TIME-DOMAIN ANALYSIS OF AN UWB PULSE DISTORTION IN WIRELESS CHANNEL

Abstract

An accurate time-domain (TD) modeling for transmission of UWB signal through a 3- dimensional building structure made of low loss dielectric materials is presented. Transmission through building is analyzed for arbitrary position of transmitter and receiver. Time-domain formulation are presented for transmission coefficient for both soft and hard polarizations, for propagation loss and then for the transmitted field at the receiver. An analytical time domain (TD) solution, based on an established FD diffraction model, is also presented for diffraction of UWB signal through same dielectric obstacle. The comparison of transmitted and reflected field proves that the transmitted field component is very significant in case of non line of sight (NLOS) communication in deep shadow regions, where the reflected and diffracted components are weak. The TD results have been validated with the inverse fast Fourier transform (IFFT) of the corresponding exact frequency domain results. The significant gain in the computational speed achieved through the proposed TD method is demonstrated by comparing its computation time with that of the exact IFFT-FD solution. Finally comparative analysis of normalized mean and mean square error between both methods is performed for different loss tangent values. It is shown that the proposed TD solution outperforms the exact IFFT-FD solution in terms of computational efficiency. Also it is observed that normalized error tends to increase for higher loss tangent values.