Experimental demonstration of cognitive spectrum sensing & notching for radar

Abstract

A cognitive radar concept is demonstrated that incorporates spectrum sensing and subsequent waveform notching to avoid in-band interference. The interference is assumed to be caused by in-band orthogonal frequency division multiplexed (OFDM) communications in the vicinity of the radar while the notched radar waveform leverages a recently developed frequency modulated (FM) noise signal structure. To emulate real-time performance, the interference signal is measured as it hops in frequency and a fast spectrum sensing algorithm is applied to assess where notches are required. Knowledge of the determined notch location is then passed to the waveform optimization process. The interference and free-space radar measurements are synthetically combined to assess the impact of the interference with and without notching and to quantify the impact of latency.