NEW CRITERIA FOR BLIND DECONVOLUTION OF NONMINIMUM PHASE SYSTEMS (CHANNELS)

A necessary and sufficient condition is derived for blind deconvolution (without observing the input) of nonminimum phase linear time-invariant systems (channels). Based on this condition, several optimization criteria are proposed, and their solution is shown to correspond to the desired response. These criteria only involve the computation of second- and fourth-order moments, implying a simple tap update procedure. The proposed methods are universal in the sense that they do not impose any restrictions on the probability distribution of the (unobserved) input sequence. We also address the problem of additive noise in the system and show that in several important cases (e.g., when the additive noise is Gaussian) the proposed criteria are essentially unaffected. © 1990 IEEE