CN111585594A - Interference cancellation device and method based on cascade digital control method - Google Patents
Interference cancellation device and method based on cascade digital control method Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- 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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- 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
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- 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
- H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
- H04B1/40—Circuits
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- H04B1/52—Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa
- H04B1/525—Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa with means for reducing leakage of transmitter signal into the receiver
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Abstract
The invention discloses an interference cancellation device and method based on a cascade digital control method, wherein the device comprises a digital radio frequency storage subsystem, a digital control analog cancellation subsystem and a digital control digital cancellation subsystem; the input end of the digital radio frequency storage subsystem receives the co-location interference signal, digitalizes the co-location interference signal, estimates the delay matching error of the system and performs delay matching processing; the digital control analog cancellation subsystem and the digital control digital cancellation subsystem form a two-stage cascade cancellation processing mode for the co-located interference signals, and the co-located interference signals are suppressed; the cancellation method comprises the following steps: initializing a system; the delay matching control unit estimates a system delay matching error and carries out delay matching processing; carrying out two-stage interference cancellation processing on the co-located interference signals; and outputting the cancelled signal to an interfered receiver through a third radio frequency transmission link, and finally realizing suppression on the co-located interference signal.
Description
Technical Field
The invention relates to the field of electromagnetic compatibility, in particular to an interference cancellation device and method based on a cascade digital control method.
Background
At present, a plurality of radio frequency transceivers are commonly and densely deployed on modern military platforms such as ships, airplanes, satellites and vehicles; such radio frequency transceivers are typically communication stations, data links, radar, navigation and positioning systems, electronic warfare equipment, friend or foe identification systems, and detection equipment, among others.
Electromagnetic energy emitted by a radio frequency transmitter in the radio frequency transceiver is often coupled to the radio frequency receiver in the same platform through radiation, conduction and other modes to form interference on the radio frequency receiver, which is called co-site interference or self-interference, and the co-site interference causes the performance of the radio frequency receiver to be reduced or even fails.
The method has the advantages that the co-site interference of military platforms is inhibited, and the electromagnetic compatibility between radio frequency transceivers is realized, so that the method has urgent military requirements and important military significance.
In the prior art, the self-adaptive interference cancellation technology is an effective technical means for inhibiting co-site interference and realizing electromagnetic compatibility between military platform radio frequency transceivers; the basic idea is as follows: and constructing a signal which has the same amplitude and opposite phase with the common-address interference signal, and overlapping the signal with the interference signal, thereby forming a cancellation effect on the interference signal.
With the information deep development of military platforms, the electromagnetic compatibility between the radio frequency transceivers of the military platforms is faced with a new challenge by using the adaptive interference cancellation technology, and the existing adaptive interference cancellation technology has the following defects: firstly, the existing interference cancellation system can not be involved in the digital baseband part of the transceiver generally, and can only carry out signal interaction with the external interface of the transceiver through a radio frequency cable; secondly, the electromagnetic environment of a battlefield is complex and changeable, the interference source and the propagation characteristic of co-site interference often have the characteristic of rapid change, and the rapid convergence and rapid tracking capability of the existing interference cancellation system is insufficient; third, military transceivers present the current state and trend of broadband, and interference cancellation systems are not capable of dealing with broadband interference signals. Fourthly, the high-sensitivity receiver faces a high-power interference source, and the interference cancellation system is difficult to provide enough interference suppression capability to suppress interference to the vicinity of the bottom noise of the receiver; fifth, sampling the interfering signal with the coupler, often accompanied by insertion loss, reduces the effective operating range of the radio frequency transmitter.
In order to solve the above problems, the patent application with the application number of CN201811155774.6 proposes a digital domain interference reconstruction radio frequency cancellation apparatus and a method thereof, the apparatus includes modules such as a digital delay, an interference reconstruction model, a coefficient identification algorithm, a digital-to-analog converter, a cancellation link, a combiner, etc., wherein the digital delay, the interference reconstruction model and the coefficient identification algorithm are operated on a digital signal processing device; the cancellation method comprises the following steps: establishing an interference reconstruction model according to the characteristics of a transmitting link, a wireless channel and a cancellation link; aligning the received and transmitted digital signals by realizing digital delay according to the received and transmitted digital signals; static coefficient identification of the model coefficient is realized by utilizing the digital delay data and the received data; the technology solves the problem of broadband interference signal cancellation capability, but has the technical problem of needing to intervene in a digital baseband part of a radio frequency transceiver.
In addition, patent with application number CN201010538860.2 proposes a co-location coupling interference tracking cancellation device, which is composed of a directional coupler, an electric tuning trap and a phase-locked loop circuit; the input end of the directional coupler is connected with a receiving antenna, the output end of the directional coupler is connected with the input end of the electric modulation wave trap, and the coupling end of the directional coupler is connected with the input end of the phase-locked loop circuit; the output end of the electric modulation wave trap is connected with the receiver, and the control end of the electric modulation wave trap is connected with the output end of the phase-locked loop circuit; the technology does not need to intervene in a digital baseband part of a radio frequency transceiver, but has the problems of difficult application to broadband interference, low convergence speed and the like.
Another patent with application number CN201320001505.0 proposes an adaptive wideband interference cancellation apparatus, which includes a first coupler, a delay unit, and an adaptive cancellation system, where the adaptive cancellation system includes: phase shifter, adjustable attenuator, correlator, coupler and synthesizer; the adjustable attenuator of the self-adaptive cancellation system is divided into a first adjustable attenuator and a second adjustable attenuator; the correlator is divided into a first correlator and a second correlator; the coupler is divided into a second coupler and a third coupler; the technology solves the problem of broadband interference signal cancellation, but has the problems that the interference signal sampling is accompanied by insertion loss, and the cancellation ratio and the convergence speed are limited.
As can be seen from the above analysis, the prior art cannot meet the strict requirement of the electromagnetic compatibility of the transceiver of the military platform, and therefore, an interference cancellation apparatus and method based on the cascaded digital control method are needed to solve the prior art problems.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide an interference cancellation device and method based on a cascade digital control method, which introduces a digital radio frequency storage technology into an interference cancellation system, digitalizes an interference source signal (namely a reference signal), and solves the problem that the interference cancellation system is restricted by being incapable of being involved in a digital baseband part of a transmitter; the digital control analog cancellation subsystem and the digital control digital cancellation subsystem are adopted to carry out two-stage cascade cancellation processing on the co-location interference, so that the rapid and deep cancellation of the broadband co-location interference is realized.
The invention is realized by the following technical scheme.
An interference cancellation device based on a cascade digital control method comprises a digital radio frequency storage subsystem, a digital control analog cancellation subsystem and a digital control digital cancellation subsystem; the input end of the digital radio frequency storage subsystem receives an interference source signal, digitalizes the interference source signal, estimates a system delay matching error and performs delay matching processing; the digital control analog cancellation subsystem and the digital control digital cancellation subsystem form a two-stage cascade cancellation processing mode for the co-located interference signals, and the co-located interference signals are suppressed.
Further, the digital radio frequency storage subsystem comprises: the system comprises a first radio frequency receiving link, a first radio frequency transmitting link, a digital delay module and a delay matching control unit;
the first radio frequency receiving link receives an interference source signal and converts the interference source signal into a digital signal to form a digital baseband signal, and the digital baseband generated by the first radio frequency receiving link is respectively transmitted to the digital delay module and the delay matching control unit;
the delay matching control unit estimates a system delay matching error according to a cross-correlation function between two input signals, and then transmits the system delay matching error to a digital delay module;
the digital delay module carries out delay processing on the interference source signal according to the system delay matching error input by the delay matching control unit and transmits the processed signal to a first radio frequency transmitting link;
the output end of the first radio frequency transmission link is provided with a transmission output port, the output end of the transmission output port is provided with a transmission antenna, and the interference source signal subjected to the delay matching processing is converted into an analog signal by the first radio frequency transmission link and is transmitted out through the transmission output port and the transmission antenna.
Furthermore, the digital control analog cancellation subsystem realizes control on the co-location interference signal in a digital signal domain and realizes suppression on the co-location interference signal in an analog signal domain, and comprises a second radio frequency receiving link, a second radio frequency transmitting link, an analog cancellation digital control module and a combiner;
the second radio frequency receiving link converts the analog radio frequency signal output from the combiner into a digital baseband signal and transmits the digital baseband signal to the analog cancellation digital control module and the delay matching control unit;
the analog cancellation digital control module is a finite length single-bit impulse response adaptive filter;
the analog cancellation digital control module receives a digital baseband signal generated by the first radio frequency receiving link and a digital baseband signal output by the second radio frequency receiving link, forms a digital baseband signal of a first-stage interference cancellation signal after operation, and transmits the digital baseband signal of the first-stage interference cancellation signal to the second radio frequency transmitting link;
the second radio frequency transmitting link converts the digital baseband signal of the first-stage interference cancellation signal into an analog radio frequency signal of the first-stage interference cancellation signal and transmits the analog radio frequency signal to the combiner;
the combiner receives the co-location interference signal caused by the transmitting antenna through a receiving input port and a receiving antenna;
the combiner superposes the analog radio frequency signal of the first-stage interference cancellation signal and the co-location interference signal, so as to cancel a part of the co-location interference signal;
the second radio frequency receiving link, the second radio frequency transmitting link, the analog cancellation digital control module and the combiner form a closed loop operation system, and continuous iteration cancellation is carried out on the co-location interference signals.
Furthermore, the digital control digital cancellation subsystem realizes control and suppression on the co-located interference signal in a digital signal domain; the digital control digital cancellation module comprises a third radio frequency transmission link and a digital control digital cancellation module;
the digital cancellation digital control module is formed by cascading a linear filter, a memoryless nonlinear filter and a linear filter in sequence;
one input end of the digital cancellation digital control module receives a digital baseband signal output by the second radio frequency receiving link;
the other input end of the digital cancellation digital control module receives a digital baseband signal output by the first radio frequency receiving link;
after the digital cancellation digital control module operates the two input signals, second-stage interference cancellation is completed, and digital baseband signals after the interference cancellation are generated;
the input end of the third radio frequency transmission link is connected with the output end of the digital cancellation digital control module, and the digital baseband signal after the second-stage interference cancellation output by the digital cancellation digital control module is converted into an analog radio frequency signal;
and the output end of the third radio frequency transmission link is provided with a receiving output port, and the analog radio frequency signal is output through the receiving port.
The cancellation method of the interference cancellation device based on the cascade digital control method comprises the following steps:
step S1, initializing the system; the output signal of the digital control analog cancellation subsystem is zero, the output signal of the second radio frequency transmission link is also approximate to zero at the moment, and the digital control analog cancellation subsystem does not play a role in restraining co-location interference temporarily;
step S2, the delay matching control unit in the digital radio frequency storage subsystem estimates the system delay matching error and carries out the delay matching processing;
step S3, using digital control analog cancellation subsystem to process the first-stage interference cancellation;
step S4, using digital control digital cancellation subsystem to process the second interference cancellation;
in step S5, the third rf transmitting link converts the digital baseband signal of the cancellation signal into an analog rf signal, and outputs the analog rf signal through the receiving output port.
Further, in step S1, the delay time τ of the digital delay module in the digital rf storage subsystem is initializedDRFMIs tau0：
τ0＝τRX1+τDA+τTX3
Wherein, tauRX1For the delay of the first RF receive chain module, τDAFor analog cancellation of delay of the digital control block, tauTX3Is the delay of the second radio frequency transmit chain module.
Further, in step S2, the system delay matching error is a time difference Δ τ between arrival of the interference source signal at the two input ports of the combiner:
Δτ＝τ0-τ1
wherein tau is1＝τRX1+τDRFM+τTX1+τCoupling of；τTX1For the delay of the first radio frequency transmission chain, tauCoupling ofA transmission delay for interference coupled from the transmit antenna to the receive antenna;
furthermore, the time difference Λ τ between the first rf receiving chain output signal and the second rf receiving chain output signal is obtained by calculating the cross-correlation function of the two signals, because Λ τ is equal to Λ τRX1-(τRX1+τDRFM+τTX1+τCoupling of+τCombiner+τRX2) Therefore, Δ τ is Λ τ + τDA+τTX3-τCombiner-τRX2(ii) a Wherein, tauCombinerIs the delay of the combiner; tau isRX2Delay for the second radio frequency receive chain; in the above formula, τDA,τTX3,τCombiner,τRX2The device of the invention has known constant value, therefore the estimated value of Λ tau can be obtained to obtain the estimated value of delta tau, after the estimated value of the system delay matching error delta tau is obtained, the delay time tau of the digital delay module is adjustedDRFMLet Δ τ be zero.
Further, in step S3, the analog cancellation digital control module outputs a signal of
Wherein n represents a sampling order of the digital signal; d (n) is the output signal of the second radio frequency receiving chain and is used as the expected signal of the self-adaptive filter; u (n) is the output signal of the first radio frequency receiving link and is used as the multi-tap input of the self-adaptive filter;
the coefficients of the adaptive filter at time n-1.
Further, in step S4, the digital cancellation digital control module is formed by cascading a linear filter l (), a memoryless nonlinear filter c (), and a linear filter g () in sequence(ii) a Let e (n) be the output signal of the digital control digital cancellation subsystem, v1(n),v2(n) are the input and output, respectively, of the non-linear filter c (then,
e(n)＝d(n)-y(n)
wherein psi (n) is an input signal of the digital control digital cancellation system; v. of1(n) is the output signal of the linear filter i (i), i.e. the input signal of the non-linear filter c (i); l (i), i ═ 0., Ml-1 is the coefficient of the linear filter l (); mlIs the length of the linear filter l (.); v. of2(n) is the output signal of the non-linear filter c (i.e., the input signal of the linear filter g.); c (P), P being 0, P being the coefficient of the linear filter c (); p is the maximum order of the nonlinear filter c (.); y (n) is the output signal of the linear filter g (.); g (i), i ═ 0.., Mg-1 is the coefficient of the linear filter g (); mgIs the length of the linear filter g (.).
Compared with the prior art, the invention has the beneficial effects that:
1) the invention introduces the digital radio frequency storage technology into the interference cancellation system for the first time, carries out digital processing on an interference source signal (namely a reference signal), solves the problem that the interference cancellation system is restricted by being incapable of being inserted into a digital baseband part of a transmitter, and ensures that the application of the digital control analog cancellation technology to co-location interference suppression has practical feasibility;
2) the invention utilizes the digital delay module and the delay matching control technology in the digital radio frequency storage technology to digitally delay the interference source signal, and solves the problem that the digital control analog cancellation technology can not realize delay matching in the application of restraining co-location interference, thereby ensuring that the application of the digital control analog cancellation technology to the co-location interference suppression has practical feasibility;
3) the invention utilizes the digital radio frequency storage technology to realize the reference sampling without insertion loss and solve the problem that the transmitting power of a transmitter is lost in the traditional reference sampling process based on a coupler, thereby reducing the maximum working distance of the transmitter;
4) the invention adopts a strategy of two-stage cascade interference cancellation and a digital control mode, has very strong flexibility of an interference cancellation algorithm, is beneficial to improving the interference cancellation ratio, the convergence speed and the tracking speed of the interference cancellation, the interference cancellation bandwidth and the like, and is suitable for recovering weak useful signals in high-power broadband interference.
Drawings
FIG. 1 is a functional block diagram of the present invention;
fig. 2 is a block diagram illustrating a first transmission link according to the present invention;
FIG. 3 is a block diagram of a first RF receiving link according to the present invention;
FIG. 4 is a schematic view of a method of use of the present invention;
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, the interference cancellation apparatus based on the cascaded digital control method provided by the present invention includes: the digital radio frequency storage subsystem, the digital control analog cancellation subsystem and the digital control digital cancellation subsystem;
an input end of the digital radio frequency storage subsystem receives an interference source signal (namely a reference signal); the digital radio frequency storage subsystem carries out digital processing on an interference source signal, so that an interference cancellation system indirectly obtains a digital baseband signal of a radio frequency transmitter, estimates a system delay matching error, carries out delay matching processing and finally outputs the interference source signal subjected to delay processing;
the digital control analog cancellation subsystem and the digital control digital cancellation subsystem form a two-stage cascade cancellation processing mode for the co-located interference signals;
the digital control analog cancellation subsystem controls the interference source signal in a digital signal domain and suppresses the co-location interference signal in an analog signal domain so as to avoid the quantization noise limitation of an analog-digital converter and has broadband cancellation capability;
the digital control digital cancellation subsystem realizes control and suppression of the co-location interference signal in a digital signal domain, and utilizes a digital signal processing technology and algorithm optimization design to accurately model and estimate the interference signal and quickly suppress the co-location interference signal.
The digital radio frequency storage subsystem includes: the system comprises a first radio frequency receiving link, a first radio frequency transmitting link, a digital delay module and a delay matching control unit;
the input end of the first radio frequency receiving link is provided with a transmitting input port;
the first radio frequency receiving link receives an interference source signal through a transmitting input port and carries out digital processing on the interference source signal to generate a digital baseband signal;
the first radio frequency receiving link respectively transmits the digital baseband signals to the digital delay module and the delay matching control unit;
the delay matching control unit estimates a system delay matching error according to a cross-correlation function between the output signal of the first radio frequency receiving link and the output signal of the second radio frequency receiving link, and then transmits the system delay matching error to the digital delay module;
the digital delay module carries out delay processing on the interference source signal according to the system delay matching error input by the delay matching control unit and transmits the processed signal to a first radio frequency transmitting link;
the first radio frequency transmission link simulates an input signal;
the output end of the first radio frequency transmission link is provided with a transmission output port;
the output end of the transmitting output port is provided with a transmitting antenna;
the interference source signal after the delay matching processing is converted into an analog signal by the first radio frequency transmission link and is transmitted out through the transmission output port and the transmission antenna.
The digital control analog cancellation subsystem comprises: the second radio frequency receiving link, the second radio frequency transmitting link, the analog cancellation digital control module and the combiner are arranged;
the input end of the combiner is provided with a receiving input port;
the input end of the receiving input port is provided with a receiving antenna;
the receiving antenna receives an interference source signal output by the transmitting output port through a self-interference coupling path to form a co-location interference signal and also receives useful signals sent from other radio frequency transmitters;
the other input end of the combiner is connected with the output end of the second radio frequency transmitting link;
the output end of the combiner is connected with the input end of the second radio frequency receiving link;
the output end of the second radio frequency receiving link is connected with the input end of the analog cancellation digital control module;
the other input end of the analog cancellation digital control module is connected with the first radio frequency receiving link and receives a digital baseband signal output by the first radio frequency receiving link;
the output end of the analog cancellation digital control module is connected with the input end of the second radio frequency transmission link;
the combiner receives the co-location interference signal caused by the transmitting antenna through the receiving input port and the receiving antenna;
the second radio frequency receiving link converts the analog radio frequency signal output from the combiner into a digital baseband signal and transmits the digital baseband signal to the analog cancellation digital control module; the analog cancellation digital control module is a finite-length unit impulse response (FIR) self-adaptive filter;
the analog cancellation digital control module receives a digital baseband signal output by the first radio frequency receiving link and a digital baseband signal output by the second radio frequency receiving link, forms a digital baseband signal of a first-stage interference cancellation signal after operation, and transmits the digital baseband signal of the first-stage interference cancellation signal to the second radio frequency transmitting link;
the second radio frequency transmitting link converts the digital baseband signal of the first-stage interference cancellation signal into an analog radio frequency signal of the first-stage interference cancellation signal and transmits the analog radio frequency signal to the combiner;
the combiner superposes the analog radio frequency signal of the first-stage interference cancellation signal and the co-location interference signal, so as to cancel a part of the co-location interference signal;
the second radio frequency receiving link, the second radio frequency transmitting link, the analog cancellation digital control module and the combiner form a closed loop operation system, and continuous iteration cancellation is carried out on the co-location interference signals.
The digital control digital cancellation subsystem comprises: a third radio frequency transmission link and a digital control digital cancellation module;
the digital cancellation digital control module is formed by cascading a linear filter, a memoryless nonlinear filter and a linear filter in sequence;
the input end of the digital cancellation digital control module is connected with the other output end of the second radio frequency receiving link and receives a digital baseband signal output by the second radio frequency receiving link;
the other input end of the digital cancellation digital control module is connected with one output end of the first radio frequency receiving link and receives a digital baseband signal output by the first radio frequency receiving link;
after the digital cancellation digital control module operates the two input signals, second-stage interference cancellation is completed, a digital baseband signal after the interference cancellation is generated, and at the moment, the co-location interference signal after the two-stage cancellation is further suppressed;
the input end of the third radio frequency transmission link is connected with the output end of the digital cancellation digital control module, and the digital baseband signal after the second-stage interference cancellation output by the digital cancellation digital control module is converted into an analog radio frequency signal;
and the output end of the third radio frequency transmission link is provided with a receiving output port, and the analog radio frequency signal is output through the receiving port.
As shown in fig. 2, the first rf receiving chain includes: low noise amplifiers, mixers, operational amplifiers, analog filters, analog-to-digital converters (ADCs), Half Band Filters (HBFs), and digital filters; the low noise amplifier, the frequency mixer, the operational amplifier, the analog filter, the analog-to-digital converter (ADC), the half-band filter (HBF) and the digital filter are electrically connected in sequence, or are formed by cascading partial components in sequence according to functional requirements;
the low noise amplifier, the mixer, the operational amplifier, the analog filter, the analog-to-digital converter (ADC), the Half Band Filter (HBF) and the digital filter jointly form a radio frequency receiving link, and the radio frequency receiving link has the function of converting an analog radio frequency signal into a digital baseband signal after power adjustment, frequency domain filtering and down-conversion.
The second radio frequency receiving link is consistent with the first radio frequency receiving link in structure.
As shown in fig. 3, the first rf transmit chain includes: digital filters, Half Band Filters (HBFs), digital to analog converters (DACs), analog filters, mixers, and power amplifiers; the filter, the half-band filter (HBF), the digital-to-analog converter (DAC), the analog filter, the frequency mixer and the power amplifier are electrically connected in sequence, or are formed by cascading partial components in sequence according to functional requirements;
the second radio frequency transmitting link and the third radio frequency transmitting link have the same structure with the first radio frequency transmitting link;
the digital filter, the half-band filter (HBF), the digital-to-analog converter (DAC), the analog filter, the mixer and the power amplifier jointly form a radio frequency transmitting link, and the radio frequency transmitting link has the function of converting a digital baseband signal into an analog radio frequency signal after frequency domain filtering, up-conversion and power adjustment.
The first radio frequency receiving chain, the second radio frequency receiving chain, the first radio frequency transmitting chain, the second radio frequency transmitting chain and the third radio frequency transmitting chain are all integrated with gain control capability.
The first radio frequency receiving link, the second radio frequency receiving link, the first radio frequency transmitting link, the second radio frequency transmitting link, the third radio frequency transmitting link and the combiner exist in a hardware form;
the digital delay module, the delay matching control unit, the analog cancellation digital control module and the digital cancellation digital control module exist in the form of logic codes or software codes inside a digital signal processing device (such as a field programmable logic array chip, a digital signal processing chip, a CPU chip and the like).
The interference cancellation method based on the cascade digital control method comprises the following steps:
step S1, initializing the system;
the output signal of the digital control analog cancellation subsystem is zero, and the output signal of the second radio frequency transmission link is also approximate to zero at the moment; the digital control analog cancellation subsystem temporarily does not play a role in restraining co-location interference;
initializing delay time tau of digital delay module in digital radio frequency storage subsystemDRFMIs tau0：
τ0＝τRX1+τDA+τTX3
Wherein, tauRX1For the delay of the first RF receive chain module, τDAFor analog cancellation of delay of the digital control block, tauTX3A delay for a second radio frequency transmit chain mode;
step S2, the delay matching control unit in the digital radio frequency storage subsystem estimates the system delay matching error and carries out the delay matching processing;
the system delay matching error is the time difference delta tau of the interference source signal reaching two input ports of the combiner;
Δτ＝τ0-τ1
wherein tau is1＝τRX1+τDRFM+τTX1+τCoupling of；τTX1For the delay of the first radio frequency transmission chain, tauCoupling ofA transmission delay for interference coupled from the transmit antenna to the receive antenna;
the time difference Λ τ between the first rf receive chain output signal and the second rf receive chain output signal is obtained by calculating the cross-correlation function of the two signals, because
Λτ＝τRX1-(τRX1+τDRFM+τTX1+τCoupling of+τCombiner+τRX2)
So that Δ τ is Λ τ + τDA+τTX3-τCombiner-τRX2
Wherein, tauCombinerIs the delay of the combiner; tau isRX2Delay for the second radio frequency receive chain; in the above formula, τDA,τTX3,τCombiner,τRX2Is a known constant value of the device, so that the estimated value of Λ tau can be obtained to obtain the estimated value of delta tau;
after the estimated value of the system delay matching error delta tau is obtained, the delay time tau of the digital delay module is adjustedDRFMLet Δ τ be zero.
Step S3, using digital control analog cancellation subsystem to process the first-stage interference cancellation;
the analog cancellation digital control module is a finite-length unit impulse response (FIR) adaptive filter, the output signal of which
Wherein n represents a sampling order of the digital signal; d (n) is the output signal of the second radio frequency receiving chain and is used as the expected signal of the self-adaptive filter; u (n) is the output signal of the first radio frequency receiving link and is used as the multi-tap input of the self-adaptive filter;
the coefficient of the FIR adaptive filter at the time n-1; the control algorithms of the adaptive filter commonly used are: least mean square error (LMS) algorithm, normalized LMS algorithm, Recursive Least Squares (RLS) algorithm, cardA kalman filter algorithm, etc.
The core algorithm of the digital control analog cancellation subsystem is used as the FIR adaptive filtering algorithm, and the main purposes are to suppress linear components in co-location interference, reduce the interference-to-signal ratio and prevent the interference-to-signal ratio from being larger than the dynamic range of an ADC (analog-to-digital converter) device in a second radio frequency receiving link; various other control and filtering methods may also be employed in this step.
Step S4, using digital control digital cancellation subsystem to process the second interference cancellation;
the digital cancellation digital control module is formed by cascading a linear filter l (), a memoryless nonlinear filter c (), and a linear filter g () according to a sequence; let e (n) be the output signal of the digital control digital cancellation subsystem, v1(n),v2(n) are the input and output, respectively, of the non-linear filter c (then,
e(n)＝d(n)-y(n)
wherein psi (n) is an input signal of the digital control digital cancellation system; v. of1(n) is the output signal of the linear filter i (i), i.e. the input signal of the non-linear filter c (i); l (i), i ═ 0., Ml-1 is the coefficient of the linear filter l (); mlIs the length of the linear filter l (.); v. of2(n) is the output signal of the non-linear filter c (i.e., the input signal of the linear filter g.); c (P), P being 0, P being the coefficient of the linear filter c (); p is the maximum order of the nonlinear filter c (.); y (n) is the output signal of the linear filter g (.); g (i), i ═ 0.., Mg-1 is the coefficient of the linear filter g (); mgIs the length of the linear filter g (.).
In step S5, the third rf transmitting link converts the digital baseband signal of the cancellation signal into an analog rf signal, and outputs the analog rf signal through the receiving output port.
The use method of the interference cancellation device based on the cascade digital control method disclosed by the invention is shown in FIG. 4; the transmitter is an interference source, and the receiver is an interfered device;
the transmitter is connected with the transmitting input port;
the receiver is connected with the receiving output port;
the interference source signal output by the transmitter enters the device through the transmitting input port, the co-location interference signal is suppressed after the cancellation processing of the device on the co-location interference signal and the useful signal, and the useful signal is transmitted to the receiver through the receiving output port.
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 interference cancellation device based on a cascade digital control method is characterized by comprising a digital radio frequency storage subsystem, a digital control analog cancellation subsystem and a digital control digital cancellation subsystem; the input end of the digital radio frequency storage subsystem receives an interference source signal, digitalizes the interference source signal, estimates a system delay matching error and performs delay matching processing; the digital control analog cancellation subsystem and the digital control digital cancellation subsystem form a two-stage cascade cancellation processing mode for the co-located interference signals, and the co-located interference signals are suppressed.
2. The apparatus of claim 1, wherein the digital radio frequency memory subsystem comprises: the system comprises a first radio frequency receiving link, a first radio frequency transmitting link, a digital delay module and a delay matching control unit;
the first radio frequency receiving link receives an interference source signal and converts the interference source signal into a digital signal to form a digital baseband signal, and the digital baseband signal generated by the first radio frequency receiving link is respectively transmitted to the digital delay module and the delay matching control unit;
the delay matching control unit estimates a system delay matching error according to a cross-correlation function between the output signal of the first radio frequency receiving link and the output signal of the second radio frequency receiving link, and then transmits the system delay matching error to the digital delay module;
the digital delay module carries out delay processing on the interference source signal according to the system delay matching error input by the delay matching control unit and transmits the processed signal to a first radio frequency transmitting link;
the output end of the first radio frequency transmission link is provided with a transmission output port, the output end of the transmission output port is provided with a transmission antenna, and the interference source signal subjected to the delay matching processing is converted into an analog signal by the first radio frequency transmission link and is transmitted out through the transmission output port and the transmission antenna.
3. The interference cancellation device based on the cascaded digital control method according to claim 2, wherein the digital control analog cancellation subsystem controls the co-located interference signal in the digital signal domain and suppresses the co-located interference signal in the analog signal domain, and includes a second rf receiving link, a second rf transmitting link, an analog cancellation digital control module and a combiner;
the second radio frequency receiving link converts the analog radio frequency signal output from the combiner into a digital baseband signal and transmits the digital baseband signal to the analog cancellation digital control module and the delay matching control unit;
the analog cancellation digital control module is a finite length single-bit impulse response adaptive filter;
the analog cancellation digital control module receives a digital baseband signal generated by the first radio frequency receiving link and a digital baseband signal output by the second radio frequency receiving link, forms a digital baseband signal of a first-stage interference cancellation signal after operation, and transmits the digital baseband signal of the first-stage interference cancellation signal to the second radio frequency transmitting link;
the second radio frequency transmitting link converts the digital baseband signal of the first-stage interference cancellation signal into a first-stage interference cancellation signal analog radio frequency signal and transmits the first-stage interference cancellation signal analog radio frequency signal to the combiner;
the combiner receives the co-location interference signal caused by the transmitting antenna through a receiving input port and a receiving antenna;
the combiner superposes the analog radio frequency signal of the first-stage interference cancellation signal and the co-location interference signal, so as to cancel a part of the co-location interference signal;
the second radio frequency receiving link, the second radio frequency transmitting link, the analog cancellation digital control module and the combiner form a closed loop operation system, and continuous iteration cancellation is carried out on the co-location interference signals.
4. The interference cancellation device based on the cascaded digital control method according to claim 3, wherein the digital control digital cancellation subsystem controls and suppresses the co-located interference signals in a digital signal domain; the digital control digital cancellation module comprises a third radio frequency transmission link and a digital control digital cancellation module;
the digital cancellation digital control module is formed by cascading a linear filter, a memoryless nonlinear filter and a linear filter in sequence;
one input end of the digital cancellation digital control module receives a digital baseband signal output by the second radio frequency receiving link;
the other input end of the digital cancellation digital control module receives a digital baseband signal output by the first radio frequency receiving link;
after the digital cancellation digital control module operates the two input signals, second-stage interference cancellation is completed, and digital baseband signals after the interference cancellation are generated;
the input end of the third radio frequency transmission link is connected with the output end of the digital cancellation digital control module, and the digital baseband signal after the second-stage interference cancellation output by the digital cancellation digital control module is converted into an analog radio frequency signal;
and the output end of the third radio frequency transmission link is provided with a receiving output port, and the analog radio frequency signal is output through the receiving port.
5. The cancellation method of the interference cancellation device based on the cascaded digital control method according to claim 1, comprising the steps of:
step S1, initializing the system; the output signal of the digital control analog cancellation subsystem is zero, the output signal of the second radio frequency transmission link is also approximate to zero at the moment, and the digital control analog cancellation subsystem does not play a role in restraining co-location interference temporarily;
step S2, the delay matching control unit in the digital radio frequency storage subsystem estimates the system delay matching error and carries out the delay matching processing;
step S3, using digital control analog cancellation subsystem to process the first-stage interference cancellation;
step S4, using digital control digital cancellation subsystem to process the second interference cancellation;
in step S5, the third rf transmitting link converts the digital baseband signal of the cancellation signal into an analog rf signal, and outputs the analog rf signal through the receiving output port.
6. The method of claim 5, wherein in step S1, the delay time τ of the digital delay module in the digital RF storage subsystem is initializedDRFMIs tau0：
τ0＝τRX1+τDA+τTX3
Wherein, tauRX1For the delay of the first RF receiving chain, τDAFor analog cancellation of delay of the digital control block, tauTX3Is the delay of the second radio frequency transmit chain.
7. The method of claim 5, wherein in step S2, the system delay matching error is the time difference Δ τ between the arrival of the aggressor signal at the two input ports of the combiner:
Δτ＝τ0-τ1
wherein tau is1＝τRX1+τDRFM+τTX1+τCoupling of；τTX1For the delay of the first radio frequency transmission chain, tauCoupling ofTo interfere with the transmission delay coupling from the transmit antenna to the receive antenna.
8. The method of claim 7, wherein the time difference Λ τ is obtained by calculating the cross-correlation function of the first RF receiving chain output signal and the second RF receiving chain output signal, because Λ τ is equal to τRX1-(τRX1+τDRFM+τTX1+τCoupling of+τCombiner+τRX2) Therefore, Δ τ is Λ τ + τDA+τTX3-τCombiner-τRX2(ii) a Wherein, tauCombinerIs the delay of the combiner; tau isRX2Delay for the second radio frequency receive chain; in the above formula, τDA,τTX3,τCombiner,τRX2The device of the invention has known constant value, therefore the estimated value of Λ tau can be obtained to obtain the estimated value of delta tau, after the estimated value of the system delay matching error delta tau is obtained, the delay time tau of the digital delay module is adjustedDRFMLet Δ τ be zero.
9. The method of claim 5, wherein in step S3, the output signal of the analog cancellation digital control module is
Wherein n represents a sampling order of the digital signal; d (n) is the output signal of the second radio frequency receiving chain and is used as the expected signal of the self-adaptive filter; u (n) is the output signal of the first radio frequency receiving link and is used as the multi-tap input of the self-adaptive filter;
the coefficients of the adaptive filter at time n-1.
10. The method according to claim 5, wherein in step S4, the digital cancellation digital control module is formed by cascading a linear filter l (), a memoryless non-linear filter c (), and a linear filter g () in sequence; let e (n) be the output signal of the digital control digital cancellation subsystem, v1(n),v2(n) are the input and output, respectively, of the non-linear filter c (then,
e(n)＝d(n)-y(n)
wherein psi (n) is an input signal of the digital control digital cancellation system; v. of1(n) is the output signal of the linear filter i (i), i.e. the input signal of the non-linear filter c (i); l (i), i ═ 0., Ml-1 is the coefficient of the linear filter l (); mlIs the length of the linear filter l (.); v. of2(n) is the output signal of the non-linear filter c (i.e., the input signal of the linear filter g.); c (P), P being 0, P being the coefficient of the linear filter c (); p is the maximum order of the nonlinear filter c (.); y (n) is a linear filter g (n)Output signal of.); g (i), i ═ 0.., Mg-1 is the coefficient of the linear filter g (); mgIs the length of the linear filter g (.).
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113067150A (en) * | 2021-03-31 | 2021-07-02 | 北京北木波谱科技有限公司 | Anti-interference antenna and control method for anti-interference antenna |
| CN113438035A (en) * | 2021-08-26 | 2021-09-24 | 中国人民解放军海军工程大学 | Interference protector for ultrashort wave radio station |
| CN113922867A (en) * | 2021-12-13 | 2022-01-11 | 中国人民解放军海军工程大学 | Non-cooperative interference cancellation device and method for partial frequency band protection |
| CN113938149A (en) * | 2021-12-08 | 2022-01-14 | 中国电子科技集团公司第三十六研究所 | Radio frequency interference canceller and method |
| CN116032707A (en) * | 2022-12-15 | 2023-04-28 | 航天行云科技有限公司 | TDD wireless communication anti-interference method and device |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101754480A (en) * | 2010-02-03 | 2010-06-23 | 西安交通大学 | Global system for mobile communication (GSM) repeater and self-adaption interference cancellation method thereof |
| CN104518808A (en) * | 2013-09-29 | 2015-04-15 | 华为技术有限公司 | Equipment and method for eliminating self-interference signals |
| CN105493416A (en) * | 2013-08-29 | 2016-04-13 | 库姆网络公司 | Full-duplex relays |
| CN105812020A (en) * | 2016-04-29 | 2016-07-27 | 湖北工业大学 | High-isolation transmit-receive common antenna duplexer and method for improving isolation |
| CN105933015A (en) * | 2016-07-06 | 2016-09-07 | 中国电子科技集团公司第三十六研究所 | Radio frequency digital interference canceller |
| 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 |
| CN110518933A (en) * | 2018-05-22 | 2019-11-29 | 北京三星通信技术研究有限公司 | Full-duplex transceiver, electronic equipment and exchange method |
-
2020
- 2020-03-27 CN CN202010230453.9A patent/CN111585594B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101754480A (en) * | 2010-02-03 | 2010-06-23 | 西安交通大学 | Global system for mobile communication (GSM) repeater and self-adaption interference cancellation method thereof |
| CN105493416A (en) * | 2013-08-29 | 2016-04-13 | 库姆网络公司 | Full-duplex relays |
| CN104518808A (en) * | 2013-09-29 | 2015-04-15 | 华为技术有限公司 | Equipment and method for eliminating self-interference signals |
| CN105812020A (en) * | 2016-04-29 | 2016-07-27 | 湖北工业大学 | High-isolation transmit-receive common antenna duplexer and method for improving isolation |
| CN105933015A (en) * | 2016-07-06 | 2016-09-07 | 中国电子科技集团公司第三十六研究所 | Radio frequency digital interference canceller |
| CN110518933A (en) * | 2018-05-22 | 2019-11-29 | 北京三星通信技术研究有限公司 | Full-duplex transceiver, electronic equipment and exchange method |
| 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 |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113067150A (en) * | 2021-03-31 | 2021-07-02 | 北京北木波谱科技有限公司 | Anti-interference antenna and control method for anti-interference antenna |
| CN113438035A (en) * | 2021-08-26 | 2021-09-24 | 中国人民解放军海军工程大学 | Interference protector for ultrashort wave radio station |
| CN113438035B (en) * | 2021-08-26 | 2021-12-31 | 中国人民解放军海军工程大学 | Interference protector for ultrashort wave radio station |
| CN113938149A (en) * | 2021-12-08 | 2022-01-14 | 中国电子科技集团公司第三十六研究所 | Radio frequency interference canceller and method |
| CN113938149B (en) * | 2021-12-08 | 2022-11-08 | 中国电子科技集团公司第三十六研究所 | Radio frequency interference canceller and method |
| CN113922867A (en) * | 2021-12-13 | 2022-01-11 | 中国人民解放军海军工程大学 | Non-cooperative interference cancellation device and method for partial frequency band protection |
| CN113922867B (en) * | 2021-12-13 | 2022-02-22 | 中国人民解放军海军工程大学 | Non-cooperative interference cancellation device and method for partial frequency band protection |
| CN116032707A (en) * | 2022-12-15 | 2023-04-28 | 航天行云科技有限公司 | TDD wireless communication anti-interference method and device |
| CN116032707B (en) * | 2022-12-15 | 2024-01-30 | 航天行云科技有限公司 | TDD wireless communication anti-interference method and device |
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