MIMO Instantaneous Blind Identification Based on Second-Order Temporal Structure and Steepest-Descent Method

This paper presents a new MIMO instantaneous blind identification algorithm based on second-order temporal property and steepest-descent method. Second-order temporal structure is reformulated in a particular way, such that each column of the unknown mixing matrix satisfies a system of nonlinear multivariate homogeneous polynomial equations. The nonlinear system is solved by an improved steepest-descent method. We convert the nonlinear system into an optimal problem by constructing an optimal objective function which includes a "valley-filled" item to obtain a valid solution. Our algorithm allows estimating the mixing matrix for scenarios with 4 sources and 3 sensors, etc. Finally, simulations show its effectiveness with more accurate solutions than the algorithm with homotopy method.