Blind turbo decoding and equalization

We present two turbo decoding structure which combine channel equalization and decoding, allowing communication in the presence of intersymbol interference (ISI). The first one combines the trellis representing each one of the constituent encoders with the ISI trellis and performs slightly better that the second structure, which treats the ISI as another constituent decoder. We show that for both methods it is possible to perform the equalisation blindly, with no a priori information available to the decoder. Compared with the case where the channel taps are known by the receiver, no loss in performance is observed. Application of the first method to the case of joint source-channel coding for hidden Markov sources is also presented.