Blind equalization with iterative joint channel and data estimation for wireless DPSK systems

A joint channel and data estimator suitable for wireless differential phase shift keying (DPSK) systems with short block sizes is proposed. No training data symbols are necessary, but a priori information may be incorporated, if available. The basic structure consists of an iterative approximation of the joint maximum-likelihood (ML) solution, which is enhanced by adaptive filtering, by shift operations, by coefficient annealing, as well as by using a priori information. To our best knowledge, this is the first time that: (i) a priori information of the data has been exploited in the context of blind equalization; and that (ii) the DPSK/ISI super trellis has been explicitly exploited for blind equalization rather than doing differential decoding for resolving the problem of phase ambiguity