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. 14, 2002
Filed:
Jun. 14, 2000
Applicant:
Inventors:
Jari M. Heinonen, Seattle, WA (US);
Michael R. Hirano, Redmond, WA (US);
Assignee:
AT&T Wireless Services, Inc., Redmond, WA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L 7/00 ; H04L 2/726 ; H04J 3/06 ;
U.S. Cl.
CPC ...
H04L 7/00 ; H04L 2/726 ; H04J 3/06 ;
Abstract
A method, apparatus and system detects a loss of synchronization between a transmitter and a receiver in a multiple-carrier communication system such as an OFDM system. A guard band synchronization detector provides a synchronization indicator based on the energy detected within a guard band where a pilot tone is transmitted adjacent to the guard band. A timing error results in energy leakage into one or more guard bands. In one embodiment, a plurality of synchronization indicators are observed to determine whether a loss of synchronization between a transmitter and a receiver in the wireless system has occurred.