Unconstrained optimization criteria for blind equalization of multichannel linear systems of nonminimum phase

Blind equalization and blind deconvolution have been an important interesting topic in diverse fields. Inouye and Habe (1995) proposed a multistage maximization criterion and a single-stage maximization criterion for attaining the blind equalization of multichannel linear time-invariant systems. However, their maximization criteria should be subjected to several constraints of equations. In this paper, we present unconstrained new maximization criteria for accomplishing the blind equalization of multichannel linear time-invariant systems. Stochastic gradient algorithms are proposed for solving the unconstrained maximization problems. Simulation examples are included to examine the performance of the proposed algorithms.