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:
Jan. 18, 1994
Filed:
Dec. 22, 1992
Louis J Vannatta, Crystal Lake, IL (US);
Timothy P Froehling, Palatine, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A frequency control circuit, and associated method, for a receiver operative to receive a TDMA signal transmitted by a transmitter in a TDMA communication system. A first frequency detector generates a first frequency control signal. A second frequency detector, comprised of a portion of a decision-directed demodulator, generates a second frequency control signal. The first frequency control signal is utilized to effectuate frequency control when a signal is continuously received by the receiver, such as times immediately subsequent to initial powering of the receiver as the receiver becomes synchronized with the TDMA signal transmitted thereto. Onces a receiver becomes synchronized to the transmitter, the receiver need only be powered during intermittent time periods when the TDMA signal is transmitted to the receiver. The second frequency control signal is utilized to effectuate frequency control only after the receiver is synchronized with the transmitter to permit intermittent operation of the receiver, and the frequency differences between the signal transmitted to the receiver and a receiver-oscillator, oscillation frequency is less than a maximum level.