A General Analysis on Diversity Estimate in a System-Dependent Wideband Directional Channel

A general framework is presented to study the diversity gains in a wideband directional channel from a physical wave-field perspective. Parameterization of the quantity is based on system-dependent channel characterization, where the propagation channel captured by multipath delays, angles-of-arrival, and angles-of-departure is defined system-dependently. Starting with a simple single-cluster-single-bounce channel and perfect receiving conditions, the theoretical framework is then extended to more general situations such as channels with multiple reradiating processes and scattering clusters. Using this methodology, we show through numerical examples that the conventional diversity estimate for wideband directional systems may lead to systematic prediction error of the achievable diversity gains