Hybrid Precoding for Massive mmWave MIMO Systems

Abstract

Due to high costs and power consumptions, fully digital baseband precoding schemes are usually prohibitive in millimeter-wave massive MIMO systems. Therefore, hybrid precoding strategies become promising solutions. In this paper, we present a novel real-time yet high-performance precoding strategy. Specifically, the eigenvectors corresponding to the larger eigenvalues of the right unitary matrix after singular value decomposition on an array response matrix are used to abstract the angle information of an analog precoding matrix. As the obtained eigenvectors correspond to the larger singular values, the major phase information of channels is captured. In this way, the iterative search process for obtaining the analog precoding vectors is avoided, and thus the hybrid precoding can be realized in parallel. To further improve its spectral-efficiency, we enlarge the resultant vector set by involving more relevant vectors in terms of their correlation values with the unconstrained optimal precoder, and a hybrid precoder is thus produced by using the vector set. The simulation results show that our proposed scheme achieves near the same performance as the orthogonal matching pursuit does, whereas it costs much fewer complexities than the OMP, and thus can be realized in parallel. INDEX TERMS Millimeter wave communication, MIMO, wireless communication, hybrid precoding. I. INTRODUCTION

Multiuser Equalizer for Hybrid Massive MIMO mmWave CE-OFDM Systems

“…In the recent years, some works based on hybrid architectures have been proposed for narrowband single-user systems [10,11]. In [10], it is proposed a solution based on the concept of orthogonal matching pursuit (OMP), where the sparse-scattering structure of mmWave channels is exploited to derive both the precoder and combiner.…”

“…Basically, a number of dominant propagation paths are selected and then they are digitally combined at baseband. To avoid the complexity of the OMP, the authors of [11] proposed a precoder, where the singular value decomposition (SVD) is used to obtain the phase information of the channel.…”

“…In this section, the analog part of the hybrid equalizer is designed. From (11) and after obtaining the solution for B…”

“…In these systems, the number of RF chains is lower than the number of antennas employed at both the user terminals (UTs) and base station (BS), reducing the cost and the power consumption. This is the architecture followed in this paper and in the last years several transmit and receive hybrid beamforming approaches have been proposed [10][11][12][13][14][15][16][17][18], as discussed in Section 1.1.…”

Evolutionary Algorithm Based Capacity Maximization of 5G/B5G Hybrid Pre-Coding Systems

“…Authors in [ 34 ] have utilized the signal to leakage noise ratio (SLNR) to design the analog pre-coder and the conventional zero forcing technique is used for the digital pre-coder. An algorithm based on singular value decomposition to design the hybrid pre-coder is discussed in [ 35 ].…”