UWB coexistence measurements with IEEE802.11a

This paper discusses the experimental coexistence study work carried out with ultra wideband (UWB) and IEEE802.11a wireless local area network (WLAN). The measurement setup followed a realistic interference scenario inside a classroom where several UWB devices were spread over the room; there was one UWB transmitter for each student position and the desired terminal was moved across the room. Another setup was for aggregate studies where numbers of UWB transmitters were located close to the desired WLAN receiver. In addition, temporary radio interference from the other sources was not controlled during the measurements. The results showed that the performance of a victim link depends mostly on the UWB activity factor and pulse repetition frequency. In short line-of-sight WLAN links, the degradation in measured data rate was typically less than 5% in usable activity factors if measured from uplink site. The corresponding degradation in downlink side is typically 5 - 10%. In through wall cases, with low WLAN signal-to-noise ratio, the impact of interference was higher.