RFI suppression in through-wall radar based on phase-coded stepped-frequency waveform

Radio frequency interference (RFI) usually makes a great impact on through-wall radar (TWR) using ultrawideband signal to achieve high range resolution. In this paper, a phase-coded stepped-frequency (PCSF) waveform is designed to improve the anti-RFI performance of TWR, based on the fact that the different initial phase of the transmitted signals will have no effect on the receiver response to the target echoes, and the RFI is uncorrelated with the transmitted signals. We present the methodology and results of a comparative study on TWR using the PCSF waveform and the conventional stepped-frequency (SF) waveform. Comparisons with simulation data and experimental measurements are given to demonstrate the suitability and efficacy of our analysis for the anti-RFI performance of PCSF waveform. The results show the TWR using PCSF waveform is immune to RFI and better detection performance is achieved.