Delay Spread Characteristics of Wideband MIMO Channels Based on Outdoor Non-Line-of-Sight Measurements

Abstract

This paper presents the delay spread characteristics based on the measurements of the wideband multipleinput multiple-output radio channels in outdoor environments. Measurement data were collected by a channel testbed which consists of four transmitters and eight receivers, and operates at a carrier frequency of 1.8 GHz with a bandwidth of 2.5 MHz. The four transmitting antennas and eight receiving antennas can work simultaneously. The experiments were originally conducted within the J. J. Pickle Research Campus, University of Texas at Austin. Based on the measurement data in the non-line-of-sight environments, the channel features such as multipath intensity profiles, root-mean-square delay spreads and their distributions were examined. It was found that the empirical probability density function of the rms delay spread in the non-line-of-sight MIMO channels roughly follows Gaussian distribution.