Dense Radio Frequency Interference Cancellation by CEMD and Temporal Windowing Processing for HFSW Radar

Abstract

Radio frequency interference (RFI) is a common source of interference in high-frequency (HF) surface wave (HFSW) radars owing to cochannel interferences (CCIs) in the user-congested HF band. The existence of RFI degrades the detection performance of HFSW radars because its amplitude is high enough to mask the sea and target echoes. Two types of common RFI can be observed in observation data. One of them presents sloping stripes (RFI SS ) in range-Doppler spectrum (RDS) and another one, which is more common, leads to vertical stripe paralleling to range axis in RDS. In this paper, a unified model in order to represent the characteristic of the two types of RFI for the frequency-modulated continuous wave (FMCW) radar system is presented. On the basis of analysis of this generalized model, a new RFI suppression algorithm based on inverse temporal windowing and complex empirical mode decomposition (CEMD) is proposed. Test results show that the proposed method can effectively suppress dense RFI without losing sea echoes in practical condition.