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. 05, 1976
Filed:
Nov. 13, 1974
Arvind M Bhopale, Beltsville, MD (US);
Rixon Inc., Silver Spring, MD (US);
Abstract
A system is provided for extracting the proper carrier phase from a single sideband suppressed carrier signal. A received signal is equalized and then product demodulated by estimated in-phase and quadrature carriers produced by a voltage controlled oscillator (VCO). The outputs of the in-phase and quadrature product demodulators are low-pass filtered producing corresponding in-phase and quadrature baseband signals. An estimator compares the in-phase baseband signal with reference levels, samples the output of the comparing circuit at the band rate and generates a sequence of estimated data signals. The error signal, which forms the input to the VCO, is produced by multiplying the recovered quadrature baseband signal with the estimated data signals and is proportional to the product of the square of the low pass filtered baseband signal and the sine of the difference between the phases of the received carrier and estimated carrier.