CN109991627B

CN109991627B - Narrow-band interference suppression method and module

Info

Publication number: CN109991627B
Application number: CN201711488234.5A
Authority: CN
Inventors: 徐敏; 翟晓东
Original assignee: COMNAV TECHNOLOGY Ltd
Current assignee: Shanghai Qintian Navigation Technology Co ltd
Priority date: 2017-12-29
Filing date: 2017-12-29
Publication date: 2022-06-07
Anticipated expiration: 2037-12-29
Also published as: CN109991627A

Abstract

The invention discloses a narrow-band interference suppression method and a module. The module comprises an interference suppression path for receiving the intermediate frequency signal, a bypass path for receiving the intermediate frequency signal, an interference control switch and a data gating switch. The interference suppression channel comprises a signal conversion module, an interference detection module and an interference processing module, wherein the signal conversion module converts an intermediate frequency signal from a time domain to a frequency domain signal, the interference detection module judges whether the frequency domain signal is interfered, acquires interference frequency point information under the condition of interference, controls the interference control switch to be closed and switches the data gating switch from the bypass channel to the interference suppression channel, the interference processing module performs interference suppression processing on the frequency domain signal according to the interference frequency point information to acquire an interference-eliminated intermediate frequency signal, and the intermediate frequency signal is output through the data gating switch; the interference detection module controls the interference control switch to be disconnected and the data gating switch to be communicated with the bypass channel under the condition of no interference. The module has low power consumption.

Description

Narrow-band interference suppression method and module

Technical Field

The invention relates to an interference suppression technology, in particular to a narrowband interference suppression method and a narrowband interference suppression module.

Background

Due to the inherent vulnerability of Global Navigation Satellite System (GNSS), the increasing complexity of electromagnetic environment and the great development of various satellite navigation interference technologies, the precision application of GNSS is a serious challenge. Of these challenges, narrowband interference is the most common and typical. Narrowband interference limits the performance of the receiver. To improve the performance of navigation receivers, narrowband interference suppression techniques are highly desirable.

The existing narrowband interference suppression technology is mainly divided into a time domain narrowband interference suppression technology and a frequency domain narrowband interference suppression technology based on FFT/IFFT. In comparison, the hardware implementation complexity of the time domain narrowband interference suppression technology is high, the convergence time is long, and the like. The core of the frequency domain narrowband interference suppression technology is that the frequency spectrum of a signal is estimated by using a digital signal processing technology, all frequency points are traversed in the frequency domain, interference frequency points exceeding a threshold are searched, and the interference frequency points exceeding the threshold are filtered, so that the purposes of effectively suppressing interference and retaining useful signals are achieved. Compared with the time domain narrowband interference suppression technology, the frequency domain narrowband interference suppression technology has no convergence problem, is insensitive to the interference type and has low sensitivity of interference detection.

In addition, in an actual application scenario, the narrow-band interference signal does not exist all the time, and if the input digital intermediate frequency signal is still subjected to series processing by the anti-interference module under the condition that the interference signal does not exist, the working power consumption of the receiver is inevitably increased.

Therefore, an improved scheme is urgently needed, the sensitivity of interference signal detection is improved, the on and off of the anti-interference module can be selected in a self-adaptive manner, and the control of the power consumption of the module is realized.

Disclosure of Invention

The problem to be solved by the invention is that the power consumption of the existing narrowband interference suppression module is large.

The invention solves the other problems of lower detection sensitivity and higher power consumption of the existing narrowband interference suppression module.

To solve at least one of the above problems, the present invention provides a narrowband interference suppression module. The module comprises an interference suppression path for receiving the intermediate frequency signal, a bypass path for receiving the intermediate frequency signal, an interference control switch and a data gating switch. The interference suppression channel comprises a signal conversion module, an interference detection module and an interference processing module, wherein the signal conversion module converts an intermediate frequency signal from a time domain to a frequency domain signal, the interference detection module judges whether the frequency domain signal is interfered, acquires interference frequency point information under the condition of interference, controls the interference control switch to be closed and switches the data gating switch from the bypass channel to the interference suppression channel, the interference processing module performs interference suppression processing on the frequency domain signal according to the interference frequency point information to acquire an interference-eliminated intermediate frequency signal, and the intermediate frequency signal is output through the data gating switch; the interference detection module controls the interference control switch to be disconnected and the data gating switch to be communicated with the bypass channel under the condition of no interference.

In another aspect of the present invention, a GNSS chip is disclosed, which includes the foregoing interference suppression module.

The invention also discloses an OEM board which is provided with the narrow-band interference suppression module.

In another aspect of the present invention, a receiver is further disclosed, and the receiver has the OEM board.

The invention also provides a narrowband interference suppression method, which is applied to a module with a bypass path and an interference suppression path and comprises the following steps: the bypass channel and the interference suppression channel both receive intermediate frequency signals; the interference suppression channel detects that the intermediate frequency signal has no interference, under the condition of no interference, the interference suppression channel is switched off and the intermediate frequency signal is controlled to be processed by the bypass channel, and under the condition of interference, the bypass channel is switched off and interference suppression processing is carried out to eliminate the interference.

Compared with the prior art, the invention has at least the following advantages:

the invention is provided with a bypass passage, an interference control switch, a data gating switch, a timing control switch and a timing module. The interference detection module outputs an enabling signal to control the interference control switch and the data gating switch so as to reduce the power consumption of all modules behind the interference detection module, and on the basis, after the timing module and the timing control switch are added, the power consumption of the whole interference suppression module starting from the overlapping windowing module is controlled based on the enabling signal output by the interference detection module, the timing time of the timing module and the corresponding control mode of the timing module, so that the power consumption is reduced. The combination of the two measures not only ensures high detection sensitivity and accuracy, but also can reduce the power consumption of the interference suppression module.

According to the method, the incoherent accumulation module is used for carrying out incoherent accumulation on the frequency domain signal (namely the output of the FFT module), so that the frequency domain peak value of the interference frequency point which is originally hidden in noise and has an unobvious peak value is prominent after the incoherent accumulation, and the accuracy and the sensitivity of the detection of the weak interference signal are improved.

In addition, in the noise estimation process, the threshold is increased along with the increase of the incoherent result and is reduced along with the decrease of the incoherent result, so that the adaptive noise estimation is realized, therefore, for the interference with constantly changing intensity and frequency, the threshold can be adaptively adjusted according to the change of the interference, and the accuracy and the sensitivity of judging the weak interference signal are improved.

Drawings

Fig. 1 is a schematic block diagram of a first embodiment of a narrowband interference suppression module of the present invention;

FIG. 2 highlights a process flow of a non-coherent accumulation module of the interference detection module of FIG. 1;

FIG. 3 is a diagram illustrating a process flow of noise estimation of the interference determination module of the interference detection module of FIG. 1;

FIG. 4 is a state transition diagram of the narrowband interference suppression module of the embodiment shown in FIG. 1

Fig. 5 is a timing diagram illustrating the operation of the narrowband interference suppression module shown in fig. 1;

fig. 6 is a functional block diagram of a second embodiment of the narrowband interference suppression module of the present invention;

fig. 7 is a schematic diagram of a sensitivity analysis of the non-coherent accumulation of the interference detection module of fig. 1 or 6.

Detailed Description

For the purpose of illustrating the technical content, the constructional features, the achieved objects and the effects of the invention in detail, reference will be made to the following detailed description of the embodiments in conjunction with the accompanying drawings.

Referring to fig. 1, fig. 1 is a diagram illustrating a first embodiment of a narrowband interference suppression module according to the present invention, which includes a bypass path and an interference suppression path. The interference suppression path includes a signal transformation module, an interference detection module 13 and an interference processing module. The signal conversion module is used for converting the received intermediate frequency signal into a frequency domain signal, and includes an overlap windowing module 11 and an FFT module 12. The interference processing module 14 is configured to eliminate an interference signal in the intermediate frequency signal, and in this embodiment, includes an interference suppression module 141, an IFFT module 142, an inverse windowing module 143, and a de-overlap processing module 144. The overlap windowing module 11 performs overlap windowing on the input intermediate frequency signal to obtain a windowed signal. The FFT module 12 performs FFT operation on the windowed signal to obtain a frequency domain signal. The interference detection module 13 includes a non-coherent accumulation module 131 and an interference determination module 132. The incoherent accumulation module 131 performs an incoherent accumulation operation on the frequency domain signal to obtain an incoherent accumulation result including signal power, and more specifically, calculates signal power of all frequency points for an N-point FFT result of the frequency domain signal, performs incoherent accumulation, and if the incoherent accumulation frequency does not reach a set frequency, continues accumulation until the incoherent accumulation frequency reaches the set frequency, and after reaching, transmits the incoherent accumulation result of all frequency points to the interference determination module. The interference determining module 132 performs noise estimation on the incoherent accumulation result to obtain a noise estimation value, determines whether the frequency domain signal has interference based on the noise estimation result and a threshold, and transmits interference frequency point information of the frequency domain signal to the interference processing module 14 in the case of interference.

Referring to fig. 2 and fig. 1, the interference detection module 13 of the present embodiment, particularly the non-coherent accumulation module 131, works as follows:

1. initialization of non-coherent accumulation parameters, number of times n of non-coherent accumulation and result P of non-coherent accumulation_ncInitialization is 0:

2. calculating the signal power P of each frequency point for the N-point FFT result of the frequency domain signal output by the FFT module 12:

P＝[P(i)]

3. non-coherent accumulation while updating the non-coherent accumulation result P_ncAnd a number of non-coherent times n;

4. judging whether the number N of incoherent accumulation reaches the set number N_ncIf not, returning to 2, and waiting for the next FFT result;

5. if the number N of incoherent accumulation reaches the set number N_ncThen the non-coherent accumulation result is transmitted to the interference determination module 132. The interference judging module 132 processes the incoherent accumulation result P_ncNoise estimation is carried out;

6. for non-coherent accumulation result P_ncThe frequency point and interference judging module 132 detects an interference frequency point by combining the estimated noise to obtain a noise estimation value, judges whether the frequency domain signal has interference based on the noise estimation result and a threshold, and judges whether the frequency domain signal has interference under the condition of interferenceAnd transmits the interference frequency point information of the frequency domain signal to the interference processing module 14. The method for determining interference may be implemented by using the prior art, which is not described herein again, or may be implemented as described in the second embodiment.

Referring to fig. 1, the interference determination module 132 includes a noise estimation module 1321 and an interference bin determination module 1322. The noise estimation module 1321 performs noise energy estimation by using a self-adaptive method, so that a threshold is calculated according to the estimated noise energy, that is, the threshold of the interference determination module increases as the incoherent result increases and decreases as the incoherent result decreases, and more specifically, the noise estimation module 1321 receives the incoherent accumulation result of the incoherent accumulation module, accumulates the last noise estimation value when the frequency point is an interference frequency point to obtain a current noise estimation value, accumulates the signal power of the frequency point when the frequency point is not an interference frequency point to obtain a current noise estimation value, calculates the mean value of the noise estimation values after the accumulation of all frequency points is completed, and updates the threshold based on the mean value. The interference frequency point judging module compares the incoherent power of each frequency point with the threshold, judges that the frequency point has interference and updates the interference frequency point information under the condition that the signal power of the frequency point is greater than the threshold, otherwise, the frequency point has no interference and updates the interference frequency point information. After the noise estimation module 1321 is adopted, the threshold can be automatically adjusted according to the change of the interference with constantly changing intensity and frequency, so that the detection accuracy is ensured, and particularly, the sensitivity can be improved and the detection accuracy can also be ensured under the condition of being used together with the incoherent accumulation module 131.

Referring to fig. 3, the working process of the interference determining module 132 is as follows:

1. incoherent accumulation result P of input frequency domain signal after incoherent accumulation_ncInitialization interference judgment threshold value T, and noise estimation value N_acc；

2. Judging whether the ith frequency point is in the band or not, if so, turning to 3, and if not, continuing to judge the next frequency point, if i is i + 1;

3. continuously judging whether the ith frequency point is an interference frequency point or not, and accumulating the signal power P of the frequency point if the ith frequency point is not the interference frequency point_nc(i) If the frequency point is the interference frequency point, accumulating the last noise estimated value

4. Judging whether the accumulation of all the N frequency points is finished, if so, continuing to 5, otherwise, jumping back to 2, and continuing to judge the next frequency point if i is i + 1;

5. after all N frequency points are accumulated, the mean value (front noise estimation value) N of the current noise estimation value is calculated_mean；

N_mean＝N_acc/N

6. The noise estimation module 1321 performs smoothing filtering processing on the current noise estimation value;

7. updating last-time estimated noise values

8. The threshold T is updated for the estimated noise multiplied by a specified coefficient.

T＝r*N_filterR is a constant

Referring to fig. 1, the interference processing module 14 receives the frequency domain signal and performs interference suppression processing on the frequency domain signal based on the interference frequency point information to eliminate interference of the intermediate frequency signal in the presence of interference. In this embodiment, the interference processing module 14 includes an interference suppression module 141, an IFFT module 142, an inverse windowing module 143, and a de-overlap processing module 144. The interference suppression module 141 performs interference suppression processing on the received intermediate frequency signal based on the interference frequency point information from the interference judgment module 132 under the condition of interference to obtain a frequency domain signal after interference suppression. The IFFT module 142 performs IFFT on the frequency domain signal after interference suppression to transform to the time domain. The inverse windowing module 143 performs inverse windowing function processing on the time domain signal. The overlap removal processing module 144 performs overlap removal processing on the time domain signal subjected to the inverse windowing processing, and finally obtains an intermediate frequency signal from which interference is removed.

With continued reference to fig. 1 and with reference to fig. 4 and 5, the interference suppression module includes an interference control switch K1, a data strobe switch K2, a timing control switch K3, and a timing module 15. The interference control switch K1 is turned off by default, is controlled only by the interference enable signal of the interference detection module 13, is turned on when the interference enable signal is valid, and is turned off when the interference enable signal is invalid. The data strobe switch K2 is connected to the bypass path as a default state, and is also controlled only by the strobe enable signal output by the interference detection module 13, and in the case of interference, the strobe enable signal is valid, so that the data strobe switch is connected to the output end of the interference processing module 14, and the intermediate frequency signal after interference suppression is output from the point b, and in the case of no interference, the strobe enable signal is invalid, so that the data strobe switch K3 is connected to the point a, so that the intermediate frequency signal is output from the bypass path. The timing module 15 outputs a timing enable signal valid at every preset time interval. The default state of the timing control switch K3 is an off state, and is controlled by the enabling signals output by the timing module 15 and the interference detection module 13, specifically, the timing control switch K3 is only off under the condition that there is no interference and the closed time interval does not reach the preset time interval, and in the case of off, the intermediate frequency signal is output after being processed by the bypass path, otherwise, the timing control switch is on, and in the case of on, the intermediate frequency signal is transmitted to the signal conversion module, and the on/off control of the timing control switch K3 is shown in the following table:

TABLE 1 ON/OFF CONTROL OF TIME CONTROL SWITCH K3

Timing module output	Interference detection module output	State of K3
			1	Enable	Conduction of
1	Disable	Conduction of
			0	Enable	Conduction of
0	Disable	Disconnect

As can be seen from the table i, the timing control switch K3 is turned off only when there is no interference and the closed time interval does not reach the preset time interval, and the intermediate frequency signal is output after being processed by the bypass path, whereas the timing control switch is turned on, and transmits the intermediate frequency signal to the signal conversion module when the timing control switch is turned on. More specifically, when the interference detection module determines that the intermediate frequency signal has interference, the output interference enable signal is valid and transmits interference frequency point information to the interference suppression module 141, the timing module outputs a timing enable signal to be valid when the recorded time interval reaches the preset time, and the timing control switch is closed when the interference enable signal is valid and the timing enable signal is valid; or the interference enabling signal output by the interference detection module is invalid under the condition of no interference, and the timing control switch is closed under the conditions that the interference enabling signal is invalid and the timing enabling signal is valid; or the timing module outputs a timing enable signal invalid when the recorded time does not reach the preset time interval, the interference detection module outputs an interference enable signal invalid when the interference detection module does not interfere with the recorded time, and the timing control switch is switched off when the timing enable signal is invalid and the interference enable signal is invalid; or the timing module outputs an invalid timing enable signal when the recorded time does not reach the preset time interval, the interference module outputs an valid interference enable signal when interference exists, and the timing control switch is closed when the interference enable signal is valid and the invalid timing enable signal.

Referring to fig. 4 and 5 and fig. 1, in fig. 1, the interference suppression module has two data paths, which are Bypass path and interference suppression path, respectively. The Bypass path is a data path for directly outputting input intermediate frequency signal data without being processed by any module of the interference suppression module; the interference suppression path is a data path for outputting the input intermediate frequency signal data after being processed by all the modules for interference suppression. The input if signal data of the interference suppression module is duplicated into two parts, and passes through the two paths respectively, and the two paths have the same delay, so that the data output by the whole module is completely seamless connected interference-removed if signal data when the data strobe switch K2 is switched. Under the control of the interference control switch K1, the data strobe switch K2 and the timing control switch K3, the whole module can be in a Bypass state, a Detector state or a CWI state, as shown in FIG. 7. The Bypass state is a module state that input intermediate frequency signal data is not processed by any interference suppression module, and is directly output after passing through a Bypass path; the Detector state is a module state that input intermediate frequency signal data reach an interference detection module, an interference detection function is started, and the intermediate frequency signal data are output through a Bypass channel under the condition that interference is not detected; the CWI state is a module state that input intermediate frequency signal data passes through an interference detection module, then passes through an interference suppression filtering module, finally passes through a de-overlap processing module, and the data passes through an interference suppression channel to be output.

Referring to fig. 4 and fig. 5 in combination with fig. 1, during the operation of the interference suppression module, the three switches in fig. 1 are used to control the conversion of the module operating state. The conversion process of the three working states is as follows:

firstly, after the module is started, the timing control switch K3 and the interference control switch K1 are disconnected, the data strobe switch K2 is conducted to an a endpoint, digital intermediate frequency signal data are output through a Bypass channel, the module is in a Bypass state, and after a period of time, the next step is carried out;

secondly, after a period of time, the timing control switch K3 is turned on, the interference control switch K1 is still turned off, the data strobe switch K2 is turned on towards the a endpoint, the digital intermediate frequency signal data reaches the interference detection module 13, the interference detection module 13 is turned on, the module is in a Detector state, the Detector state is an excessive state of the module, when the interference is not detected, the module is recovered to a Bypass state, the circulation is continued from the first step, and when the module detects the interference, the module starts to enter a CWI state;

and thirdly, the timing control switch K3 and the interference control switch K1 are conducted, the data strobe switch K2 is conducted to the b endpoint, the module is in a CWI state, if the interference detection module cannot detect the interference times exceeding a preset threshold value, the module is recovered to the Bypass state, circulation is continued from the first step, otherwise, the module is maintained in the CWI state.

According to the operation conditions of each module of the interference suppression module in three states and different working states, the power consumption of the modules is greatly different, and the power consumption is in a Bypass state, a Detector state and a CWI state from small to large, wherein the power consumption of the interference suppression module in the Bypass state can be ignored, the power consumption of the interference suppression module in the CWI state is maximum, and the power consumption in the Detector state is between the two states.

Referring to fig. 6, fig. 6 is a diagram illustrating a second embodiment of power consumption control according to the present invention, and the same working processes are not repeated, but the differences are described in detail as follows:

the default state of the disturbance control switch K1 is off. The default state of the data strobe K2 is to pass through the bypass path. The frequency domain signal processed by the FFT module is first transmitted to the non-coherent accumulation module 131. After incoherent accumulation, the data is transmitted to the interference determining module 132. The interference determining module 132 determines whether the incoherent accumulation result has interference. In the absence of interference, the generated interference enable signal disables Disable and the strobe enable signal disables Disable. The disturbance control switch K1 is turned off under the control of the disable enable signal. The data strobe switch K2 passes through the bypass path under the control of the enable signal Disable that strobes inactive. In the case of interference, the interference determining module 132 generates an interference enable valid signal and a gating enable valid signal, and transmits the interference frequency point information to the interference suppressing module 141. The disturbance control switch K1 is closed under the control of the disturbance Enable valid signal Enable. The data strobe switch K3 is connected to the output of the interference processing module 14 under the control of the strobe Enable valid signal Enable. The frequency domain signal is transmitted to the interference suppression module 141 with the interference control switch K1 closed. The interference suppression module 141 performs interference suppression processing based on the interference frequency point information from the interference determination module 132 of the interference detection module 13. The operation of the IFFT module 142, the inverse windowing module 143, and the de-overlap processing module 144 is as described above, and will not be described herein again.

Referring to fig. 5, the power consumption analysis of the two modes is as follows:

the two power consumption control modes lead the module to be in three different working states, and when the module is in a certain complex interference environment, the total power consumption of the module is optimized by switching the three working states with different power consumption.

Firstly, the module is started and initialized to be in a Bypass state, and the timing control module controls the switch K3 to switch at preset time intervals t₁The second is conducted, the module starts to enter a Detector state for a duration t₂And secondly, the interference detection module detects that interference exists, if the interference does not exist, the interference detection module outputs a Disable signal to enable the switch K1 and the switch K3 to be disconnected, the Bypass state is recovered, and the switch K3 continues to wait for the next preset time interval to be switched on. In fig. 5, no disturbance is detected after the switch K3 is turned on for the first 4 time intervals. At the 5 th time interval, after the timing control module turns on the switch K3, the interference detection module detects the interference and the module enters the CWI state. The power consumption in this process is

P₁＝5*t₁*p_B+4*t₂*p_D；

Wherein p is_BFor the Bypass state power consumption, p_DPower is consumed for the module Detector state.

Second, the module is in the CWI state for a duration t due to the conduction of switch K3₂And secondly, the interference detection module continuously detects the input intermediate frequency data until the number of times that the interference is not continuously detected exceeds a preset threshold value, and the interference detection module controls the switches K1 and K3 to be switched off and returns to the Bypass state again. The power consumption in this process is

P₂＝t₃*p_C；

Wherein p is_CIs the power consumption in the module CWI state.

And finally, after the module returns to the Bypass state again, the switch K3 continues to wait for the next time interval to be conducted, so that the module enters a Detector state, the interference detection module detects whether the interference exists again, the process is continued, and the process is circulated. The power consumption of the whole module can be expressed as

P＝P₁+P₂+…；

On the one hand, the power consumption p of the interference suppression module due to the Bypass state_BCan be ignored, on the other hand, the duration t of the Detector state₂Overall operation of the comparison moduleThe length of time is negligible, so the power consumption of the last module can be approximated to the power consumption of the CWI state:

P≈P₂；

that is, all power consumption of the module is used for the purpose of interference suppression, and when no interference exists, the module hardly generates power consumption, thereby achieving the purpose of power consumption control of the interference suppression module.

Referring to fig. 7, the interference detection module of the present embodiment mainly uses a frequency domain signal non-coherent accumulation algorithm to perform interference frequency point detection. The incoherent accumulation enables the interference frequency points which are originally hidden in noise and have unobvious peak values to be subjected to incoherent accumulation, so that the interference frequency points have prominent peak values, the improvement of the accuracy and the sensitivity of the detection of weak interference signals is facilitated, and more specifically, the frequency point f which is not very obvious to the frequency domain peak value after FFT (fast Fourier transform) conversion is adopted₁And f₂And the ratio of the interference signal to the noise mean value is not outstanding, so that the interference frequency point is difficult to detect. However, after several times of non-coherent integration accumulation (7a +7b +7c + … …), the energy of the interference frequency point will gradually become prominent and gradually tend to be stable, as shown in fig. 7d, frequency point f after several times of non-coherent integration accumulation₁And f₂Is greater than the threshold value and is detected.

To a certain extent, the interference-to-signal ratio tends to be more stable with the increase of the number of incoherent integration accumulations, and the detection sensitivity of the interference signal is better, but when the number of incoherent integration accumulations is excessively increased, the detection sensitivity of the interference signal is increased to a limited extent, and certain overhead and power consumption of hardware resources are brought on the contrary, and when the number of incoherent integration accumulations is 1, the interference signal is degraded to be the simplest interference detector, and the detection sensitivity of the interference signal is the weakest. Therefore, in practical applications, the number of non-coherent accumulations is configured as an empirical value, and the empirical value can be set to 64, such as 1, 2, 5, 7, 11, 15, 16, 18, 20, 25, 27, 29, 35, 39, 43, 48, 52, 55, 57, 59, 61, 63, 64, etc., as verified by simulation.

Claims

1. The narrow-band interference suppression module is characterized in that: the module comprises an interference suppression path for receiving the intermediate frequency signal, a bypass path for receiving the intermediate frequency signal, an interference control switch and a data gating switch, wherein,

the interference suppression channel comprises a signal conversion module, an interference detection module and an interference processing module, and the interference control switch is used for connecting or disconnecting the signal conversion module and the interference processing module; the signal conversion module converts an intermediate frequency signal from a time domain to a frequency domain signal, the interference detection module judges whether the frequency domain signal is interfered, acquires interference frequency point information and controls the interference control switch to be closed and the data gating switch to be switched from the bypass path to the interference suppression path under the condition of interference, the interference processing module performs interference suppression processing on the frequency domain signal according to the interference frequency point information to acquire an interference-eliminated intermediate frequency signal, and the intermediate frequency signal is output through the data gating switch; the interference detection module controls the interference control switch to be disconnected and the data gating switch to be communicated with the bypass channel under the condition of no interference;

the interference detection module comprises a noncoherent accumulation module and an interference judgment module, the noncoherent accumulation module executes noncoherent accumulation operation on the frequency domain signal to obtain a noncoherent accumulation result comprising signal power, the interference judgment module carries out noise estimation on the noncoherent accumulation result to obtain a noise estimation value, judges whether the frequency domain signal has interference or not based on the noise estimation result and a threshold value, and transmits interference frequency point information of the frequency domain signal to the interference processing module under the condition of interference;

the interference judging module comprises a noise estimating module and an interference frequency point judging module, wherein the noise estimating module receives the incoherent accumulation result of the incoherent accumulation module, accumulates the last noise estimation value under the condition that a frequency point is an interference frequency point to obtain a current noise estimation value, accumulates the intensity value of the frequency point under the condition that the frequency point is not the interference frequency point to obtain a current noise estimation value, calculates the mean value of the noise estimation values after the accumulation of all the frequency points is finished, and updates the threshold value based on the mean value;

the interference frequency point judging module compares the incoherent power of each frequency point with the threshold, judges that the frequency point has interference and updates the interference frequency point information under the condition that the signal power of the frequency point is greater than the threshold, and transmits the interference frequency point information of the frequency domain signal to the interference processing module, otherwise, the frequency point has no interference and updates the interference frequency point information.

2. The narrowband interference suppression module of claim 1, further characterized by: the interference suppression module comprises a timing control switch and a timing module, wherein the timing module records the time interval of disconnection of the timing control switch, the timing control switch is disconnected only under the condition that the time interval which is free of interference and closed does not reach the preset time interval, and under the condition that the timing control switch is disconnected, an intermediate frequency signal is output after being processed by a bypass channel, otherwise, the timing control switch is closed, and under the condition that the timing control switch is closed, the intermediate frequency signal is transmitted to the signal conversion module.

3. The narrowband interference suppression module of claim 2, wherein: the interference detection module outputs an effective interference enabling signal when judging that the intermediate frequency signal has interference, the timing module outputs the effective timing enabling signal when the recorded time interval reaches the preset time, and the timing control switch is closed under the control of the effective interference enabling signal and the effective timing enabling signal;

or the interference enabling signal output by the interference detection module is invalid under the condition of no interference, and the timing control switch is closed under the conditions that the interference enabling signal is invalid and the timing enabling signal is valid;

alternatively, the first and second electrodes may be,

the timing module outputs a timing enabling signal invalid under the condition that the recorded time does not reach a preset time interval, the interference detection module outputs an interference enabling signal invalid under the condition of no interference, and the timing control switch is disconnected under the conditions that the timing enabling signal is invalid and the interference enabling signal is invalid;

or the timing module outputs an invalid timing enable signal when the recorded time does not reach the preset time interval, the interference detection module outputs an valid interference enable signal when interference exists, and the timing control switch is closed when the interference enable signal is valid and the invalid timing enable signal.

4. The narrowband interference suppression module of claim 1, further characterized by:

and the interference processing module receives the frequency domain signal and carries out interference suppression processing on the frequency domain signal based on the interference frequency point information under the condition of interference so as to eliminate the interference of the intermediate frequency signal.

5. The narrowband interference suppression module of claim 1, further characterized by: the noncoherent accumulation module calculates the signal power of all frequency points according to the N-point FFT result of the frequency domain signal, performs noncoherent accumulation, continues accumulation until the noncoherent accumulation times reach the set times if the noncoherent accumulation times do not reach the set times, and transmits the noncoherent accumulation results of all the frequency points to the interference judgment module after the noncoherent accumulation times reach the set times.

6. The narrowband interference suppression module of claim 5, wherein: the set number is between 1 and 64.

7. The narrowband interference suppression module of claim 4, wherein: the threshold of the interference judging module is increased along with the increase of the incoherent result and is reduced along with the reduction of the incoherent result.

The GNSS chip is characterized in that: comprising the narrowband interference suppression module of any of claims 1 to 7.

The OEM board card is characterized in that: comprising the narrowband interference suppression module of claim 8.

10. The receiver is characterized in that: comprising the OEM board of claim 9.

11. The narrowband interference suppression method is characterized by comprising the following steps: the method is applied to a module with a bypass path and an interference suppression path, and comprises the following steps:

the bypass channel and the interference suppression channel both receive intermediate frequency signals;

the interference suppression channel switches off the interference suppression channel and controls the intermediate frequency signal to be processed by the bypass channel under the condition of no interference, and switches off the bypass channel and performs interference suppression processing on the frequency domain signal under the condition of interference so as to eliminate the interference;

wherein the interference suppression processing comprises: performing incoherent accumulation operation on the frequency domain signals to obtain an incoherent accumulation result comprising signal power, performing noise estimation on the incoherent accumulation result to obtain a noise estimation value, judging whether the frequency domain signals have interference or not based on the noise estimation result and a threshold, and transmitting interference frequency point information of the frequency domain signals to an interference suppression channel under the condition of interference;

the noise estimation of the incoherent accumulation result to obtain a noise estimation value, and the judgment of whether the frequency domain signal is interfered based on the noise estimation result and a threshold value comprises the following steps:

receiving a judgment result of the interference frequency point judgment module;

accumulating the last noise estimation value under the condition that the frequency point is an interference frequency point to obtain a current noise estimation value, accumulating the signal power of the frequency point under the condition that the frequency point is not the interference frequency point to obtain the current noise estimation value, calculating the mean value of the noise estimation values after the accumulation of all the frequency points is finished, and updating the threshold value based on the mean value;

and comparing the incoherent power of each frequency point with the threshold, judging that the frequency point has interference and updating the interference frequency point information under the condition that the signal power of the frequency point is greater than the threshold, and otherwise, the frequency point has no interference and updates the interference frequency point information.

12. The narrowband interference suppression method according to claim 11, further comprising: the non-coherent accumulation specifically comprises the steps of calculating the signal power of all frequency points according to the N-point FFT result of the frequency domain signal, carrying out non-coherent accumulation, if the number of the non-coherent accumulation times does not reach the set number, continuing accumulation until the number of the non-coherent accumulation times reaches the set number, and after the number of the non-coherent accumulation times reaches the set number, transmitting the non-coherent accumulation results of all the frequency points to carry out noise estimation.

13. The narrowband interference suppression method according to claim 12, further comprising: the set number is between 1 and 64.

14. The narrowband interference suppression method according to claim 13, further comprising: and setting a time interval for receiving the intermediate frequency signal, and controlling the intermediate frequency signal to be transmitted to the bypass channel only under the condition that the time interval for receiving the intermediate frequency signal does not reach the preset time interval and no interference is detected, otherwise, the intermediate frequency signal is processed by the interference suppression channel.