Theory of multipath shape factors for small-scale fading wireless channels

This paper presents a new theory of multipath shape factors that greatly si mplifies the description of small-scale fading statistics of a wireless rec eiver. A method is presented for reducing a multipath channel with arbitrar y spatial complexity to three shape factors that have simple intuitive geom etrical interpretations. Furthermore, these shape factors are shown to desc ribe the statistics of received signal fluctuations in a fading multipath c hannel. Analytical expressions for level-crossing rate, average fade durati on, envelope autocovariance, and coherence distance are all derived using t he new shape factor theory and then applied to several classical examples f or comparison.