Modeling of wideband mobile radio channels based on propagation measurements

Abstract

Synthetic models of the wideband mobile radio channel are required for mobile radio system design and optimization based on simulations. Additionally wideband models are implemented into hardware channel simulations which approximate the physical radio channel for experimental investigations. These models mainly correspond to a transversal filter structure. They are described by a small set of parameters like tap delays statistics of the tap amplitudes and their corresponding Doppler spectra. Additionally long-term fading and distance dependence can be implemented. For the derivation of such models from a set of wideband measured complex impulse responses a mathematical heuristical approach is presented to determine these model parameters for a given number of taps with constant delays. Every tap is described by its complex time-varying amplitude including its statistic and Doppler spectrum. Additionally long-term fading due to shadowing and distance dependence are taken into account. The procedure yields a reasonable model for a given wideband measured radio channel to approximate the statistical properties of the physical channel.