United States Patent 7,706,833
Kaewell, Jr. April 27, 2010
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Unified dual-mode GSM/UMTS clock
Abstract
A unified dual-mode global system for mobile communication (GSM)/universal mobile telecommunication systems (UMTS) clock and a transceiver employing the unified GSM/UMTS clock are disclosed. A reference clock generates a reference clock signal and a local oscillator (LO) generates a LO signal based on the reference clock signal. A frequency divider selectively generates either a GSM clock signal or a UMTS clock signal by converting a frequency of the LO signal by a predetermined factor. Both the GSM clock signal and the UMTS clock signal are generated based on the common reference clock signal. The reference clock signal frequency may be a GSM fundamental frequency or a UMTS fundamental frequency. An interpolator and/or a decimator may be used for matching frequencies of UMTS baseband signal and the UMTS clock signal or frequencies of GSM baseband signal and the GSM clock signal.
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Inventors: Kaewell, Jr.; John David (Jamison, PA)
Assignee: InterDigital Technology Corporation (Wilmington, DE)
Appl. No.: 11/433,959
Filed: May 15, 2006
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Related U.S. Patent Documents
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Application Number Filing Date Patent Number Issue Date
60681712 May., 2005
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Current U.S. Class: 455/552.1 ; 455/255; 455/260; 455/553.1
Current International Class: H04M 1/00 (20060101)
Field of Search: 455/552.1-553.1,255,256,257,258-265
