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. 06, 1982
Filed:
Aug. 15, 1980
Smith A Rhodes, Falls Church, VA (US);
Communications Satellite Corporation, Washington, DC (US);
Abstract
A synchronization preamble for each TDMA burst consists of an alternating sequence of the two MSK tones on every other MSK bit interval. Such a preamble does not exhibit random polarity reversals at the two MSK frequencies as occurs during the message burst. The receiving circuit therefore directly processes the preamble symbols to extract carrier phase and symbol synchronization without conventionally squaring the IF to remove polarity modulation. A 6 dB increase in synchronization SNR is thereby provided since the requisite synchronizer filtering need only be effected at the fundamental frequencies F.sub.L and F.sub.H rather than at the their second harmonics 2F.sub.L and 2F.sub.H as is required when squaring is employed.