Signal detection is fundamental to digital wireless communications.
But, these communications are plagued by uncontrollable environmental elements that degrade effectiveness. Mitigation of multipath propagation, optimum detection in non-ideal noise, and fade mitigation can increase channel capacity and increase the effective range. Under certain assumptions, the matched filter is known to provide optimum signal detection. However, experience has shown that because the environment is never as assumed, the performance of most communications systems falls short of optimal performance. Variations of these traditional linear detectors have a large installed customer and user base.