Patent ID: 8180372
Filing Date: 2012-05-15
Classification: G01S

Abstract:
1. A positioning method comprising: generating at a terminal a GS(geostationary-satellite)-synchronizing frequency to receive a geostationary-satellite signal, the geostationary-satellite signal being transmitted from a geostationary-satellite on a geostationary-satellite frequency; receiving at the terminal the geostationary-satellite signal on a GS(geostationary-satellite)-receiving frequency; calculating at the terminal a GST(geostationary-satellite and Terminal) frequency difference, the GST frequency difference being a difference between the GS-receiving frequency and the GS-synchronizing frequency; obtaining at the terminal an GS ratio, the GS ratio being a ratio of the GST frequency difference to the geostationary-satellite frequency; correcting at the terminal a frequency error of a reference oscillator of the terminal based on the GS ratio, generating at the terminal a BS(Base Station)-synchronizing frequency to receive a base-station signal from a communication base station, the base-station signal being transmitted on an official frequency of the communication base station; receiving at the terminal the base-station signal on a BS-receiving frequency; calculating at the terminal a BST(Base Station and Terminal) frequency difference, the BST frequency difference being a difference between the BS-receiving frequency and the BS-synchronizing frequency; obtaining at the terminal a BS ratio, the BS ratio being a ratio of the BST frequency difference to the official frequency; transmitting the BS ratio as a BS frequency error ratio from the terminal to the communication base station, the BS frequency error ratio being a ratio of a BS frequency error to the official frequency of the base-station signal, the BS frequency error being a difference between the official frequency and a frequency of the base-station signal; transmitting the BS frequency error ratio from the communication base station to a positioning device; and calculating at the positioning device a position of the positioning device by receiving a satellite signal on a frequency accounting for the BS frequency error.