The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 13, 2008
Filed:
Nov. 07, 2003
Mehul Mehta, Reading, GB;
Mehul Mehta, Reading, GB;
Synad Technologies Limited, Berkshire, GB;
Abstract
A method of synchronising an Orthogonal Frequency Division Multiplexed (OFDM) IEEE 802.11a data packet at a receiver is disclosed. The 802.11a data packet has a series of short training sequence (STS) symbols as a preamble. Cross-correlation at the receiver of the STS in the 802.11a packet PLCP preamble with the modified reference STS, that is circular shifted by eight samples, results in a main correlation peak but with reduced pre- and post-lobes. To locate the cross-correlation peak, a running second derivative of the cross-correlation function is performed. Peak selection employs a running comparison of the position and magnitude of all peaks in the intermediate neighbourhood of the local peaks. Following selection of a peak from within the cross-correlation function of the first STS in the PLCP preamble, both the position and magnitude of the first STS is compared to those of the second STS. Based on the two independent calculations, the start of the OFDM frame is estimated.