A Novel Threshold-Based Coherent TOA Estimation for IR-UWB Systems

• Published in: IEEE transactions on vehicular technology Vol. 58; no. 8; pp. 4675 - 4681
• Main Authors: Xu, A.Y.-Z., Au, E.K.S., Wong, A.K.-S., Qin Wang
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-10-2009; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Approximation; Closed-form solution; Coherence; Counting; Delay; Detection, estimation, filtering, equalization, prediction; Exact sciences and technology; Exact solutions; Filtering; Gold; Impulse radio; Information, signal and communications theory; Matched filters; Mathematical analysis; Optimization; Position measurement; ranging; Signal and communications theory; Signal processing; Signal resolution; Signal, noise; Telecommunications and information theory; Thresholds; time of arrival (TOA); Time of arrival estimation; Ultra wideband technology; Ultrawideband; ultrawideband (UWB); Level crossing; Parameter estimation; High precision; ultrawideband (UWB); Ultra wide band; Absolute error; Arrival time; ranging; Cross correlation; time of arrival (TOA); System simulation; Impulse radio; Time hopping communication; Distance measurement; Mean error; Impulse
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/TVT.2009.2020990

Precise time-of-arrival (TOA) estimation is challenging in dense multipath environments because the leading-edge path of a received signal may not be the strongest path. In this paper, we propose a threshold-based coherent TOA estimation scheme for impulse radio-based ultrawideband (UWB) systems. The scheme uses a dedicated ranging sequence with a good cross-correlation property and a search-back process that considers the count of threshold crossings to find the leading edge of the received signal. We derive an approximate closed-form expression for the optimal threshold that restrains the mean absolute error. We show by simulations that high-precision short-distance ranging is achieved without introducing too much latency.