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:
Mar. 02, 2004
Filed:
Jun. 14, 2000
Methods and apparatus for use in obtaining frequency synchronization in an ofdm communication system
Jari M. Heinonen, Seattle, WA (US);
Michael R. Hirano, Redmond, WA (US);
Steven E. McMeekin, Nederland, CO (US);
Reijo Savola, Raahe, FI;
William H. Warner, Maple Ridge, CA;
AT&T Wireless Services, Inc., Redmond, WA (US);
Abstract
An iterative method involves performing a coarse frequency correction process which adjusts receiver frequency so that a pilot tone signal is within a predetermined frequency range and, after performing the coarse frequency correction process, performing a fine frequency correction process which adjusts receiver frequency so that the pilot tone signal is substantially aligned with a pilot tone reference within the predetermined frequency range. By performing these processes, the receiver frequency may be adjusted so that the alias pilot tone signal is substantially aligned with the pilot tone reference and the pilot tone signal is undesirably shifted outside the predetermined frequency range. To eliminate this condition, the method further involves performing the coarse frequency correction process again and, after performing the coarse frequency correction process again, performing the fine frequency correction process again. By performing the coarse frequency correction process again, receiver frequency is adjusted so that the pilot tone signal is within both the predetermined frequency range and the Nyquist sampling frequency range. By performing the fine frequency correction process again, receiver frequency is adjusted so that the pilot tone signal is substantially aligned with the pilot tone reference.