GNSS (Global Navigation Satellite System) signal separation device

Abstract

The utility model discloses a GNSS (Global Navigation Satellite System) signal separation device, belonging to the technical field of anti-interference of satellite navigation signals. Two input periodic signals are subjected to pre-stage processing through the signal conditioning module, the signals are converted into the acquisition range of the digital-to-analog converter, the digital-to-analog converter in the single-chip microcomputer is used for sampling output signals, fundamental waves and harmonic waves are obtained through Fourier transform algorithm analysis, and two original waveforms A'and B 'are generated through the digital synthesis module. The frequency difference between a generated waveform and an original waveform is obtained through a multiplication and filter circuit, drift is suppressed, a D signal is generated again through a DDS module, the signal frequency is determined by subtracting 5-10 Hz from the obtained A'or B 'signal frequency by the system, the large frequency difference is obtained, the processing time is shortened, and therefore the problem of introduction delay is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of satellite navigation signal anti-interference, in particular to a GNSS signal separation device. Background Art

[0002] GNSS (Global Navigation Satellite System) is a space-based, wireless navigation and positioning system that can provide users with all-weather three-dimensional coordinates, velocity, and time information anywhere on the Earth's surface or in near-Earth space. However, its performance is easily affected by interference signals. Therefore, a GNSS signal separation device is needed to improve the performance of the GNSS receiving system. This device separates and filters out unnecessary signals or interference, reduces multipath effects and interference signals, and improves the quality of the received signal and positioning accuracy, thereby improving the overall reliability and stability of the system.

[0003] The signals received by existing GNSS receivers are often the superposition of multiple signals. During the signal processing process of the signal separation device, the aliased signals need to be separated and filtered, which will introduce a certain delay, thus affecting the real-time application of the separation device. Utility Model Content

[0004] The purpose of the present invention is to provide a GNSS signal separation device to solve the above-mentioned technical problems.

[0005] Technical solution: A GNSS signal separation device, including a signal source generation module, a signal conditioning module, a signal acquisition and digital processing module and a signal output module, wherein:

[0006] The signal source generating module is used to generate a signal source to be separated;

[0007] The signal conditioning module includes a DC bias circuit for raising the voltage of the signal;

[0008] The signal acquisition and digital processing module includes a single chip microcomputer, which is equipped with a digital-to-analog converter. The digital-to-analog converter samples the conditioned signal and analyzes the signal spectrum through a Fourier transform algorithm to separate the fundamental and harmonic waves to obtain two original signals;

[0009] The signal output module includes a digital synthesis module for reconstructing two original signals and suppressing signal drift.

[0010] In a further embodiment, the single chip microcomputer is an STM32G473 chip, so that the digital-to-analog converter in the chip digitally samples the input signal and extracts the frequency and amplitude of the fundamental wave and harmonics through a Fourier transform algorithm.

[0011] In a further embodiment, the digital synthesis module is an AD9833 module capable of generating two separate signals from frequency and type information obtained from signal spectrum analysis.

[0012] In a further embodiment, the signal conditioning module further includes an adding circuit for adding the two signals and conditioning the signals to a voltage range suitable for sampling by the digital synthesis module.

[0013] In a further embodiment, the digital synthesis module includes a DDS module for generating a D signal, wherein the frequency of the D signal is based on the reconstructed two original signals minus 5-10 Hz, and can generate a reconstructed signal consistent with the frequency of the original signal.

[0014] Beneficial effects: The utility model performs pre-stage processing on the input two-cycle signal through the signal conditioning module, converts the signal into the acquisition range of the digital-to-analog converter, uses the digital-to-analog converter inside the single-chip microcomputer to sample the output signal, obtains the fundamental and harmonic waves through Fourier transform algorithm analysis, and generates two original waveforms A' and B' through the digital synthesis module. Through multiplication and filtering circuits, the frequency difference between the generated waveform and the original waveform is obtained, the drift is suppressed, and a DDS module is used to generate a D signal. The frequency of this signal is determined by the system by subtracting 5 to 10 Hz from the obtained A' or B' signal frequency, thereby obtaining a larger frequency difference, shortening the processing time, and thus reducing the problem of introducing delays. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the present utility model. DETAILED DESCRIPTION

[0016] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features known in the art are not described to avoid confusion with the present invention.

[0017] like Figure 1 As shown, a GNSS signal separation device, hereinafter referred to as "the device", includes a signal source generation module, a signal conditioning module, a signal acquisition and digital processing module and a signal output module, wherein: the signal source generation module is used to generate a signal source to be separated; the signal conditioning module includes a DC bias circuit for raising the voltage of the signal; the signal acquisition and digital processing module includes a single-chip microcomputer, which is equipped with a digital-to-analog converter, which samples the conditioned signal and analyzes the signal spectrum through a Fourier transform algorithm to separate the fundamental wave and harmonics to obtain two original signals; the signal output module includes a digital synthesis module for reconstructing the two original signals and suppressing signal drift.

[0018] Specifically, the single chip microcomputer adopts the STM32G473 chip, and the digital synthesis module adopts the AD9833 module.

[0019] like Figure 1 As shown, in this embodiment, the signal sources to be separated are superimposed and processed by an adder. After the signal enters the signal conditioning module, it is first voltage-boosted by a DC bias circuit to ensure that the signal is within the acquisition range of the digital-to-analog converter inside the single-chip microcomputer. After conditioning, the signal enters the digital-to-analog converter for digital sampling. The sampled signal is analyzed by a Fourier transform algorithm to extract the fundamental and harmonic information of the signal and calculate the frequency of the two original signals. In order to generate two separated original signals, the DDS module is used to reconstruct signals A' and B'. Since the reconstructed signal is not completely consistent with the frequency of the original signal, drift may occur. Therefore, this embodiment uses multiplication and filtering circuits to calculate the frequency difference between the generated waveform and the original waveform. Since the frequency difference is small, the processing speed is slow. In order to speed up the processing speed, another DDS module is used in this embodiment to generate a D signal. The frequency of the D signal is determined by the system based on the frequency of the A' or B' signal minus 5 to 10 Hz, so as to generate a larger frequency difference and shorten the processing time. Finally, the frequency difference is sent to the microcontroller as feedback. After processing, it drives the DDS module again to adjust the output waveforms A' and B' in real time, achieving real-time tracking of the signal frequency and effectively suppressing drift.

[0020] The signal output module of the utility model reconstructs the two original signals A' and B' after drift suppression, ensures that the frequency of the signal is consistent with the original signal, effectively suppresses drift, shortens the signal processing time, and reduces the phenomenon of introducing delay.

[0021] The multiplication and filtering circuits and the Fourier algorithm in this application are common knowledge.

[0022] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be interpreted as limiting the present invention itself. Various changes may be made to it in form and detail without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A GNSS signal separation device, characterized in that: It includes a signal source generation module, a signal conditioning module, a signal acquisition and digital processing module, and a signal output module, among which: The signal source generating module is used to generate a signal source to be separated; The signal conditioning module includes a DC bias circuit for raising the voltage of the signal; The signal acquisition and digital processing module includes a single chip microcomputer, which is equipped with a digital-to-analog converter. The digital-to-analog converter samples the conditioned signal and analyzes the signal spectrum through a Fourier transform algorithm to separate the fundamental and harmonic waves to obtain two original signals; The signal output module includes a digital synthesis module for reconstructing two original signals and suppressing signal drift.

2. A GNSS signal separation device according to claim 1, characterized in that: The single chip microcomputer is an STM32G473 chip.

3. The GNSS signal separation device according to claim 1, characterized in that: The digital synthesis module is an AD9833 module.

4. The GNSS signal separation device according to claim 1, characterized in that: The signal conditioning module further includes an adding circuit for adding the two signals and conditioning the signals to a voltage range suitable for sampling by the digital synthesis module.

5. The GNSS signal separation device according to claim 1, characterized in that: The digital synthesis module includes a DDS module for generating a D signal, wherein the frequency of the D signal is based on the reconstructed two original signals minus 5-10 Hz.

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