Open Access

Autocorrelation Properties of OFDM Timing Synchronization Waveforms Employing Pilot Subcarriers

EURASIP Journal on Wireless Communications and Networking20092009:538978

DOI: 10.1155/2009/538978

Received: 13 June 2008

Accepted: 7 January 2009

Published: 23 February 2009

Abstract

We investigate the autocorrelation properties of timing synchronization waveforms that are generated by embedded frequency domain pilot tones in orthogonal frequency division multiplex (OFDM) systems. The waveforms are composed by summing a selected number of OFDM subcarriers such that the autocorrelation function (ACF) of the resulting time waveform has desirable sidelobe behavior. Analytical expressions for the periodic and aperiodic ACF sidelobe energy are derived. Sufficient conditions for minimum and maximum aperiodic ACF sidelobe energy for a given number of pilot tones are presented. Several useful properties of the pilot design problem, such as invariance under transformations and equivalence of complementary sets are demonstrated analytically. Pilot tone design discussion is expanded to the ACF sidelobe peak minimization problem by including various examples and simulation results obtained from a genetic search algorithm.

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Authors’ Affiliations

(1)
Communications Research Centre, Terrestrial Wireless Systems Research Branch
(2)
Electronics Engineering Department, Ankara University

Copyright

© O. Üreten and S. Taşcıoğlu. 2009

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.