Performance evaluation of threshold-based UWB ranging methods - Leading edge vs. search back -

Accurate ranging is one of the most promising applications of ultra wideband radio in sensor networks. Amongst variety of ranging methods, threshold-based ranging is a primitive, but robust technique suitable for battery-limited systems. This contribution reports the performance of two threshold-based ranging methods: leading edge detection and search back method. The evaluation utilized real-world measured propagation channels and followed the band plan and the transmit power restriction of the IEEE802.15.4a-2007 standard. Effects of the system bandwidth and the center frequency on ranging performance were analyzed. The following conclusions were obtained from the analyses: 1) the leading edge detection outperforms the search back method; 2) accurate ranging in the low band is promising even under the transmit power restrictions, while the use of the high band necessitates a fundamental countermeasure to improve the limited signal level at the receiver; and finally, 3) use of the wider bandwidth does not always provide better ranging performance.