On the design of optimum subband filters for decision feedback generalized sidelobe canceller

This paper presents a decision feedback subband generalized sidelobe canceller (GSC), in which the design of the statistically optimum filter bank decomposition of the signals passing through the lower branch of the GSC as well as the signal after the decision feedback based on the minimum mean-square error criterion is addressed. The new beamformer not only renders superior interference cancellation capability, but also possesses a fast convergence rate due to the subband processing scheme and removal of the desired signal subband component in the output of the GSC via the decision feedback. Furthermore, to mitigate the computational overhead in the determination of the subband filter coefficients, an iterative procedure is also addressed. The convergence behavior of the new beamformer is conducted as well to justify the rationale of the new approach. Simulations are furnished to verity the superiority of the new beamformer.