Sidelobe blanking in the presence of noise-like interference

Abstract

Interference suppression in antenna arrays is an important topic for target detection in radar systems. This thesis investigates the performance of two different algorithms for determining whether a detection lies in the sidelobe or mainlobe of an antenna in the presence of noise-like interference (NLI). Both algorithms are based on a combination of sidelobe blanking (SLB) and sidelobe cancellation (SLC). The first algorithm is a simple cascading of SLC and SLB, while the second algorithm is a modification of this where multiple guard channels are used. The performance is evaluated with Monte Carlo simulations, where the antenna is modelled as a linear phased-array antenna and interference and target signals are modelled as uncorrelated, single-frequency plane waves. The influence of covariance estimation error, number of NLI sources, placement of auxiliary antennas, signal-to-noise ratio (SNR) and jammer-to-noise ratio (JNR) on performance and suitable blanking threshold is investigated. It is shown that the second algorithm performs better than the first when the number of NLI sources are few relative to the number of auxiliary antennas, and reduces to the same performance as the first algorithm when this is not the case.