Reduced dimension and reduced rank robust ABF for large sensor count arrays

The generalized sidelobe cancellation (GSC) structure requires a number of auxiliary array correlation matrix inversions proportional to the number of steering directions [H. L. Van Trees, 2002]. The steering invariant sidelobe cancellation (SISC) process achieves reduced complexity, robust adaptive beamforming (ABF) without this proportionality [N. Owsley and N. Tague, March 2003]. This paper extends previous SISC work with implementation considerations, a modification for signal mismatch robustness and comparisons with other reduced complexity ABFs. The comparison metrics are: (1) beam patterns; (2) beamformer response and (3) array gain (AG) time series. The results indicate either the same or improved AG performance relative to other reduced dimension ABF techniques but with lower computational burden.