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. 16, 1993
Filed:
Sep. 30, 1991
Applicant:
Inventors:
David E Borth, Palatine, IL (US);
Bruce D Mueller, Palatine, IL (US);
Kevin L Baum, Hoffman Estates, IL (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04L / ;
U.S. Cl.
CPC ...
375 39 ; 375 56 ; 375 85 ; 375 94 ; 371 43 ;
Abstract
A Viterbi equalizer for decoding a .pi./4 DQPSK modulated signal. Because symbol values of adjacent symbols of a .pi./4 DQPSK signal are offset in phase relative to one another, allowable values of succeeding states of a .pi./4 DQPSK signal are four in number. The signal paths of the Viterbi equalizer are thereby limited in number to four allowable next-states, and the Viterbi equalizer is operative to select certain ones of the paths connecting the states at the adjacent time intervals as survivor paths to form maximum likelihood paths thereby.