GNSS signal self-adaption quick traction method

Abstract

The invention discloses a GNSS signal self-adaption quick traction method. The GNSS signal self-adaption quick traction method comprises the method that carrier frequency, phase tracking, pseudo code phase tracking and bit synchronization are conducted according to the state of traction enable signals; when the time of bit synchronization reaches a preset value, a bit synchronization frequency counter is adjusted, and the position of a maximum value and the position of a minimum value can be searched in an energy column diagram; bit synchronization and traction are judged whether to be failed or not according to the position of the maximum value, the position of the minimum value and the bit synchronization frequency counter. The GNSS signal self-adaption quick traction method can achieve quick traction of strong signals, improve the successful rate of traction of weak signals, and reduce the probability of bit synchronization errors.

Description

technical field [0001] The present application relates to the field of satellite positioning and navigation communication, and in particular to a GNSS signal self-adaptive fast traction method. Background technique [0002] Global satellite positioning and navigation systems (GNSS), such as the GPS system, the Galileo system, the Beidou system, generally include a constellation of satellites that transmit GNSS signals that can be used by a receiver to determine the receiver's position. Satellite orbits are arranged in multiple planes so that the signal can be received from at least four satellites at any location on Earth. The GNSS signal transmitted by each GNSS satellite is a direct sequence spread spectrum signal. Each satellite transmits a different PRN (Pseudo Random Noise, pseudo-random noise) code, so that signals can be sent from several satellites at the same time and received by a receiver at the same time, with almost no interference between them. The term "sate...

AI Technical Summary

Problems solved by technology

[0006] There are following deficiencies in this traditional scheme: 1, fixed pulling time and bit synchronous time, cause average pulling time long, be unfavorable for the reduction of time to first fix (TTFF)

2. Taking the captured rough carrier frequency as the initial value, there is a risk that the loop cannot be successfully closed when the frequency estimate is too rough

3. There is a lack of bit synchronization verification mechanism. If the bit synchronization is wrong, it will cause an error in the order of milliseconds in the launch time, and the satellite cannot be used for settlement, which is a waste of resources

4. The bit synchronization position is obtained only at the end of the traction, resulting in the moment of turning into tracking, the locking of the carrier phase and the pseudo code phase is affected by the bit inversion. At this time, immediate demodulation and positioning will affect the demodulation bit error rate (BER ) and positioning accuracy

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