Abstract: The natural gradient algorithm works more efficiently than the ordinary gradient algorithm, and the block recursive method is feasible to real-time processing. To benefit from the above advantages, a block recursive blind source separation (BSS) approach is presented. Firstly, based on natural gradient and nonlinear principle component analysis, a matrix equation is obtained by block recursive updating, and then the matrix equation is solved by using QR factorization and back substitution to obtain the optimal separating matrix. Compared with other existing recursive-type BSS methods, the proposed algorithm leads to 10dB improvement in orthogonality performance index, and the average running time reduces by 65％, which is verified by extensive numerical simulation experiments.

Key words: blind source separation, natural gradient, nonlinear principle component analysis, block recursive