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:
Jun. 07, 1977
Filed:
Nov. 14, 1975
Marvin Aaron Epstein, Monsey, NY (US);
International Telephone and Telegraph Corporation, Nutley, NJ (US);
Abstract
Baudot code characters each having start and stop bits are transmitted in the form of a MSK digital data signal having a stop-start triangle corresponding to adjacent stop and start bits of two adjacent Baudot characters. The MSK signal is correlated with MSK correlation waveforms to produce first and second correlation signals. Each of the first and second correlation signals are coupled to a different one of two delay lines each having three output taps separated by one bit time. The output signals from the output taps at a given time are appropriately summed to provide inphase and quadrature triangle signals. These triangle signals are operated on by an arithmetic unit to calculate many time and phase conditions of the MSK signal at one time and to produce third, fourth and fifth correlation signals as a function of assumed bit times. These third, fourth and fifth correlation signals are operated on by a ratio calculator to produce a ratio signal proportional to the ratio of a minimum magnitude squared to a maximum magnitude squared for all carrier phase angles for each of the assumed bit times. A synchronization detected signal is produced when the ratio signal value is less than a given amplitude threshold.