Blind beamforming using fractional Fourier transform domain cyclostationarity

A new scheme of blind beamforming algorithm is proposed in this paper. The beamformer efficiently filters out the compact desired chirp signal and significantly suppress the cyclically uncorrelated nonstationary interference and stationary (colored) Gaussian noise by identifying and utilizing the optimum fractional Fourier transform (FrFT) domain second-order cyclostationarity. This greatly improves the beamformer output signal-to-interference plus noise ratio (SINR) by effectively reducing the optimum FrFT domain noncyclic signal-colored noise cross-terms in the presence of finite data length de-correlation operation. Simulation results show that the new method works well under a wide range of signal-to-noise ratio and signal-to-interference ratio.