CN109995458B - Narrow-band interference suppression method and module - Google Patents
Narrow-band interference suppression method and module Download PDFInfo
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- CN109995458B CN109995458B CN201711488235.XA CN201711488235A CN109995458B CN 109995458 B CN109995458 B CN 109995458B CN 201711488235 A CN201711488235 A CN 201711488235A CN 109995458 B CN109995458 B CN 109995458B
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- H04J11/0023—Interference mitigation or co-ordination
- H04J11/0066—Interference mitigation or co-ordination of narrowband interference
Abstract
The invention discloses a narrow-band interference suppression method and a module. The module comprises an overlapping windowing module, an FFT module, an interference detection module and an interference processing module. And the overlapping windowing module performs overlapping windowing processing on the input intermediate frequency signal to obtain a windowed signal. And the FFT module performs FFT operation on the windowed signal to obtain a frequency domain signal. The interference detection module performs an incoherent accumulation operation on the frequency domain signal to obtain an incoherent accumulation result, performs noise estimation on the incoherent accumulation result to obtain a noise estimation value, and judges whether the frequency domain signal has interference or not based on the noise estimation result and a threshold value. And the interference processing module 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 intermediate frequency signal. The invention enables the interference frequency points which are originally hidden in noise and have unobvious peak values to have prominent frequency domain peak values after incoherent accumulation, and is beneficial to improving the accuracy and the sensitivity of detecting weak interference signals.
Description
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 invention solves the problem that the detection sensitivity of the existing narrow-band interference suppression module is lower.
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 suppression module comprises a signal conversion module, an interference detection module and an interference processing module. The signal conversion module converts the received intermediate frequency signal from a time domain signal to a frequency domain signal. The interference detection module comprises a noncoherent accumulation module and an interference judgment module, wherein 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. 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.
The invention also discloses a GNSS chip, which comprises the 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 method for suppressing the narrow-band interference, which comprises the following steps: converting an input intermediate frequency signal into a frequency domain signal; the method comprises the steps of performing incoherent accumulation operation on frequency domain signals to obtain an incoherent accumulation result, performing noise estimation on the incoherent accumulation result to obtain a noise estimation value, judging whether the frequency domain signals have interference or not on the basis of the noise estimation result and a threshold, obtaining interference frequency point information under the condition of interference, receiving the frequency domain signals, and performing interference suppression processing on the frequency domain signals on the basis of the interference frequency point information to eliminate the interference in the intermediate frequency signals.
Compared with the prior art, the invention has at least the following advantages:
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.
On the other hand, 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.
Drawings
Fig. 1 is a schematic block diagram of a first embodiment of a narrowband interference suppression module of the present invention;
FIG. 2 is a process flow diagram of one embodiment of the interference detection module of FIG. 1;
FIG. 3 is a schematic diagram of a sensitivity analysis of non-coherent accumulation for the interference detection module of FIG. 1;
fig. 4 is a functional block diagram of a second embodiment of the narrowband interference suppression module of the present invention;
FIG. 5 is a flow chart of the processing of the interference determination module of the embodiment shown in FIG. 4;
fig. 6 is a schematic block diagram of a third embodiment of a narrowband interference suppression module of the present invention;
fig. 7 is a state transition diagram of the narrowband interference suppression module of the embodiment shown in fig. 6;
fig. 8 is a timing diagram illustrating the operation of the narrowband interference suppression module shown in fig. 6;
fig. 9 is a schematic block diagram of a narrowband interference suppression module according to a fourth embodiment of the present invention.
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 of a narrowband interference suppression module according to a first embodiment of the present invention, which is a narrowband interference suppression module based on incoherent accumulation. The module 1 comprises a signal variation module, an interference detection module 13 and an interference processing module 14. The signal conversion module is configured to convert the received intermediate frequency signal into a frequency domain signal, and in this embodiment, includes an overlap windowing module 11 and an FFT module 12. 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. initializing incoherent accumulation parameters, initializing incoherent accumulation times n to 0, and incoherent accumulation result PncInitialization 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 PncAnd a number of non-coherent times n;
4. judging whether the incoherent accumulation number N reaches the set number NncIf not, returning to 2, and waiting for the next FFT result;
5. if the number N of incoherent accumulation reaches the set number NncThen the non-coherent accumulation result is transmitted to the interference determination module 132. The interference judging module 132 processes the incoherent accumulation result PncNoise estimation is carried out;
6. for non-coherent accumulation result PncThe frequency point, interference judging module 132 combines the estimated noise to detect the interference frequency point to obtainAnd obtaining a noise estimation value, judging whether the frequency domain signal has interference based on a noise estimation result and a threshold, and transmitting interference frequency point information of the frequency domain signal to the interference processing module 14 under the condition of interference. 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 processing module 14 receives the frequency domain signal and performs interference suppression on the frequency domain signal based on the interference frequency point information to eliminate the 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 inverse windowing processing, and finally obtains an intermediate frequency signal with interference removed.
Referring to fig. 3, 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 unobtrusive peak values to be highlighted after the incoherent accumulation, so that the accuracy and the sensitivity of detecting weak interference signals are improved. Specifically, as shown in fig. 3a to 3c, the frequency point f, in which the frequency domain peak is not very obvious after FFT, is1And 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 and accumulation (3a +3b +3c + … …), the energy of the interference frequency point will gradually become prominent, as shown in fig. 3d, after several times of non-coherent integration and accumulation, the frequency point f1And f2Is greater than the threshold value and is detected.
To a certain extent, the better the interference signal detection sensitivity is with the increase of the number of non-coherent integration accumulations, but when the number of non-coherent integration accumulations is excessively increased, the interference signal detection sensitivity is raised to a limited extent, and when the number of non-coherent integration accumulations is 1, the interference signal detection sensitivity is degraded to the simplest interference detector, and is weakest. Therefore, in practical applications, the number of times of non-coherent accumulation is set to 16 to 64, for example, 1, 2, 5, 7, 11, 15, 16, 18, 20, 25, 27, 29, 35, 39, 43, 48, 52, 55, 57, 59, 61, 63, 64, and the like.
Referring to fig. 4, in the second embodiment of the narrowband interference suppression module according to the present invention, the interference determining module 132 includes a noise estimating module 1321 and an interference frequency point determining 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. 5 in conjunction with fig. 4, the interference determination module 132 has the following steps:
1. incoherent accumulation result P of input frequency domain signal after incoherent accumulationncInitialization interference judgment threshold value T, and noise estimation value Nacc；
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 pointnc(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, calculating the mean value (current noise estimation value) N of the noise estimation valuesmean；
Nmean＝Nacc/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*NfilterR is a constant
Although the two embodiments greatly improve the detection sensitivity of the interference suppression module to the interference signal, the power consumption of the interference suppression module is relatively large, and particularly, the interference suppression module will greatly occupy the hardware resource of the whole navigation receiver module under the condition of normally opening. The first method is as follows: the power consumption of all hardware modules of the whole interference suppression module is controlled from a signal conversion module (an overlapping windowing module), so that the whole interference suppression module does not need to be opened when no interference exists, and the power consumption of the interference suppression module can be ignored; the second method comprises the following steps: and controlling the power consumption of all working modules behind the interference detection module, so that the interference suppression module opens the subsequent modules only when interference exists, and the power consumption is reduced.
Referring to fig. 6, fig. 6 is a first embodiment of the invention for reducing power consumption, in which 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 by default and is only controlled by the strobe enable signal output by the interference detection module 13, and in the case of interference, the strobe enable signal is valid to make the data strobe switch communicate with 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 to make the data strobe switch K3 communicate with the point a, and make the intermediate frequency signal 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 open 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 open when there is no interference and the closed time interval does not reach the preset time interval, and when the timing control switch is open, the if signal is output after being processed by the bypass path, otherwise, the timing control switch is closed, and when the timing control switch is closed, the if 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. 6 and 7, in fig. 6, 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 which is output after the input intermediate frequency signal data is processed by all modules for interference suppression, and at least comprises a signal conversion module, an interference detection module and an interference processing module. 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. 7 in combination with fig. 6 and 8, during the operation of the interference suppression module, the three switches in fig. 6 are used to control the switching of the module operation 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 gating 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 the next step is carried out after a period of time;
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 end point, 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 gating 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, and 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. 9, fig. 9 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 incoherent 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 interference determination module 132 of the interference detection module 13 generates an invalid interference enable signal Disable and an invalid strobe enable signal 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 effective interference enable signal and an effective gating enable signal, and transmits the interference frequency point information to the interference suppressing module 141. The interference control switch K1 is closed under the control of an active interference Enable signal Enable. The data strobe switch K3 is connected to the output of the disturb processing module 14 under control of an active strobe Enable 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 bin 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 overlap removing module 144 are as described above, and are not described herein again.
Referring to fig. 8 in conjunction with fig. 6, 7 and 9, the power consumption analysis of the two modes is as follows:
the two power consumption control modes result in that the module is in three different working states, and when the module is in a certain complex interference environment, the module switches the three working states with different power consumption to optimize the total power consumption of the module, as shown in fig. 8.
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. 6, no disturbance is detected after turning on switch K3 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*pB+4*t2*pD；
Wherein p isBFor the Bypass state power consumption, pDPower 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*pc；
Wherein p isCIs 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 stateBCan be ignored, on the other hand, the duration t of the Detector state2The overall length of the module operating time is negligible compared to the total module operating time, 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.
Claims (14)
1. The narrowband interference suppression module is characterized in that: the suppression module comprises a signal conversion module, an interference detection module and an interference processing module, wherein,
the signal conversion module converts the received intermediate frequency signal from a time domain signal into a frequency domain signal;
the interference detection module comprises a noncoherent accumulation module and an interference judgment module, wherein the noncoherent accumulation module performs noncoherent accumulation operation on the frequency domain signal to obtain a noncoherent accumulation result comprising signal power, the interference judgment module performs noise estimation on the noncoherent accumulation result to obtain a noise estimation value, the interference judgment module comprises a noise estimation module and an interference frequency point judgment module, wherein,
the noise estimation module receives the incoherent accumulation result of the incoherent accumulation module, accumulates the last noise estimation value under the condition that the 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, otherwise, the frequency point has no interference and updates the interference frequency point information,
judging whether the frequency domain signal has interference or not based on a noise estimation result and a threshold value, and transmitting interference frequency point information of the frequency domain signal to the interference processing module under the condition of interference;
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.
2. 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.
3. The narrowband interference suppression module of claim 2, wherein: the set number is between 1 and 64.
4. The narrowband interference suppression module of claim 1, further characterized by: the threshold of the interference processing module increases as the non-coherent result increases and decreases as the non-coherent result decreases.
5. The narrowband interference suppression module according to any of claims 1 to 4, characterized by: the interference suppression module comprises an interference control switch, a data gating switch and a bypass path for receiving the intermediate frequency signal, wherein,
the interference judging module outputs an interference enabling signal and a gating enabling signal under the condition of detecting interference;
the interference control switch receives the effective interference enabling signal to be closed, and transmits the frequency domain signal to the interference processing module;
the data gating switch is connected to the bypass path and the output end of the interference processing module, and receives the effective gating enabling signal to output the result of the interference processing module;
the interference detection module generates an invalid interference enable signal and an invalid gating enable signal under the condition that interference is not detected, wherein the interference control switch is controlled by the invalid interference enable signal to be switched off; the data strobe switch is controlled by the invalid strobe enable signal to be communicated with the bypass passage, and the intermediate frequency signal is output.
6. The narrowband interference suppression module of claim 5, wherein: 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 is free of interference and closed does not reach the preset time interval, and under the condition of disconnection, an intermediate frequency signal is output after being processed by a bypass passage, otherwise, the timing control switch is closed, and under the condition that the timing switch is closed, the intermediate frequency signal is transmitted to the signal conversion module.
7. The narrowband interference suppression module of claim 6, 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 enabling signal output by the timing module under the condition that the recorded time does not reach the preset time interval is invalid, the interference enabling signal output by the interference detection module under the condition of no interference is invalid, and the timing control switch is disconnected under the control of the invalid timing enabling signal and the invalid interference enabling signal;
or, the timing module generates an invalid timing enable signal when the recorded time does not reach a preset time interval, the interference detection module outputs an effective interference enable signal when interference exists, and the timing control switch is closed under the control of the effective interference enable signal and the invalid timing enable signal.
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 any of claims 1 to 7.
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 comprises the following steps:
converting an input intermediate frequency signal into a frequency domain signal;
performing incoherent accumulation operation on the frequency domain signal to obtain an incoherent accumulation result including signal power, performing noise estimation on the incoherent accumulation result to obtain a noise estimation value, judging whether the frequency domain signal is interfered or not based on the noise estimation result and a threshold, and obtaining interference frequency point information under the condition of interference
Under the condition of interference, receiving the frequency domain signal and performing interference suppression processing on the frequency domain signal based on the interference frequency point information to eliminate interference in the intermediate frequency signal, wherein the performing noise estimation on the incoherent accumulation result to obtain a noise estimation value comprises:
receiving a judgment result of the interference frequency point judgment module;
and 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 intensity value 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.
12. The narrowband interference suppression method according to claim 11, further comprising: the performing a non-coherent accumulation operation on the frequency domain signals comprises: and calculating the signal power of all frequency points according to the N-point FFT result of the frequency domain signal, performing incoherent accumulation, if the number of incoherent accumulation times does not reach the set number of times, continuing accumulation until the number of incoherent accumulation times reaches the set number of times, and transmitting the incoherent accumulation results of all the frequency points to the interference judgment module after the number of incoherent accumulation times reaches the set number of times.
13. The narrowband interference suppression method according to claim 12, further comprising: the set number is between 1 and 64.
14. A method of narrowband interference suppression according to any of the claims 11 to 13, characterized by: the threshold increases as the incoherent result increases and decreases as the incoherent result decreases.
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| CN102759739A (en) * | 2011-04-26 | 2012-10-31 | 中国科学院微电子研究所 | Rapid associated acquisition device and method thereof |
| CN105549035A (en) * | 2015-12-22 | 2016-05-04 | 武汉梦芯科技有限公司 | Baseband signal frequency domain narrowband interference detection elimination apparatus and method thereof |
| CN106772268A (en) * | 2016-12-27 | 2017-05-31 | 哈尔滨工业大学 | A kind of weak signal blind checking method under white Gaussian noise |
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| CN102759739A (en) * | 2011-04-26 | 2012-10-31 | 中国科学院微电子研究所 | Rapid associated acquisition device and method thereof |
| CN105549035A (en) * | 2015-12-22 | 2016-05-04 | 武汉梦芯科技有限公司 | Baseband signal frequency domain narrowband interference detection elimination apparatus and method thereof |
| CN106772268A (en) * | 2016-12-27 | 2017-05-31 | 哈尔滨工业大学 | A kind of weak signal blind checking method under white Gaussian noise |
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Inventor after: Wang Yongquan Inventor after: Xu Min Inventor after: Zhai Xiaodong Inventor before: Xu Min Inventor before: Zhai Xiaodong |