Adaptive Beamforming for Noncircular Signals

Many manmade signals have nonzero noncircularity coefficients such as those used in AM, BPSK, and ASK systems. They are called noncircular signals which have coexisted moment and conjugate moment at the second-order. This redundancy is herein exploited to derive a blind scheme for source separation and classification based on the NonCircularity REstoral (NCRE4) filtering. The present blind scheme has three major advantages: 1) involves only the second-order statistics (SOS) and has a faster convergence speed than the traditional high-order statistics (HOS) methods; and 2) does not require any a prioriknowledge about the content and/or direction of the signal-of-interest (SOI).