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:
Apr. 08, 1980
Filed:
Oct. 16, 1978
Terence E Sumner, Hoffman Estates, IL (US);
Charles A Backof, Jr, Hoffman Estates, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A digital signal detector is disclosed that detects a serial bit stream transmitted at a predetermined bit frequency. Bit transitions are totallized in a counter over a predetermined time interval. Bit transitions occurring during a good window interval increment the totallized count by one. Bit transitions occurring during a bad window interval decrement the totallized count by one. Bit transitions occurring during a marginal window interval, situated between the good and bad window intervals, do not affect the totallized count. If the counter reaches a predetermined count during the time interval, a detect signal is provided indicating that the digital signal has been detected. The counter can be further loaded with a threshold count for tailoring the digital signal detector for operation at a particular signal-to-noise ratio. Periodic signals that have frequencies that are submultiples of the bit frequency are detected by correlating the digital signal between two predetermined stages of a shift register. The digital signal detector may provide a detector output signal when both the digital signal is detected and periodic signals having submultiple frequencies are not present.