A Practical Approach to Hybrid Beamforming for 5G Wi-Fi Systems

The conventional implementation of large-scale antenna arrays with full digital antenna (FDA) beamforming is not practical due to complexity, high cost and power consumption. Hybrid beamforming (HBF) architecture combines digital beamforming in the baseband and analog beamforming in the RF part using low-cost phase shifters. This architecture helps reduce the number of RF chains and the system complexity with an acceptable performance loss. In this paper, we investigate the effectiveness of the HBF technology in application to the upcoming 5G Wi-Fi IEEE standard 802.11be. A detailed comparative analysis of different antenna array configurations and beamforming schemes suggests the most cost-efficient HBF scheme based on a modular antenna array (MAA). This practical HBF-MAA scheme with a 16-element antenna and only 4 RF chains demonstrates in line-of-sight channels the data rates close to the expensive 16-element FDA scheme and significantly outperforms a 4-element FDA which has equivalent complexity.