the achievable sum-rate, where the analog precoding algorithm apply the phase alignment technology and GLRAM approach to obtain RF precoder/combiner with high array gain provided by massive MIMO system. Then, the block diagonalization (BD) technology is performed to obtain the digital precoding matrix for the multiplexing gain. Simulation results show that the modified GLRAM based hybrid precoding algorithm for OSA architecture can reduce the number of iterations. Compared with the existing hybrid precoding algorithm, it achieves higher spectral efficiency and lower complexity.