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:
Nov. 18, 2014
Filed:
Apr. 30, 2012
I. Zakir Ahmed, Bangalore, IN;
Vijaya Yajnanarayana, Bangalore, IN;
I. Zakir Ahmed, Bangalore, IN;
Vijaya Yajnanarayana, Bangalore, IN;
National Instruments Corporation, Austin, TX (US);
Abstract
A system and method for estimating carrier frequency offset Δf and carrier phase offset φinherent in a received CPM signal. Samples of a continuous phase modulated (CPM) signal are received. A maximum of an objective function J is determined over a two-dimensional region parameterized by frequency offset v and phase offset w. The coordinates vand wof a maximizing point in the region represent estimates of the carrier frequency offset Δf and the carrier phase offset φ. To evaluate the objective function J at a point (v,w), apply a frequency shift of amount −v and a phase shift of amount −w to the received samples to obtain modified samples, and perform Viterbi demodulation on the modified samples to obtain a winning path metric value at a final time. The winning path metric value is the objective function value J(v,w).