Patent ID: 6907346
Filing Date: 2005-06-14
Classification: G01S,H04B

Abstract:
1. A GPS receiver comprising: a frequency conversion means for converting a high-frequency GPS signal into an intermediate frequency GPS signal, wherein the high-frequency GPS signal is transmitted as transmission data from an artificial satellite by modulating a carrier wave through a signal spectrum-spread by a spread code; a synchronization hold means for obtaining the transmission data by receiving the intermediate frequency GPS signal supplied from the frequency conversion means and acquiring and holding synchronization of the carrier wave and phase synchronization of the spread code; a control means for controlling repetition of an intermittent operation which operates the synchronization hold means to obtain the transmission data, then stops operating the synchronization hold means, and again operates the synchronization hold means after lapse of a specified time by using, as initial values, a carrier wave frequency and a spread code phase valid for the most recent stop condition; and a positioning operation means for performing a positioning operation by using the transmission data obtained through the synchronization hold means and finding and outputting positioning information indicative of a current position.