We investigate timing tolerances of ultra wideband (UWB) impulse radios. We quantify the bit-error-rate (BER) sensitivity to epoch timing offset under different operating conditions, including frequency flat fading channels, dense multipath fading channels, multiple access with time hopping, and various receiver types including sliding correlators and RAKE combiners. Our systematic approach to BER derivations under mistiming can be extended to a wide range of channel fading types. Through analyses and simulations, we illustrate that the reception quality of a UWB impulse radio is highly sensitive to both timing acquisition and tracking errors. In particular, time-hopping-based multiple-access systems exhibit little tolerance to acquisition errors, and the energy capture capability of a RAKE combiner can be severely compromised by mistiming.
Bibliographical noteFunding Information:
Manuscript received April 23, 2003; revised February 27, 2004. Z. Tian was supported by the National Science Foundation under Grant CCR-0238174. G. B. Ginnakis was supported by the Army Research Laboratory/CTA under Grant DAAD19-01-2-011 and the National Science Foundation under Grant EIA-0324804. Parts of the work in this paper were presented at the IEEE SPAWC Conference, Rome, Italy, June 2003 and the IEEE GLOBECOM Conference, San Francisco, CA, Dec. 2003. The associate editor coordinating the review of this manuscript and approving it for publication was Dr. Martin Haardt.
- Performance analysis
- RAKE receiver
- Ultra wideband communications