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. 19, 1996
Filed:
Feb. 24, 1995
Imran Malik, Germantown, MD (US);
D Ray Lowe, Gaithersburg, MD (US);
Hughes Aircraft Co., Los Angeles, CA (US);
Abstract
A method and apparatus for adjusting the postamble false detection probability threshold for transmission systems that carry telephony network signals using binary-phase shift-keying (BPSK) burst transmission format. The postamble marks the end of a burst transmission. The method and apparatus herein classifies the type of signal present on the telephony network and utilizes a control loop to change the threshold, if necessary, to minimize the probability of false detection of the postamble during demodulation. Transmission of speech signals, which are bursty in nature, suffer little degradation from false detection of a postamble. However, transmission of fax, voice-band data modems and other types of longer-duration signals are severely affected by a false detection of the postamble unique word. Therefore, fax, modem and other longer duration signals have their threshold adjusted to minimize the false detection probability after the signal has been classified as such.