Maximum-likelihood estimation of FIR channels excited by convolutionally encoded inputs

If error correcting coding is present in the information symbols, the chann el estimation procedure may be further complicated, since the encoder intro duces a nonlinear operation on the information symbols (in the field of rea ls). Moreover, because of the encoder's memory, the input to the channel ma y not be i.i.d. Therefore classical blind channel equalization methods may not be suitable for systems with coding, In this letter, a blind stochastic maximum-likelihood channel estimation algorithm is proposed for convolutio nally coded signals transmitted through a multipath channel. The performanc e of the estimator is explored, based on the evaluation of approximate Cram er-Rao bounds. The CRB's are used in turn to obtain approximate expressions for the probability of error. Finally, some illustrative simulations are p resented.