Modified Generalized sidelobe canceller for MIMO space-time adaptive processing

In this paper, we address the problem of space-time adaptive processing (STAP) for airborne collocated multiple-input multiple-output(MIMO) radars using a generalized sidelobe canceller(GSC). A collocated MIMO radar that transmits orthogonal waveforms is equivalent to a virtual array with coherent amplitude weights. On this account, the blocking matrix(BM) of the GSC is not orthogonal to the target steering vector and the output SCNR of the GSC processor degrades. In order to improve the performance, the modified Gram-Schmidt orthogonalization(MGSO)-based channel preprocessing method is proposed to modify the blocking matrix of the GSC processor. We prove that this modified GSC processor can achieve the optimal STAP performance. We also show that the proposed method has reduced computational complexity and fast convergence rate. Numerical simulations validate the effectiveness of the proposed methods.