부산대학교 도서관

Increasing demand for higher data-rate wireless connectivity with lower latency is fueling the explorations of millimeter-wave (mmWave) spectrum and massive MIMO communications. Both technologies are recognized as the key enablers of 5G and beyond 5G (B5G) networks. Hybrid beamforming is one of the most promising energy and cost-effective approaches to realize mmWave massive MIMO communications with lower complexity and smaller training overhead. With the motivation of giving more insights and in-deep technical recommendations to B5G network designers regarding hybrid beamforming, we present a hybrid beamforming taxonomy in terms of channel state information (CSI) availability, frequency bandwidth, architecture complexity, analog beamformer components, number of users, connectivity to RF chains, and the digital and analog beamforming design. Furthermore, we provide a comprehensive survey on the state-of-the-art use-cases for each classification followed by identification of the future challenges and open research issues.