Interference monitoring and suppression method and system for GNSS (Global Navigation Satellite System) signal, receiver and medium

Abstract

The invention provides a GNSS signal interference monitoring and suppression method and system, a receiver and a medium, and particularly relates to the technical field of satellite navigation communication, and the scheme comprises the steps: obtaining an intermediate frequency signal based on a received GNSS signal; based on the differential cumulative power spectrum of the intermediate frequency signal, performing interference detection on the intermediate frequency signal, identifying the type of the interference signal according to the characteristic parameter of the interference signal, setting the notch frequency, and performing filtering processing on the intermediate frequency signal to obtain a target signal and a filtered signal; and evaluating the filtered signal according to the energy of the signal, and when the filtered signal is evaluated to be invalid, identifying the characteristic parameters of the interference signal again, and adjusting the notch frequency to perform filtering processing until the evaluation is valid. According to the scheme, the interference signals in the environment can be dynamically detected and identified, and the notch frequency can be adjusted, so that the interference signals are effectively detected and adaptively suppressed, and the anti-interference performance of the single-antenna GNSS receiver to various interference environments is improved.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation communication technology, and in particular to a method, system, receiver and medium for monitoring and suppressing interference of GNSS signals. Background Art

[0002] Position, Navigation and Time (PNT) technology is widely used in civil navigation, financial trade, Internet of Things, autonomous driving, smart cities and other fields. At present, the Global Navigation Satellite System (GNSS) is one of the important sources of PNT information. However, the fragility of GNSS signals makes them easily interfered by various radio frequency signals, such as radio signals broadcast by VHF / UHF TV antennas, high-power continuous wave interference, swept frequency interference and multiple continuous wave interference emitted by portable jammers, etc., which will seriously affect the use of GNSS and even threaten the property and life safety of society and users.

[0003] Since the GNSS receiver itself does not have the ability to suppress the influence of interference, improving the anti-interference ability of the GNSS receiver is an urgent problem to be solved. In the prior art, there are mainly two technical means for anti-interference of GNSS receivers. One is multi-antenna technology, which can reduce the signal in the direction of the interference source through beam technology, and amplify the useful signals in other directions to suppress the GNSS interference signal, but it has the disadvantages of high hardware cost, high computational complexity and large amount of calculation. The other is single antenna technology, which is widely used in civilian fields such as mobile phones, smart wearables, and navigators. It has the advantages of small size, low hardware cost, low computational complexity and small amount of calculation. At present, scholars' research on the anti-interference technology of single-antenna receivers is mainly aimed at environments with specific interference types. However, in actual environments, the types of interference signals are often unknown and change randomly, which makes the anti-interference ability of single-antenna GNSS receivers suitable for environments with specific interference types poor. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a method, system, receiver and medium for interference monitoring and suppression of GNSS signals, aiming to solve the problem of poor anti-interference capability of single-antenna GNSS receivers in the prior art.

[0005] In order to achieve the above object, the present invention provides a method for monitoring and suppressing interference of GNSS signals in a first aspect, comprising the following steps:

[0006] Based on the received GNSS signal, an intermediate frequency signal is obtained;

[0007] Performing spectrum estimation on the intermediate frequency signal to obtain a differential cumulative power spectrum of the intermediate frequency signal;

[0008] If the differential cumulative power spectrum of the intermediate frequency signal exceeds a preset differential cumulative power spectrum threshold, an interference warning signal is issued, and characteristic parameters of the interference signal are obtained using the differential cumulative power spectrum;

[0009] Setting a notch frequency according to characteristic parameters of the interference signal, filtering the intermediate frequency signal based on the notch frequency, and obtaining a target signal and a filtered signal;

[0010] The filtered signal is evaluated according to the energy of the signal. When the filtered signal is evaluated to be invalid, the characteristic parameters of the interference signal are re-evaluated, the notch frequency is adjusted, and the intermediate frequency signal is re-filtered until the filtered signal obtained by evaluation is valid; when the filtered signal is evaluated to be valid, the target signal is output.

[0011] Optionally, performing spectrum estimation on the intermediate frequency signal to obtain a differential cumulative power spectrum of the intermediate frequency signal includes:

[0012] Acquiring the power spectral density of the intermediate frequency signal, integrating and normalizing the power spectral density to obtain a normalized cumulative spectral density;

[0013] Based on the normalized cumulative spectral density and a preset cumulative spectral density reference value, a differential cumulative power spectrum of the intermediate frequency signal is obtained.

[0014] Optionally, the step of determining the differential cumulative power spectrum threshold value includes:

[0015] Acquire historical data of the GNSS signal, and based on the historical data of the GNSS signal, obtain a fluctuation range of the differential cumulative power spectrum of the intermediate frequency signal;

[0016] Based on the fluctuation range of the differential cumulative power spectrum of the intermediate frequency signal, the mean and variance of the differential cumulative power spectrum are obtained, and based on the mean and the variance, the threshold value of the differential cumulative power spectrum is determined.

[0017] Optionally, the obtaining characteristic parameters of the interference signal by using the differential cumulative power spectrum includes:

[0018] Pre-collecting parameters and types of several existing interference signals, and establishing differential cumulative power spectrum models of the existing interference signals based on the parameters and types of the respective existing interference signals to obtain a model database;

[0019] The characteristic parameters of the differential cumulative power spectrum are extracted, and the characteristic parameters of the interference signal are obtained by using the characteristic parameters of the differential cumulative power spectrum and the differential cumulative power spectrum models of each of the existing interference signals.

[0020] Optionally, if the pre-established differential cumulative power spectrum models of the existing interference signals do not match the type of the interference signal, after obtaining the characteristic parameters of the interference signal, the method further includes:

[0021] Determining the type of the interference signal based on the characteristic parameters of the interference signal;

[0022] Based on the characteristic parameters of the interference signal and the type of the interference signal, a differential cumulative power spectrum model of the interference signal is constructed, and the model database is updated.

[0023] Optionally, the characteristic parameters of the interference signal include at least the interference signal frequency and the number of interference signals, and an adaptive notch filter is used to filter the intermediate frequency signal, and the notch frequency is set according to the characteristic parameters of the interference signal, and the intermediate frequency signal is filtered based on the notch frequency to obtain the target signal and the filtered signal, including:

[0024] Based on the number of interference signals, setting the number of the adaptive notch filters;

[0025] Based on the interference signal frequency, adjusting the initial frequency of the adaptive notch filter;

[0026] The intermediate frequency signal is filtered based on the initial notch frequencies of each of the adaptive notch filters to obtain a target signal and a filtered signal.

[0027] Optionally, evaluating whether the filtered signal is effective includes:

[0028] If the difference between the energy of the filtered signal and the energy of the standard GNSS signal is less than or equal to a preset energy threshold, the filtered signal is determined to be invalid; otherwise, the filtered signal is determined to be valid.

[0029] A second aspect of the present invention provides a GNSS signal interference monitoring and suppression system, the system comprising:

[0030] A receiver front-end preprocessing unit, used to obtain an intermediate frequency signal based on the received GNSS signal;

[0031] A DCSP interference warning unit is used to perform spectrum estimation on the intermediate frequency signal to obtain a differential cumulative power spectrum of the intermediate frequency signal; if the differential cumulative power spectrum of the intermediate frequency signal exceeds a preset differential cumulative power spectrum threshold value, an interference warning signal is issued;

[0032] A DCSP interference identification unit, configured to obtain characteristic parameters of an interference signal using the differential cumulative power spectrum according to the warning information of the DCSP interference warning module;

[0033] A parameter matching notch filter unit, used for setting a notch frequency according to characteristic parameters of the interference signal, filtering the intermediate frequency signal based on the notch frequency, and obtaining a target signal and a filtered signal;

[0034] The filter evaluation and optimization unit is used to evaluate the filtered signal according to the energy of the signal. When the filtered signal is evaluated to be invalid, the characteristic parameters of the interference signal are re-estimated, the notch frequency is adjusted, and the intermediate frequency signal is re-filtered until the filtered signal obtained by evaluation is valid; when the filtered signal is evaluated to be valid, the target signal is output.

[0035] A third aspect of the present invention provides a single-antenna anti-interference receiver, on which a GNSS signal interference monitoring and suppression program is stored. When the GNSS signal interference monitoring and suppression program is executed by a processor, any step of the above-mentioned GNSS signal interference monitoring and suppression method is implemented.

[0036] A fourth aspect of the present invention provides a computer-readable storage medium, on which a GNSS signal interference monitoring and suppression program is stored. When the GNSS signal interference monitoring and suppression program is executed by a processor, the steps of any one of the above-mentioned GNSS signal interference monitoring and suppression methods are implemented.

[0037] Compared with the prior art, the beneficial effects of this solution are as follows:

[0038] The present invention obtains an intermediate frequency signal based on a received GNSS signal, thereby obtaining a differential cumulative power spectrum of the intermediate frequency signal through spectrum estimation; based on the differential cumulative power spectrum of the intermediate frequency signal, interference detection is performed on the intermediate frequency signal, and the type of the interference signal is identified according to characteristic parameters of the interference signal and a notch frequency is set to filter the intermediate frequency signal to obtain a target signal and a filtered signal; then the filtered signal is evaluated according to the energy of the signal, and when the filtered signal is evaluated to be invalid, the notch frequency is adjusted in time, and then filtering is performed again to obtain an effectively filtered target signal.

[0039] It can be seen that the present invention can not only issue a warning prompt when an interference signal is detected, but also automatically identify the type of interference. When it is detected that the filtering effect is invalid, it can also judge the change in the type of interference signal, so as to adjust the filtering frequency in time, and realize dynamic detection and identification of interference signals in the environment and adjustment of the notch frequency to ensure that the interference signal is effectively detected and suppressed, thereby improving the anti-interference performance of the single-antenna GNSS receiver in various interference environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0041] Figure 1 It is a schematic diagram of the structure of the interference monitoring and suppression system of the GNSS signal of the present invention;

[0042] Figure 2 It is a flow chart of the interference monitoring and suppression method of GNSS signals of the present invention;

[0043] Figure 3 Schematic diagram of differential power spectrum under different interference environments of the present invention;

[0044] Figure 4 It is a schematic diagram of the influence of the smoothing factor and the forgetting factor on the continuous wave filtering effect of the present invention. DETAILED DESCRIPTION

[0045] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0046] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0047] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0048] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0049] As used in this specification and the appended claims, the term "if" may be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if [described condition or event] is detected" may be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0050] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0052] At present, in terms of anti-interference of single-antenna GNSS receivers, methods such as Robust interference mitigation (RIM), including time domain complex signal processing, frequency domain complex signal processing, time domain pulse blanking and frequency domain pulse blanking, can effectively suppress GNSS interference signals. Their performance is usually affected by the hardware parameters of the receiver front end, and the accuracy requirements of ADC and sampler are relatively high. However, the notch filter can quickly attenuate the input signal at a specified frequency point. For narrowband interference with a small frequency fluctuation range, it can assist the current tracking frequency based on the tracking results of the previous moment, reduce the error between the notch frequency and the real interference frequency, thereby improving the accuracy of filtering out interference signals and reducing the loss of useful signals; for narrowband interference with a large frequency fluctuation range, the notch filter needs to quickly adjust the tracking step size to ensure stable tracking of the interference signal. At the same time, the number of interference signals also determines the number of notches. It can be seen that the performance parameter settings of the notch filter to achieve satisfactory interference filtering performance are also different for different characteristics of different interference signals. However, notch filters usually use fixed performance parameters, and this type of notch technology is often only applicable to specific types of interference signals.

[0053] However, the types of interference signals in actual environments are often unknown and change randomly. There is still a lack of research on how to enable a single-antenna receiver to autonomously monitor the interference environment in an unknown interference environment and suppress the impact of interference.

[0054] Aiming at the problem of poor anti-interference ability of single-antenna GNSS receiver in the prior art, the present invention proposes a method and system for monitoring and suppressing interference of GNSS signals based on joint spectrum value difference and notch technology, so as to conduct exploratory research on the application in the field of GNSS anti-interference. The present invention mainly takes the intermediate frequency signal collected by the front end of the GNSS receiver as the object, detects the interference signal and identifies the interference type according to the differential power spectrum value (DCSP) of the intermediate frequency signal, integrates the identification information to dynamically adjust the notch filter parameters, filters the interference signal in the intermediate frequency signal, thereby suppressing the interference signal, and realizes a complete and independent anti-interference solution integrating GNSS interference detection, identification and adaptive suppression by evaluating the notch effect and dynamically monitoring the change of the interference environment. Without changing the internal structure of the receiver, the single antenna receiver can realize the dynamic perception and suppression of the interference signal through simple modules and small amount of calculation, which can greatly improve the anti-interference ability of the single antenna GNSS receiver. In addition, the filtered signal is input to the receiver correlator for subsequent signal processing, ensuring the functional independence of the receiver front end, interference detection module and receiver correlator to avoid mutual interference between the various functional modules and ensure the accuracy and stability of the system.

[0055] Exemplary Methods

[0056] An embodiment of the present invention provides a method for interference monitoring and suppression of GNSS signals, which is deployed on a single-antenna receiver, but is not limited to this. It can also be other electronic devices such as mobile phones, smart wearable products, navigators, computers, servers, single-chip microcomputers and microcontrollers that can receive GNSS signals. It is aimed at the situation of anti-interference detection, identification and suppression of single-antenna GNSS receivers.

[0057] The structure of the single antenna receiver of this embodiment is as follows Figure 1 As shown, it includes an antenna module, an interference monitoring and suppression system for GNSS signals and a power supply, and the interference monitoring and suppression system for GNSS signals includes a receiver front-end preprocessing unit, a switch module, a DCSP interference warning unit, a DCSP interference identification unit, a parameter matching notch filter unit, a filter evaluation and optimization unit and a receiver correlator, wherein the receiver front-end preprocessing unit has an input end and an output end, the switch module has three input ends and two output ends, the DSCP interference warning module has an input end and two output ends, the DCSP interference identification unit has an input end and an output end, the parameter matching notch filter unit has two input ends and two output ends, the filter evaluation and optimization unit module has one input end and two output ends, and the receiver correlator has two input ends. The signals sent by the navigation satellite and the jammer are received by the receiver front-end preprocessing unit. The receiver front-end preprocessing unit processes the received signals to obtain intermediate frequency signals. The intermediate frequency signal data is input to the first input end of the switch module. The first output end of the switch module is connected to the input end of the DCSP interference warning unit. The first output end of the DCSP interference warning unit outputs a non-interference alarm and original intermediate frequency data, and inputs them to the first input end of the receiver correlator; the second output end of the DCSP interference warning unit outputs interference warning information, and inputs it to the input end of the DCSP interference identification unit. The output end of the DCSP interference warning unit outputs interference type and interference signal The characteristic parameters are obtained and input into the first input end of the parameter matching notch filter unit. The first output end of the parameter matching notch filter unit outputs the filtering data and inputs into the second input end of the receiver correlator. The second output end of the parameter matching notch filter unit outputs the signal at the notch frequency, that is, the filtered signal, and inputs into the input end of the filtering evaluation and optimization unit. The first output end of the filtering evaluation and optimization unit outputs the invalid filtering and inputs into the second input end of the switch module. The second output end of the filtering evaluation and optimization unit outputs the valid filtering and inputs into the third input end of the switch module. Meanwhile, the third input end of the switch module is connected to the second input end of the parameter matching notch filter unit.

[0058] The receiver front-end preprocessing unit is used to obtain an intermediate frequency signal based on the received GNSS signal;

[0059] The DCSP interference warning unit is used to perform spectrum estimation on the intermediate frequency signal to obtain the differential cumulative power spectrum of the intermediate frequency signal; if the differential cumulative power spectrum of the intermediate frequency signal exceeds a preset differential cumulative power spectrum threshold value, an interference warning signal is issued;

[0060] A DCSP interference identification unit is used to obtain characteristic parameters of interference signals using differential cumulative power spectrum according to the warning information of the DCSP interference warning module;

[0061] A parameter matching notch filter unit is used to set a notch frequency according to the characteristic parameters of the identified interference signal, and filter the intermediate frequency signal based on the notch frequency to obtain a target signal and a filtered signal;

[0062] The filter evaluation and optimization unit is used to evaluate the filtered signal according to the energy of the signal. When the evaluation of the filtered signal is invalid, the notch frequency is readjusted and the filtering process is repeated to obtain an updated target signal and output the updated target signal; when the evaluation of the filtered signal is valid, the target signal is output.

[0063] The single-antenna receiver of this embodiment can effectively detect interference signals and identify the interference type, integrate the identification information to dynamically adjust the notch filter parameters, filter the interference signal in the intermediate frequency signal, thereby suppressing the interference signal, and dynamically monitor the change of the interference environment by evaluating the notch effect. It can be seen that the single-antenna receiver can realize the dynamic perception and suppression of interference signals by the single-antenna receiver through simple modules and small amount of calculation without changing the internal structure of the receiver, which can greatly improve the anti-interference ability of the single-antenna GNSS receiver.

[0064] The interference monitoring and suppression system for GNSS signals in the above-mentioned single antenna receiver is used to implement the interference monitoring and suppression method for GNSS signals. The flowchart of the method is as follows: Figure 2 As shown, it mainly includes the following steps:

[0065] Step S100: obtaining an intermediate frequency signal based on the received GNSS signal.

[0066] Specifically, the GNSS signal transmitted by the navigation satellite and the interference signal transmitted by the jammer are received by the antenna and processed by the receiver front end to obtain the intermediate frequency data. The intermediate frequency data is input to the switch module, and the switch module is initially set to the invalid switch closed and the valid switch open state.

[0067] When the invalid switch of the switch module is closed and the valid switch is opened, the switch module inputs a null value to the parameter matching notch filter unit and simultaneously inputs an intermediate frequency signal to the DCSP interference warning module.

[0068] Step S200: performing spectrum estimation on the intermediate frequency signal to obtain a differential cumulative power spectrum of the intermediate frequency signal.

[0069] Step S300: If the differential cumulative power spectrum of the intermediate frequency signal exceeds a preset differential cumulative power spectrum threshold, an interference warning signal is issued, and characteristic parameters of the interference signal are obtained using the differential cumulative power spectrum.

[0070] Specifically, the DCSP interference warning module compares the DCSP array of the intermediate frequency signal with the preset threshold. If the DCSP is lower than the threshold level, the interference alarm is not triggered, and the intermediate frequency signal is directly input into the receiver correlator module for correlation processing. If the DCSP value exceeds the preset threshold, that is, the interference signal is detected, the interference alarm is triggered, and the intermediate frequency signal and the DCSP array are input into the DCSP interference identification module for processing. That is, based on the differential cumulative power spectrum of the intermediate frequency signal and the preset differential cumulative power spectrum threshold value, it is determined whether there is interference. If the differential cumulative power spectrum of the intermediate frequency signal exceeds the preset differential cumulative power spectrum threshold value, it is determined that there is interference and an interference warning signal is issued, and then the differential cumulative power spectrum is used to obtain the characteristic parameters of the interference signal.

[0071] Step S400: setting a notch frequency according to characteristic parameters of the interference signal, filtering the intermediate frequency signal based on the notch frequency, and obtaining a target signal and a filtered signal.

[0072] Specifically, the initial frequency of the notch is set to be the same as the frequency of the interference signal according to the characteristic parameters of the interference signal, so as to filter out the frequency component corresponding to the interference signal, and obtain the filtered intermediate frequency signal (i.e., the target signal), and the signal corresponding to the set notch frequency (i.e., the filtered signal). It should be stated that in the actual use of the receiver, the current notch frequency may be updated for this use, or it may be the effective notch frequency corresponding to the last filtering, which may be invalid for this filtering process. It needs to be evaluated in the filtering effect evaluation stage, and the notch frequency needs to be updated if necessary.

[0073] Step S500: Evaluate the filtered signal according to the energy of the signal. When the filtered signal is evaluated to be invalid, re-identify the characteristic parameters of the interference signal by steps S200 and S300, adjust the notch frequency according to the updated characteristic parameters of the interference signal, and re-filter the intermediate frequency signal until the filtered signal obtained by evaluation is valid; when the filtered signal is evaluated to be valid, output the target signal.

[0074] This embodiment can not only issue a warning prompt when an interference signal is detected, but also automatically identify the type of interference. When it is detected that the filtering effect is invalid, it can also judge the change in the type of interference signal, so as to adjust the filtering frequency in time, and realize dynamic detection and identification of interference signals in the environment and adjustment of the notch frequency to ensure that the interference signal is effectively detected and adaptively suppressed, thereby improving the anti-interference performance of the single-antenna GNSS receiver in various interference environments.

[0075] In one implementation, performing spectrum estimation on the intermediate frequency signal of step S200 to obtain a differential cumulative power spectrum of the intermediate frequency signal specifically includes:

[0076] Step S210: acquiring the power spectrum density of the intermediate frequency signal, integrating and normalizing the power spectrum density to obtain a normalized cumulative spectrum density;

[0077] Specifically, the DCSP interference warning module estimates the spectral value of the intermediate frequency data, normalizes it, and performs differential processing to obtain the DCSP value of the intermediate frequency data. The DSCP value estimation process is as follows:

[0078] The signal r(t) received by the receiver antenna at time t is actually the satellite signal s i (t), the superposition effect of thermal noise η(t) and potential interference signal J(t) can be expressed by formula (1), that is:

[0079]

[0080] Where L is the total number of visible satellites, and δ(t) is the interference flag. δ(t) = 0 means that the system is not affected by interference, and δ(t) = 1 means that the system is affected by interference signals. The process of the antenna and the front-end receiver processing the received signal to obtain intermediate frequency data is approximately a linear system, and its transfer function is expressed as h(t).

[0081] To estimate the power spectrum density of the received signal, linear estimation methods such as autocorrelation estimation, autocovariance method and periodogram method, or nonlinear estimation methods such as maximum likelihood method and maximum entropy method can be used. Taking the periodogram method as an example, the signal The power spectrum density S(f) is expressed by formula (2), that is:

[0082]

[0083] in refers to Fourier transform, N is the total length of the data sequence used for power spectrum estimation, L is the total number of visible satellites in the received signal, and n represents the time series.

[0084] Similarly, the power spectrum density J(f) and transfer function H(f) of the interference signal are estimated. The noise signal is a stationary signal, and the power spectrum can be represented by the constant N0. Therefore, the power spectrum density PSD(f) of the intermediate frequency data is expressed by formula (3), that is:

[0085] PSD(f)=S(f)|H(f)| 2 +N0|H(f)| 2 +δJ(f)|H(f)| 2 (3)

[0086] Integrate and normalize the signal PSD to obtain the normalized cumulative spectral density CSP norm (f), expressed by formula (4), namely:

[0087]

[0088] Among them, f s Refers to the sampling frequency of the receiver front end.

[0089] Step S220: obtaining a differential cumulative power spectrum of the intermediate frequency signal based on the normalized cumulative spectral density and a preset cumulative spectral density reference value.

[0090] Specifically, based on the cumulative spectral density of the normal intermediate frequency signal, the reference value CSP is defined as ref (f) is expressed by formula (5), namely:

[0091]

[0092] Since the defined reference value CSP ref (f) is only related to the receiver front-end characteristic H(f) and is not affected by the signal size. Therefore, the differential cumulative power spectrum DCSP(f) is expressed by formula (6), that is:

[0093] DCSP(f)=CSP norm (f)-CSP ref (f) (6)

[0094] In one implementation, the step of determining the differential cumulative power spectrum threshold value in step S300 includes:

[0095] Step S310: acquiring historical data of the GNSS signal, and obtaining a fluctuation range of a differential cumulative power spectrum of the intermediate frequency signal based on the historical data of the GNSS signal;

[0096] Specifically, the normal historical GNSS signal data of the receiver on different dates and at different times are counted to ensure that the fluctuation range of the differential cumulative power spectrum of the intermediate frequency signal obtained can more comprehensively and reasonably represent the laws and characteristics of the historical normal GNSS signal data, so as to lay a good foundation for the subsequent accurate detection of interference signals.

[0097] Step S320: based on the fluctuation range of the differential cumulative power spectrum of the intermediate frequency signal, obtain the mean and variance of the differential cumulative power spectrum, and determine the threshold value of the differential cumulative power spectrum based on the mean and variance.

[0098] Specifically, if the differential cumulative power spectrum of the intermediate frequency signal exceeds a preset differential cumulative power spectrum threshold, an interference warning signal is issued. The interference decision algorithm is as follows:

[0099] Since the satellite signal power is much smaller than the base noise, the influence of the satellite signal power spectrum is ignored. Then, the differential power spectrum DCSP(f) of the normal signal is expressed by formula (7), that is:

[0100]

[0101] It can be seen that in a non-interference environment, the differential power spectrum DCSP(f) of the normal signal fluctuates around 0; in an interference environment, the power level of the interference signal is equivalent to or even higher than the noise level and cannot be ignored. Therefore, considering the power of the interference signal, the differential power spectrum DCSP(f) of the interfered intermediate frequency signal is expressed by formula (8), that is:

[0102]

[0103] It can be seen that the differential power spectrum DCSP(f) of the interfered intermediate frequency signal is much larger than 0.

[0104] Taking into account the characteristics of the differential power spectrum DCSP(f) of the intermediate frequency signal with and without interference, this embodiment uses hypothesis testing to obtain an interference warning criterion based on DCSP, which is expressed by formula (9), that is:

[0105]

[0106] Among them, H0 represents the null hypothesis, indicating that the received signal is not affected by the interference signal, and the DCSP interference warning module does not issue an interference alarm; H1 represents the alternative hypothesis, indicating that there is an interference signal in the received signal, and the DCSP interference warning module issues an interference alarm.

[0107] According to the normal historical GNSS data received by the single antenna receiver, the fluctuation range of the differential power spectrum DCSP(f) of the intermediate frequency signal of the normal signal is obtained by statistics, and the threshold value λ of the differential cumulative power spectrum is determined according to the mean and variance of the differential power spectrum DCSP(f) th (f), by obtaining the differential power spectrum DCSP(f) of the intermediate frequency signal in the current environment and the threshold value λ th (f) Make a comparison and make an interference decision. The decision rule is expressed by formula (10), that is:

[0108]

[0109] It can be seen that if the differential power spectrum DCSP(f) of the intermediate frequency signal in the current environment is less than or equal to the threshold value λ th (f), it means that the received signal is not affected by the interference signal, and the DCSP interference warning module does not issue an interference alarm; if the differential power spectrum DCSP(f) of the intermediate frequency signal in the current environment is greater than the threshold value λ th (f), it means that there is an interference signal in the received signal, and the DCSP interference warning module issues an interference alarm to remind the staff that there is interference in the current environment, and further determines the type of interference signal and adjusts the visible wave frequency of the parameter matching notch filter unit.

[0110] In one implementation, in step S300, the characteristic parameters of the interference signal are obtained by using the differential cumulative power spectrum, which specifically includes:

[0111] Step S330: pre-collecting parameters and types of several existing interference signals, and based on the parameters and types of each existing interference signal, respectively establishing differential cumulative power spectrum models of the existing interference signals to obtain a model database;

[0112] Specifically, known interference signals are collected in advance. It should be noted that the known interference signals here refer to several common interference signals, such as continuous wave, multi-frequency continuous wave and swept frequency wave interference, etc. The characteristic parameters of different types of existing interference signals are used to establish differential cumulative power spectrum models of various types of interference signals in the interference identification module according to the parameters and types of the interference signals, and a model database is obtained.

[0113] Step S340: extract characteristic parameters of the differential cumulative power spectrum, and use the characteristic parameters of the differential cumulative power spectrum and the differential cumulative power spectrum models of each existing interference signal to obtain the characteristic parameters of the interference signal.

[0114] Specifically, since the differential power spectra DCSP(f) of different interference signals have different characteristics at fixed frequencies, the characteristic parameters of the differential power spectrum DCSP(f) of the intermediate frequency signal input to the DCSP interference identification unit can be compared with the differential cumulative power spectrum models of each existing interference signal to obtain the type and characteristic parameters of the interference signal in the current environment.

[0115] It should be stated that the characteristic parameters used in constructing the differential cumulative power spectrum model of the existing interference signal refer to the characteristic parameters of the common type of interference signal obtained based on historical data. This type of interference signal is common and often represents an interval composed of some continuous or discontinuous point values. The type and characteristic parameters of the interference signal in the current environment obtained by comparing the characteristic parameters of the differential power spectrum DCSP(f) of the intermediate frequency signal with the constructed model refer to the characteristic parameters of the interference signal included in the intermediate frequency signal in the current environment, which is a value of the characteristic parameters of this type of interference signal and is included in the above-mentioned interval.

[0116] For example, Figure 3 The DCSP models of several common interference signals are shown in Figure 1. B represents the single-side bandwidth of the receiver front end, and B J represents the interference bandwidth, f J represents interference power, the horizontal axis represents frequency, and the vertical axis represents the differential power spectrum of various interference signals.

[0117] First, the following criteria are used to identify continuous wave interference, multi-frequency continuous wave interference and swept frequency wave interference respectively. The specific criteria are as follows:

[0118] When the interference signal is a continuous wave interference, f mx -f mn =Δf, Where Δf is the frequency interval, f mx The interference frequency corresponding to the maximum value of its DCSP; f mn The interference frequency corresponding to the minimum value of its DCSP, f s is the sampling frequency, N is the number of sampling points;

[0119] When the interference signal is a swept frequency wave interference, f mx -f mn >Δf, And B J =(f mx -f mn ) / 2<B, where is DCSP(f) in [f mx , f mn ] first-order differential within the frequency band, B represents the unilateral bandwidth of the receiver front end, B J Indicates the interference bandwidth.

[0120] When the interference signal is a swept frequency wave interference, f mx -f mn >2B>Δf, And B J ≥(f mx -f mn ) / 2>B.

[0121] When the interference signal is a multi-frequency continuous wave interference, f mx -f mn >Δf,f mx,i -f mn，i =Δf, where f mx，i for [f mn , f mx ](or [f mx , f mn ]) The interference frequency corresponding to the DCSP maximum value in the frequency band, f mn,i for [f mn , f mx ](or [f mx , f mn ]) The interference frequency corresponding to the DCSP minimum value in the frequency band.

[0122] Then, the interference type identification is achieved by comparing the extracted DCSP characteristic parameters of the GNSS signal with the interference signal DCSP model in the database of the DCSP interference identification unit. It can be seen that the characteristic parameters involved in this implementation include f mx 、f mn ;, f mx，i 、f mn，i and wait.

[0123] from Figure 3 It can be seen that the differential power spectra of swept wave, continuous wave and multi-frequency continuous wave within the 2B bandwidth have obvious differences and are relatively easy to identify.

[0124] In one implementation, if the pre-established differential cumulative power spectrum models of the existing interference signals do not match the type of the interference signal, after obtaining the characteristic parameters of the interference signal, the method further includes:

[0125] Based on the characteristic parameters of the interference signal, the type of the interference signal is determined; based on the characteristic parameters of the interference signal and the type of the interference signal, a differential cumulative power spectrum model of the interference signal is constructed, and the model database is updated.

[0126] It can be seen that if the differential cumulative power spectrum model corresponding to the interference signal type under the current environment is not pre-established, then the characteristic parameters of the interference signal under the current environment are used to identify the type to which it belongs, and then the differential cumulative power spectrum model of the interference signal is constructed using the type and characteristic parameters, so as to update and expand the model database pre-established by the differential cumulative power spectrum models of several existing interference signals, which is conducive to improving the efficiency of identifying interference signals in the future. Therefore, the present invention adopts the DCSP model to identify interference signals, and by expanding the model database, it can be applied to more complex interference environments and has strong scalability.

[0127] In one implementation, in step S400, the characteristic parameters of the interference signal include at least the frequency of the interference signal and the number of the interference signal, and an adaptive notch filter is used to filter the intermediate frequency signal, the notch frequency is set according to the characteristic parameters of the interference signal, and the intermediate frequency signal is filtered based on the notch frequency to obtain the target signal and the filtered signal, specifically including:

[0128] Step S410: setting the number of adaptive notch filters based on the number of interference signals;

[0129] Step S420: adjusting the initial frequency of the adaptive notch filter based on the interference signal frequency;

[0130] Step S430: filtering the intermediate frequency signal based on the initial notch frequencies of each adaptive notch filter to obtain a target signal and a filtered signal.

[0131] Specifically, the parameter matching notch filter unit sets the corresponding processing parameters and quantity of the notch filter according to the identified interference type and characteristic parameters of the interference signal, and processes the original intermediate frequency signal data to obtain the filtered target signal, and inputs the filtered signal obtained by the filtering process into the filtering evaluation and optimization unit. Among them, the parameter matching notch filter unit includes an adaptive wave limiter, and uses an adaptive notch filter to filter the interference signal. The transfer function of the adaptive notch filter is shown in formula (11), that is:

[0132]

[0133] Where z is the Z transform operator, r determines the notch filter bandwidth, and its value range is generally 0.95 to 1. The coefficient α is the cosine value of the notch frequency, and the unit of the notch frequency is radians. When the sampling frequency is f s When the notch frequency f stop =f s arccos(α) / 2π, in Hz. Therefore, the frequency of the interference signal can be adaptively tracked by updating α in the transfer function of the notch filter. Assume that the updated value of α obtained at time n of the time series is recorded as The specific update process of α is shown in formula (12), that is:

[0134]

[0135] Among them, x[n] = r[n] / D(z) is the intermediate parameter of the notch filter, that is, the signal component corresponding to the notch frequency; c[n] is the smoothed notch frequency f stop The signal component at; d[n] represents the notch frequency f stop The energy of the signal component at , that is, the energy of the filtered signal filtered by the notch filter; n is the time series. γ is the forgetting factor, and λ is the smoothing factor. Since different forgetting factors and smoothing factors have different tracking and filtering effects on interference signals, they will also affect the final interference suppression effect.

[0136] For example, Figure 4 The figure shows the signal-to-noise ratio of the target signal obtained by setting different values ​​for the parameters γ and λ in the filtering process under the continuous wave interference environment. Figure 4 It can be seen that the closer the parameters γ and λ are to 1, the higher the signal-to-noise ratio of the target signal obtained after filtering the continuous wave, that is, the better the filtering effect of the notch filter. Similarly, other types of interference can also be modeled and analyzed. By adjusting the values ​​of the parameters γ and λ, the parameter range corresponding to the optimal filtering effect can be obtained.

[0137] Therefore, according to the identified interference type and parameters, the adaptive filter is set with corresponding parameters that match the interference type: according to the frequency of the interference signal, the initial value of the notch frequency of the notch filter is set; according to the number of interference signals, the number of notches is set; according to the influence of the forgetting factor and the smoothing factor on the signal quality after filtering, the forgetting factor and the smoothing factor parameters with the best filtering effect are selected. In this embodiment, the signal-to-noise ratio is used to evaluate the filtering effect. As other preferred implementations, other indicators can also be selected for evaluation.

[0138] In one embodiment, in step S500, when the evaluation of the filtered signal is invalid, the interference signal characteristic parameters are identified again through step S300, and the notch frequency is adjusted, and the intermediate frequency signal is filtered again until the evaluation of the obtained filtered signal is valid; when the evaluation of the filtered signal is valid, the target signal is output, which specifically includes:

[0139] If the difference between the energy of the filtered signal and the energy of the standard GNSS signal is less than or equal to the preset energy threshold, the notch frequency is adjusted in real time, and the filtering process is repeated on the intermediate frequency signal before the first filtering to obtain an updated target signal. Then, based on the updated target signal, it is evaluated whether the filtering is effective. If not, the notch frequency is repeatedly adjusted and the filtering process is performed until the evaluation is effective, and then the updated target signal is output. If the difference between the energy of the filtered signal and the energy of the standard GNSS signal is greater than the preset energy threshold, the target signal is output.

[0140] Specifically, the frequency of the filtered signal is used to test whether the filtering process is effective. The evaluation algorithm is as follows:

[0141] First, extract the intermediate parameter d[n] of the notch filter in formula (12), which represents the notch frequency f stop The signal energy at the notch filter is the energy of the signal removed by the notch filter.

[0142] When f stop When there is an interference signal, the filtered signal is the interference signal, the notch filter successfully filters out the interference signal, and the filtered signal is input into the correlator for processing, while the notch filter continues to track and filter out the interference signal;

[0143] When f stop When there is no interference signal, the filtered signal is a normal signal. At this time, the filtering effect of the notch filter is invalid, the useful signal is filtered out, and the original intermediate frequency signal is input to the correlator for processing and solving, which means that the interference environment has changed. The interference warning and identification module re-detects and identifies the interference of the intermediate frequency signal and resets the notch filter parameters.

[0144] Then, according to the empirical data, the normal signal is obtained at f stop The standard energy E ref , the filtering effect is evaluated by hypothesis testing, and the corresponding evaluation criteria are shown in formula (13), that is:

[0145]

[0146] It can be seen that when the notch filter effectively filters out interference, since the power of the interference signal is much greater than the navigation signal, d[n]>>E ref When the notch filter is ineffective, the energy level of the filtered normal signal is equivalent to the energy standard, that is, d[n]≈E ref .

[0147] When the filter evaluation and optimization unit determines that the filter is effective, the switch module keeps the invalid switch disconnected and the effective switch closed, and the data after the notch filter is input into the receiver correlator for subsequent processing. At the same time, the intermediate frequency data at the next moment is directly input into the parameter matching notch filter unit by the switch module; when the filter evaluation and optimization unit determines that the filter is invalid, it indicates that the interference environment has changed, the switch module switches to the invalid switch closed, the effective switch disconnected, and the parameter matching notch filter unit inputs the original intermediate frequency data into the receiver correlator for processing. At the same time, after the intermediate frequency data readjusts the notch frequency at the next moment, the filtering process is repeated to obtain the updated target signal and output the updated target signal to re-monitor and identify the interference, so as to ensure the effective suppression of the interference signal in the receiver. The parameters of the notch filter are adjusted dynamically and targeted by the interference type, which reduces the loss of normal signals, avoids the problem that the traditional filter can only deal with a single interference, and improves the anti-interference performance of the notch filter; at the same time, the evaluation and optimization unit evaluates and feedbacks the filtering effect, realizes the dynamic monitoring of the GNSS interference environment and the notch interference adjustment, which is more practical.

[0148] In summary, the present invention can not only issue an early warning prompt when an interference signal is detected, but also automatically identify the type of interference, and can also judge the change in the type of interference signal when the filtering effect is detected to be invalid, so as to timely adjust the filtering frequency, realize dynamic detection and identification of interference signals in the environment, and adjust the notch frequency to ensure that the interference signal is effectively detected and suppressed, thereby improving the anti-interference performance of the single-antenna GNSS receiver to various interference environments. It can be seen that the present invention adopts a simple differential spectrum value combined with a notch device, which can realize the detection, identification and adaptive suppression of various interference environments with the advantages of lower computational complexity and low hardware cost, and has important engineering significance and application value.

[0149] In addition, the system corresponding to the present invention only needs to perform analog-to-digital conversion on the received GNSS signal at the front end, and then various processing functions can be realized between the intermediate frequency and the baseband. There is no need to change the internal structure of the receiver signal processing. The engineering implementation is simple and is not affected by the navigation satellite signal structure and parameters. It can be applied to various satellite navigation systems such as GPS and Beidou, and has strong versatility.

[0150] Corresponding to the above-mentioned GNSS signal interference monitoring and suppression method, an embodiment of the present invention further provides a single-antenna anti-interference receiver, on which a GNSS signal interference monitoring and suppression program is stored. When the GNSS signal interference monitoring and suppression program is executed by a processor, the steps of the above-mentioned GNSS signal interference monitoring and suppression method are implemented.

[0151] An embodiment of the present invention also provides a computer-readable storage medium, on which a GNSS signal interference monitoring and suppression program is stored. When the GNSS signal interference monitoring and suppression program is executed by a processor, the steps of any one of the GNSS signal interference monitoring and suppression methods provided in the embodiment of the present invention are implemented.

[0152] It should be understood that the serial numbers of the steps in the above embodiments do not imply a sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0153] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the above-mentioned device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0154] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0155] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0156] In the embodiments provided by the present invention, it should be understood that the disclosed apparatus / terminal equipment and method can be implemented in other ways. For example, the apparatus / terminal equipment embodiments described above are only illustrative, for example, the division of the above modules or units is only a logical function division, and in actual implementation, other division methods can be used, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0157] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it should be understood by those skilled in the art that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features therein may be replaced by equivalents. However, these modifications or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A method for monitoring and suppressing interference of GNSS signals, characterized in that: The following steps are involved: Based on the received GNSS signal, an intermediate frequency signal is obtained; Performing spectrum estimation on the intermediate frequency signal to obtain a differential cumulative power spectrum of the intermediate frequency signal; If the differential cumulative power spectrum of the intermediate frequency signal exceeds a preset differential cumulative power spectrum threshold, an interference warning signal is issued, and characteristic parameters of the interference signal are obtained using the differential cumulative power spectrum; Setting a notch frequency according to characteristic parameters of the interference signal, filtering the intermediate frequency signal based on the notch frequency, and obtaining a target signal and a filtered signal; The filtered signal is evaluated according to the energy of the signal. When the filtered signal is evaluated to be invalid, the characteristic parameters of the interference signal are re-identified, the notch frequency is adjusted, and the intermediate frequency signal is re-filtered until the filtered signal obtained by evaluation is valid; when the filtered signal is evaluated to be valid, the target signal is output.

2. The interference monitoring and suppression method of GNSS signals according to claim 1, characterized in that: The performing spectrum estimation on the intermediate frequency signal to obtain a differential cumulative power spectrum of the intermediate frequency signal includes: Acquiring the power spectral density of the intermediate frequency signal, integrating and normalizing the power spectral density to obtain a normalized cumulative spectral density; Based on the normalized cumulative spectral density and a preset cumulative spectral density reference value, a differential cumulative power spectrum of the intermediate frequency signal is obtained.

3. The interference monitoring and suppression method of GNSS signals according to claim 1, characterized in that: The step of determining the differential cumulative power spectrum threshold value comprises: Acquire historical data of the GNSS signal, and based on the historical data of the GNSS signal, obtain a fluctuation range of the differential cumulative power spectrum of the intermediate frequency signal; Based on the fluctuation range of the differential cumulative power spectrum of the intermediate frequency signal, the mean and variance of the differential cumulative power spectrum are obtained, and based on the mean and the variance, the threshold value of the differential cumulative power spectrum is determined.

4. The GNSS signal interference monitoring and suppression method according to claim 1, characterized in that: The step of obtaining characteristic parameters of the interference signal by using the differential cumulative power spectrum includes: Pre-collecting parameters and types of several existing interference signals, and establishing differential cumulative power spectrum models of the existing interference signals based on the parameters and types of the respective existing interference signals to obtain a model database; The characteristic parameters of the differential cumulative power spectrum are extracted, and the characteristic parameters of the interference signal are obtained by using the characteristic parameters of the differential cumulative power spectrum and the differential cumulative power spectrum models of each of the existing interference signals.

5. The interference monitoring and suppression method of GNSS signals according to claim 4, characterized in that: If the pre-established differential cumulative power spectrum models of the existing interference signals do not match the type of the interference signal, after obtaining the characteristic parameters of the interference signal, the method further includes: Determining the type of the interference signal based on the characteristic parameters of the interference signal; Based on the characteristic parameters of the interference signal and the type of the interference signal, a differential cumulative power spectrum model of the interference signal is constructed, and the model database is updated.

6. The interference monitoring and suppression method of GNSS signals according to claim 1, characterized in that: The characteristic parameters of the interference signal at least include the interference signal frequency and the number of interference signals, and an adaptive notch filter is used to filter the intermediate frequency signal. The notch frequency is set according to the characteristic parameters of the interference signal, and the intermediate frequency signal is filtered based on the notch frequency to obtain the target signal and the filtered signal, including: Based on the number of interference signals, setting the number of the adaptive notch filters; Based on the interference signal frequency, adjusting the initial frequency of the adaptive notch filter; The intermediate frequency signal is filtered based on the initial notch frequencies of each of the adaptive notch filters to obtain a target signal and a filtered signal.

7. The interference monitoring and suppression method of GNSS signals according to claim 1, characterized in that: Evaluating whether the filtered signal is effective, including: If the difference between the energy of the filtered signal and the energy of the standard GNSS signal is less than or equal to a preset energy threshold, the filtered signal is determined to be invalid; otherwise, the filtered signal is determined to be valid.

8. A GNSS signal interference monitoring and suppression system, characterized in that: The system comprises: A receiver front-end preprocessing unit, used to obtain an intermediate frequency signal based on the received GNSS signal; A DCSP interference warning unit is used to perform spectrum estimation on the intermediate frequency signal to obtain a differential cumulative power spectrum of the intermediate frequency signal; if the differential cumulative power spectrum of the intermediate frequency signal exceeds a preset differential cumulative power spectrum threshold value, an interference warning signal is issued; A DCSP interference identification unit, configured to obtain characteristic parameters of an interference signal using the differential cumulative power spectrum according to the warning information of the DCSP interference warning module; A parameter matching notch filter unit, used for setting a notch frequency according to characteristic parameters of the interference signal, filtering the intermediate frequency signal based on the notch frequency, and obtaining a target signal and a filtered signal; The filter evaluation and optimization unit is used to evaluate the filtered signal according to the energy of the signal. When the filtered signal is evaluated to be invalid, the characteristic parameters of the interference signal are re-identified, the notch frequency is adjusted, and the intermediate frequency signal is re-filtered until the filtered signal obtained by evaluation is valid; when the filtered signal is evaluated to be valid, the target signal is output.

9. A single-antenna anti-interference receiver, characterized in that: The single-antenna receiver stores a GNSS signal interference monitoring and suppression program, and when the GNSS signal interference monitoring and suppression program is executed by the processor, the steps of the GNSS signal interference monitoring and suppression method as described in any one of claims 1-7 are implemented.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a GNSS signal interference monitoring and suppression program, which, when executed by a processor, implements the steps of the GNSS signal interference monitoring and suppression method as described in any one of claims 1 to 7.

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