Anti-interference device based on Beidou satellite navigation system

Abstract

This application discloses an anti-interference device based on the BeiDou satellite navigation system, comprising a power supply circuit, an RF front-end module, a control and communication circuit, an ADC analog-to-digital converter (ADC), a DAC digital-to-analog converter (DAC), and an anti-interference module. The power supply terminal of the RF front-end module is connected to the power supply circuit. The output terminal of the RF front-end module is connected in series with the ADC, the anti-interference module, and the DAC, and then connected to the control and communication circuit. The anti-interference module includes an anti-interference filter circuit, an interference signal detection circuit, and an interference suppression circuit connected in series. The anti-interference filter circuit includes an adaptive filter and a multi-stage filter unit connected in series. The interference signal detection circuit includes a signal monitoring unit, a signal processing unit, and a threshold judgment unit connected in series. The interference suppression circuit is implemented using a reverse signal transmission unit. Through innovative circuit design, this application can effectively cope with various interference signals and significantly improve the anti-interference performance of the BeiDou satellite navigation system in complex electromagnetic environments.

Description

Technical Field

[0001] This utility model relates to the field of satellite navigation technology, and in particular to an anti-interference device based on the BeiDou satellite navigation system. Background Technology

[0002] The BeiDou Navigation Satellite System plays a vital role in numerous fields, including military and civilian applications, and the stability and reliability of its signals are of paramount importance. However, with the development of electronic countermeasures technology, BeiDou signals face various interference threats, such as suppressive and deceptive interference, which seriously affect the accuracy and reliability of navigation and positioning. Existing anti-interference methods have certain limitations, such as insufficient anti-interference performance in complex electromagnetic environments and poor adaptability to certain new types of interference signals. Therefore, developing an efficient and reliable anti-interference device, especially optimizing anti-interference circuits, is of great significance for improving the anti-interference capability of the BeiDou Navigation Satellite System.

[0003] In the prior art, invention patent CN105259560A discloses a miniaturized BeiDou satellite navigation anti-interference array signal processing board and its anti-interference processing method. The board includes: an analog-to-digital conversion module, an anti-interference processing module, a digital-to-analog conversion module, a clock distribution module, and a power supply module. The analog-to-digital conversion module quantizes the received analog intermediate frequency (IF) signal and outputs a digital IF signal. The anti-interference processing module performs digital bandpass filtering and digital down-conversion processing on the N-channel digital IF signals output by the analog-to-digital conversion module, converting them into N-channel baseband complex signals. The N-channel baseband complex signals are then subjected to anti-interference filtering according to an anti-interference algorithm to obtain the anti-interference processed digital IF signal. The digital-to-analog conversion module converts the digital IF signal output by the anti-interference processing module into an analog IF signal and outputs it to the radio frequency front-end module. This scheme adopts the spatiotemporal joint DMI+CNLMS algorithm, which combines the advantages of fast convergence of block processing and fast tracking of continuous processing. Although it has excellent anti-interference performance, it is highly complex: the anti-interference algorithm is complex and requires high hardware resources and computing power, making it unsuitable for applications that are extremely sensitive to cost and power consumption; in addition, the algorithm has high real-time requirements and high requirements for hardware processing speed and stability. Utility Model Content

[0004] A brief overview of embodiments of the present invention is provided below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0005] This utility model aims to provide an anti-interference device based on the BeiDou satellite navigation system. Through innovative anti-interference circuit design, it effectively improves the anti-interference performance of BeiDou signals in complex electromagnetic environments, ensuring high accuracy and high reliability of navigation and positioning.

[0006] Specifically, this application discloses an anti-interference device based on the BeiDou satellite navigation system, comprising a power supply circuit, a radio frequency (RF) front-end module, a control and communication circuit, an ADC (analog-to-digital converter), a DAC (digital-to-analog converter), and an anti-interference module. The power supply terminal of the RF front-end module is connected to the power supply circuit. The output terminal of the RF front-end module is connected in series with the ADC, the anti-interference module, and the DAC, and then connected to the control and communication circuit. The anti-interference module includes an anti-interference filter circuit, an interference signal detection circuit, and an interference suppression circuit connected in series. The anti-interference filter circuit includes an adaptive filter (or adaptive filter bank) and a multi-stage filtering unit connected in series. The interference signal detection circuit includes a signal monitoring unit, a signal processing unit, and a threshold judgment unit connected in series. The interference suppression circuit is implemented using a reverse signal transmission unit.

[0007] As a specific implementation, one input terminal of the anti-interference filtering circuit is connected to the output terminal of the ADC analog-to-digital converter to receive the digital intermediate frequency signal, and the other input terminal is connected to the feedback signal of the interference signal detection circuit to adjust the parameters of the adaptive filter. The adaptive filter is implemented using a digitally programmable filter chip and its follower circuit to dynamically adjust the filtering parameters. The multi-stage filtering unit includes a gating switch, a low-pass filter (LPF), a high-pass filter (HPF), and a band-pass filter (BPF). The control terminal of the gating switch is connected to the adaptive filter, and the output terminal of the gating switch is connected to the low-pass filter, high-pass filter, and band-pass filter, respectively. This multi-stage filtering unit dynamically determines the conduction path of the gating switch based on the signal output by the adaptive filter, thereby selecting an appropriate filter (low-pass filter, high-pass filter, or band-pass filter) to filter the input signal. The specific filter or combination of filters selected depends on the frequency characteristics of the interference signal.

[0008] This anti-interference filtering circuit filters the input digital signal to remove interference signals. It employs an adaptive filter that adjusts the filtering parameters according to the frequency and intensity of the interference signal, effectively filtering out suppressive interference signals. Furthermore, it incorporates various types of filters (such as low-pass, high-pass, and band-pass filters), which can be intelligently switched and combined via a selection switch to accurately filter interference signals in different frequency bands. In addition, during the filtering process, digital signal processing algorithms (such as wavelet transform and short-time Fourier transform) can be used to extract and analyze signal features, further optimizing the filtering effect; these details are not elaborated here.

[0009] As a specific implementation, the interference signal detection circuit is used to monitor the input signal in real time, detecting the presence, type, and characteristic parameters of interference signals. The signal monitoring unit is implemented using a multi-band signal monitoring circuit composed of multiple bandpass filters (BPFs) connected in parallel, used to monitor the signal strength and frequency characteristics of the BeiDou satellite navigation signal in its frequency band and surrounding frequency bands, in order to quickly identify the presence and type of interference signals (such as suppressive interference, deceptive interference, etc.). The signal processing unit is used to extract the characteristic parameters of the interference signal based on the monitored signal strength and frequency characteristics; the threshold judgment unit outputs the judgment result based on the extracted characteristic parameters and a preset threshold.

[0010] As a further implementation, the signal processing unit is implemented using a DSP chip of model TMS320C6748.

[0011] As a further implementation, the interference suppression circuit generates a reverse signal that cancels out the interference signal based on the characteristic parameters of the interference signal output by the signal processing unit, and transmits the reverse signal (through the transmitting antenna), thereby achieving active suppression of the interference signal.

[0012] Furthermore, the anti-interference device also includes a clock module connected to the control and communication circuitry, which provides a high-precision, low-jitter clock signal for the entire anti-interference device, ensuring the synchronous operation of each module. As a specific implementation, this clock module is implemented using a high-performance clock distribution chip (such as the AD9528).

[0013] Furthermore, the anti-interference device also includes a storage module connected to the control and communication circuitry: used to store the data and parameters required for system operation.

[0014] Furthermore, the anti-interference device also includes a communication interface module connected to the control and communication circuit, including a serial port, USB interface, Ethernet interface, wireless communication module, etc.

[0015] This application implements an anti-interference module through the aforementioned scheme. Through innovative circuit design, it effectively copes with various interference signals, significantly improving the anti-interference performance of the BeiDou satellite navigation system in complex electromagnetic environments, and ensuring high accuracy and reliability of navigation and positioning. This application requires no complex calculations and has low requirements for existing hardware. The main body of the anti-interference module is implemented using a DSP chip and can be integrated as an independent module into the existing BeiDou satellite signal processing system, facilitating the modification of existing systems. Furthermore, by transmitting a reverse signal to actively cancel interference signals, the anti-interference capability is further enhanced, especially showing a significant suppression effect on strong interference signals. Attached Figure Description

[0016] This invention can be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which the same or similar reference numerals are used throughout the drawings to denote the same or similar parts. These drawings, together with the following detailed description, are incorporated in and form part of this specification, and are used to further illustrate preferred embodiments of the invention and explain the principles and advantages of the invention. In the drawings:

[0017] Figure 1 This is a schematic diagram of the anti-interference device according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic block diagram of the anti-interference module according to an embodiment of the present utility model;

[0019] Figure 3 This is a schematic diagram illustrating the implementation principle of the anti-interference module in an embodiment of this utility model. Detailed Implementation

[0020] Embodiments of the present invention will now be described with reference to the accompanying drawings. Elements and features described in one drawing or embodiment of the present invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that, for clarity, representations and descriptions of components and processes unrelated to the present invention and known to those skilled in the art have been omitted from the drawings and description.

[0021] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0022] See Figure 1 This utility model provides an anti-interference device based on the BeiDou satellite navigation system, including a power supply circuit, an RF front-end module, a control and communication circuit, an ADC analog-to-digital converter, a DAC digital-to-analog converter, and an anti-interference module. The power supply terminal of the RF front-end module is connected to the power supply circuit. The output terminal of the RF front-end module is connected in series with the ADC analog-to-digital converter, the anti-interference module, and the DAC digital-to-analog converter, and then connected to the control and communication circuit.

[0023] The power supply circuit provides a stable power supply to the entire anti-interference device, ensuring the normal operation of each module. As a specific embodiment, this power supply circuit is implemented using a highly integrated, high-power, wide-voltage-input DC-DC power converter chip (e.g., LM22677) and its follower circuit.

[0024] The radio frequency (RF) front-end module receives BeiDou satellite navigation signals and converts them into intermediate frequency (IF) analog signals suitable for subsequent processing. It typically includes a low-noise amplifier (LNA), mixer, and filters to effectively amplify weak satellite signals and down-convert them to IF signals. This module can be implemented using existing RF front-end modules.

[0025] The control and communication circuit is responsible for the operation control of the anti-interference device and data communication with other system modules. It generally uses a combination of high-performance microprocessors (such as ARM processors) and field-programmable gate arrays (FPGAs) to realize real-time control and management of various aspects such as interference signal detection, anti-interference filtering, and interference suppression.

[0026] An analog-to-digital converter (ADC) is used to convert the analog intermediate frequency (IF) signal output from the RF front-end module into a digital signal for subsequent digital signal processing. It can be implemented using a high-precision ADC chip (such as the AD9566).

[0027] A DAC (Digital-to-Analog Converter) converts the digital signal processed by the anti-interference module into an analog signal, which is then output to the RF front-end module or control and communication circuits. High-performance DAC chips can be used to ensure the accuracy and stability of the digital-to-analog conversion.

[0028] See Figure 2 The anti-interference module is the core component of this device, which includes an anti-interference filter circuit, an interference signal detection circuit, and an interference suppression circuit connected in series.

[0029] See Figure 3 The anti-interference filtering circuit includes interconnected adaptive filters (or adaptive filter banks) and multi-stage filtering units; the interference signal detection circuit includes a signal monitoring unit, a signal processing unit, and a threshold judgment unit connected in series; the interference suppression circuit is implemented using a reverse signal transmission unit.

[0030] The principle of the above-mentioned modules in this application is explained as follows: The radio frequency front-end module receives BeiDou satellite navigation signals and converts them into intermediate frequency analog signals. The ADC analog-to-digital converter converts the intermediate frequency analog signals into digital signals and outputs them to the anti-interference module. The anti-interference filtering circuit of the anti-interference module filters the input digital signals to remove out-of-band interference signals. The interference signal detection circuit monitors the filtered signal in real time and detects the presence of interference signals and their characteristic parameters. Based on the characteristics of the interference signals, the interference suppression circuit outputs the inverse signal corresponding to the interference signal to suppress the interference signals and improve the quality of BeiDou signals. The processed digital signal is converted into an analog signal by the DAC digital-to-analog converter and output to the radio frequency front-end module or the control and communication circuit. The control and communication circuit dynamically adjusts the working state of the anti-interference module according to the preset anti-interference strategy and real-time monitoring data, and communicates with other system modules to achieve intelligent anti-interference operation.

[0031] Specifically, one input of the anti-interference filter circuit is connected to the output of the ADC analog-to-digital converter to receive the digital intermediate frequency signal, and the other is connected to the feedback signal of the interference signal detection circuit to adjust the parameters of the adaptive filter. The adaptive filter is implemented using a digital programmable filter chip and its follower circuit to dynamically adjust the filtering parameters. The multi-stage filtering unit includes a gating switch, a low-pass filter (LPF), a high-pass filter (HPF), and a band-pass filter (BPF). The control terminal of the gating switch is connected to the adaptive filter, and the output terminal of the gating switch is connected to the low-pass filter, high-pass filter, and band-pass filter, respectively. This multi-stage filtering unit dynamically determines the conduction path of the gating switch according to the signal output by the adaptive filter, thereby selecting an appropriate filter (low-pass filter, high-pass filter, or band-pass filter) to filter the input signal.

[0032] The aforementioned adaptive filter can be an adaptive filter bank. Filter banks include various types of filters, such as low-pass filters, high-pass filters, and band-pass filters, which can be switched and combined via gating switches to achieve precise filtering of interference signals in different frequency bands. The specific filter or combination of filters chosen depends on the frequency characteristics of the interference signal. In particular, for deceptive interference, a signal correlation-based filtering circuit is designed based on the aforementioned filter bank. By calculating the correlation between the received signal and the reference signal pre-stored in the BeiDou satellite navigation system, deceptive signals with low correlation to the reference signal are identified and eliminated.

[0033] The interference signal detection circuit is used to monitor the input signal in real time, detecting the presence, type, and characteristic parameters of interference signals. The signal monitoring unit is implemented using a multi-band signal monitoring circuit composed of multiple bandpass filters (BPFs) connected in parallel. This circuit monitors the signal strength and frequency characteristics of the BeiDou satellite navigation signal's frequency band and surrounding frequency bands to quickly identify the presence and type of interference signals (such as suppressive interference, deceptive interference, etc.). The signal processing unit extracts the characteristic parameters of the interference signal based on the monitored signal strength and frequency characteristics. The threshold judgment unit outputs the judgment result based on the extracted characteristic parameters and a preset threshold. In this embodiment, the signal processing unit is implemented using a TMS320C6748 DSP chip.

[0034] The interference suppression circuit generates a reverse signal that cancels out the interference signal based on the characteristic parameters of the interference signal output by the signal processing unit, and transmits it through a suitable transmitting antenna, thereby canceling out the interference signal in space and reducing the impact of interference on the BeiDou signal.

[0035] The various circuit modules within the anti-interference device interact and coordinate with each other via a high-speed communication bus. The control and communication circuits are responsible for real-time control and management of all aspects, including interference signal detection, anti-interference filtering, and interference suppression.

[0036] In addition, the anti-interference device also includes a clock module, a storage module, and a communication interface module connected to the control and communication circuits. The clock module provides a high-precision, low-jitter clock signal to the entire anti-interference device, ensuring synchronized operation of all modules. This clock module uses a high-performance clock distribution chip (such as the AD9528). The storage module stores the data and parameters required for system operation. The communication interface module includes serial ports, USB interfaces, Ethernet interfaces, wireless communication modules, etc.

[0037] This application implements an anti-interference module through the above-mentioned scheme. Through innovative circuit design, it can effectively cope with various interference signals, significantly improve the anti-interference performance of Beidou satellite navigation system in complex electromagnetic environment, and ensure high accuracy and high reliability of navigation and positioning.

[0038] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0039] Although the present invention has been disclosed above through the description of specific embodiments, it should be understood that all the embodiments and examples described above are exemplary and not restrictive. Those skilled in the art can design various modifications, improvements, or equivalents to the present invention within the spirit and scope of the appended claims. These modifications, improvements, or equivalents should also be considered to be included within the protection scope of the present invention.

Claims

1. A BeiDou satellite navigation system-based anti-interference device, characterized in that: The system includes a power supply circuit, an RF front-end module, a control and communication circuit, an ADC (Analog-to-Digital Converter), a DAC (Digital-to-Analog Converter), and an anti-interference module. The power supply terminal of the RF front-end module is connected to the power supply circuit. The output terminal of the RF front-end module is connected in series with the ADC, the anti-interference module, and the DAC, and then connected to the control and communication circuit. The anti-interference module includes an anti-interference filter circuit, an interference signal detection circuit, and an interference suppression circuit connected in series. The anti-interference filter circuit includes an adaptive filter and a multi-stage filter unit connected in series. The interference signal detection circuit includes a signal monitoring unit, a signal processing unit, and a threshold judgment unit connected in series. The interference suppression circuit is implemented using a reverse signal transmission unit.

2. The anti-jamming device based on the Beidou satellite navigation system according to claim 1, characterized in that: The anti-interference filtering circuit has one input terminal connected to the output terminal of the ADC analog-to-digital converter to receive the digital intermediate frequency signal, and another input terminal connected to the feedback signal of the interference signal detection circuit to adjust the parameters of the adaptive filter. The adaptive filter is implemented using a digital programmable filter chip and its follower circuit. The multi-stage filtering unit includes a gating switch, a low-pass filter, a high-pass filter, and a band-pass filter. The control terminal of the gating switch is connected to the adaptive filter, and the output terminal of the gating switch is connected to the low-pass filter, the high-pass filter, and the band-pass filter, respectively. The multi-stage filtering unit dynamically determines the conduction path of the gating switch according to the signal output by the adaptive filter.

3. The anti-jamming device based on the Beidou satellite navigation system according to claim 1, characterized in that: In the interference signal detection circuit, the signal monitoring unit is implemented using a multi-band signal monitoring circuit composed of multiple bandpass filters connected in parallel, which is used to monitor the signal strength and frequency characteristics of the Beidou satellite navigation signal in its frequency band and surrounding frequency bands; the signal processing unit is used to extract the feature parameters of the interference signal based on the monitored signal strength and frequency characteristics; the threshold judgment unit outputs the judgment result based on the extracted feature parameters and the preset threshold.

4. The anti-jamming device based on the Beidou satellite navigation system according to claim 3, characterized in that: The signal processing unit is implemented using a DSP chip of model TMS320C6748.

5. The anti-jamming device based on the Beidou satellite navigation system according to claim 3, characterized in that: The interference suppression circuit generates a reverse signal that cancels out the interference signal based on the characteristic parameters of the interference signal output by the signal processing unit, and then transmits the reverse signal.

6. The anti-jamming device based on the Beidou satellite navigation system according to claim 1, characterized in that: The anti-interference device also includes a clock module connected to the control and communication circuitry.

7. The anti-jamming device based on the Beidou satellite navigation system according to claim 6, characterized in that: The clock module is implemented using a clock distribution chip with the chip model AD9528.

8. The anti-jamming device based on the Beidou satellite navigation system according to claim 1, characterized in that: The anti-interference device also includes a storage module connected to the control and communication circuitry.

9. The anti-jamming device based on the Beidou satellite navigation system according to claim 1, characterized in that: The anti-interference device also includes a communication interface module connected to the control and communication circuitry.

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