A Sensing-Based Over-the-Air Phased Array Antennas Phase Calibration Method With Greedy Algorithm

Phase errors of phased array antennas can cause gain degradation that necessitates calibration to compensate this effect. Over-the-air (OTA) calibration methods are promising for avoiding interruption of communication applications for specific calibration conditions. However, typical calibration methods have the assumption that precise knowledge about calibration should be exchanged, such as relative positions and cost function (CF) values, which are difficult to obtain in practical mobile communication systems. To overcome this, a sensing-based OTA calibration method is proposed in which sensing methods aided by cameras or infrastructure sensors could locate user equipment (UE) and regard it as calibration reference source. Then, greedy algorithm is integrated into new radio (NR) beam management process, where UE measures directional channel state information-reference signals (CSI-RSs) reserved for calibration and feeds back the optimal beam index instead of CF values. Consequently, UE received power is maximized so as to achieve phase calibration. The simulation results exhibit that even when locating error exists, the proposed method can correct phase errors with a low overhead in terms of reserved NR CSI-RSs.