Sidelobe canceller jamming using hot-clutter

Abstract

Coherent Sidelobe Cancellation (CSLC) is a coherent processing technique that has the potential of reducing noise jamming through the antenna side lobes. Present CSLCs have the capability of reducing the noise jamming by 25 to 35 dB. The maximum number of side lobe jammers that can be handled by a CSLC is equal to the number of auxiliary antennas. The performance of CSLC is governed by nonlinear stochastic differential equations that are not solvable by analytic means. Therefore this thesis employs simulation techniques to solve these equations. The CSLC becomes saturated as the number of jammers in different directions exceeds the number of loops. Jammer multipath adds an additional degree of freedom for each multipath signal that has a direction different than that of the main jammer. The objective of this thesis was to determine the effect that these multipath or hot clutter signals have on a CSLC. It was found that hot clutter produced substantial degradations on single, double and triple CSLCs. The effect was most pronounced for single cancellers where multipath with a magnitude of 1% of the jamming signal reduced the cancellation ratio by 18 dB. Comparable numbers for double and triple cancellers were 11 dB.