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. 19, 1993
Filed:
Aug. 21, 1992
Kiomars Anvari, Walnut Creek, CA (US);
Teknekron Communications System, Inc., Berkeley, CA (US);
Abstract
A method and apparatus for generating a frequency offset estimate and a timing offset estimate from a base band signal. In an important application of the invention, a modulated carrier signal is transmitted over a transmission channel and then received and demodulated to generate the base band signal. The modulated carrier signal comprises data having a transmitted symbol frequency and phase, and a carrier signal modulated by the data. The invention simultaneously generates from the base band signal a frequency offset estimate representing the difference between the transmitted and received carrier signal frequency, and a timing offset estimate representing the difference between the transmitted symbol phase and the recovered symbol phase of the base band signal. In preferred embodiments, the base band signal is a digital signal sampled at a rate which exceeds the Nyquist rate. Typically, a sampling rate of more than two samples per symbol is adequate to meet this condition. A pair of nonlinear operations is performed on this digital base band signal, and the resulting two nonlinear signals are processed to generate the frequency offset and timing offset estimates.