Comparison of Hybrid Beamforming Systems Using Phase Shifters and Switches

Abstract

Hybrid beamforming systems represent a promising architectural approach for massive multiple-input multiple-output (MIMO) systems operating at millimetre wave frequency. The hybrid beamforming approach splits the beamforming process into an analogue beamforming network and a digital beamforming of reduced size. Recent research reveals the benefit of using a combination of phase shifters and switches to further increase energy efficiency. A switch-off functionality of an arbitrary number of antenna chains is moreover interesting in times of low mobile communication cell utilisation. Within this work, we compare different hybrid beamforming architectures using phase shifters and switches. To enable a fair comparison between the different architectures RF losses within the analogue beamforming network are taken into account.