大规模MIMO关键技术及应用

Abstract

The explosive growth of wireless device usage has pushed the demand for wireless data to unforeseen levels, resulting in a serious spectrum shortage problem. Hence, the wireless research community is aiming to develop massive Multi-input Multi-output (MIMO) technology for increasing spectral efficiency (SE, as measured in bits/s/Hz) by one or two orders of magnitude, while simultaneously saving an order of magnitude (or more) in transmit power. The main challenge in creating a massive MIMO device is performance erosion induced by pilot contamination. Furthermore, techniques associated with beamforming, precoding, and signal detection may significantly restrict the performance gains of massive MIMO systems. In this survey, we present a comprehensive list of potential massive MIMO techniques and highlight their pros and cons. We first evaluate the performance advantages of massive MIMO techniques in terms of capacity, SE, energy efficiency (EE, as measured in bits/Joule), transmit diversity, mutual coupling, etc. Afterward, we classify the massive MIMO techniques into four categories, namely channel measurement/modeling, channel estimation, beamforming/precoding, and signal detection. Finally, we discuss a critical issue associated with the implementation and standardization of millimeter-wave based massive MIMO systems.