Accuracy of an UWB localization system based on a CMOS chip

In this paper, we analyze the achievable location accuracy of a high-precision localization system using time-difference-of-arrival measurements of ultra wide-band (UWB) pulses. This system is under development at our institute and based on a low-power CMOS chip. Similar commercially available localization systems achieve location accuracies (location error standard deviation) down to 15cm under line-of-sight conditions in a working range of 20m indoors (30cm in a 100m range outdoors). We review the fundamental limits of the ranging accuracy of any localization system satisfying the regulatory constraints for UWB emissions. Next, we incorporate realistic characteristics of the UWB radio channel and the CMOS receiver into the analysis. We show that the ranging accuracy is heavily influenced by the available signal-to-noise ratio, i.e., the distance between the antennas, and the multi-path nature of the UWB radio channel. The effect of sampling time jitter of the receiver clock is shown to be negligible. With our proposed system design a ranging accuracy down to 1cm in a working range of 40m can be achieved, which outperforms the accuracy of existing systems.

[1]  Robert A. Scholtz,et al.  Ranging in a dense multipath environment using an UWB radio link , 2002, IEEE J. Sel. Areas Commun..

[2]  W. Gregorwich,et al.  Ultra-wideband for navigation and communications , 2001, 2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542).

[3]  S. Kay.  Fundamentals of statistical signal processing: estimation theory , 1993 .

[4]  Debra McKeown,et al.  Ultra-wideband Radio Technology , 2004 .

[5]  Steven Kay,et al.  Fundamentals Of Statistical Signal Processing , 2001 .

[6]  Woo Cheol Chung,et al.  An accurate ultra wideband (UWB) ranging for precision asset location , 2003, IEEE Conference on Ultra Wideband Systems and Technologies, 2003.

[7]  Christoph Sandner,et al.  A subpicosecond jitter PLL for clock generation in 0.12-/spl mu/m digital CMOS , 2003 .

[8]  Kaveh Pahlavan,et al.  Super-resolution TOA estimation with diversity for indoor geolocation , 2004, IEEE Transactions on Wireless Communications.

[9]  Behzad Razavi,et al.  A 10-Gb/s CMOS clock and data recovery circuit with a half-rate binary phase/frequency detector , 2003, IEEE J. Solid State Circuits.

[10]  Alan F. Murray,et al.  IEEE International Solid-State Circuits Conference , 2001 .

[11]  J.K. Townsend,et al.  The effects of timing jitter on the performance of impulse radio , 2002, 2002 IEEE Conference on Ultra Wideband Systems and Technologies (IEEE Cat. No.02EX580).

[12]  A. Bevilacqua,et al.  An ultra-wideband CMOS LNA for 3.1 to 10.6 GHz wireless receivers , 2004, 2004 IEEE International Solid-State Circuits Conference (IEEE Cat. No.04CH37519).

[13]  R.J. Fontana,et al.  Recent system applications of short-pulse ultra-wideband (UWB) technology , 2004, IEEE Transactions on Microwave Theory and Techniques.

[14]  Zafer Sahinoglu,et al.  The Cramer-Rao bounds of hybrid TOA/RSS and TDOA/RSS location estimation schemes , 2004, IEEE Communications Letters.