A new iterative method for improving equalizer performance in mobile fading channels

A new adaptive method called off-line sliding window (OLSW) is introduced to improve the performance of slowly adaptive equalizers when they are used to equalize fast fading channels in general and mobile channels in particular. Application of the OLSW adaptive method to the DFE-RLS equalizer (a decision feedback equalizer that uses the recursive least square algorithms for adaptation) when it is used within a proposed digital mobile communication system for North America is investigated. The simulation results show beside the performance improvement, that the performance of the DFE-RLS equalizers that utilize the OLSW method is less sensitive to the tracking speed. Also, this method avoids the build up of roundoff errors over time for the RLS algorithms.