Spatio-diversity gain of a system-dependent wideband directional channel

Estimations of spatio-diversity gain (SDIV) in the wideband directional channel suffer from imprecise modeling of multipath angular spread (AS). Using previously published measurements and a synthetic array and channel parameterization, we show that AS exhibits dependence on both line-source distribution and operating frequency. As a result, SDIV is calculated through the integration of a continuous density function defined on the entire signal space. Using this methodology, we show through numerical examples that the conventional diversity estimate for directional systems may lead to systematic prediction error of the achievable diversity gain.