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:
Sep. 27, 2005
Filed:
Feb. 16, 2001
Vijitha Weerackody, New York, NY (US);
Vijitha Weerackody, New York, NY (US);
Agere Systems Inc., Allentown, PA (US);
Abstract
An Orthogonal Frequency Division Multiplexing (OFDM) transmission utilizes random phases across the OFDM sub-carrier components and differential encoding so that the phase information (i.e., phase values) does not have to be explicitly transmitted to a receiver. The OFDM data symbols are differentially encoded so that the phase information on the symbols that are multiplied together in the differential encoder is the same. Assuming use of a differential phase shift keying (DPSK) system, a phase sequence is used having 'V' random phase values, where θis the phase value in the nsub-carrier in the kOFDM symbol and is periodic in n with V as the period. A current input symbol is then differentially encoded relative to the Vprevious encoded output from the encoder so that the phase values on the symbols multiplied together in the differential encoding process are the same.