Patent ID: 7162216
Filing Date: 2007-01-09
Classification: H03L,H04B

Abstract:
1. A wireless communication system comprising: an oscillation system circuit which receives a first control signal, which provides a local oscillation signal having one of a first frequency and a second frequency being different from the first frequency in accordance with an indication of the first control signal, and which includes a phase comparator which detects a difference in phase between a reference signal and a signal based on the local oscillation signal, a charge pump circuit which generates a voltage in response to the phase difference detected by said phase comparator, and a filter including a capacitor and receiving the voltage outputted from the charge pump circuit, wherein a frequency of the local oscillation signal to be provided from the oscillation system is changed in accordance with a voltage outputted from the filter; a reception system circuit which merges a signal received by an antenna with the local oscillation signal; setting means which sets a predetermined voltage to the filter in response to a second control signal; and control means which generates the first control signal and generates the second control signal in response to a change that the local oscillation signal to be provided from the oscillation system circuit is changed from the first frequency to the second frequency.