Chip scale atomic clock (CSAC)-based high-high sensitivity global navigation satellite system (GNSS) receiver and recapture realization method thereof

Abstract

The present invention provides a CSAC-based high-high sensitivity GNSS receiver and a recapture realization method thereof. The CSAC-based high-high sensitivity GNSS receiver comprises a CSAC module for providing a reference signal; an antenna for receiving a radio frequency signal; a radio frequency front end for processing the radio frequency signal based on the reference signal and outputting a digital IF signal; a conventional baseband processing module used for capturing and tracking the digital IF signal, demodulating the message of digital IF signal and estimating the carrier-to-noise ratio of the digital IF signal, wherein when the result of the carrier-to-noise ratio estimation is greater than a predetermined threshold value, the conventional baseband processing module captures and tacks, otherwise, in a high-sensitivity work mode, a high-sensitivity tracking and capturing module captures and tracks; a high-sensitivity tracking and recapturing module used for processing the digital IF information outputted by the radio frequency front end to realize the high-sensitivity capture and tracking; and a navigation calculation and auxiliary parameter calculation module used for providing a needed local code phase estimated value and a carrier frequency estimated value for the high-sensitivity capture and tracking. The sensitivity and dynamic performance of the GNSS receiver of the present invention can be improved substantially.

Description

technical field [0001] The invention belongs to the technical field of navigation and positioning, and in particular relates to a CSAC-based high-sensitivity GNSS receiver and a recapture implementation method, which are suitable for navigation and positioning of pedestrians, vehicles and aircraft in weak GNSS signal environments such as indoors and urban canyons. Background technique [0002] Global Navigation Satellite Systems (GNSS) include GPS in the United States, Glonass in Russia, Galileo in Europe, BDS in China, and other related augmentation systems. Due to its technical advantages such as global continuous coverage, high positioning accuracy, fast, all-weather observation, and easy operation, GNSS has been widely used in three-dimensional navigation, positioning, and timing services for aviation, aerospace, land, and ocean users. [0003] As a radio navigation and positioning system, the key to the normal operation of GNSS lies in the accurate measurement of signal...

AI Technical Summary

Problems solved by technology

In the Chinese patent CN101666869A, only the carrier frequency error is corrected, but the influence of the carrier frequency change rate is not corrected

[0007] Affected by phase noise, the existing temperature-compensated crystal oscillator (TCXO) and constant temperature crystal oscillator (OCXO) can support coherent integration of hundreds of milliseconds; continuing to lengthen the coherence time will not help improve the output signal-to-noise ratio, but will lead to attenuation of coherent gain

Therefore, the accuracy and stability of traditional reference crystal oscillators become the main constraints to further improve GNSS sensitivity

Atomic clocks used in space satellites and high-precision timekeeping equipment are difficult to use in general-purpose GNSS receivers due to high cost, huge size, and huge power consumption

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