CN111600620A - Analog cancellation device and method for eliminating interference - Google Patents

Analog cancellation device and method for eliminating interference Download PDF

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CN111600620A
CN111600620A CN202010230455.8A CN202010230455A CN111600620A CN 111600620 A CN111600620 A CN 111600620A CN 202010230455 A CN202010230455 A CN 202010230455A CN 111600620 A CN111600620 A CN 111600620A
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signal
module
cancellation
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interference
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CN111600620B (en
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孟进
何方敏
秦焕丁
王青
葛松虎
李毅
李斌
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Naval University of Engineering PLA
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
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Abstract

The invention discloses an analog cancellation device and method for eliminating interference, wherein the device comprises a sampling module, a vector modulation module, a synthesis feedback module and a control module; the sampling module directly extracts the interference signal from the transmitting end of the interference signal source; the vector modulation module synthesizes a cancellation signal; the synthesis feedback module completes the synthesis of the cancellation signal and the interference signal and forms an error signal; the control module calculates the first reference signal and the error signal to generate two paths of weights; the cancellation method comprises the following steps: carrying out time delay processing on the reference path; down-converting the first reference signal and the error signal to a fixed intermediate frequency; obtaining a weight value by using the first reference signal and the error signal; synthesizing the weight and the signal subjected to orthogonal power division to obtain a cancellation signal; synthesizing the cancellation signal and the interference signal to obtain an error signal; the invention adopts the structure of the frequency mixer and the Gilbert multiplier to solve the problems of interference cancellation and direct current bias of the frequency mixer in the 1 GHz-18 GHz wide frequency band.

Description

Analog cancellation device and method for eliminating interference
Technical Field
The invention relates to the technical field of electromagnetic compatibility, in particular to an analog cancellation device and method for eliminating interference.
Background
Under the co-location environment with limited space, such as ships, war chariot, airplanes and the like, the problem of co-location radiation interference of a high-power transmitter to a high-sensitivity receiver is prominent; the self-adaptive interference cancellation technology is a method for solving the active interference cancellation of electromagnetic interference, and the principle is that a reference signal is extracted at a high-power sending end, a cancellation signal with the same amplitude and opposite phase as the interference signal of a receiving end is obtained by adjusting the amplitude and the phase, and then the cancellation signal is synthesized with a receiving signal, so that the cancellation of the interference signal is completed; current adaptive interference cancellation techniques can be classified into short-wave, ultra-short-wave, and microwave adaptive interference cancellation techniques according to different operating frequencies.
The short wave and ultrashort wave self-adaptive interference cancellation technology is mature at present, and because the working frequency is low, the relevant control circuit can be directly used for operation to obtain a weight value; for the microwave frequency band, especially in the frequency band range of 1 GHz-18 GHz, the working frequency of the self-adaptive interference cancellation technology is high, and the requirement on the structural design of a filter and a circuit is high when the related operation is directly carried out in the radio frequency domain, so that a mixer is needed to carry out down-conversion of the microwave frequency band to an intermediate frequency and then carry out the related operation; however, limited by analog devices, microwave adaptive interference cancellation has several problems: (1) dc bias of the mixer: when the frequency mixer works, self-mixing can occur due to the self nonlinear characteristic, so that a zero-intermediate frequency direct current signal is generated, and a post-stage filter cannot distinguish the direct current signal from a required weight signal and cannot filter the signal; (2) the coverage frequency band is narrow: a general cancellation system can only cover a single frequency band, such as an L frequency band, an S frequency band, a C frequency band, and the like, and the cancellation effect is good in the frequency band, and becomes poor after exceeding the range of the frequency band; (3) delay matching: the microwave interference cancellation system has high working frequency, the cancellation performance is sensitive to delay mismatch, and even a small delay matching error can cause large influence on the system, so that the microwave interference cancellation system has high requirement on the precision of delay matching.
The ultrashort wave electromagnetic interference cancellation device (application number CN201010198092.0), a self-adaptive interference cancellation device and a debugging method thereof (application number CN201110223502.7), a self-adaptive broadband interference cancellation device (application number CN201320001505.0) and a co-location coupling interference tracking cancellation device (application number CN201010538860.2) in chinese patent are all mature applications of the self-adaptive cancellation technology in the short wave and ultrashort wave frequency bands, but the microwave frequency band interference cancellation technology is not related yet.
In addition, a chinese patent co-frequency interference protection device for microwave communication (application No. CN201811155746.4), a dual-band multi-channel radio frequency interference cancellation device (application No. CN201811155041.2), a radio frequency adaptive interference cancellation device and a debugging method thereof (application No. CN201811155735.6) are interference protection means for microwave frequency bands, but the coverage frequency band is narrow (2 GHz-4 GHz), and the problem of mixer dc offset exists, which affects the interference cancellation performance.
Therefore, an analog cancellation apparatus and method for canceling interference are needed to solve the problems of the prior art.
Disclosure of Invention
In view of the above-mentioned deficiencies of the prior art, an object of the present invention is to provide an analog cancellation apparatus and method for eliminating interference, which employs a technique of fixed local oscillator and a structural technique of "mixer + gilbert multiplier" to solve the problem of interference cancellation in a wide frequency band of 1 GHz-18 GHz and the inherent dc offset of the mixer, thereby improving the interference cancellation performance.
The invention is realized by the following technical scheme.
An analog cancellation device for eliminating interference comprises a sampling module, a vector modulation module, a synthesis feedback module and a control module;
the sampling module is used for directly extracting an interference signal from a transmitting end of an interference signal source, forming a first reference signal and a second reference signal, and then processing the second reference signal into a first in-phase path signal and a first quadrature path signal;
the vector modulation module is used for synthesizing the cancellation signal and transmitting the cancellation signal to the synthesis feedback module; one input end of the sampling module is electrically connected with one output end of the sampling module and receives a first in-phase path signal and a first quadrature path signal;
the synthesis feedback module is used for receiving the interference signal input from the receiving antenna, completing the synthesis of the cancellation signal and the interference signal and forming an error signal;
and the control module is used for calculating the first reference signal and the error signal to generate two paths of weights and transmitting the weights to the vector modulation module.
Furthermore, the device also comprises an analog delay module, which is used for carrying out delay processing on the first reference signal so as to enable the first reference signal and the error signal to be in a matching state in time sequence; the output end of the analog delay module is provided with a first down-conversion module, and the analog delay module transmits the first reference signal subjected to delay processing to the first down-conversion module.
Furthermore, the synthesis feedback module comprises a synthesizer and a feedback coupler, wherein the input end of the synthesizer is electrically connected with the output end of the vector modulation module and receives the cancellation signal; the other input end of the synthesizer is connected with a receiving antenna and receives an interference signal radiated by a transmitting antenna; the synthesizer completes the synthesis of the cancellation signal and the interference signal to form an error signal; the output end of the synthesizer is connected with the input end of the feedback coupler; the coupling end of the feedback coupler is provided with a second down-conversion module, the feedback coupler transmits the error signal to the second down-conversion module, and the straight-through end of the feedback coupler is connected with the receiving end; the feedback coupler divides the formed error signal into two paths, one path is transmitted to the second down-conversion module through the coupling end, and the other path is transmitted to the receiving end through the straight-through end.
Furthermore, the device also comprises a local oscillator generating circuit; the local oscillation generating circuit is used for generating local oscillation signals; the output end of the local oscillator generating circuit is provided with a power divider; the local oscillator signal is transmitted to the power divider; the power divider divides the local oscillation signal into two paths of signals and respectively transmits the two paths of signals to the first down-conversion module and the second down-conversion module.
Further, the first down-conversion module comprises a mixer and a low-pass filter, and the first down-conversion module down-converts the first reference signal to a fixed intermediate frequency under the action of the local oscillator signal and transmits the first reference signal converted to the fixed intermediate frequency to the control module; the second down-conversion module comprises a frequency mixer and a low-pass filter, and the second down-conversion module down-converts the error signal to a fixed intermediate frequency under the action of the local oscillator signal and transmits the error signal of the fixed intermediate frequency to the control module.
Further, the control module includes a second quadrature power divider, a gilbert multiplier, and a first-order low-pass control circuit; the first-order low-pass control circuit is in a product input mode; the second orthogonal power divider generates a second in-phase path signal and a second orthogonal path signal after orthogonally dividing the first reference signal input to the control module, the two paths of signals are multiplied by the error signal through two paths of Gilbert multipliers respectively, and two paths of weights are generated through a first-order low-pass control circuit.
Furthermore, the orthogonal output end of the control module is connected with the orthogonal input end of the vector modulation module; the orthogonal output end of the control module is connected with the orthogonal input end of the vector modulation module; the two paths of weights generated by the control module are respectively transmitted to the vector modulation module through the orthogonal output end and the in-phase output end; the vector modulation module weights a first in-phase path signal and a first orthogonal path signal formed after orthogonal power division of a second reference signal and two paths of weights, and synthesizes a cancellation signal which has the same amplitude and is opposite to the interference signal; a first orthogonal power divider is arranged in the sampling module; and the first orthogonal power divider processes the second reference signal into a first in-phase signal and a first orthogonal signal.
A cancellation method of an analog cancellation device for eliminating interference comprises the following steps:
step S1: measuring delay differences of a reference path and an error feedback path by using a vector network analyzer, and performing delay compensation by using an analog delay module to enable a first reference signal and an error signal to be in a matching state in time sequence;
step S2: the first down-conversion moduleUnder the action of local oscillator signals, a first reference signal X is generatedS1(t) down-converting to a fixed intermediate frequency; the second down-conversion module down-converts the error signal to a fixed intermediate frequency under the action of the local oscillation signal, and a post-stage filters the intermediate frequency signal by using a low-pass filter;
step S3: the control module is used for controlling a first reference signal X at a middle frequency bandS1(t) calculating with the error signal, and generating a weight by adopting a first-order low-pass control circuit;
step S4: the vector modulation module multiplies the first orthogonal path signal and the first in-phase path signal after orthogonal power division by using two paths of weights output by the control module respectively, and then the first orthogonal path signal and the first in-phase path signal are synthesized to obtain a cancellation signal;
step S5: the synthesis feedback module synthesizes the cancellation signal and the interference signal to obtain an error signal, and then feeds the error signal back to the second down-conversion module, and the other path is sent to the receiving end.
Further, step S3 includes the following sub-steps:
substep S31: the control module is used for dividing the first reference signal X at the intermediate frequency through a second orthogonal power dividerS1(t) the quadrature power is divided into a second in-phase signal and a second quadrature signal:
Figure BDA0002429124100000051
in the formula, kRF_SFor radio frequency band gain, kRF_LOIs local oscillator gain, kconvFor frequency conversion gain, ESTo reference signal amplitude, ELOIs the amplitude of the local oscillator signal, omegaIFAt an intermediate angular frequency.
Substep S32: the second in-phase path signal and the second quadrature path signal are respectively operated with the error signal through two paths of Gilbert multipliers:
Figure BDA0002429124100000052
in the formula, kRF_SFor radio frequency band gain, kRF_LOIs local oscillator gain, kconvFor frequency conversion gain, ESTo reference signal amplitude, ELOIs the amplitude of the local oscillator signal, omegaIFAt an intermediate angular frequency.
ξ1(t)、ξ2(t) correlations of the IF reference signal in-phase and quadrature paths, respectively, with the error signal expressed as a product.
Substep S33 coupling ξ1(t)、ξ2(t) sending the signal to a first-order low-pass control circuit to obtain a weight value expression of a second in-phase path signal and a second quadrature path signal:
Figure BDA0002429124100000053
in the formula, kRF_SFor radio frequency band gain, kRF_LOIs local oscillator gain, kconvFor variable frequency gain, kIFAt an intermediate frequency gain, ESTo reference signal amplitude, ELOIs the amplitude of the local oscillator signal, omegaIFIntermediate frequency angular frequency;
substep S34: combining the steps S2 and S31, the error signal is obtained as:
Figure BDA0002429124100000061
the system cancellation ratio is:
Figure BDA0002429124100000062
in the formula, ES、EIAmplitude of the reference signal and the interference signal, omega frequency of the reference signal, phi initial phase, WI(t)、WQ(t) weights, k, for the in-phase and quadrature paths, respectivelyRF_SIs the coefficient of the second quadrature power divider, ELOAmplitude, omega, of the local oscillator signalIFAt an intermediate frequency, kRF_LOIs the power division coefficient, k, of the power dividerconvThe frequency conversion gain of the down-conversion module; according to the formula, the cancellation ratio of the system can be obtained quantitatively.
Further, in step S2, a local oscillator is setThe signal being XLO(t), the weights of the same-phase path and the orthogonal path are WI(t) and WQ(t) error signal is Xerr(t)；
The second reference signal XS2(t) is divided into a first in-phase signal X after passing through a first quadrature power dividerS21(t) and a first quadrature path signal XS22(t)；
In-phase path signal XS21(t) and quadrature path signal XS22(t) feeding to a vector modulation module;
the vector modulation module weights the weight value transmitted by the control module to obtain a cancellation signal Y (t) ═ WI(t)XS21(t)+WQ(t)XS22(t)；
The vector modulation module sends the cancellation signal to a synthesis feedback module, and the cancellation signal is synthesized with the interference signal to obtain an error signal Xerr(t)＝XI(t)-Y(t)；
The error signal is fed back to the second down-conversion module and the control module, and the system adopts an LMS (least mean square) algorithm to find the optimal weight value to form a closed-loop signal processing process.
Compared with the prior art, the invention has the beneficial effects that:
1) the invention adopts a structure of 'frequency mixer + Gilbert multiplier', the output of a first down-conversion module is connected with an orthogonal power divider in a control module to obtain signals of an in-phase path and an orthogonal path, the signals are multiplied by error feedback signals through two paths of Gilbert multipliers, and then a first-order low-pass control circuit is used for obtaining a weight, and the process effectively avoids the problem of direct current bias when the frequency mixer is directly used for obtaining the weight;
2) the invention adopts the fixed local oscillator technology, fixes the reference signal and the error signal to the intermediate frequency for processing, designs the cancellation device as a closed loop processing system, forms closed loop processing on the interference signal, continuously corrects the processing result, solves the interference cancellation problem of the 1 GHz-18 GHz wide frequency band, can effectively deal with the broadband interference problem, and ensures the cancellation performance;
3) after the sampling module generates a sampling signal, the reference signal is divided into an in-phase path signal and an orthogonal path signal by using the power divider and then input to the vector modulation module, while the traditional circuit structure adopts a structure of firstly dividing power and then sampling, the structure of the sampling module reduces the number of couplers and reduces the complexity of an analog circuit;
4) the invention adopts the analog delay module to match the delay difference of the reference path and the error feedback path in sections, and can improve the precision of delay matching so as to increase the interference cancellation ratio of the system.
Drawings
FIG. 1 is a block diagram of the system of the present invention;
FIG. 2 is a schematic diagram of the delay of each module of the present invention;
FIG. 3 is a schematic block diagram of a first-order low-pass control circuit according to the present invention;
FIG. 4 is a diagram of cancellation effect under single frequency interference according to the present invention;
fig. 5 is a diagram of cancellation effect of the present invention under broadband interference.
Detailed Description
The technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings, and it is to be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.
The present invention will be described in further detail below with reference to specific embodiments and with reference to the attached drawings.
As shown in fig. 1, an analog cancellation apparatus for eliminating interference includes a local oscillator generating circuit, a power divider, a sampling module, an analog delay module, a first down-conversion module, a second down-conversion module, a control module, a vector modulation module, and a synthesis feedback module;
wherein, a reference path is formed by a signal transmission path from the sampling module, the analog delay module to the first down-conversion module;
an error deaf path is formed by a signal transmission path from the sampling module, the vector modulation module, the synthesis feedback module to the second down-conversion module;
the local oscillation signal generated by the local oscillation generating circuit is input to the power divider;
the power divider divides the local oscillation signal into two paths of signals and respectively transmits the two paths of signals to the first down-conversion module and the second down-conversion module.
The transmitting end of the interference signal source is connected with a transmitting antenna;
the sending end of the interference signal source is simultaneously connected with a sampling module;
the sampling module directly extracts the interference signal from the sending end of the interference signal source and forms a reference signal XS(t)；
The sampling module is used for sampling a reference signal XS(t) is divided into two paths: first reference signal XS1(t) and a second reference signal XS2(t)；
A first orthogonal power divider is arranged in the sampling module;
the first orthogonal power divider divides a second reference signal X into a plurality of reference signalsS2(t) the treatment is divided into two paths: first in-phase path signal XS21(t) and a first quadrature path signal XS22(t)；
One output end of the sampling module is electrically connected with the input end of the vector modulation module, and a first in-phase signal XS21(t) and a first quadrature path signal XS22(t) feeding to a vector modulation module;
the vector modulation module is used for synthesizing cancellation signals;
the other output end of the sampling module is electrically connected with the analog delay module to convert the first reference signal X into a first reference signalS1(t) delivering to a simulation delay module;
analog delay module for first reference signal XS1And (t) carrying out time delay processing, measuring respective time delay of the reference path and the error feedback path through a vector network analyzer, and then compensating by adopting a radio frequency wire (the error feedback path comprises more components, so that the time delay is only compensated in the reference path).
The output end of the analog delay module is electrically connected with the input end of the first down-conversion module;
analog delay module for first reference signal XS1(t) delaying the first reference signal XS1(t) feeding to a first downconversion module;
the first frequency-down conversion module comprises a frequency mixer and a low-pass filter, and the frequency mixer and the low-pass filter convert a first reference signal X under the action of a local oscillator signalS1(t) down-converting to a fixed intermediate frequency;
the output end of the first down-conversion module is electrically connected with the input end of the control module;
the first down-conversion module transmits the first reference signal which is changed into the fixed intermediate frequency to the control module.
On the other hand, a receiving end of the interference signal is sequentially provided with a synthesis feedback module and a receiving antenna from near to far;
the sending end of the interference signal sends out a radio frequency signal through a transmitting antenna, in particular a radio frequency signal in a frequency band of 1 GHz-18 GHz;
let the receiving antenna receive the interference signal as XI(t)；
The output end of the vector modulation module is electrically connected with the input end of the synthesis feedback module and transmits the cancellation signal to the synthesis feedback module;
the synthesis feedback module receives an interference signal X input from a receiving antennaI(t), completing cancellation of signal and interference signal XI(t) synthesizing to form an error signal;
the analog delay module carries out delay processing on the first reference signal so as to enable the first reference signal and the error signal to be in a matching state in time sequence;
the output end of the synthesis feedback module is electrically connected with the second down-conversion module, and the synthesis feedback module transmits the error signal to the second down-conversion module;
specifically, the synthesis feedback module comprises a synthesizer and a feedback coupler;
the input end of the synthesizer is electrically connected with the output end of the vector modulation module and receives a cancellation signal;
the other input end of the synthesizer is connected with a receiving antenna for receiving the interference signal X radiated by the transmitting antennaI(t)；
Synthesis ofThe device completes cancellation signal and interference signal XI(t) synthesizing to form an error signal;
the output end of the synthesizer is connected with the input end of the feedback coupler;
the coupling end of the feedback coupler is connected with the input end of the second down-conversion module, and the straight-through end of the feedback coupler is connected with the receiving end;
the feedback coupler divides the formed error signal into two paths, one path is transmitted to the second down-conversion module through the coupling end, and the other path is transmitted to the receiving end through the straight-through end.
The second down-conversion module comprises a mixer and a low-pass filter;
specifically, the coupling end of the feedback coupler is connected to the RF end of the mixer of the second down-conversion module. The second down-conversion module down-converts the error signal to a fixed intermediate frequency under the action of the local oscillator signal;
the output end of the second down-conversion module is electrically connected with the other input end of the control module;
the second down-conversion module transmits the error signal which is changed into the fixed intermediate frequency to the control module;
the control module calculates a first reference signal and an error signal in a middle frequency band to generate two paths of weights;
the control module comprises a second orthogonal power divider, a Gilbert multiplier and a first-order low-pass control circuit;
the first-order low-pass control circuit adopts a product input mode;
the second orthogonal power divider generates a second in-phase path signal and a second orthogonal path signal after passing through the orthogonal power divider from a first reference signal input to the control module, the two paths of signals are respectively multiplied by the error signal through two paths of Gilbert multipliers, and two paths of weights are generated through a first-order low-pass control circuit;
the in-phase output end of the control module is connected with the in-phase input end (I path) of the vector modulation module;
the orthogonal output end of the control module is connected with the orthogonal input end (Q path) of the vector modulation module;
the two paths of weights generated by the control module are respectively transmitted to the vector modulation module through the orthogonal output end and the in-phase output end;
the vector modulation module is used for converting the first in-phase signal X into a first in-phase signal XS21(t) and a first quadrature path signal XS22(t) multiplying the two paths of weights to synthesize and interfere signal XI(t) equal amplitude and opposite phase cancellation signals;
the synthesis feedback module receives the interference signal X input from the receiving antennaI(t), completing cancellation of signal and interference signal XI(t) synthesizing and forming an error signal; the system adopts an LMS algorithm (least mean square algorithm) to find the optimal weight, the whole device forms closed-loop processing of interference signals, processing results are continuously corrected, and finally error signals meeting requirements are transmitted to a receiving end to fulfill the aim of eliminating interference.
The invention provides an analog cancellation method for eliminating interference, which comprises the following steps:
step S1: measuring the delay difference of a reference path and an error feedback path by using a vector network analyzer, and compensating by using a radio frequency delay line in an analog delay module, wherein the delay condition of each module is shown in figure 2;
step S2: the first frequency-down conversion module converts a first reference signal X under the action of a local oscillator signalS1(t) down-converting to a fixed intermediate frequency; the second down-conversion module down-converts the error signal to a fixed intermediate frequency under the action of the local oscillator signal, and the later stage uses a low-pass filter to obtain an intermediate frequency signal;
let local oscillator signal be XLO(t), the weights of the same-phase path and the orthogonal path are WI(t) and WQ(t) error signal is Xerr(t)；
The second reference signal XS2(t) is divided into a first in-phase signal X after passing through a first quadrature power dividerS21(t) and a first quadrature path signal XS22(t)；
In-phase path signal XS21(t) and quadrature path signal XS22(t) feeding to a vector modulation module;
the vector modulation module weights the weight value transmitted by the control module to obtain a cancellation signal Y (t) ═ WI(t)XS21(t)+WQ(t)XS22(t)；
The vector modulation module sends the cancellation signal to a synthesis feedback module, and the cancellation signal is synthesized with the interference signal to obtain an error signal Xerr(t)＝XI(t)-Y(t)；
The error signal is fed back to the second down-conversion module and the control module, and the system adopts an LMS algorithm to find the optimal weight value to form a closed-loop signal processing process.
Step S3: the control module is used for controlling a first reference signal X at a middle frequency bandS1(t) calculating with the error signal, and generating a weight by adopting a first-order low-pass control circuit;
the method comprises the following substeps:
substep S31: the control module is used for dividing the first reference signal X at the intermediate frequency through a second orthogonal power dividerS1(t) the quadrature power is divided into a second in-phase signal and a second quadrature signal:
Figure BDA0002429124100000121
in the formula, kRF_SFor radio frequency band gain, kRF_LOIs local oscillator gain, kconvFor frequency conversion gain, ESTo reference signal amplitude, ELOIs the amplitude of the local oscillator signal, omegaIFAt an intermediate angular frequency.
Substep S32: the second in-phase path signal and the second quadrature path signal are respectively operated with the error signal through two paths of Gilbert multipliers:
Figure BDA0002429124100000122
in the formula, kRF_SFor radio frequency band gain, kRF_LOIs local oscillator gain, kconvFor frequency conversion gain, ESTo reference signal amplitude, ELOIs the amplitude of the local oscillator signal, omegaIFAt an intermediate angular frequency.
ξ1(t)、ξ2(t) IF reference signal in-phase path (second in-phase path signal) and positive, respectivelyCross-path (second quadrature path) with the error signal.
Substep S33 coupling ξ1(t)、ξ2(t) sending the signal to a first-order low-pass control circuit to obtain a weight value expression of a second in-phase path signal and a second quadrature path signal:
Figure BDA0002429124100000131
in the formula, kRF_SFor radio frequency band gain, kRF_LOIs local oscillator gain, kconvFor variable frequency gain, kIFAt an intermediate frequency gain, ESTo reference signal amplitude, ELOIs the amplitude of the local oscillator signal, omegaIFAt an intermediate angular frequency.
Substep S34: combining the steps S2 and S31, the error signal is obtained as:
Figure BDA0002429124100000132
the system cancellation ratio is:
Figure BDA0002429124100000133
in the formula, ES、EIAmplitude of the reference signal and the interference signal, omega frequency of the reference signal, phi initial phase, WI(t)、WQ(t) weights, k, for the in-phase and quadrature paths, respectivelyRF_SIs the coefficient of the second quadrature power divider, ELOAmplitude, omega, of the local oscillator signalIFAt an intermediate frequency, kRF_LOIs the power division coefficient, k, of the power dividerconvThe frequency conversion gain of the down-conversion module; the cancellation ratio of the system can be obtained quantitatively according to the formula;
step S4: the vector modulation module multiplies the first in-phase path signal and the first quadrature path signal by two paths of weights output by the control module respectively, and then the two paths of weights are synthesized to obtain a cancellation signal;
step S5: the synthesis feedback module firstly synthesizes the cancellation signal and the interference signal to obtain an error signal, and then feeds one path of the error signal back to the second down-conversion module, and sends the other path of the error signal to the receiving end.
In this embodiment, the single-frequency interference signal is exemplified by 3.9GHz and 4.2GHz, the center frequency of system operation is 4GHz, and the bandwidth is 100MHz, so as to obtain a signal spectrum of the single-frequency interference signal and the cancelled broadband interference signal;
fig. 4 shows the frequency spectrum of a single-frequency interference signal received by a receiving end and the cancelled signal frequency spectrum;
it can be seen that the cancellation device provided by the invention can realize the cancellation ratio of about 54 dB;
FIG. 5 shows the frequency spectrum of a broadband interference signal received by a receiving end and the frequency spectrum of the canceled signal;
it can be seen that the cancellation device provided by the invention can suppress the amplitude of the broadband interference signal below-80 dBm, and can ensure effective suppression of the interference signal.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention.

Claims (10)

1. An analog cancellation device for eliminating interference is characterized by comprising a sampling module, a vector modulation module, a synthesis feedback module and a control module;
the sampling module is used for directly extracting an interference signal from a transmitting end of an interference signal source, forming a first reference signal and a second reference signal, and then processing the second reference signal into a first in-phase path signal and a first quadrature path signal;
the vector modulation module is used for synthesizing the cancellation signal and transmitting the cancellation signal to the synthesis feedback module; one input end of the sampling module is electrically connected with one output end of the sampling module and receives a first in-phase path signal and a first quadrature path signal;
the synthesis feedback module is used for receiving the interference signal input from the receiving antenna, completing the synthesis of the cancellation signal and the interference signal and forming an error signal;
and the control module is used for calculating the first reference signal and the error signal to generate two paths of weights and transmitting the weights to the vector modulation module.
2. The analog cancellation device according to claim 1, further comprising an analog delay module, configured to delay the first reference signal so that the first reference signal and the error signal are in a time-sequence matching state; the output end of the analog delay module is provided with a first down-conversion module, and the analog delay module transmits the first reference signal subjected to delay processing to the first down-conversion module.
3. The analog cancellation apparatus according to claim 2, wherein the synthesis feedback module comprises a synthesizer and a feedback coupler, an input terminal of the synthesizer is electrically connected to an output terminal of the vector modulation module, and receives the cancellation signal; the other input end of the synthesizer is connected with a receiving antenna and receives an interference signal radiated by a transmitting antenna; the synthesizer completes the synthesis of the cancellation signal and the interference signal to form an error signal; the output end of the synthesizer is connected with the input end of the feedback coupler; the coupling end of the feedback coupler is provided with a second down-conversion module, the feedback coupler transmits the error signal to the second down-conversion module, and the straight-through end of the feedback coupler is connected with the receiving end; the feedback coupler divides the formed error signal into two paths, one path is transmitted to the second down-conversion module through the coupling end, and the other path is transmitted to the receiving end through the straight-through end.
4. The analog cancellation apparatus according to claim 3, further comprising a local oscillator generating circuit; the local oscillation generating circuit is used for generating local oscillation signals; the output end of the local oscillator generating circuit is provided with a power divider; the local oscillator signal is transmitted to the power divider; the power divider divides the local oscillation signal into two paths of signals and respectively transmits the two paths of signals to the first down-conversion module and the second down-conversion module.
5. The analog cancellation device according to claim 4, wherein the first down-conversion module comprises a mixer and a low-pass filter, and the first down-conversion module down-converts the first reference signal to the fixed intermediate frequency under the action of the local oscillator signal and transmits the first reference signal changed to the fixed intermediate frequency to the control module; the second down-conversion module comprises a frequency mixer and a low-pass filter, and the second down-conversion module down-converts the error signal to a fixed intermediate frequency under the action of the local oscillator signal and transmits the error signal of the fixed intermediate frequency to the control module.
6. The analog cancellation device according to claim 5, wherein the control module comprises a second quadrature power divider, a gilbert multiplier, and a first-order low-pass control circuit; the first-order low-pass control circuit is in a product input mode; the second orthogonal power divider generates a second in-phase path signal and a second orthogonal path signal after orthogonally dividing the first reference signal input to the control module, the two paths of signals are multiplied by the error signal through two paths of Gilbert multipliers respectively, and two paths of weights are generated through a first-order low-pass control circuit.
7. The analog cancellation apparatus according to claim 6, wherein the quadrature output terminal of the control module is connected to the quadrature input terminal of the vector modulation module; the orthogonal output end of the control module is connected with the orthogonal input end of the vector modulation module; the two paths of weights generated by the control module are respectively transmitted to the vector modulation module through the orthogonal output end and the in-phase output end;
the vector modulation module weights a first in-phase path signal and a first orthogonal path signal formed after orthogonal power division of a second reference signal and two paths of weights, and synthesizes a cancellation signal which has the same amplitude and is opposite to the interference signal;
a first orthogonal power divider is arranged in the sampling module; and the first orthogonal power divider processes the second reference signal into a first in-phase signal and a first orthogonal signal.
8. The cancellation method of the analog cancellation device for canceling interference according to claim 1, comprising the steps of:
step S1: measuring delay differences of a reference path and an error feedback path by using a vector network analyzer, and performing delay compensation by using an analog delay module to enable a first reference signal and an error signal to be in a matching state in time sequence;
step S2: the first frequency-down conversion module converts a first reference signal X under the action of a local oscillator signalS1(t) down-converting to a fixed intermediate frequency; the second down-conversion module down-converts the error signal to a fixed intermediate frequency under the action of the local oscillation signal, and a post-stage filters the intermediate frequency signal by using a low-pass filter;
step S3: the control module is used for controlling a first reference signal X at a middle frequency bandS1(t) calculating with the error signal, and generating a weight by adopting a first-order low-pass control circuit;
step S4: the vector modulation module multiplies the first orthogonal path signal and the first in-phase path signal after orthogonal power division by using two paths of weights output by the control module respectively, and then the first orthogonal path signal and the first in-phase path signal are synthesized to obtain a cancellation signal;
step S5: the synthesis feedback module synthesizes the cancellation signal and the interference signal to obtain an error signal, and then feeds the error signal back to the second down-conversion module, and the other path is sent to the receiving end.
9. The analog cancellation method for canceling interference according to claim 8, wherein step S3 includes the following sub-steps:
substep S31: the control module is used for dividing the first reference signal X at the intermediate frequency through a second orthogonal power dividerS1(t) positiveThe power is divided into a second in-phase path signal and a second quadrature path signal:
Figure FDA0002429124090000031
in the formula, kRF_SFor radio frequency band gain, kRF_LOIs local oscillator gain, kconvFor frequency conversion gain, ESTo reference signal amplitude, ELOIs the amplitude of the local oscillator signal, omegaIFAt an intermediate angular frequency.
Substep S32: the second in-phase path signal and the second quadrature path signal are respectively operated with the error signal through two paths of Gilbert multipliers:
Figure FDA0002429124090000041
in the formula, kRF_SFor radio frequency band gain, kRF_LOIs local oscillator gain, kconvFor frequency conversion gain, ESTo reference signal amplitude, ELOIs the amplitude of the local oscillator signal, omegaIFAt an intermediate angular frequency.
ξ1(t)、ξ2(t) correlations of the IF reference signal in-phase and quadrature paths, respectively, with the error signal expressed as a product.
Substep S33 coupling ξ1(t)、ξ2(t) sending the signal to a first-order low-pass control circuit to obtain a weight value expression of a second in-phase path signal and a second quadrature path signal:
Figure FDA0002429124090000042
in the formula, kRF_SFor radio frequency band gain, kRF_LOIs local oscillator gain, kconvFor variable frequency gain, kIFAt an intermediate frequency gain, ESTo reference signal amplitude, ELOIs the amplitude of the local oscillator signal, omegaIFIntermediate frequency angular frequency;
substep S34: combining the steps S2 and S31, the error signal is obtained as:
Figure FDA0002429124090000043
the system cancellation ratio is:
Figure FDA0002429124090000044
in the formula, ES、EIAmplitude of the reference signal and the interference signal, omega frequency of the reference signal, phi initial phase, WI(t)、WQ(t) weights, k, for the in-phase and quadrature paths, respectivelyRF_SIs the coefficient of the second quadrature power divider, ELOAmplitude, omega, of the local oscillator signalIFAt an intermediate frequency, kRF_LOIs the power division coefficient, k, of the power dividerconvThe frequency conversion gain of the down-conversion module; according to the formula, the cancellation ratio of the system can be obtained quantitatively.
10. The analog cancellation method according to claim 8, wherein in step S2, the local oscillator signal is XLO(t), the weights of the same-phase path and the orthogonal path are WI(t) and WQ(t) error signal is Xerr(t)；
The second reference signal XS2(t) is divided into a first in-phase signal X after passing through a first quadrature power dividerS21(t) and a first quadrature path signal XS22(t)；
In-phase path signal XS21(t) and quadrature path signal XS22(t) feeding to a vector modulation module;
the vector modulation module weights the weight value input by the control module to obtain a cancellation signal Y (t) ═ WI(t)XS21(t)+WQ(t)XS22(t)；
The vector modulation module sends the cancellation signal to a synthesis feedback module, and the cancellation signal is synthesized with the interference signal to obtain an error signal Xerr(t)＝XI(t)-Y(t)；
The error signal is fed back to the second down-conversion module and the control module, and the system adopts an LMS algorithm to find the optimal weight value to form a closed-loop signal processing process.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113824458A (en) * 2021-11-23 2021-12-21 湖北工业大学 Three-channel self-adaptive co-location broadband interference suppression method and system
CN114448759A (en) * 2022-02-07 2022-05-06 北京融为科技有限公司 Interference cancellation system suitable for non-local oscillator homologous dual polarized signals
CN115955258A (en) * 2023-03-13 2023-04-11 中国人民解放军国防科技大学 Navigation signal receiving and transmitting isolation self-adaptive cancellation method based on reference waveform

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107645299A (en) * 2017-09-19 2018-01-30 中国人民解放军海军工程大学 Adaptation control circuit and control method for adaptive interference cancellation device
CN109120288A (en) * 2018-09-30 2019-01-01 中国人民解放军海军工程大学 Radio frequency adaptive interference cancellation device and its adjustment method
CN109150215A (en) * 2018-09-30 2019-01-04 中国人民解放军海军工程大学 Numerical model analysis adaptive interference cancellation device
CN109274388A (en) * 2018-09-30 2019-01-25 中国人民解放军海军工程大学 The radio frequency compensation device and its method of numeric field interference reconstruct
CN109412639A (en) * 2018-09-30 2019-03-01 中国人民解放军海军工程大学 Microwave communication common-frequency interference preventer
CN109495090A (en) * 2018-09-30 2019-03-19 中国人民解放军海军工程大学 Digital precise delay match circuit

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107645299A (en) * 2017-09-19 2018-01-30 中国人民解放军海军工程大学 Adaptation control circuit and control method for adaptive interference cancellation device
CN109120288A (en) * 2018-09-30 2019-01-01 中国人民解放军海军工程大学 Radio frequency adaptive interference cancellation device and its adjustment method
CN109150215A (en) * 2018-09-30 2019-01-04 中国人民解放军海军工程大学 Numerical model analysis adaptive interference cancellation device
CN109274388A (en) * 2018-09-30 2019-01-25 中国人民解放军海军工程大学 The radio frequency compensation device and its method of numeric field interference reconstruct
CN109412639A (en) * 2018-09-30 2019-03-01 中国人民解放军海军工程大学 Microwave communication common-frequency interference preventer
CN109495090A (en) * 2018-09-30 2019-03-19 中国人民解放军海军工程大学 Digital precise delay match circuit

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
张鹏: "《FMCW雷达射频对消系统的研究与基带设计》", 《中国优秀硕士学位论文全文数据库信息科技辑》 *
潘云龙: "《射频干扰对消系统理论与技术研究》", 《中国博士学位论文全文数据库信息科技辑》 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113824458A (en) * 2021-11-23 2021-12-21 湖北工业大学 Three-channel self-adaptive co-location broadband interference suppression method and system
CN113824458B (en) * 2021-11-23 2022-02-15 湖北工业大学 Three-channel self-adaptive co-location broadband interference suppression method and system
CN114448759A (en) * 2022-02-07 2022-05-06 北京融为科技有限公司 Interference cancellation system suitable for non-local oscillator homologous dual polarized signals
CN114448759B (en) * 2022-02-07 2024-01-09 北京融为科技有限公司 Interference cancellation system suitable for non-local oscillator homologous dual-polarized signals
CN115955258A (en) * 2023-03-13 2023-04-11 中国人民解放军国防科技大学 Navigation signal receiving and transmitting isolation self-adaptive cancellation method based on reference waveform
CN115955258B (en) * 2023-03-13 2023-05-30 中国人民解放军国防科技大学 Navigation signal receiving and transmitting isolation self-adaptive cancellation method based on reference waveform

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