Circuit for synchronizing CDMA mobile phones
First Claim
1. A receiver for use in a communication system having a transmitter for transmitting a spread-spectrum signal, said receiver comprising:
- receiver means for receiving said spread spectrum signal and for recovering a network clock signal therefrom;
an oscilator for producing an oscillator clock signal;
frequency comparator means coupled to said receiver means and said oscillator for receiving said network clock signal and said oscillator clock signal and for producing a calibration factor based on a comparison of the network clock signal and said oscillator clock signal;
a controller coupled to said oscilator and said frequency comparator means for outputting a wake-up signal based on said calibration factor.
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Accused Products
Abstract
A frequency calibration circuit for use in a spread spectrum receiver. The receiver includes circuitry for receiving a spread spectrum signal from a base station and for recovering a network clock signal therefrom, a low frequency oscillator for producing an oscillator clock signal, and a frequency comparator that takes as inputs the network clock signal and the oscillator clock signal and produces a calibration factor based on the difference between the clock signals. A controller coupled to the low frequency oscillator amd the frequency comparator utilizes the calibration factor together with the low frequency oscillator clock signal to output a accurate and precision timed signal thereby being able to accurately require the timing of the paging channel.
46 Citations
5 Claims
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1. A receiver for use in a communication system having a transmitter for transmitting a spread-spectrum signal, said receiver comprising:
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receiver means for receiving said spread spectrum signal and for recovering a network clock signal therefrom; an oscilator for producing an oscillator clock signal; frequency comparator means coupled to said receiver means and said oscillator for receiving said network clock signal and said oscillator clock signal and for producing a calibration factor based on a comparison of the network clock signal and said oscillator clock signal; a controller coupled to said oscilator and said frequency comparator means for outputting a wake-up signal based on said calibration factor. - View Dependent Claims (2, 3)
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4. A receiver for use in a communication system having a transmitter for transmitting a spread-spectrum signal, said receiver comprising:
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receiver means for receiving said spread spectrum signal and for recovering a network clock signal therefrom; an oscillator for producing an oscillator clock signal; frequency comparator means coupled to said receiver means and said oscillator for receiving said network clock signal and said oscillator clock signal and for producing a calibration factor based on a comparison of the network clock signal and said oscillator clock signal; and a controller coupled to said oscillator and said frequency comparator means for outputting a wake-up signal after a predetermined period of time, the predetermined period of time being calculated from said oscillator clock signal and said calibration factor. - View Dependent Claims (5)
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Specification