Adaptive interference cancellation using time-varying beamforming weights for wideband LFM waveforms

A system employing a narrow receiver bandwidth can achieve high range resolution through 'stretch' processing of linear frequency modulated (LFM) waveforms. At the output of the stretch processor the spatial statistics of interferers are time-varying, and consequently time-varying beamforming weights are required to achieve adequate interference cancellation. In this paper we describe a family of time-varying adaptive beamforming algorithms and assess their performance in terms of the quality of the resulting target range profiles. We show that there are performance advantages in using methods that constrain the weight vector to be smoothly time-varying.