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:
Aug. 14, 1984
Filed:
Apr. 09, 1982
Hikmet Sari, Alfortville, FR;
U.S. Philips Corporation, New York, NY (US);
Abstract
Carrier recovery arrangement in a receiving system for digital data which are transmitted by sixteen-state amplitude and phase modulation (16 QAM), the arrangement having, successively six parallel paths (V.sub.1 -V.sub.6) each including the series arrangement of a multiplying circuit (M.sub.i) and a low-pass filter (F.sub.i); a selection circuit for selecting one of the three pairs of filter output signals thus obtained; a phase control circuit having a Costas signal processing circuit receiving the selected pair of signals and producing a signal representative of the phase error of the received signal, a filter and a voltage-controlled oscillator; and a phase-shifting circuit receiving the output signal of the oscillator in order to couple this output signal to respective second inputs of the multiplying circuits (M.sub.1)-(M.sub.6), this signal coupling being effected with a phase shift zero for (M.sub.1), .theta. for (M.sub.3), 2.theta. for (M.sub.5), and with a phase shift .pi./2 for (M.sub.2), .theta.+.pi./2 for (M.sub.4), and 2.theta.+.pi./2 for (M.sub.6), where .theta. is equal to tan.sup.-1 (1/2).
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile