Patent ID: 8044855

Claim:
A GPS receiver apparatus comprising: a reception unit comprising a radio frequency unit and a demodulator, the reception unit configured to receive a GPS signal transmitted from a GPS satellite and acquire a navigation message; a synchronization controller configured to control a reception frequency of the GPS signal and a frequency and a phase of a code of the GPS signal to ensure synchronization with the GPS signal, and generate a timing signal synchronized with a signal timing of the navigation message in the synchronized GPS signal; a calculation processor configured to calculate a current time based on time information included in the navigation message acquired by the reception unit; and a power controller configured to: start power supply to the reception unit, the synchronization controller, and the calculation processor in response to an acquisition request for a specific information contained in a specific sub-frame of sub-frames of the navigation message; stop the power supply to the reception unit while keeping the power supply to the synchronization controller and the calculation processor after the reception unit acquires the time information contained in one of the sub-frames of the navigation message; stop the power supply to the calculation processor while keeping the power supply to the synchronization controller after the calculation processor calculates the current time; and stop the power supply to the synchronization controller after a predetermined period has been elapsed from a time when the power supply to the calculation processor is stopped.