Fast Antenna and Beam Switching Method for mmWave Handsets with Multiple Subarrays

Millimeter-wave (mmWave) communication has become a promising option for meeting the multi-fold increase in demand for mobile data in the fifth-generation (5G) mobile broadband. However, when mmWave is applied to a mobile terminal device, communication can be frequently broken due to rampant hand blockage. Although this problem can be overcome by configuring multiple sets of subarrays at different locations, developing a fast and efficient operation that can find the best subarray and beam direction with power, complexity, and latency constraints is extremely challenging. In this study, we propose a fast antenna and beam switching method termed 'Fast-ABS' that uses only one antenna module for the reception to predict the best beam of other subarrays. Through extensive simulations, we demonstrate that Fast-ABS achieves efficient and seamless connectivity under hand blockage. In addition, we implement Fast-ABS on software radios and integrate it into the 5G New Radio physical layer. Our experiments show that the performance of the proposed beam switching method is close to that of an 'Oracle' solution that can instantaneously identify the best beam of other subarrays even in complex non-line-of-sight scenarios.