A Null Broadening Method for High Dynamic GNSS Space-time Interference Suppression Based on the Uniform Circular Array

The power inversion (PI) algorithm can effectively suppress interferences for the Global Navigation Satellite System (GNSS), without knowing the prior information of the interference directions. In the high dynamic scenarios, however, sharp nulls of the beam-pattern formed by the conventional PI algorithm might lead to performance degradation of interference suppression as the interferences might move out of the nulls. Null broadening is one of the most feasible approaches to mitigate this problem. Based on the assumption that the angular mismatch magnitudes follow the Gaussian distribution, we develop a space-time covariance matrix taper (ST-CMT) null broadening scheme for uniform circular arrays (UCAs), and incorporate the ST-CMT scheme into the PI algorithm. Illustrative simulation results validate the efficiency of the proposed ST-CMT scheme.