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:
Oct. 02, 2007
Filed:
Jan. 28, 2003
Applicant:
Yhean-sen Lai, Warren, NJ (US);
Inventor:
Yhean-Sen Lai, Warren, NJ (US);
Assignee:
Agere Systems Inc., Allentown, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L 27/28 (2006.01); H04L 1/00 (2006.01); H04B 1/10 (2006.01);
U.S. Cl.
CPC ...
Abstract
A COFDM demodulator providing independent DQPSK symbol amplitude and phase equalization provides improved soft-symbol estimates by reducing the possibility of clipping in the differential demodulator, improving the tolerance of the differential demodulator to finite word length effects, correcting for phase drifting between adjacent subcarriers, and improving signal-to-noise ratio (SNR) calculation accuracy for maximal ratio combining applications. Separate acquisition and tracking modes for the amplitude and phase equalizers are provided that handle start-up, reacquisition, and steady-state operation of the demodulator.