Combining time-frequency analysis and array processing for multi-interferences mitigation in GNSS application

Interferences mitigation techniques have been intensively studied due to their importance for ensuring the reliability, accuracy and continuity of global navigation satellite system (GNSS) services and a series of research results have been achieved. However, The multi-interferences suppression performance of existing methods for global navigation satellite system (GNSS) receivers is degraded seriously due to their lack of the degree of freedom (DoF). To address that problem, a space-time-frequency processor (STFP) is proposed by combining time-frequency (TF) analysis and spatial processing. Based on the circularity of interferences in TF domain, a least common period block principle is introduced to segment the received signals into blocks. Then the corresponding TF points belonging to each block are grouped into batches and the minimum power distortionless response (MPDR)-based space-time-frequency beamformer is adopted to nullify the interferences. Simulation results show that the proposed method can suppress more wide-band interferences (WBI) without increasing the number of antenna elements and cope with the interferences arriving from the same direction as GNSS signals.