CN214480649U - Device for removing spur interference of WIFI system and WIFI system - Google Patents

Device for removing spur interference of WIFI system and WIFI system Download PDF

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CN214480649U
CN214480649U CN202022606224.0U CN202022606224U CN214480649U CN 214480649 U CN214480649 U CN 214480649U CN 202022606224 U CN202022606224 U CN 202022606224U CN 214480649 U CN214480649 U CN 214480649U
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刘小同
蔡金辰
焦金良
牛进
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Jingchen Semiconductor Shenzhen Co ltd
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Jingchen Semiconductor Shenzhen Co ltd
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Abstract

The utility model provides a get rid of device and WIFI system that WIFI system spurs disturbed, the device includes: the multi-stage interference removal modules are connected in series; the interference removing modules are used for carrying out frequency spectrum shifting on the input signals, filtering the signals after the frequency spectrum shifting to obtain spurs interference signals, shifting the frequency spectrums of the spurs interference signals back to original frequencies, and removing the spurs interference signals from the input signals. The utility model discloses get rid of device of WIFI system spur interference can be better eliminate the influence of spur interfering signal to the receiver performance, avoid the too big problem that arouses the unable normal work of receiver of spur interfering signal.

Description

Device for removing spur interference of WIFI system and WIFI system
Technical Field
The utility model belongs to the technical field of signal processing and specifically relates to a get rid of device and WIFI system that WIFI (Wireless Fidelity, Wireless internet access) system spurs disturbed.
Background
In the design of a WIFI chip system, various spurs are generated due to existence of non-ideal factors, and the performance of a receiver is deteriorated. For example, after RX DC Calibration (RX DC Calibration), due to the influence of RF (Radio Frequency) circuit and Calibration precision, the receiver generates DC Offset (DC Offset) at DC (Direct Current), and due to the existence of oscillator XOSC Frequency harmonic (harmonic Wave), the receiver is in the receiving band, causing CW (continuous Wave) interference; in an actual WIFI chip system, due to radio frequency leakage of an HDMI (High Definition Multimedia Interface) clock and data, interference of HDMI is caused in a received frequency band range. When the strength of these spurs is large enough to reach a certain threshold, the receiver will not function properly.
For the elimination of spurs interference, a Frequency domain processing mode is generally adopted, that is, after FFT (fast Fourier transform) processing is performed on an input signal, spurs larger than a certain threshold are detected in a Frequency domain response, and a corresponding position is set to 0 to process the influence of spurs interference on a system. When the receiver has a small frequency offset, spectral spread can be caused on a sampling point by a spur signal, and only the frequency response at the interference point can be eliminated by adopting a frequency domain processing method, but the interference cannot be completely eliminated.
SUMMERY OF THE UTILITY MODEL
The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, an object of the utility model is to provide a get rid of device of WIFI system spur interference, can get rid of spur interfering signal through the device, guarantee that the receiver normally works.
A second object of the present invention is to provide a WIFI system.
In order to achieve the above object, an embodiment of a first aspect of the present invention provides a device for removing spurr interference of a WIFI system, the device including: a multi-stage interference removal module, the multi-stage interference removal module being connected in series; the interference removing modules are used for carrying out frequency spectrum shifting on the input signals, filtering the signals after the frequency spectrum shifting to obtain spurs interference signals, shifting the frequency spectrums of the spurs interference signals back to original frequencies, and removing the spurs interference signals from the input signals.
According to the utility model discloses get rid of device of WIFI system spur interference, the serial connection structure of module is got rid of based on multistage interference, when handling input signal, it carries out frequency spectrum shifting and filtering processing to input signal to get rid of the module through multistage interference, in order to obtain the spur interfering signal in the input signal, compare in handling input signal in the frequency domain, the problem of the frequency response of interference point department can only be eliminated, the device of getting rid of WIFI system spur interference of this embodiment is through carrying out frequency spectrum shifting and filtering processing to input signal, can get rid of the spur interfering signal in the input signal, and to a great extent eliminate the influence of spur interfering signal butt joint performance, avoid spur interfering signal too big arouse the unable problem of normal work of receiver.
In some embodiments, the multi-stage interference removal module comprises: a first stage interference removing module, configured to obtain a dc offset interference signal In an input IQ signal and a delay signal of the input IQ (In-Phase Quadrature modulation) signal, remove the dc offset interference signal from the delay signal of the input IQ signal, and select and output a first output signal based on the input IQ signal and the signal from which the dc offset interference signal is removed; the second-stage interference removing module is connected with the output end of the first-stage interference removing module, and is used for performing first frequency spectrum shifting on the first output signal at an HDMI interference frequency point, filtering the signal subjected to frequency spectrum shifting, performing second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the HDMI interference frequency point so as to obtain an HDMI interference signal in the first output signal, obtain a time delay signal of the first output signal, remove the HDMI interference signal from the time delay signal of the first output signal, and selectively output a second output signal; a third-stage interference removing module, an input end of which is connected to an output end of the second-stage interference removing module, and configured to perform first frequency spectrum shifting on a CW interference frequency point for the second output signal, filter the frequency spectrum shifted signal, and perform second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the CW interference frequency point, so as to obtain a CW interference signal in the second output signal, obtain a time delay signal of the second output signal, remove the CW interference signal from the time delay signal of the second output signal, and select to output a third output signal; an output module, an input end of the output module is connected with an output end of the third-stage interference removing module, and the output module is configured to obtain an output signal from which interference is removed based on the input IQ signal and the third output signal.
In some embodiments, the first stage interference removal module comprises: a first filter for filtering an input IQ signal to obtain a DC offset interference signal in the input IQ signal; the input end of the first selector is connected with the output end of the first filter and is used for selecting the output of the direct current offset interference signal; the input end of the first delayer is connected with the input end of the first filter and used for obtaining a delay signal of the input IQ signal; a first operator, a first input end of which is connected to an output end of the first selector, and a second input end of which is connected to an output end of the first delayer, for removing the dc offset interference signal from the delayed signal of the input IQ signal; a second selector, a first input end of the second selector is connected to the input end of the first filter, a second input end of the second selector is connected to the output end of the first arithmetic unit, and the second selector is configured to select and output a first output signal based on the IQ signal and the signal without the dc offset interference signal.
In some embodiments, the second stage interference removal module comprises: the input end of the first HDMI interference removal unit is connected with the output end of the second selector, the first HDMI interference removal unit is used for carrying out first frequency spectrum shifting on the first output signal at a first HDMI interference sub-frequency point, filtering the signal subjected to frequency spectrum shifting, and carrying out second frequency spectrum shifting on the filtered signal so as to shift the filtered signal back to the first HDMI interference sub-frequency point, so that a first HDMI interference sub-signal in the first output signal is obtained; the input end of the second HDMI interference removal unit is connected with the output end of the second selector, the second HDMI interference removal unit is used for carrying out first frequency spectrum shifting on the first output signal at a second HDMI interference sub-frequency point, filtering the signal subjected to frequency spectrum shifting, carrying out second frequency spectrum shifting on the filtered signal so as to shift the filtered signal back to the second HDMI interference sub-frequency point, and obtaining a second HDMI interference sub-signal in the first output signal; a first input end of the second arithmetic unit is connected with an output end of the first HDMI interference removing unit, and a second input end of the second arithmetic unit is connected with an output end of the second HDMI interference removing unit, so as to obtain an HDMI interference signal in the first output signal according to the first HDMI interference sub-signal and the second HDMI interference sub-signal; the input end of the second delayer is connected with the output end of the second selector, and is used for obtaining a delay signal of the first output signal; a first input end of the third arithmetic unit is connected with an output end of the second arithmetic unit, and a second input end of the third arithmetic unit is connected with an output end of the second delayer, so as to remove the HDMI interference signal from the delay signal of the first output signal; and a first input end of the third selector is connected with the output end of the second selector, and a second input end of the third selector is connected with the output end of the third arithmetic unit and is used for selectively outputting the second output signal.
In some embodiments, the first HDMI interference removing unit includes: the input end of the first frequency spectrum shifter is connected with the output end of the second selector, and the first frequency spectrum shifter is used for carrying out first-time frequency spectrum shifting on the first output signal at a first HDMI interference sub-frequency point; the input end of the second filter is connected with the output end of the first frequency spectrum shifter, and the second filter is used for filtering the signal subjected to frequency spectrum shifting by the first frequency spectrum shifter; the input end of the second frequency spectrum shifter is connected with the output end of the second filter, and the second frequency spectrum shifter is used for carrying out second-time frequency spectrum shifting on the signal filtered by the second filter so as to shift the signal filtered by the second filter back to the first HDMI interference sub-frequency point to obtain a first HDMI interference sub-signal in the first output signal; an input end of the fourth selector is connected with an output end of the second spectrum shifter, an output end of the fourth selector is connected with a first input end of the second arithmetic unit, and the fourth selector is used for selectively outputting the first HDMI interference sub-signal.
In some embodiments, the second HDMI interference removing unit includes: the input end of the third spectrum shifter is connected with the output end of the second selector, and the third spectrum shifter is used for carrying out first spectrum shifting on the first output signal at the second HDMI interference sub-frequency point; the input end of the third filter is connected with the output end of the third spectrum shifter, and the third filter is used for filtering the signal subjected to spectrum shifting by the third spectrum shifter; an input end of the fourth spectrum shifter is connected with an output end of the third filter, and the fourth spectrum shifter is used for performing second spectrum shifting on the signal filtered by the third filter so as to shift the filtered signal back to the second HDMI interference sub-frequency point, so that a second HDMI interference sub-signal in the first output signal is obtained; an input end of the fifth selector is connected with an output end of the fourth spectrum shifter, and the fifth selector is used for selectively outputting the second HDMI interference component signal.
In some embodiments, the third stage interference removal module comprises: a first CW interference removing unit, an input end of which is connected to an output end of the third selector, and the first CW interference removing unit is configured to perform first frequency spectrum shifting on the second output signal at a first CW interference sub-frequency point, filter a signal after the frequency spectrum shifting, and perform second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the first CW interference sub-frequency point, so as to obtain a first CW interference sub-signal in the second output signal; a second CW interference removing unit, an input end of which is connected to an output end of the third selector, and the second CW interference removing unit is configured to perform first frequency spectrum shifting on the second output signal at a second CW interference sub-frequency point, filter the signal after frequency spectrum shifting, and perform second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the second CW interference sub-frequency point, so as to obtain a second CW interference sub-signal in the second output signal; a fourth arithmetic unit, a first input end of which is connected to the output end of the first CW interference removing unit, and a second input end of which is connected to the output end of the second CW interference removing unit, for obtaining a CW interference signal in the second output signal according to the first CW interference sub-signal and the second CW interference sub-signal; an input end of the third delayer is connected with an output end of the third selector, and the third delayer is used for obtaining a delay signal of the second output signal; a fifth arithmetic unit, a first input end of which is connected with an output end of the fourth arithmetic unit, a second input end of which is connected with an output end of the third time delay unit, and the fifth arithmetic unit is used for removing the CW interference signal from the time delay signal of the second output signal; a first input end of the sixth selector is connected to the output end of the third selector, a second input end of the sixth selector is connected to the output end of the fifth arithmetic unit, and the sixth selector is configured to selectively output the third output signal.
In some embodiments, the first CW interference removal unit includes: the input end of the fifth frequency spectrum shifter is connected with the output end of the third selector, and the fifth frequency spectrum shifter is used for carrying out first frequency spectrum shifting on the second output signal at the first CW interference sub-frequency point; an input end of the fourth filter is connected with an output end of the fifth frequency spectrum shifter, and the fourth filter is used for filtering the signal subjected to frequency spectrum shifting by the fifth frequency spectrum shifter; a sixth spectrum shifter, an input end of the sixth spectrum shifter is connected to an output end of the fourth filter, and the sixth spectrum shifter is configured to perform a second spectrum shifting on the signal filtered by the fourth filter, so as to shift the filtered signal back to the first CW interference sub-frequency point, thereby obtaining a first CW interference sub-signal in the second output signal; an input end of the seventh selector is connected to an output end of the sixth spectrum shifter, an output end of the seventh selector is connected to a first input end of the fourth arithmetic unit, and the seventh selector is configured to selectively output the first CW interference component signal.
In some embodiments, the second CW interference removing unit includes: an input end of the seventh spectrum shifter is connected with an output end of the third selector, and the seventh spectrum shifter is used for carrying out first spectrum shifting on the second output signal at a second CW interference sub-frequency point; an input end of the fifth filter is connected with an output end of the seventh spectrum shifter, and the fifth filter is used for filtering the signal subjected to spectrum shifting by the seventh spectrum shifter; an eighth spectrum shifter, an input end of the eighth spectrum shifter being connected to an output end of the fifth filter, the eighth spectrum shifter being configured to perform a second spectrum shifting on the signal filtered by the fifth filter to shift the filtered signal back to the second CW interference sub-frequency point, so as to obtain a second CW interference sub-signal in the second output signal; an eighth selector, an input end of the eighth selector is connected to an output end of the eighth spectrum shifter, an output end of the eighth selector is connected to a second input end of the fourth arithmetic unit, and the eighth selector is configured to selectively output the second CW interference component signal.
In some embodiments, any one of the first spectrum mover, the third spectrum mover, the fifth spectrum mover and the seventh spectrum mover includes: a first input end of the first adder obtains a negative normalization value of an interference frequency point; first Z-1Logic cell, the first Z-1The input end of the logic unit is connected with the output end of the first adder, and the first Z is-1The output end of the logic unit is connected with the second input end of the first adder; the input end of the first limit logic unit is connected with the output end of the first adder; the input end of the first LUT unit is connected with the output end of the first limit logic unit; and a first input end of the first multiplier receives an input signal, a second input end of the first multiplier is connected with an output end of the first LUT unit, and an output end of the first multiplier is connected with an input end of a filter corresponding to the output side of the spectrum shifter.
In some embodiments, any one of the second filter, the third filter, the fourth filter, and the fifth filter comprises: a first input end of the second adder is connected with an output end of the first multiplier in the corresponding frequency spectrum shifter; a second multiplier, saidThe first input end of the second multiplier is connected with the output end of the second adder, and the second input end of the second multiplier is used for receiving the updating step length; a third adder, a first input of the third adder being connected to the output of the second multiplier; the input end of the second limit logic unit is connected with the output end of the third adder, and the output end of the second limit logic unit is connected with the input end of the frequency spectrum shifter corresponding to the output side of the filter; second Z-1Logic cell, the second Z-1The input end of the logic unit is connected with the output end of the third adder, and the second Z is-1The output end of the logic unit is connected with the second input end of the third adder; a third limit logic unit, an input terminal of the third limit logic unit and the second Z-1And the output end of the third limiting logic unit is connected with the second input end of the second adder.
In some embodiments, any one of the second spectrum mover, the fourth spectrum mover, the sixth spectrum mover, and the eighth spectrum mover includes: the input end of the third multiplier is connected with the output end of the second limit logic unit in the filter corresponding to the input side of the frequency spectrum shifter, and the output end of the third multiplier is used for outputting an HDMI interference sub signal or a CW interference sub signal; a first input end of the fourth adder is used for receiving the normalized value of the interference frequency point; third Z-1Logic cell, the third Z-1The input end of the logic unit is connected with the output end of the fourth adder, and the third Z-1The output end of the logic unit is connected with the second input end of the fourth adder; the input end of the fourth limit logic unit is connected with the output end of the fourth adder; and the input end of the second LUT unit is connected with the output end of the fourth limit logic unit, and the output end of the second LUT unit is connected with the second input end of the third multiplier.
In order to achieve the above object, an embodiment of a second aspect of the present invention provides a WIFI system, which includes: the receiver and the device for removing spurs interference of the WIFI system described in the above embodiment; the apparatus is configured to remove spur interference in an IQ signal received by the receiver.
According to the utility model discloses WIFI system gets rid of the spurr interference in the IQ signal based on the device of getting rid of WIFI system spurr interference, subtracts the spurr interference signal in the input signal promptly in the time domain, and the influence of elimination spurr interference signal that can be better to the receiver performance avoids the too big problem that arouses the unable normal work of receiver of spurr interference signal.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a block diagram of a device structure for removing spurr interference of a WIFI system according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a device structure for removing spurr interference of a WIFI system according to an embodiment of the present invention;
fig. 3 is a schematic diagram of an implementation structure of a spectrum mover and filter according to an embodiment of the present invention;
fig. 4a is a schematic diagram of a time domain waveform with an interference signal collected at 20M bandwidth according to an embodiment of the present invention;
fig. 4b is a schematic diagram of a frequency response of a band interference signal collected at 20M bandwidth according to an embodiment of the present invention;
fig. 5a is a schematic diagram of a time domain waveform with an interfering signal collected at 40M bandwidth according to an embodiment of the present invention;
fig. 5b is a schematic diagram of a frequency domain response with jammer signal collected at 40M bandwidth according to an embodiment of the present invention;
fig. 6a is a schematic diagram of a time domain waveform with an interfering signal collected at 80M bandwidth according to an embodiment of the present invention;
fig. 6b is a schematic diagram of a frequency domain response with jammer signal collected at 80M bandwidth according to an embodiment of the present invention;
fig. 7a is a schematic diagram of a time domain waveform of a DC interference signal estimated by an apparatus for removing spurr interference of a WIFI system with 80M bandwidth according to an embodiment of the present invention;
fig. 7b is a schematic diagram of the frequency domain response of the DC interference signal estimated by the apparatus for removing spur interference of a WIFI system with 80M bandwidth according to an embodiment of the present invention;
fig. 8a is a schematic diagram of a time domain waveform of a CW interference signal estimated by an apparatus for removing spurs of a WIFI system according to an embodiment of the present invention;
fig. 8b is a schematic diagram of the frequency domain response of the CW interference signal estimated by the apparatus for removing spurs interference of the WIFI system with 80M bandwidth according to an embodiment of the present invention;
fig. 9a is a schematic diagram of a time domain waveform of a device input signal with 80M bandwidth to remove spurs interference of a WIFI system according to an embodiment of the present invention;
fig. 9b is a schematic diagram of a frequency domain response of a device input signal with 80M bandwidth to remove spurs interference from a WIFI system, according to an embodiment of the present invention;
fig. 10a is a schematic diagram of a time domain waveform of a device output signal with 80M bandwidth removed from spurs interference of a WIFI system according to an embodiment of the present invention;
fig. 10b is a schematic diagram of a frequency domain response of a device output signal with 80M bandwidth removed from spurs interference of a WIFI system according to an embodiment of the present invention;
fig. 11 is a block diagram of a WIFI system in accordance with one embodiment of the present invention.
Reference numerals: a multi-stage interference removal module 1; a first-stage interference removing module 10; a second stage interference removal module 20; a third stage interference removal module 30; an output module 40;
a first filter 11; a first selector 12; a first delayer 13; a first arithmetic unit 14; a second selector 15; a first HDMI interference removing unit 21; a second HDMI interference removing unit 22; a second arithmetic unit 23; a second delayer 24; a third arithmetic unit 25; a third selector 26;
a first spectrum mover 210; a second filter 220; a second spectrum shifter 230; a fourth selector 240; a third spectrum shifter 250; a third filter 260; a fourth spectrum shifter 270; a fifth selector 280; a first CW interference removing unit 31; a second CW interference removing unit 32; a fourth arithmetic unit 33; a third delayer 34; a fifth arithmetic unit 35; a sixth selector 36; a fifth spectrum mover 310; a fourth filter 320; a sixth spectrum shifter 330; a seventh selector 340; a seventh spectrum mover 350; a fifth filter 360; an eighth spectrum shifter 370; an eighth selector 380;
a first adder 390; first Z-1 A logic unit 400; a first limit logic unit 590; a first LUT unit 410; a first multiplier 420; a second adder 430; a second multiplier 440; a third adder 450; a second limit logic unit 600; second Z-1 A logic unit 460; a third limit logic unit 610; a third multiplier 470; a fourth adder 480; third Z-1 A logic unit 490; a fourth limit logic unit 620; a second LUT unit 500;
a WIFI system 2; a receiver 3; and a device 4 for removing spur interference of the WIFI system.
Detailed Description
Embodiments of the present invention are described in detail below, and the embodiments described with reference to the drawings are exemplary.
In this embodiment, for the defects of the frequency domain processing method, a device for removing spur interference of a WIFI system is used to process an input signal received by a receiver, and the principle of the method is mainly to process the input signal in a time domain to obtain a spur interference signal, and subtract the obtained spur interference signal from the input signal, so as to eliminate the influence of the spur interference signal on the receiver and avoid the situation that the reception cannot normally work due to the excessively high strength of the spur interference signal.
Interference frequency points for dc offset interference, HDMI interference and CW interference are shown in table 1, fsFor the sampling frequency, x1(n) is the output signal of the digital frequency converter.
TABLE 1
Figure BDA0002774085610000091
The frequency spectrum shifting of the signal is mainly realized by adopting a frequency conversion method, a formula (1-1) defines a digital frequency conversion calculation method, x (n) is the input of a digital frequency converter, a complex signal from A/D sampling, and f is the input of the digital frequency converter, namely the frequency point of an interference signal.
Formula (1-1):
Figure BDA0002774085610000092
formula (1-2): y1(n) ═ y1(n-1) + { x1(n) -y1(n-1) }. alpha.
Formula (1-3):
Figure BDA0002774085610000093
TABLE 2
Updating the step size alpha Signal bandwidth (-3dB)
2-4 800K
2-5 400K
2-6 200K
2-7 100K
2-8 50K
2-9 25K
2-10 12.5K
2-11 6.25K
2-12 3.125K
2-13 1.5K
2-14 0.75K
2-15 0.375K
The output of the digital frequency converter is filtered out of band noise by a low-pass filter, and the formula (1-2) defines a digital expression. x1(n) is a filter input, y1(n) is a filter output, α is an update step, and the update step is related to a filter bandwidth, as shown in table 2, it can indicate that α outputs a signal bandwidth under different values, in order to quickly capture an interference signal, in the embodiment, a variable step coefficient is used to implement, as shown in formula (1-3), where cnt is a counter of an input signal sampling point, and a value of the variable step coefficient α is selected according to formula (1-3) according to a count value at a current time. The step size alpha at which the low pass filter eventually settles can be configured according to the register settings.
An apparatus for removing spurr interference of a WIFI system according to an embodiment of the first aspect of the present invention is described below with reference to fig. 1 to 10.
As shown in fig. 1, the utility model discloses remove device 4 of WIFI system spur interference includes that multistage interference gets rid of module 1, and module 1 serial connection is got rid of to multistage interference, and wherein, the module is got rid of in a plurality of interferences for carry out the spectrum to the input signal and move, and move the signal after the spectrum moves and filter in order to obtain spur interfering signal, and move the spectrum of spur interfering signal back to former frequency department, and get rid of spur interfering signal from the input signal. After the input signal is processed by the device 4 for removing the spurr interference of the WIFI system, the input signal for removing the spurr interference signal can be obtained.
In the embodiment, the multi-stage interference removing modules 1 are connected in series, for example, the multi-stage interference removing modules 1 are connected in series in sequence by three stages of interference removing modules, the input signal is subjected to spectrum shifting and filtering processing based on a three-stage serial structure, that is, the input signal enters the three stages of interference removing modules in sequence, when the input signal enters the first stage of interference removing modules, the first stage of interference removing modules processes the input signal to remove the dc interference signal in the input signal and outputs the signal as the input signal of the next stage of interference removing modules, that is, the output signal of the previous stage of interference removing modules serves as the input signal of the next stage of interference removing modules, the input signal from which the dc interference signal is removed enters the second stage of interference removing modules, and the second stage of interference removing modules performs spectrum shifting and filtering processing on the input signal to remove the HDMI interference signal in the input signal, and the output signal passing through the second-stage interference removal module is used as the input signal of the third-stage interference removal module, and the third-stage interference removal module performs spectrum shifting and filtering processing on the input signal to remove the CW interference signal in the input signal, namely the input signal is processed by the third-stage interference removal module to obtain the spur interference signal in the input signal and remove the spur interference signal from the input signal.
When the multi-stage interference removing module 1 processes an input signal, the input signal is mainly subjected to spectrum shifting processing through a plurality of interference removing modules, namely, the input signal is shifted to a direct current position according to a frequency point of a spurt interference signal, the spurt interference signal is selected through a low-pass filter, out-of-band noise is filtered, the spectrum of the spurt interference signal is shifted back to an original frequency position to obtain the spurt interference signal, the obtained spurt interference signal is subtracted from a time-delayed input signal in a time domain to obtain the input signal without the spurt interference, and the input signal is processed by a device 4 for removing the spurt interference of a WIFI system spurt receiver to eliminate the influence of the spurt interference signal on the performance of the interface.
In the embodiment, each stage of the interference removing module may be a circuit composed of hardware electronic units such as a spectrum shifter, an adder, a multiplier, and a filter, so as to perform frequency shifting, filtering, and the like, thereby removing interference.
According to the utility model discloses get rid of device 4 of WIFI system spur interference, get rid of module 1's serial connection structure based on multistage interference, when handling input signal, it carries out frequency spectrum shifting and filtering processing to input signal to get rid of module 1 through multistage interference, in order to obtain the spur interfering signal in the input signal, compare in handling input signal in the frequency domain, the problem of the frequency response of interference point department can only be eliminated, the device 4 of getting rid of WIFI system spur interference of this embodiment is through carrying out frequency spectrum shifting and filtering processing to input signal, can get rid of the spur interfering signal in the input signal, and at the influence of to a great extent elimination spur interfering signal butt joint performance, avoid spur interfering signal too big arouse the unable normal problem of work of receiver.
In some embodiments, as shown in fig. 2, the multi-stage interference removal module 1 includes a first stage interference removal module 10, a second stage interference removal module 20, a third stage interference removal module 30, and an output module 40. The first-stage interference removing module 10 is configured to obtain a dc offset interference signal in the IQ input signal and a time-delay signal of the IQ input signal, remove the dc offset interference signal from the time-delay signal of the IQ input signal, and select to output a first output signal based on the IQ input signal and the signal after the dc offset interference signal is removed.
For example, the first stage interference removing module 10 is, for example, a DC RMV module, an IQ input signal is, for example, an IQ input signal x, the IQ input signal x is a 10-bit IQ complex signal, where the decimal is 9 bits, as can be seen from fig. 2, bypass _ DC _ tone and bypass _ DC are register configurable signals, whether the DC RMV module is active or inactive is controlled by controlling the register configurable signal to enter the DC RMV module, the DC RMV module obtains a DC offset interference signal in the input signal x by performing filtering processing on the input signal x, and the input signal x enters the DC RMV module to obtain a time delay signal thereof, and removes the DC offset interference signal from the time delay signal of the input signal x and outputs a first output signal. In this process, the first output signal may be selectively output by controlling whether bypass _ dc _ tone and bypass _ dc are enabled or disabled.
The second-stage interference elimination module 20 is, for example, an HDMI RMV module, an input terminal of the HDMI RMV module is connected to an output terminal of the first-stage interference elimination module 10, the HDMI interference signal in the first output signal is selected by carrying out the first frequency spectrum shifting on the first output signal at the HDMI interference frequency point and filtering the signal after the frequency spectrum shifting, and performing a second spectrum shifting on the filtered HDMI interference signal to shift the HDMI interference signal back to the HDMI interference point to obtain the HDMI interference signal in the first output signal, and, the first output signal passes through the second-stage interference removing module 20 to obtain the delay signal of the first output signal, and the HDMI interference signal is removed from the delay signal of the first output signal, namely, the HDMI interference signal is subtracted from the delay signal of the first stage output signal, and the selective output of the second output signal is activated or deactivated by controlling bypass _ HDMI _ tone [0], bypass _ HDMI _ tone [1] and bypass _ HDMI.
The input end of the third-stage interference removing module 30, for example, a CW RMV module, is connected to the output end of the second-stage interference removing module 20, and the CW interference signal in the second output signal is selected by performing a first spectrum shifting on the second output signal at a CW interference frequency point and filtering the spectrum shifted signal, and the second spectrum shifting is performed on the filtered CW interference signal to shift the CW interference signal back to a CW interference point, so as to obtain the CW interference signal in the second output signal, and the second output signal passes through the third-stage interference removing module 30 to obtain a delay signal of the second-stage output signal, and the CW interference signal is removed from the delay signal of the second output signal, and the third output signal is selectively output by controlling bypass _ CW _ tone [0], bypass _ CW _ tone [1], and bypass _ CW valid or invalid.
The input end of the output module 40 is connected to the output end of the third-stage interference removing module 30, and by controlling bypass _ all to be valid or invalid, the output module 40 is configured to obtain an output signal after interference removal or an input IQ signal that is not processed by the multistage interference removing module 1 based on the input IQ signal and the third output signal.
In summary, when processing the input IQ signal to remove the spurs interference signal, the input IQ signal enters the first-stage interference removal module 10, the first-stage interference removal module 10 may select the dc offset interference signal therein, subtract the dc offset interference signal from the delay signal of the input IQ signal to obtain a first output signal, and send the first output signal to the second-stage interference removal module 20. The first output signal enters the second-stage interference removing module 20, the second-stage interference removing module 20 may select an HDMI interference signal therein, subtract the HDMI interference signal from the delay signal of the first output signal to obtain a second output signal, and finally send the second output signal to the third-stage interference removing module 30. The second output signal enters the third stage interference removing module 30, the third stage interference removing module 30 may select a CW interference signal therein, subtract the CW interference signal from the delay signal of the second output signal, and output a third output signal, the third output signal enters the output module 40, and the output module 40 selects and outputs a signal without interference, that is, the input IQ signal is processed by the third stage interference removing module, and then selects and outputs a signal without spurr interference from the output module 40.
In some embodiments, as shown in fig. 2, the first stage interference removing module 10 includes a first filter 11, a first selector 12, a first delayer 13, a first operator 14, and a second selector 15. An input IQ signal, for example, an input signal x, passes through a first filter 11, for example, a low pass filter, and is used for performing filtering processing on the input signal x to obtain a DC offset interference signal in the input IQ signal, that is, an interference signal at DC, and outputs a signal x _ DC0, a signal x _ DC0 passes through a first selector 12, an input end of the first selector 12 is connected with an output end of the first filter 11, the first selector 12 selects the output signal x _ DC0 or the signal 0 by controlling bypass _ DC _ tone to be enabled or disabled, and when bypass _ DC _ tone is disabled, the first selector 12 selects the output DC offset interference signal x _ DC0 as an output signal, that is, the output signal x _ mux0 is x _ DC 0; when bypass _ dc _ tone is enabled, the first selector 12 selects signal 0 as an output signal, that is, x _ mux0 is equal to 0, the input end of the first delayer 13 is connected to the input end of the first filter 11 for obtaining the delayed signal x _ dly0 of the input signal x, the first operator 14 is configured to subtract the dc offset interference signal from the delayed signal of the input IQ signal, that is, the delayed signal x _ dly0 and the output signal x _ mux0 are subtracted by the first operator 14 to obtain the output signal x _ sub0, that is, x _ sub0 is equal to x _ dly0-x _ mux 0. A first input end of the second selector 15 is connected to the input end of the first filter 11, a second input end of the second selector 15 is connected to the output end of the first arithmetic unit 14, the second selector 15 selects and outputs a first output signal based on the IQ input signal and the signal after the dc offset interference signal is removed by controlling whether bypass _ dc is enabled or disabled, and when bypass _ dc is disabled, the second selector 15 selects the output signal x _ sub0 as the output signal of the first-stage interference removal module 10, that is, the output signal x _ mux1 is x _ sub 0; when bypass _ dc is active, the second selector 15 selects the input signal x as the output signal of the first stage interference removal module 10, i.e., the output signal x _ mux1 ═ x.
The bypass _ dc and bypass _ dc _ tone are register configurable signals, whether the first-stage interference removing module 10 works can be controlled by controlling the bypass _ dc and bypass _ dc _ tone to be effective or ineffective, the first output signal is selected to be output, and when the bypass _ dc and bypass _ dc _ tone are ineffective, the input signal x can remove the direct-current offset interference signal in the input signal through the first-stage interference removing module 10.
In some embodiments, as shown in fig. 2, the second-stage interference removing module 20 includes a first HDMI interference removing unit 21, a second HDMI interference removing unit 22, a second operator 23, a second delayer 24, a third operator 25, and a third selector 26. The input end of the first HDMI interference removing unit 21 is connected to the output end of the second selector 15, the first HDMI interference removing unit 21 is configured to perform first frequency spectrum shifting on the first output signal at the first HDMI interference sub-frequency point, filter the signal after the frequency spectrum shifting, and perform second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the first HDMI interference sub-frequency point, so as to obtain a first HDMI interference sub-signal in the first output signal, and the first HDMI interference removing unit 21 is mainly configured to process the first output signal, so as to obtain the first HDMI interference sub-signal in the first output signal. The input end of the second HDMI interference removing unit 22 is connected to the output end of the second selector 15, the second HDMI interference removing unit 22 is configured to perform first frequency spectrum shifting on the first output signal at the second HDMI interference sub-frequency point, filter the signal after the frequency spectrum shifting, and perform second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the second HDMI interference sub-frequency point, so as to obtain a second HDMI interference sub-signal in the first output signal, and the second HDMI interference removing unit 22 is mainly configured to process the first output signal, so as to obtain the second HDMI interference sub-signal in the first output signal. A first input end of the second arithmetic unit 23 is connected with an output end of the first HDMI interference removing unit 21, and a second input end of the second arithmetic unit 23 is connected with an output end of the second HDMI interference removing unit 22, and is configured to obtain an HDMI interference signal in the first output signal according to the first HDMI interference sub-signal and the second HDMI interference sub-signal; the input terminal of the second delayer 24 is connected to the output terminal of the second selector 15, and is configured to obtain a delayed signal of the first output signal; a first input end of the third arithmetic unit 25 is connected with an output end of the second arithmetic unit 23, and a second input end of the third arithmetic unit 25 is connected with an output end of the second time delayer 24, so as to remove the HDMI interference signal from the time delay signal of the first output signal; a first input terminal of the third selector 26 is connected to the output terminal of the second selector 15, and a second input terminal of the third selector 26 is connected to the output terminal of the third arithmetic unit 25, for selectively outputting the second output signal.
For example, after the first output signal is subjected to spectrum shifting and filtering by the first HDMI interference removing unit 21 and the second HDMI interference removing unit 22, a first HDMI interference sub-signal and a second HDMI interference sub-signal in the first output signal can be obtained, the two interference sub-signals are added by the second arithmetic unit 23, the HDMI interference signal in the first output signal is obtained after the addition, and the first output signal x _ mux1 outputs the delayed signal of the first output signal through the second delayer 24, the HDMI interference signal and the delayed signal of the first output signal pass through the third operator 25, the third operator 25 processes the two input signals, for subtracting the HDMI interference signal from the delayed signal of the first output signal to obtain an output signal, e.g. x _ sub1, which is selected by the third selector 26 to output a second output signal, e.g. x _ mux 4.
In some embodiments, as shown in fig. 2, the first HDMI interference removing unit 21 is configured to process the first output signal of the first-stage interference removing module 10, where the first HDMI interference removing unit 21 includes a first spectrum shifter 210, a second filter 220, a second spectrum shifter 230, and a fourth selector 240. The bypass _ hdmi _ tone [0] is a register configurable signal, and the input signal of the selector is controlled by controlling the validity or the invalidity of the bypass _ hdmi _ tone [0 ].
The first output signal x _ mux1 enters the first spectrum shifter 210, the input terminal of the first spectrum shifter 210 is connected to the output terminal of the second selector 15, and the input frequency point of the first spectrum shifter 210 is-fhdmioThe first output signal x _ mux1 is shifted by the first spectrum shifter 210 to output a dc signal x _ ddc0, the signal x _ ddc0 enters the second filter 220, the input terminal of the second filter 220 is connected to the output terminal of the first spectrum shifter 210 for matching the signal passed through the first spectrum shifter 210The signal after the spectrum shift of the spectrum shifter 210 is filtered to output a signal x _ dc1, the signal x _ dc1 is sent to the second spectrum shifter 230, the input end of the second spectrum shifter 230 is connected with the output end of the second filter 220, the second spectrum shifter 230 performs the second spectrum shift on the signal x _ dc1 filtered by the second filter 220, so as to shift the signal after the second filter 220 back to the first HDMI interference sub-frequency point, i.e. the signal x _ dc1 is shifted back to fhdmioAt the frequency point, to obtain the first HDMI victim sub-signal in the first output signal, and output the signal x _ ddc1, the signal x _ ddc1 controls bypass _ HDMI _ tone [0] via the fourth selector 240]And when the signal is valid or invalid, the fourth selector 240 is used for selecting the output signal x _ ddc1 or the signal 0, an input terminal of the fourth selector 240 is connected with an output terminal of the second spectrum shifter 230, an output terminal of the fourth selector 240 is connected with a first input terminal of the second arithmetic unit 23, and the signal x _ ddc1 outputs a first HDMI interference sub-signal, namely x _ mux2, after passing through the fourth selector 240. When bypass _ hdmi _ tone [0]]When active, the fourth selector 240 outputs a signal of 0; when bypass _ hdmi _ tone [0]]When inactive, the fourth selector 240 outputs x _ mux2 ═ x _ ddc 1.
As shown in fig. 2, the first output signal enters the first HDMI interference removing unit 21 and enters the second HDMI interference removing unit 22 at the same time, and the second HDMI interference removing unit 22 includes a third spectrum shifter 250, a third filter 260, a fourth spectrum shifter 270, and a fifth selector 280. The bypass _ hdmi _ tone [1] is a register configurable signal, and the input signal of the selector is controlled by controlling the validity or the invalidity of the bypass _ hdmi _ tone [1 ].
The first output signal enters the third spectrum shifter 250, the input terminal of the third spectrum shifter 250 is connected to the output terminal of the second selector 15, and the input frequency point of the third spectrum shifter 250 is-fhfmioThe first output signal x _ mux1 is shifted by the third spectrum shifter 250 to output a dc signal x _ ddc2, the signal x _ ddc2 enters the third filter 260, the input terminal of the third filter 260 is connected to the output terminal of the third spectrum shifter 250 for filtering the shifted signal by the third spectrum shifter 250 to output a signal x _ dc2, and the signal x _ dc2 enters the fourth spectrum shifter 250A spectrum shifter 270, an input end of the fourth spectrum shifter 270 is connected with an output end of the third filter 260, the fourth spectrum shifter 270 performs a second spectrum shifting on the signal x _ dc2 filtered by the third filter 260, so as to shift the signal filtered by the third filter 260 back to a second HDMI interference sub-frequency point, i.e. shift the signal x _ dc2 back to fhdmioAt the frequency point, to obtain a second HDMI interference division signal in the first output signal, and output the signal x _ ddc3, the signal x _ ddc3 passes through the fifth selector 280 by controlling bypass _ HDMI _ tone [1]]And when the signal is valid or invalid, the fifth selector 280 is used for selecting the output signal x _ ddc3 or the signal 0, the input end of the fifth selector 280 is connected with the output end of the fourth spectrum shifter 270, the output end of the fifth selector 280 is connected with the second input end of the second arithmetic unit 23, and the signal x _ ddc3 outputs a second HDMI interference component signal, namely x _ mux3, after passing through the fifth selector 280. When bypass _ hdmi _ tone [1]]When active, the fifth selector 280 outputs a signal of 0; when bypass _ hdmi _ tone [1]]When inactive, the fifth selector 280 outputs x _ mux3 ═ x _ ddc 3. After the x _ mux3 and the x _ mux2 are added by the second arithmetic unit 23, the added signal is subtracted from the time delay signal x _ mux1_ dly of the first output signal x _ mux1 to obtain an output signal x _ sub1, the x _ sub1 signal selectively outputs a second output signal x _ mux4 through the third selector 26, the third selector 26 selectively outputs the first output signal x _ mux1 or the signal x _ sub1 by controlling the bypass _ hdmi to be active or inactive, and when the bypass _ hdmi signal is active, the second output signal x _ mux4 output by the third selector 26 is x _ mux 1; when bypass _ hdmi is inactive, the second output signal x _ mux4 output by the third selector 26 is x _ sub1, and the second output signal of the second stage interference removal module 20 can be obtained by such a method, where the delay of the second delayer 24 is 7 symbols, the delay of the spectrum shifter is 3 symbols, and the delay of the filter is 1 symbol.
In some embodiments, as shown in fig. 2, the third stage interference removal module 30 includes a first CW interference removal unit 31, a second CW interference removal unit 32, a fourth operator 33, a third delayer 34, a fifth operator 35, and a sixth selector 36. The input end of the first CW interference removing unit 31 is connected to the output end of the third selector 26, and the first CW interference removing unit 31 is configured to perform first frequency spectrum shifting on the second output signal at the first CW interference sub-frequency point, filter the signal after the frequency spectrum shifting, and perform second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the first CW interference sub-frequency point, so as to obtain a first CW interference partial signal in the second output signal; the input end of the second CW interference removing unit 32 is connected to the output end of the third selector 26, and the second CW interference removing unit 32 is configured to perform first frequency spectrum shifting on the second output signal at the second CW interference sub-frequency point, filter the signal after the frequency spectrum shifting, and perform second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the second CW interference sub-frequency point, so as to obtain a second CW interference sub-signal in the second output signal; a first input end of the fourth operator 33 is connected to the output end of the first CW interference removing unit 31, and a second input end of the fourth operator 33 is connected to the output end of the second CW interference removing unit 32, and is configured to obtain a CW interference signal in the second output signal according to the first CW interference sub-signal and the second CW interference sub-signal; an input terminal of the third delayer 34 is connected to an output terminal of the third selector 26, and the third delayer 34 is configured to obtain a delayed signal of the second output signal; a first input terminal of the fifth operator 35 is connected to the output terminal of the fourth operator 33, a second input terminal of the fifth operator 35 is connected to the output terminal of the third time delay unit 34, and the fifth operator 35 is configured to remove the CW interference signal from the time delay signal of the second output signal; a first input terminal of the sixth selector 36 is connected to the output terminal of the third selector 26, a second input terminal of the sixth selector 36 is connected to the output terminal of the fifth arithmetic unit 35, and the sixth selector 36 is configured to selectively output the third output signal.
For example, the second output signal, for example, x _ mux4, enters the first CW interference removing unit 31 and the second CW interference removing unit 32, the two interference removing units perform spectrum shifting and filtering processing on the second output signal x _ mux4, after the processing is completed, the first CW interference removing unit 31 outputs the first CW interference sub-signal, the second CW interference removing unit 32 outputs the second CW interference sub-signal, the first CW interference sub-signal and the second CW interference sub-signal enter the fourth arithmetic unit 33 for addition, and output the added CW interference signal to the fifth arithmetic unit 35, and the second output signal outputs the time delay signal of the second output signal to the fifth arithmetic unit 35 through the third time delay unit 34, the fifth arithmetic unit 35 processes the received interference signal and the CW time delay signal to obtain the second output signal from which the interference signal is removed, and selectively outputs the signal through the sixth selector 36, a third output signal is obtained.
In some embodiments, as shown in fig. 2, the first CW interference removing unit 31 includes a fifth spectrum shifter 310, a fourth filter 320, a sixth spectrum shifter 330, and a seventh selector 340. The second output signal enters a fifth spectrum shifter 310, the input terminal of the fifth spectrum shifter 310 is connected to the output terminal of the third selector 26, and the first CW interference sub-frequency point of the fifth spectrum shifter 310 is-fcwoAfter the second output signal x _ mux4 is subjected to the first spectrum shifting by the fifth spectrum shifter 310, the second output signal x _ mux4 outputs a dc signal x _ ddc4, and the output signal x _ ddc4 is sent to the fourth filter 320, the input end of the fourth filter 320 is connected to the output end of the fifth spectrum shifter 310, the signal x _ ddc4 is filtered to output a signal x _ dc3, the output signal x _ dc3 is sent to the sixth spectrum shifter 330, the input end of the sixth spectrum shifter 330 is connected to the output end of the fourth filter 320, the sixth spectrum shifter 330 is used for performing the second spectrum shifting on the filtered signal x _ dc3, i.e. the signal x _ 3 is shifted back to the first spectrum shiftercwoAt the frequency point, the sixth spectrum shifter 330 outputs the signal x _ ddc5, so as to obtain the first CW interference component signal in the second output signal, i.e. the frequency f in the second output signal x _ mux4cwoFinally, the signal x _ ddc5 enters the seventh selector 340, the input terminal of the seventh selector 340 is connected to the output terminal of the sixth spectrum shifter 330, the output terminal of the seventh selector 340 is connected to the first input terminal of the fourth operator 33, after the signal enters the seventh selector 340, the seventh selector 340 outputs the signal x _ mux5, when bypass _ CW _ tone [0]]When the signal is active, the seventh selector 340 outputs a signal x _ mux5 ═ 0; when bypass _ cw _ tone [0]]When the signal is inactive, the seventh selector 340 outputs the signal x _ mux5 ═ x _ ddc5, where bypass _ cw _ tone [0]]The signals are configurable for the registers.
In some embodiments, as shown in fig. 2, the second CW interference removing unit 32 includes a seventh spectrum shifter 350, a fifth filter 360, an eighth spectrum shifter 370 and an eighth selector 380, when the second output signal enters the first CW interference removing unit 31, the second output signal also enters the second CW interference removing unit 32, the second output signal enters the seventh spectrum shifter 350, an input end of the seventh spectrum shifter 350 is connected to an output end of the third selector 26, and an input frequency point of the seventh spectrum shifter 350 is-fcw1The second output signal is subjected to the first spectrum shifting by the seventh spectrum shifter 350 to output a direct current signal x _ ddc6, the signal x _ ddc6 enters the fifth filter 360 to be filtered to output a signal x _ dc4, the signal x _ dc4 enters the eighth spectrum shifter 370, the input end of the eighth spectrum shifter 370 is connected with the output end of the fifth filter 360, the eighth spectrum shifter is used for carrying out the second spectrum shifting on the signal filtered by the fifth filter 360 to shift the filtered signal back to the second CW interference sub-frequency point, namely, the signal x _ dc4 is shifted back to fcw1At the frequency point, after the second frequency spectrum shifting, the eighth frequency spectrum shifter 370 outputs the signal x _ ddc7, i.e. the second CW interference component signal in the second output signal x _ mux4, and finally, the eighth selector 380 selectively outputs the signal x _ ddc7, an input end of the eighth selector 380 is connected to an output end of the eighth frequency spectrum shifter 370, an output end of the eighth selector 380 is connected to a second input end of the fourth arithmetic unit 33, the eighth selector 380 is used for selectively outputting the second CW interference component signal, and the output signal is x _ mux 6. When bypass _ cw _ tone [1]]When the signal is active, the eighth selector 380 outputs the signal x _ mux6 ═ 0, when bypass _ cw _ tone [1 []When the signal is inactive, the eighth selector 380 outputs the signal x _ mux6 ═ x _ ddc7, where bypass _ cw _ tone [1 []Is configurable for the register.
The seventh selector 340 outputs a signal x _ mux5 and the eighth selector 380 outputs a signal x _ mux6, which is added by the fourth operator 33, outputs a signal x _ add2 and enters the fifth operator 35, the second output signal x _ mux4 enters the fifth operator 35 by the third delayer 34, the fifth operator 35 processes two input signals to output a signal x _ sub2, namely, the output signal x _ sub2 is the signal x _ add2 subtracted from the delayed signal x _ mux4_ dly of the second output signal x _ mux4, and finally, the signal x _ sub2 selectively outputs a third output signal x _ mux7 by the sixth selector 36, the sixth selector 36 selects to output the second output signal x _ sub 4 or the signal x _ sub2 by controlling the bypass _ cw to be enabled or disabled, the sixth selector 36 selects to output a signal x _ mux 36, when the bypass _ mux 36 is enabled, the sixth selector 36 outputs a signal x _ mux 36, when the sixth selector 36 outputs a signal x _ mux 36, 3636, 7, when the sixth selector outputs a bypass 3636, a bypass 34, a bypass _ mux _ 36, thereby obtaining the output signal of the third stage interference cancellation module 30. The time delay of the third delayer 34 is 7 symbols, the time delay of the spectrum shifting module is 3 symbols, and the time delay of the filter is 1 symbol. The x _ mux7 signal passes through the output module 40, and an output signal of the apparatus for removing spurs interference, for example, y, when bypass _ all is valid, y equals x, at this time, no spurs interference signal is removed from the input signal, and the output signal y is output as it is with the input signal x; when bypass _ all is invalid, y is x _ mux7, the removal of spurs interference signals of the WIFI system is achieved, different interferences are removed through the multi-stage interference removal module respectively, the influence of the spurs interference signals on the performance of the receiver can be eliminated, and the performance of the receiver for removing the spurs interference signals is analyzed through simulation.
In some embodiments, as shown in fig. 3, a schematic diagram of an implementation structure of a spectrum shifter and a filter according to an embodiment of the present invention is shown. The first spectrum shifter 210 and the third spectrum shifter 250 are used for shifting the frequency spectrum of the input signal, and when the input signal enters the spectrum shifter, the first input end of the first adder 390 obtains the negative normalization value of the interference frequency point, for example, the first spectrum shifter 210 obtains the interference frequency point fhdmioNegative normalized value of-fhdmio/fsThe third spectrum shifter 250 obtains the interference frequency point fhdmi1Negative normalized value of-fhdmi1/fsFirst Z is-1The input of the logic unit 400 is connected to the output of the first adder 390, first Z-1The output end of the logic unit 400 is connected to the second input end of the first adder 390, the input end of the first limit logic unit 590 is connected to the output end of the first adder 390, and the input end of the first LUT (Look Up Table) unit 410 is connected to the first limit logic unitThe output ends of the units 590 are connected, the first LUT unit 410 is a sine function and cosine function lookup table, the first input end of the first multiplier 420 receives the input signal x, the second input end of the first multiplier 420 is connected with the output end of the first LUT unit 410, the output end of the first multiplier 420 is connected with the input end of the filter corresponding to the output side of the spectrum shifter, for example, the first multiplier 420 may be connected with the input end of the second filter 220, and the input signal is processed by each unit and the algorithm, so that the signal is shifted to a direct current position.
The fifth spectrum shifter 310 and the seventh spectrum shifter 350 are used for shifting the spectrum of the input signal, and the first input end of the first adder 390 obtains the negative normalization value of the interference frequency point, for example, the fifth spectrum shifter 310 obtains the interference frequency point fcwoNegative normalized value of-fcwo/fsThe seventh spectrum shifter 350 obtains the interference frequency point fcw1Negative normalized value of-fcw1/fsAfter the input signal is processed by each unit and the arithmetic processor, the signal is moved to a direct current position.
In some embodiments, as shown in FIG. 3, the filter includes a second adder 430, a second multiplier 440, a third adder 450, a second limit logic 600, and a second Z-1Logic unit 460 and third limit logic unit 610. For example, after the first spectrum shifter 210 performs the first spectrum shifting on the first output signal under the specific interference, the first spectrum shifter outputs the signal x _ ddc0, the output signal x _ ddc0 enters the second filter 220, and the first input end of the second adder 430 is connected to the output end of the first multiplier 420 in the corresponding spectrum shifter; the first input terminal of the second multiplier 440 is connected to the output terminal of the second adder 430, the second input terminal of the second multiplier 440 is used for receiving the update step length, i.e. the step length α, the first input terminal of the third adder 450 is connected to the output terminal of the second multiplier 440, the output terminal of the third adder 450 is connected to the input terminal of the second limit logic unit 600, the input terminal of the second limit logic unit 600 is connected to the output terminal of the third adder 450, the output terminal of the second limit logic unit 600 is connected to the input terminal of the spectrum shifter corresponding to the output side of the filter, for example, the input terminal of the second limit logic unit 600The output side is connected to the input end of the corresponding second spectrum shifter 230, second Z-1The input of the logic unit 460 is connected to the output of the third adder 450, the second Z-1The output of the logic unit 460 is connected to the second input of the third adder 450, and the input of the third limit logic unit 610 is connected to the second Z-1The output of the logic unit 460 is connected, and the output of the third limit logic unit 610 is connected to the second input of the second adder 430. And filtering the signal subjected to the frequency spectrum shift through each unit in the filter, and outputting a filtered direct current signal. The third filter 260, the fourth filter 320, and the fifth filter 360 function the same as the second filter 220.
In some embodiments, the input signal is processed by a filter and then enters a spectrum shifter, for example, a second spectrum shifter 230, and the second spectrum shifter 230 is used to process the output signal of the filter, i.e., shift the filtered signal back to a specific interference frequency point, so as to obtain an interference signal in the output signal.
A first input end of the third multiplier 470 is connected to an output end of the second limit logic unit 600 in the filter corresponding to the input side of the spectrum shifter, for example, the third multiplier 470 in the second spectrum shifter 230 is connected to an output end of the second limit logic unit 600 in the second filter 220 for outputting the HDMI interference division signal, a first input end of the fourth adder 480 is used for receiving the normalized value of the interference frequency point, and a third Z is used for receiving the normalized value of the interference frequency point-1The input of the logic unit 490 is connected to the output of the fourth adder 480, the third Z-1An output of the logic unit 490 is connected to a second input of the fourth adder 480; the input of the fourth limit logic unit 620 is connected to the output of the fourth adder 480, the input of the second LUT unit 500 is connected to the output of the fourth limit logic unit 620, and the output of the second LUT unit 500 is connected to the second input of the third multiplier 470.
In the above, each module or unit may adopt a hardware circuit composed of some hardware electronic units such as an adder, a multiplier, a filter, a spectrum shifter, and the like to realize a corresponding function, and has an actual circuit structure.
In summary, according to the utility model discloses a device 4 of getting rid of WIFI system spur interference, get rid of the serial connection structure of module 1 based on multistage interference, when handling input signal, the frequency spectrum that module 1 goes on input signal is got rid of through multistage interference is moved and filtering process, spur interference signal in the input signal is obtained, and in the time domain, subtract spur interference signal who obtains from the input signal, obtain the input signal of getting rid of spur interference, compare in only handling input signal in the frequency domain, the problem of the frequency response of interference point department can only be eliminated, spur interference signal in the input signal is subtracted in the time domain to this embodiment, the influence of spur interference signal to the receiver performance can be better eliminated, avoid spur interference signal too big the problem that causes the unable normal work of receiver.
After the device 4 for removing the spur interference of the WIFI system removes the spur interference signal in the WIFI system, the effect of the device for removing the interference signal is verified through system simulation, the simulation result shows that the performance of the receiver is obviously improved after the spur interference signal is removed, and the sensitivity of the receiver is improved by 7.1dB for 80M signal bandwidth; for a 40M signal bandwidth, the receiver sensitivity is improved by 12.4dB, and for a 20M signal bandwidth, the receiver sensitivity is improved by 1.2 dB.
The system modeling and simulation process is illustrated below.
For example, the WIFI TX module generates a normalized OFDM signal, and then obtains an adjustment factor of the signal according to a noise floor and an added signal-to-noise ratio, where the calculation of the noise floor is related to a noise coefficient and a filter bandwidth, and the noise coefficient and the filter bandwidth are brought into a calculation formula of the noise floor at a standard temperature, so as to obtain noise floor values under different parameters. And adjusting the size of the output OFDM signal according to the obtained signal adjustment factor, and collecting a noise source by a sampling chip module, wherein the collected noise source comprises DC and CW spur interference signals, and a pure noise source is obtained after high-order narrow-band filtering. Then, the energy of a pure noise signal is calculated through a pure noise source module, then a noise adjusting factor is obtained according to a noise substrate, pure noise output by the pure noise source module and noise containing DC and CW spur interference signals output by a sampling chip module are adjusted according to the obtained noise adjusting factor, finally, OFDM signals and the noise signals are added to obtain output signals, then, the output signals are subjected to gain dynamic adjustment through automatic gain control, sequentially enter a first filtering module, an RX IQ imbalance correction module and a second filtering module, then pass through a device 4 for removing spur interference of a WIFI system, and finally are sent to a digital front-end module. The RX IQ imbalance correction module is used for correcting IQ imbalance of the receiver, and when the filtering module carries out filtering processing on input signals, the filtering module carries out processing on the input signals with different sampling rates according to different models of the filtering module.
Two kinds of data of 20M, 40M and 80M bandwidth WIFI signals under different noises, such as pure noise and noise with DC and CW, are given below, respectively, and the sensitivity simulation results of per < ═ 0.1 when the apparatus 4 for removing spur interference of the WIFI system is turned on and off are shown in table 3.
TABLE 3
Figure BDA0002774085610000211
TABLE 4
Figure BDA0002774085610000212
Table 3 shows the values of the parameters when the apparatus 4 for removing spurs interference of the WIFI system is turned on and off at different bandwidths in case of pure noise. Table 4 is values of respective parameters when the device 4 for removing the spur interference of the WIFI system is turned on and off when the noise includes DC and CW interference.
As can be seen from table 3, for the noise source without spur interference, turning on the apparatus 4 for removing spur interference of the WIFI system has no any loss in the sensitivity of the receiver compared to turning off the apparatus 4 for removing spur interference of the WIFI system, and as can be seen from table 4, for the noise source with spur interference, turning on the apparatus 4 for removing spur interference of the WIFI system has an improvement in the sensitivity of the receiver by 7.1dB compared to turning off the apparatus 4 for removing spur interference of the WIFI system for 80M signal bandwidth; for a 40M signal bandwidth, the receiver sensitivity is improved by 12.4dB, and for a 20M signal bandwidth, the receiver sensitivity is improved by 1.2 dB.
The schematic diagram of the simulated frequency spectrum after the interference removal is performed by the device 4 for removing the spurr interference of the WIFI system is as follows.
Fig. 4 is a schematic diagram of noise with DC interference and CW interference collected at 20M bandwidth according to an embodiment of the present invention. FIG. 4a shows a time domain waveform of a lower band interference signal of a 20M bandwidth signal; fig. 4b shows a diagram of the frequency domain response with the interfering signal, and as can be seen from fig. 4b, the two interfering signals of CW are-25M and 15M, respectively.
Fig. 5 is a schematic diagram of noise of DC interference and CW interference collected at 40M bandwidth according to an embodiment of the present invention. FIG. 5a shows a time domain waveform of a lower band interference signal of a 40M bandwidth signal; fig. 5b shows a diagram of the frequency domain response with an interfering signal, and from fig. 5b it can be seen that the two interfering signals of CW are-35M and 5M, respectively.
Fig. 6 is a schematic diagram of noise of DC interference and CW interference collected at 80M bandwidth according to an embodiment of the present invention. FIG. 6a shows a time domain waveform of a lower band interference signal of an 80M bandwidth signal; FIG. 6b shows a schematic diagram of the frequency domain response with an interfering signal; as can be seen from fig. 6b, the two interfering signals of CW are-15M and 25M, respectively.
Fig. 7 is a schematic waveform diagram of a time domain waveform and a frequency domain response of a DC interference signal estimated by an apparatus for removing spurr interference of a WIFI system with a bandwidth of 80M according to an embodiment of the present invention. FIG. 7a shows a time domain waveform of a DC interference signal; fig. 7b shows the frequency domain response of the DC interference signal.
Fig. 8 is a schematic waveform diagram of the time domain waveform and the frequency domain response of the CW interference signal estimated by the apparatus for removing spurs interference of the WIFI system with 80M bandwidth according to an embodiment of the present invention. Figure 8a shows a time domain waveform of a CW interference signal; fig. 8b shows the frequency domain response of a CW interference signal.
Fig. 9 is a waveform diagram illustrating a time domain waveform and a frequency domain response of a device input signal with 80M bandwidth for removing spur interference of a WIFI system according to an embodiment of the present invention. FIG. 9a shows a time domain waveform of an input signal; b in fig. 9 represents the frequency domain response of the input signal.
Fig. 10 is a waveform diagram illustrating a time domain waveform and a frequency domain response of an output signal of an apparatus with an 80M bandwidth for removing spur interference of a WIFI system according to an embodiment of the present invention. FIG. 10a shows a time domain waveform of an input signal; fig. 10b shows the frequency domain response of the input signal. As can be seen from fig. 10, after the input signal with the DC interference and the CW interference is filtered by the apparatus 4 for removing the spur interference of the WIFI system, the interference signal can be effectively removed, and the influence of the interference signal on the performance of the receiver is eliminated.
A WIFI system according to a second aspect of the present invention is described below with reference to the drawings.
As shown in fig. 11, the WIFI system 2 of the embodiment of the present invention includes a receiver 3 and the device 4 for removing spurr interference of the WIFI system mentioned in the above embodiment. Wherein, the apparatus 4 for removing spurs interference of WIFI system removes spurs interference in IQ signal received by the receiver 3.
According to the utility model discloses WIFI system 2, the device 4 through getting rid of WIFI system spur interference gets rid of the spur interference in the IQ signal, and the influence of elimination spur interference signal that can be better to receiving machine 3 performance avoids spur interference signal too big, appears the problem of the unable normal work of receiving machine 3.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example.
While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (13)

1. An apparatus for removing spurr interference of a WIFI system, comprising:
a multi-stage interference removal module, the multi-stage interference removal module being connected in series;
the interference removing modules are used for carrying out frequency spectrum shifting on the input signals, filtering the signals after the frequency spectrum shifting to obtain spurs interference signals, shifting the frequency spectrums of the spurs interference signals back to original frequencies, and removing the spurs interference signals from the input signals.
2. The apparatus for removing spurs interference of a WIFI system according to claim 1, wherein the multi-stage interference removing module comprises:
a first-stage interference removing module, configured to obtain a dc offset interference signal in an IQ input signal and a delay signal of the IQ input signal, remove the dc offset interference signal from the delay signal of the IQ input signal, and select to output a first output signal based on the IQ input signal and the signal without the dc offset interference signal;
the second-stage interference removing module is connected with the output end of the first-stage interference removing module, and is used for performing first frequency spectrum shifting on the first output signal at an HDMI interference frequency point, filtering the signal subjected to frequency spectrum shifting, performing second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the HDMI interference frequency point so as to obtain an HDMI interference signal in the first output signal, obtain a time delay signal of the first output signal, remove the HDMI interference signal from the time delay signal of the first output signal, and selectively output a second output signal;
a third-stage interference removing module, an input end of which is connected to an output end of the second-stage interference removing module, and configured to perform first frequency spectrum shifting on a CW interference frequency point for the second output signal, filter the frequency spectrum shifted signal, and perform second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the CW interference frequency point, so as to obtain a CW interference signal in the second output signal, obtain a time delay signal of the second output signal, remove the CW interference signal from the time delay signal of the second output signal, and select to output a third output signal;
an output module, an input end of the output module is connected with an output end of the third-stage interference removing module, and the output module is configured to obtain an output signal from which interference is removed based on the input IQ signal and the third output signal.
3. The apparatus for removing spurs interference of a WIFI system according to claim 2, wherein the first stage interference removing module comprises:
a first filter for filtering an input IQ signal to obtain a DC offset interference signal in the input IQ signal;
the input end of the first selector is connected with the output end of the first filter and is used for selecting the output of the direct current offset interference signal;
the input end of the first delayer is connected with the input end of the first filter and used for obtaining a delay signal of the input IQ signal;
a first operator, a first input end of which is connected to an output end of the first selector, and a second input end of which is connected to an output end of the first delayer, for removing the dc offset interference signal from the delayed signal of the input IQ signal;
a second selector, a first input end of the second selector is connected to the input end of the first filter, a second input end of the second selector is connected to the output end of the first arithmetic unit, and the second selector is configured to select and output a first output signal based on the IQ signal and the signal without the dc offset interference signal.
4. The apparatus for removing spurs interference of WIFI system according to claim 3, wherein the second stage interference removing module comprises:
the input end of the first HDMI interference removal unit is connected with the output end of the second selector, the first HDMI interference removal unit is used for carrying out first frequency spectrum shifting on the first output signal at a first HDMI interference sub-frequency point, filtering the signal subjected to frequency spectrum shifting, and carrying out second frequency spectrum shifting on the filtered signal so as to shift the filtered signal back to the first HDMI interference sub-frequency point, so that a first HDMI interference sub-signal in the first output signal is obtained;
the input end of the second HDMI interference removal unit is connected with the output end of the second selector, the second HDMI interference removal unit is used for carrying out first frequency spectrum shifting on the first output signal at a second HDMI interference sub-frequency point, filtering the signal subjected to frequency spectrum shifting, carrying out second frequency spectrum shifting on the filtered signal so as to shift the filtered signal back to the second HDMI interference sub-frequency point, and obtaining a second HDMI interference sub-signal in the first output signal;
a first input end of the second arithmetic unit is connected with an output end of the first HDMI interference removing unit, and a second input end of the second arithmetic unit is connected with an output end of the second HDMI interference removing unit, so as to obtain an HDMI interference signal in the first output signal according to the first HDMI interference sub-signal and the second HDMI interference sub-signal;
the input end of the second delayer is connected with the output end of the second selector, and is used for obtaining a delay signal of the first output signal;
a first input end of the third arithmetic unit is connected with an output end of the second arithmetic unit, and a second input end of the third arithmetic unit is connected with an output end of the second delayer, so as to remove the HDMI interference signal from the delay signal of the first output signal;
and a first input end of the third selector is connected with the output end of the second selector, and a second input end of the third selector is connected with the output end of the third arithmetic unit and is used for selectively outputting the second output signal.
5. The apparatus for removing spurs in a WIFI system according to claim 4, wherein the first HDMI interference removing unit comprises:
the input end of the first frequency spectrum shifter is connected with the output end of the second selector, and the first frequency spectrum shifter is used for carrying out first-time frequency spectrum shifting on the first output signal at a first HDMI interference sub-frequency point;
the input end of the second filter is connected with the output end of the first frequency spectrum shifter, and the second filter is used for filtering the signal subjected to frequency spectrum shifting by the first frequency spectrum shifter;
the input end of the second frequency spectrum shifter is connected with the output end of the second filter, and the second frequency spectrum shifter is used for carrying out second-time frequency spectrum shifting on the signal filtered by the second filter so as to shift the signal filtered by the second filter back to the first HDMI interference sub-frequency point to obtain a first HDMI interference sub-signal in the first output signal;
an input end of the fourth selector is connected with an output end of the second spectrum shifter, an output end of the fourth selector is connected with a first input end of the second arithmetic unit, and the fourth selector is used for selectively outputting the first HDMI interference sub-signal.
6. The apparatus for removing spurs in a WIFI system according to claim 5, wherein the second HDMI interference removing unit comprises:
the input end of the third spectrum shifter is connected with the output end of the second selector, and the third spectrum shifter is used for carrying out first spectrum shifting on the first output signal at the second HDMI interference sub-frequency point;
the input end of the third filter is connected with the output end of the third spectrum shifter, and the third filter is used for filtering the signal subjected to spectrum shifting by the third spectrum shifter;
an input end of the fourth spectrum shifter is connected with an output end of the third filter, and the fourth spectrum shifter is used for performing second spectrum shifting on the signal filtered by the third filter so as to shift the filtered signal back to the second HDMI interference sub-frequency point, so that a second HDMI interference sub-signal in the first output signal is obtained;
an input end of the fifth selector is connected with an output end of the fourth spectrum shifter, and the fifth selector is used for selectively outputting the second HDMI interference component signal.
7. The apparatus for removing spurs interference of WIFI system according to claim 6, wherein the third stage interference removing module comprises:
a first CW interference removing unit, an input end of which is connected to an output end of the third selector, and the first CW interference removing unit is configured to perform first frequency spectrum shifting on the second output signal at a first CW interference sub-frequency point, filter a signal after the frequency spectrum shifting, and perform second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the first CW interference sub-frequency point, so as to obtain a first CW interference sub-signal in the second output signal;
a second CW interference removing unit, an input end of which is connected to an output end of the third selector, and the second CW interference removing unit is configured to perform first frequency spectrum shifting on the second output signal at a second CW interference sub-frequency point, filter the signal after frequency spectrum shifting, and perform second frequency spectrum shifting on the filtered signal to shift the filtered signal back to the second CW interference sub-frequency point, so as to obtain a second CW interference sub-signal in the second output signal;
a fourth arithmetic unit, a first input end of which is connected to the output end of the first CW interference removing unit, and a second input end of which is connected to the output end of the second CW interference removing unit, for obtaining a CW interference signal in the second output signal according to the first CW interference sub-signal and the second CW interference sub-signal;
an input end of the third delayer is connected with an output end of the third selector, and the third delayer is used for obtaining a delay signal of the second output signal;
a fifth arithmetic unit, a first input end of which is connected with an output end of the fourth arithmetic unit, a second input end of which is connected with an output end of the third time delay unit, and the fifth arithmetic unit is used for removing the CW interference signal from the time delay signal of the second output signal;
a first input end of the sixth selector is connected to the output end of the third selector, a second input end of the sixth selector is connected to the output end of the fifth arithmetic unit, and the sixth selector is configured to selectively output the third output signal.
8. The apparatus for removing spurr interference of a WIFI system according to claim 7, wherein the first CW interference removing unit comprises:
the input end of the fifth frequency spectrum shifter is connected with the output end of the third selector, and the fifth frequency spectrum shifter is used for carrying out first frequency spectrum shifting on the second output signal at the first CW interference sub-frequency point;
an input end of the fourth filter is connected with an output end of the fifth frequency spectrum shifter, and the fourth filter is used for filtering the signal subjected to frequency spectrum shifting by the fifth frequency spectrum shifter;
a sixth spectrum shifter, an input end of the sixth spectrum shifter is connected to an output end of the fourth filter, and the sixth spectrum shifter is configured to perform a second spectrum shifting on the signal filtered by the fourth filter, so as to shift the filtered signal back to the first CW interference sub-frequency point, thereby obtaining a first CW interference sub-signal in the second output signal;
an input end of the seventh selector is connected to an output end of the sixth spectrum shifter, an output end of the seventh selector is connected to a first input end of the fourth arithmetic unit, and the seventh selector is configured to selectively output the first CW interference component signal.
9. The apparatus for removing spurr interference of a WIFI system according to claim 8, wherein the second CW interference removing unit comprises:
an input end of the seventh spectrum shifter is connected with an output end of the third selector, and the seventh spectrum shifter is used for carrying out first spectrum shifting on the second output signal at a second CW interference sub-frequency point;
an input end of the fifth filter is connected with an output end of the seventh spectrum shifter, and the fifth filter is used for filtering the signal subjected to spectrum shifting by the seventh spectrum shifter;
an eighth spectrum shifter, an input end of the eighth spectrum shifter being connected to an output end of the fifth filter, the eighth spectrum shifter being configured to perform a second spectrum shifting on the signal filtered by the fifth filter to shift the filtered signal back to the second CW interference sub-frequency point, so as to obtain a second CW interference sub-signal in the second output signal;
an eighth selector, an input end of the eighth selector is connected to an output end of the eighth spectrum shifter, an output end of the eighth selector is connected to a second input end of the fourth arithmetic unit, and the eighth selector is configured to selectively output the second CW interference component signal.
10. The apparatus for removing spurr interference in a WIFI system according to claim 9, wherein any one of the first spectrum mover, the third spectrum mover, the fifth spectrum mover and the seventh spectrum mover includes:
a first input end of the first adder obtains a negative normalization value of an interference frequency point;
first Z-1Logic cell, the first Z-1The input end of the logic unit is connected with the output end of the first adder, and the first Z is-1The output end of the logic unit is connected with the second input end of the first adder;
the input end of the first limit logic unit is connected with the output end of the first adder;
the input end of the first LUT unit is connected with the output end of the first limit logic unit;
and a first input end of the first multiplier receives an input signal, a second input end of the first multiplier is connected with an output end of the first LUT unit, and an output end of the first multiplier is connected with an input end of a filter corresponding to the output side of the spectrum shifter.
11. The apparatus for removing spurr interference in a WIFI system according to claim 10, wherein any one of the second filter, the third filter, the fourth filter and the fifth filter comprises:
a first input end of the second adder is connected with an output end of the first multiplier in the corresponding frequency spectrum shifter;
a second multiplier, a first input terminal of which is connected to the output terminal of the second adder, and a second input terminal of which is used for receiving the update step length;
a third adder, a first input of the third adder being connected to the output of the second multiplier;
the input end of the second limit logic unit is connected with the output end of the third adder, and the output end of the second limit logic unit is connected with the input end of the frequency spectrum shifter corresponding to the output side of the filter;
second Z-1Logic cell, the second Z-1The input end of the logic unit is connected with the output end of the third adder, and the second Z is-1The output end of the logic unit is connected with the second input end of the third adder;
a third limit logic unit, an input terminal of the third limit logic unit and the second Z-1And the output end of the third limiting logic unit is connected with the second input end of the second adder.
12. The apparatus for removing spur interference of a WIFI system according to claim 11, wherein any one of the second spectrum mover, the fourth spectrum mover, the sixth spectrum mover and the eighth spectrum mover includes:
the input end of the third multiplier is connected with the output end of the second limit logic unit in the filter corresponding to the input side of the frequency spectrum shifter, and the output end of the third multiplier is used for outputting an HDMI interference sub signal or a CW interference sub signal;
a first input end of the fourth adder is used for receiving the normalized value of the interference frequency point;
third Z-1Logic cell, the third Z-1The input end of the logic unit is connected with the output end of the fourth adder, and the third Z-1The output end of the logic unit is connected with the second input end of the fourth adder;
the input end of the fourth limit logic unit is connected with the output end of the fourth adder;
and the input end of the second LUT unit is connected with the output end of the fourth limit logic unit, and the output end of the second LUT unit is connected with the second input end of the third multiplier.
13. A WIFI system, comprising:
a receiver and the device for removing spurs interference of the WIFI system of any one of claims 1 to 12;
the apparatus is configured to remove spur interference in an IQ signal received by the receiver.
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