Dual-frequency sounder for UMTS frequency-division duplex channels

A single-frequency wideband chirp sounder designed and implemented at UMIST was modified to carry out simultaneous measurements at the uplink and downlink frequencies of the UMTS bands. Measurements in the dense urban environment of Manchester city centre were carried out using both a trolley and a van, and power delay profiles were obtained over the two 60 MHz channels allocated for the frequency-division duplex links. Small-scale characterisation is determined from scattering functions and from power delay profiles. Both functions showed differences in the multipath structure between the two channels. Scattering functions with both sparse scattering and dense scattering were detected. The effects of moving vehicles on a stationary user are also presented. These results are preceded by a presentation of the sounder architecture and various back-to-back tests demonstrating its performance capabilities. These include linearity tests with multiple tones, and ambiguity functions of the two frequency bands.