Efficient decision feedback equalizer for sparse multipath channels

In this paper a computationally e cient Decision Feedback Equalizer (DFE) is proposed. The new equalizer is appropriate for channels with long and sparse impulse response (IR) as those encountered in many wireless communications applications. The main feature of the algorithm is that the actual size of the computationally demanding feedback lter is signi cantly reduced. This is achieved by exploiting the particular form of the multipath channel to derive a tractable expression for the causal part of the overall discrete channel IR (including the feedforward lter). Based on the above expression the feedback lter can be built so as to act only to a properly selected set of tap positions. The new DFE exhibits considerable computational savings and faster convergence as compared to the conventional DFE, o ering the same steady-state performance.