Triple-Handshake-Based Semi-blind Beamforming in mmWave Massive MIMO

Hybrid precoding has been used in millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) system to reduce the high cost and power consumption of full digital precoding. However, conventional hybrid precoding requires complex channel estimation before beamforming, which needs pretty high pilot consumption or complex computation. In this paper, we propose a triple-handshake-based semi-blind beamforming method whose basic process is called handshake, which composed of two basic steps--beam impulse and beam calibration in time division duplex (TDD). The simulation results demonstrate that this semi-blind beamforming can achieve a pretty good performance with extremely low complexity and power consumption. In addition, compared with other methods without perfect channel status information (CSI), our method reaches a better spectral efficiency, as well.