Blind equalization of nonlinear channels from second order statistics using precoding and channel diversity

This paper considers the blind equalization problem for nonlinear Volterra type channels excited by real IID (independent and identically distributed) symbols. Previous work has shown that under the right conditions the equalizers can be found from the second order statistics of the channel output as long as the number of subchannels exceeds the number of kernels. In order to alleviate this requirement, we consider the use of a simple precoding device previous to transmission which provides a tradeoff between effective data rate and number of subchannels required. Necessary and sufficient conditions for blind equalizability under this scheme are given, and an algorithm for the computation of the equalizers is presented.