Methods and apparatus are described for processing data in a wireless communication network. Iterative estimation techniques are used to enable tracking of time-varying communication channels. A signal is transmitted over a channel in the network, the signal comprising a sequence of symbols carried on a plurality of sub-carriers. Boot-up estimator estimates, in a time domain, parameters of a model of the channel based on the received signal. A domain converter transforms at least one of the estimated parameters from the time domain to provide at least one transformed parameter in a second domain. An equalizer and decoder determine estimates of symbols from the received signal using the at least one transformed parameter, and tracking estimator updates the estimated model parameters during reception of the signal using at least one estimated symbol.