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. 05, 2002
Filed:
Feb. 04, 1999
Mark L. Fowler, Ithaca, NY (US);
James A. Johnson, Newark Valley, NY (US);
Lockheed Martin Corporation, Bethesda, MD (US);
Abstract
A phase-based approach to estimating the frequency of complex sinusoids in the presence of noise that simultaneously reduces the threshold level and makes it frequency-independent. The approach relies on a filter bank approach: apply the signal to a highly overlapped, four-channel filter bank, detect which channel the signal is in, and apply a phase-based frequency estimation technique to the selected channel output. The computational complexity of the method is kept low by deriving a closed form for the resulting estimator and showing that it leads to an inherent decimation. Further improvement in performance can be obtained by cascading several stages of the four-channel filter bank; the performance tends toward that of the ML method as the number of stages increases.