Open Access

Blind Synchronization in Asynchronous UWB Networks Based on the Transmit-Reference Scheme

  • Relja Djapic1Email author,
  • Geert Leus2,
  • Alle-Jan van der Veen2 and
  • António Trindade2
EURASIP Journal on Wireless Communications and Networking20072006:037952

https://doi.org/10.1155/WCN/2006/37952

Received: 15 September 2005

Accepted: 13 December 2006

Published: 24 January 2007

Abstract

Ultra-wideband (UWB) wireless communication systems are based on the transmission of extremely narrow pulses, with a duration inferior to a nanosecond. The application of transmit reference (TR) to UWB systems allows to side-step channel estimation at the receiver, with a tradeoff of the effective transmission bandwidth, which is reduced by the usage of a reference pulse. Similar to CDMA systems, different users can share the same available bandwidth by means of different spreading codes. This allows the receiver to separate users, and to recover the timing information of the transmitted data packets. The nature of UWB transmissions—short, burst-like packets—requires a fast synchronization algorithm, that can accommodate several asynchronous users. Exploiting the fact that a shift in time corresponds to a phase rotation in the frequency domain, a blind and computationally effcient synchronization algorithm that takes advantage of the shift invariance structure in the frequency domain is proposed in this paper. Integer and fractional delay estimations are considered, along with a subsequent symbol estimation step. This results in a collision-avoiding multiuser algorithm, readily applicable to a fast acquisition procedure in a UWB ad hoc network.

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Authors’ Affiliations

(1)
TNO-ICT
(2)
Department of Electrical Engineering, Delft Institute of Microelectronics and Submicron-technology (DIMES), Delft University of Technology

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Copyright

© Relja Djapic et al. 2006

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.