Spatio-temporal investigation of UTRA FDD channels

Smart antennas promise to provide range extension and capacity enhancements crucial to the successful deployment of Universal Mobile Telecommunications System (UMTS) networks. The frequency offset between the uplink and downlink in the frequency division duplex (FDD) air interface gives rise to a frequency dependency in the channel responses and potential problems in downlink beamforming. In order to investigate this, a highly novel dual-band, dual-polarised channel sounding trial was performed in the UMTS FDD bands by the University of Bristol. The wideband measurements were conducted in the City of Bristol, encompassing urban city and sub-urban residential scenarios and subsequent post processing was performed to extract channel parameters across the two bands. This paper presents the results and analysis done for the single polarisation static measurements. It was observed that in most instances, there was a higher degree of scattering in the higher frequency band, resulting in larger angular spreads and delay spreads. The channels also exhibited a strong degree of de-correlation when viewed from the spatial and temporal domains.