A new receiver for digital mobile radio channels with large multipath delay

A new receiver structure is proposed for the equalisation of data links affected by large multipath delays. It is constituted by a symbol-by-symbol MAP detector which exploits the "sparse" nature of the channel, constituted by a few nonzero powerful taps spaced by many zero taps of negligible amplitude, to achieve a complexity tied to the number of nonzero taps and not to the overall channel length. When the channel is time-varying, an efficient nonlinear Kalman-like channel estimator is employed to track only the nonzero taps.