Blind Doppler Estimation for MPSK-Based Electromagnetic Interferences
Yanwu Ding, Khanh Dai Pham, Dan Shen, Genshe Chen, Yimin Daniel Zhang · 2023
Geolocation of electromagnetic interference (EMI) is a critical mission for uninterrupted satellite op-eration. One of the useful methods for this purpose is based on the analysis of the EMI Doppler signatures. Because of high-speed motions and complicated orbits of satellites, the Doppler frequencies are time-varying with higher-order phase trajectories. In this paper, we segment the Doppler signals into periodical short time periods and, by modeling the Doppler signature in each short time period as a linear frequency modulated (LFM) waveform, perform Doppler signature analysis using the short-time Fourier transform (STFT). Such approach is robust to EMI when its waveform is an unknown M-ary phase shift keying (MPSK) signal. Furthermore, noticing that such approach suffers from frequent outliers at low signal-to-noise ratio (SNR) scenarios, we develop an outlier suppression scheme to achieve enhanced Doppler estimation.