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:
Aug. 05, 2003
Filed:
Feb. 25, 2000
Michael H. Myers, Poway, CA (US);
Northrop Grumman Corporation, Redondo Beach, CA (US);
Abstract
A radio receiver ( ) processes a carrier signal having a Doppler shifted frequency and carrying a coded signal having variable phase and amplitude. The coded signal is divided into a preamble portion and a message portion. A memory ( ) stores samples of the coded signal representing at least some of the predetermined symbols of the preamble. A logic unit ( ) divides the stored samples into a plurality of sample groups and identifies one sample group having the minimum variation of envelope amplitude. That sample group is used to provide additional samples by which the Doppler shift of the carrier frequency is estimated ( ). The coded signal is delayed by a delay operation ( ) and has its Doppler shift reduced. The Doppler reduced coded signal is processed by a filter operation ( ) and a demodulator ( ).