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:
Oct. 04, 1983
Filed:
Nov. 07, 1980
Henry D Chadwick, Reston, VA (US);
David W Matthews, Mt. Airy, MD (US);
Satellite Business Systems, McLean, VA (US);
Abstract
A method and apparatus for measuring signal to noise ratio in a time division multiple access (TDMA) communications system which does not require that normal communications be interrupted. The signal to noise ratio measurement is performed on the unmodulated carrier which typically occurs in the preamble of each information burst in the TDMA format. In order to perform the measurements on the carrier of the same burst in each frame, the carrier and noise powers are sampled at a predetermined time with respect to specified information which occurs at the same time in each frame, normally the frame reference burst. After being converted to the receiver intermediate frequency, the unmodulated carrier is fed to both a narrow band pass filter having a pass band at the intermediate frequency and a narrow band stop filter having a stop band at the intermediate frequency. The ratio of the band pass filter output to the band stop filter output is the signal to noise ratio within a very small error.