Open Access

Robust OFDM Timing Synchronisation in Multipath Channels

EURASIP Journal on Wireless Communications and Networking20082008:675048

DOI: 10.1155/2008/675048

Received: 11 September 2007

Accepted: 21 April 2008

Published: 8 May 2008

Abstract

This paper addresses pre-FFT synchronisation for orthogonal frequency division multiplex (OFDM) under varying multipath conditions. To ensure the most efficient data transmission possible, there should be no constraints on how much of the cyclic prefix (CP) is occupied by intersymbol interference (ISI). Here a solution for timing synchronisation is proposed, that is, robust even when the strongest multipath components are delayed relative to the first arriving paths. In this situation, existing methods perform poorly, whereas the solution proposed uses the derivative of the correlation function and is less sensitive to the channel impulse response. In this paper, synchronisation of a DVB single-frequency network is investigated. A refinement is proposed that uses heuristic rules based on the maxima of the correlation and derivative functions to further reduce the estimate variance. The technique has relevance to broadcast, OFDMA, and WLAN applications, and simulations are presented which compare the method with existing approaches.

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Authors’ Affiliations

(1)
Centre for Communications Research, Bristol University
(2)
Hayes, Fujitsu Laboratories of Europe
(3)
Institute for Digital Communications, University of Edinburgh

Copyright

© C.Williams et al. 2008

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.