Performance Assessment of Sidelobe Jamming Cancellation Using Stretch Processing

We investigate via simulation the performance of the two major classes of algorithms that cancel sidelobe jamming in a wideband phased array radar that uses stretch processing of beamspace output. The deramper in stretch processing renders the statistics of the jamming non-stationary. One approach for addressing the non-stationarity is to divide the stretched output into segments and apply narrowband equalization on each segment. The other approach is to model the weight vector as time-varying. To each approach we also add subbanding to decrease the non-stationarity of the stretched jammer signals and time-taps to combat dispersion across the array. We show via simulation that since the jammers are in the sidelobe region, both approaches provide comparable performance in terms of cancellation ratio (CR) and loss in signal-to-interference-plus-noise ratio (SINR). But since the segmentation-based approach is approximately eight times less complex and channelization through subbanding aids in channel equalization, its subbanded variant is the preferred algorithm for wideband sidelobe cancellation.