Maximum Likelihood Delay-Doppler Imaging of Fading Mobile Communications Channels

This memo presents a new recursive algorithm for maximum likelihood estimation of the delay-Doppler characteristics of fast-fading mobile communication channels. The channel is modelled as an FIR filter with rapidly varying complex coefficients. The parameters of interest are the mean channel taps and the tap covariance. The structure of the channel tap covariance matrix is exploited to provide convergence to constrained channel estimates.