Analogue beamforming solution for beam‐alignment problem

Abstract

Listen

Translate article

Analogue only beamforming generally refers to a structure of analogue phase shifters that have no control over the amplitude of the signals and are utilised in millimetre-wave massive multi-input multi-output systems to reduce the cost and power consumption. Conventional analogue only beamforming methods are based on beam-training and subspace sampling where the transmitter and receiver select the best beamformer and combiner from a list of predefined beam patterns to maximise the beamforming gain. In this study, first, the beam-alignment problem is formulated as a quadratic optimisation problem with quadratic constraints. Then, a practical solution for analogue only beamforming is proposed to maximise beamforming gain. The proposed method has no assumption on the array structure or isotropic antenna elements in the array. Also, a new method is proposed to design sub-codebooks to reduce the construction time of the codebook. Simulation results also corroborate the analytical results and performance of the proposed method.