Doppler Adaptive Suppression of Interference in Moving Target Indicator Radar

This paper presents temporal processing for removal of RF interference in pulse-Doppler radar. With spectrumsharing between radar and communications users becoming more common, unintentional spectral overlap of RF sources becomes unavoidable. Approaches for interference suppression include adaptive spatial nulling which is of limited effectiveness when the RF interference is in a radar array mainlobe. Typically, mainlobe interference cancellation methods require identification and exploitation of the known characteristics of the interferer. In this paper, we present an approach for mainlobe interference suppression which is agnostic to most interference characteristics. Rather, it exploits only the periodic structure of pulse-Doppler radar waveforms and the bandlimited nature of the interference. The Doppler-adaptive suppression of interference (DASI) method is a generalized “Doppler-sidelobe canceller” using the sample covariance matrix of slow-time pulses averaged over fast-time samples. Simulation results indicate that interference which occupies a large fraction of the signal band can be adaptively suppressed without a priori knowledge of interference temporal characteristics.