Carrier frequency detection method and device for GPS satellite and GPS receiver

Abstract

The invention discloses a global position system (GPS) satellite carrier frequency detection method, a detection device and a GPS receiver. The GPS satellite carrier frequency detection method is a method used for detecting whether a detection value of a carrier frequency of a GPS satellite which does not participate in locating services. The method includes a first step of calculating the movement velocity of the GPS receiver through utilization of location information and Doppler information of a satellite which is chosen to be used for GPS positioning, and obtaining a Doppler frequency calculation value of the carrier frequency of the GPS satellite which does not participate in the locating services, a second step of comparing the Doppler frequency calculation value of the carrier frequency of the GPS satellite which does not participate in the locating services and a Doppler frequency measured value of a digital carrier frequency locked loop of the GPS satellite, and a third step of ensuring that the Doppler frequency measured value of the digital carrier frequency locked loop of the GPS satellite which does not participate in the locating services is wrong when the Doppler frequency calculation value is inconsistent with the Doppler frequency measured value.

Description

[0001] This application is a divisional application of an invention patent application filed on June 30, 2009 with the application number 200910158460.6 and the title of the invention is "GPS Satellite Carrier Frequency Detection Method and Device and GPS Receiver". technical field [0002] The present invention generally relates to a GPS (Global Positioning System) technology, and in particular to a technology for detecting the carrier frequency of GPS satellites. Background technique [0003] Such as figure 1 As shown, a general GPS receiver is mainly composed of an antenna 10, a preamplifier 20, a radio frequency-intermediate frequency (RF / IF) converter 30, an analog-to-digital (A / D) converter 40, a digital baseband processor 50, and a navigation processor 60 and control display unit 70. The radio frequency signal (RF) transmitted by the GPS satellite is received by the antenna 10 and filtered by a passive band-pass filter (not shown in the figure) to reduce out-of-band ...

AI Technical Summary

Problems solved by technology

from image 3 It can be seen that at the positions of 500s, 1000s and 1500s, there is a problem of tracking Doppler frequency offset, and the offset is around 200Hz-400Hz, which directly leads to a deviation of more than 100m between the positioning result and the real position

The main reason is that in the case of weak signals, due to the influence of noise and multipath, it is difficult to ensure the long-term stability of the frequency-locked loop tracking. When frequency deviation occurs, the use of carrier-locked detection cannot reflect whether the tracking is normal.

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