CN105634539B - A kind of interference elimination method and device - Google Patents
A kind of interference elimination method and device Download PDFInfo
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- CN105634539B CN105634539B CN201511033616.XA CN201511033616A CN105634539B CN 105634539 B CN105634539 B CN 105634539B CN 201511033616 A CN201511033616 A CN 201511033616A CN 105634539 B CN105634539 B CN 105634539B
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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
- H04B1/50—Circuits using different frequencies for the two directions of communication
- 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
This application involves field of communication technology more particularly to a kind of interference elimination methods and device, including：Receive the first baseband signal；Receive the first baseband signal；It is determined from least one multistage nonlinear terms of the second baseband signal of transmission, it is corresponding with the self-interference signal being leaked in the first baseband signal, k rank nonlinear terms, and frequency spectrum shift is carried out to K rank nonlinear terms using predeterminated frequency offset, interference signal is obtained, k is positive integer；Calculate the first frequency offset between first baseband signal and interference signal；According to first frequency offset and the predeterminated frequency offset, frequency spectrum shift is carried out to each multistage nonlinear terms at least one multistage nonlinear terms respectively；Signal reconstruction is carried out using at least one multistage nonlinear terms after frequency spectrum shift, obtains reconstruction signal；And carry out interference elimination using the first baseband signal of reconstruction signal pair.
Description
Technical field
This application involves field of communication technology more particularly to a kind of interference elimination methods and device.
Background technology
In communication system, the transmitting signal of communication equipment may interfere the reception signal of the equipment, generally by this
Kind interference is known as self-interference.There are many scenes existing for self-interference, such as：Interfering between different communication standard, same communication
Interfering between standard different frequency range, the interference etc. in same frequency range.
In communication equipment, self-interference be because the equipment transmitting terminal send baseband signal by uplink transmitting path it
Afterwards, due to the factors such as non-linear of radio-frequency devices, the harmonic wave interference that the baseband signal that the receiving terminal of the equipment receives is brought.
Since these harmonic waves can not directly acquire, in the prior art, in order to eliminate the influence of the self-interference docking collection of letters number, hair can be utilized
The multistage nonlinear terms for the baseband signal that sending end is sent simulate these harmonic waves, to eliminating self-interference.Specifically, may be used
Scheme shown in FIG. 1 eliminates self-interference.Fig. 1 is self-interference reconfigurable circuit structural schematic diagram.In Fig. 1, X is the sent
Two baseband signals, Rx are desired received signal, and d is the self-interference signal that the second baseband signal X is generated, N0For white noise,
In, the second baseband signal X is known signal.
In Fig. 1, by the way that the second baseband signal X is passed through nonlinear terms generative circuit 101, frequency spectrum shift circuit 102, delay
After device 103, the processing of wave digital lowpass filter (Low Pass Filter, LPF) 104, pass through finite impulse response (Finite
Impulse Response, FIR) filter 105 receiverd polynomial coefficient generating circuit 106 generate multinomial coefficient W, according to
The coefficient of each rank nonlinear terms of 101 output of multinomial coefficient W setting nonlinear terms generative circuit, and will be provided with the more of coefficient
Rank nonlinear terms are exported as reconstruction signal d '.Finally, by the first baseband signal Rx+ of reconstruction signal d ' and Baseband Receiver access
d+N0Operation obtains Rx+d+N0- d ', so that received signal quality gets a promotion.
In Fig. 1, frequency spectrum shift circuit 102 is used to carry out each rank nonlinear terms that nonlinear terms generative circuit 101 generates
Frequency spectrum shift so that each rank nonlinear terms move after center frequency point and Baseband Receiver access output signal center frequency point pair
Together, so that self-interference signal d can be eliminated.But frequency spectrum shift circuit 102 is when carrying out frequency spectrum shift at present
Spectrum offset, the center frequency point after being moved so as to cause each rank nonlinear terms and Baseband Receiver are carried out using predeterminated frequency offset
The center frequency point of the output signal of access can not accurate alignment so that while eliminating self-interference signal d, generation can be by
The residual signals gradually dissipated cause the signal received inaccurate, thereby reduce received signal quality.
Invention content
A kind of interference elimination method of the embodiment of the present application offer and device overcome when eliminating self-interference because of frequency
Offset inaccuracy leads to the problem of reconstruction signal inaccuracy, the problem of improving received signal quality.
The embodiment of the present application provides a kind of interference elimination method, including：Receive the first baseband signal；Receive the first base band letter
Number；It determines, and is leaked in the first baseband signal from least one multistage nonlinear terms of the second baseband signal of transmission
Self-interference signal is corresponding, k rank nonlinear terms, and carries out frequency spectrum shift to k rank nonlinear terms using predeterminated frequency offset, obtains
To interference signal, k is positive integer；Calculate the first frequency offset between first baseband signal and interference signal；According to
First frequency offset and the predeterminated frequency offset, it is multistage non-to each at least one multistage nonlinear terms respectively
Linear term carries out frequency spectrum shift；Signal reconstruction is carried out using at least one multistage nonlinear terms after frequency spectrum shift, is reconstructed
Signal；And carry out interference elimination using the first baseband signal of reconstruction signal pair.
According to method provided by the embodiments of the present application, the first frequency between the first baseband signal and interference signal is first determined
Rate offset, to unpredictable first frequency offset in acquisition system；Then further according to first frequency offset and
Predeterminated frequency offset carries out frequency spectrum shift to each the multistage nonlinear terms generated by the second baseband signal, so that root
The center frequency point of the reconstruction signal obtained according to each multistage nonlinear terms after frequency spectrum shift can in the first baseband signal
Self-interference signal center frequency point alignment, to when carrying out self-interference elimination according to reconstruction signal, overcome because of frequency
Offset inaccuracy leads to the problem of reconstruction signal inaccuracy, the problem of improving received signal quality.
Optionally, the first frequency offset between the first baseband signal and interference signal is calculated, including：To be segmented cross product
Mode calculate the first frequency offset between the first baseband signal and interference signal.
In the above method, more accurate first frequency offset can be obtained by being segmented cross product, is connect so as to improve
The quality of the collection of letters number.
Optionally, the first frequency offset between the first baseband signal and interference signal is calculated in a manner of being segmented cross product
Amount, including：
The segmentation cross product Z between the first baseband signal and interference signal is determined according to following formulam：
Wherein, RxData (n) is the first baseband signal,For the conjugated signal of interference signal；L believes for the first base band
Number or interference signal sampled point quantity；
According to segmentation cross product ZmFirst frequency offset △ f (m) are determined by following formula：
Wherein, Arg (Zm) it is segmentation cross product ZmArgument main value, FsFor the sampling of the first baseband signal or interference signal
Frequency.
Optionally, the first frequency offset between the first baseband signal and interference signal is calculated in a manner of being segmented cross product
Amount, including：
The segmentation cross product Z between the first baseband signal and interference signal is determined according to following formulam：
Wherein, RxData (n) is the first baseband signal,For the conjugated signal of interference signal；L believes for the first base band
Number or interference signal sampled point quantity；
According to segmentation cross product ZmFirst frequency offset △ f (m) are determined by following formula：
Wherein, Arg (Zm) it is segmentation cross product ZmArgument main value, FsFor the sampling of the first baseband signal or interference signal
Frequency.
Optionally, according to first frequency offset and predeterminated frequency offset, respectively at least one multistage nonlinear terms
In each multistage nonlinear terms carry out frequency spectrum shift, including：Using first frequency offset and predeterminated frequency offset it
With frequency spectrum shift is carried out to each multistage nonlinear terms at least one multistage nonlinear terms respectively；Alternatively, to the first frequency
Rate offset carries out smothing filtering, obtains second frequency offset；Using second frequency offset and predeterminated frequency offset it
With frequency spectrum shift is carried out to each multistage nonlinear terms at least one multistage nonlinear terms respectively.
In the above method, by carrying out smothing filtering to first frequency offset, so as to avoid the occurrence of the of mistake
One frequency offset, to reduce the error of first frequency offset.
Optionally, smothing filtering is carried out to first frequency offset, obtains the second frequency offset after smothing filtering, packet
It includes：First frequency offset is multiplied with default weighted value and obtains weighted frequency offset；By the weighted frequency offset with
The sum of first frequency offset after last smothing filtering is determined as second frequency offset.
The embodiment of the present application provides a kind of interference blanking unit, including：Nonlinear terms generative circuit, for according to the second base
Band signal generates at least one multistage nonlinear terms；Frequency spectrum shift circuit, for from least one multistage nonlinear terms
It determines k ranks nonlinear terms corresponding with the self-interference signal being leaked in the first baseband signal, and utilizes predeterminated frequency offset
Frequency spectrum shift is carried out to the k ranks nonlinear terms, obtains interference signal, k is positive integer；Frequency discriminator, for calculating described first
First frequency offset between baseband signal and the interference signal；The frequency spectrum shift circuit is additionally operable to according to described
One frequency offset and the predeterminated frequency offset, it is multistage to each at least one multistage nonlinear terms respectively
Nonlinear terms carry out frequency spectrum shift；Signal reconstruction circuit is used for using described at least one multistage non-linear after frequency spectrum shift
Item carries out signal reconstruction, obtains reconstruction signal；Interference cancellation circuit, for being believed first base band using the reconstruction signal
Number carry out interference elimination.
Optionally, frequency discriminator is specifically used for：It is calculated in a manner of being segmented cross product between the first baseband signal and interference signal
First frequency offset.
Optionally, frequency discriminator is specifically used for：
The segmentation cross product Z between the first baseband signal and interference signal is determined according to following formulam：
Wherein, RxData (n) is the first baseband signal,For the conjugated signal of interference signal；L believes for the first base band
Number or interference signal sampled point quantity；
According to segmentation cross product ZmFirst frequency offset △ f (m) are determined by following formula：
Wherein, Arg (Zm) it is segmentation cross product ZmArgument main value, FsFor the sampling of the first baseband signal or interference signal
Frequency.
Optionally, frequency discriminator is specifically used for：
The segmentation cross product Z between the first baseband signal and interference signal is determined according to following formulam：
Wherein, RxData (n) is the first baseband signal,For the conjugated signal of interference signal；L believes for the first base band
Number or interference signal sampled point quantity；
According to segmentation cross product ZmFirst frequency offset △ f (m) are determined by following formula：
Wherein, Arg (Zm) it is segmentation cross product ZmArgument main value, FsFor the sampling of the first baseband signal or interference signal
Frequency.
Optionally, the frequency spectrum shift circuit is specifically used for：Utilize the first frequency offset and the predeterminated frequency
The sum of offset carries out frequency spectrum shift to each multistage nonlinear terms at least one multistage nonlinear terms respectively；
Alternatively, described device further includes loop filter, the loop filter is used to carry out the first frequency offset smooth
Filtering obtains second frequency offset；Then the frequency spectrum shift circuit is specifically used for：Utilize the second frequency offset and institute
The sum of predeterminated frequency offset is stated, each multistage nonlinear terms at least one multistage nonlinear terms are carried out respectively
Frequency spectrum shift.
Optionally, loop filter is specifically used for：First frequency offset is multiplied with default weighted value acquisition weighting frequency
Rate offset；Weighted frequency offset and the sum of the first frequency offset after last smothing filtering are determined as second frequency
Offset.
The embodiment of the present application provides a kind of communication equipment, including：Any one interference blanking unit, reception as described above
Machine, processor, the interference blanking unit are coupling between the receiver and the processor；The receiver is for connecing
Receive the first baseband signal；The processor is for generating the second baseband signal；The interference blanking unit is used for according to described the
Two baseband signals carry out signal reconstruction, obtain reconstruction signal, and carried out to first baseband signal using the reconstruction signal
Interference is eliminated.
Description of the drawings
Fig. 1 is self-interference reconfigurable circuit structural schematic diagram；
Fig. 2 is the principle schematic of frequency spectrum shift provided by the embodiments of the present application；
Fig. 3 is a kind of interference elimination method flow diagram provided by the embodiments of the present application；
Fig. 4 is a kind of spectrum diagram provided by the embodiments of the present application；
Fig. 5 is a kind of spectrum diagram provided by the embodiments of the present application；
Fig. 6 (a) is a kind of interference blanking unit structural schematic diagram provided by the embodiments of the present application；
Fig. 6 (b) is a kind of interference blanking unit structural schematic diagram provided by the embodiments of the present application；
Fig. 7 is a kind of communication apparatus construction schematic diagram provided by the embodiments of the present application.
Specific implementation mode
Device provided by the embodiments of the present application, device and method both can be used for that base station is sent, user equipment receives, and also might be used
For user equipment send, base station receive the case where, in introduction below, will with the network equipment (such as：Base station) it receives, is all
As user equipment (such as：Mobile terminal) send for illustrate, user equipment receive, the network equipment send principle class
Seemingly, implement to can refer to the case where network equipment receives, user equipment is sent, overlaps will not be repeated.
Self-interference is widely present in communication system.Such as：In certain communications systems, equipment supports such as long term evolution
(Long Term Evolution, LTE), Wideband Code Division Multiple Access (Wideband Code Division Multiple
Access, WCDMA), two in Wireless Fidelity (Wireless Fidelity, WiFi) and bluetooth (Blue Tooth, BT)
Kind or a variety of communication standards, the transmitting signal of equipment may dock the collection of letters number and cause self-interference.
In some communication systems, the transmitting signal of certain band communication standard A may be to the communication standard B of other frequency range
Reception signal formed self-interference.
In other communication systems, even if equipment only supports single communication standard, but transmitting signal can still dock the collection of letters
Number self-interference is caused, such as：2 rank intermodulation distortion (the 2 order Inter Modulation of LTE system uplink signal
Distortion, IMD2) self-interference is caused to downlink signal, or under carrier aggregation scene, some carrier wave uplink subharmonic
It is distorted the signal that (Harmonic Distortion, HD) is generated, just falls into the reception bandwidth of other carrier waves, will also result in
Emit the self-interference of the signal docking collection of letters number.
In order to reduce the influence of the self-interference signal docking collection of letters number, self-interference reconfigurable circuit pair shown in FIG. 1 may be used
The second baseband signal sent is reconstructed, and obtains reconstruction signal, then subtracts reconstruct from the first baseband signal received
Signal, to eliminate self-interference, so that received signal quality gets a promotion.It should be noted that self-interference reconfigurable circuit
Structure can also have other forms, the embodiment of the present application not to limit this, and details are not described herein.
Specifically, the nonlinear terms generative circuit in self-interference reconfigurable circuit can be according to the second baseband signal X of transmission
At least one multistage nonlinear terms are generated, such as：Second nonlinear item X2, third-order non-linear item X3, Nonlinear Fourth Order item X4, five
Rank nonlinear terms X5..., p rank nonlinear terms XpDeng the selection of p value is decided according to the actual requirements；Then, self-interference reconfigurable circuit
In frequency spectrum shift circuit by the frequency spectrum shift predeterminated frequency offset of at least one multistage nonlinear terms of generation of generation, and lead to
Cross delay circuit and carry out time delay processing so that when the multistage nonlinear terms delayed in the time domain with the first baseband signal for receiving
It can be aligned；Finally to time delay, treated that multistage nonlinear terms pass sequentially through LPF filters and FIR filter is filtered,
And it is multinomial by being generated according to multinomial coefficient generative circuit by the filtered at least one multistage nonlinear terms of FIR filter
The coefficient of each multistage nonlinear terms of formula coefficient W settings, the multistage nonlinear terms provided with coefficient are defeated as reconstruction signal d '
Go out.
In above process, using predeterminated frequency offset to multistage non-linear according to each of the second baseband signal generation
Item carries out frequency spectrum shift, can to need the self-interference eliminated to believe in the center frequency point and the first baseband signal of reconstruction signal d '
Number center frequency point alignment, to obtain preferable self-interference eradicating efficacy.Predeterminated frequency offset, which is usually basis, to be predicted
Interference signal center frequency point and the frequency departure of the center frequency point of self-interference signal for needing to eliminate determine.
For example, as shown in Fig. 2, being the principle schematic of frequency spectrum shift provided by the embodiments of the present application.In Fig. 2, the
The carrier wave launching frequency of two baseband signals is 710MHz, then in its 3 subharmonic (Harmonic Distortion 3, HD3)
Heart frequency point is 2130MHz can predict dry if the reception frequency point of a carrier wave of the first baseband signal received is 2140MHz
It is -10MHz that the center frequency point of signal, which is disturbed, with respect to the frequency departure of the center frequency point of the first baseband signal, then can be by predeterminated frequency
Offset is set as -10MHz.In order to eliminate the self-interference in the first baseband signal, then need to be obtained by the second baseband signal
It is at least one it is multistage it is non-linear in each multistage nonlinear frequency spectrum shift -10MHz so that after according to frequency spectrum shift
The center frequency point for the reconstruction signal that at least one multistage nonlinear reconstruction goes out and the self-interference signal in the first baseband signal
Center frequency point alignment.
Predeterminated frequency offset can only correct predictable frequency departure, and in a practical situation, there is also very much
If unpredictable frequency departure can not just make the center frequency point and the first base band of multistage nonlinear terms without correcting
The center frequency point for the self-interference eliminated is needed to be aligned in signal, so that receiving the quality of signal reduces.Unpredictable frequency
There are many reasons for the generation of rate deviation, for example, due to phaselocked loop (the Phase Lock in the second baseband signal transmitting path
Loop, PLL) error that generates after frequency locking；The error etc. generated after phaselocked loop frequency locking in Baseband Receiver access.These frequencies
Deviation there may be, it is also possible to be not present, can not predict, thus can not be determined when carrying out frequency spectrum shift one accurately frequency
Rate offset.
Based on above-mentioned technical problem, as shown in figure 3, being that a kind of interference elimination method flow provided by the embodiments of the present application is shown
It is intended to.
Method flow in Fig. 3 can be executed by equipment such as user equipment, base station, routers.
Referring to Fig. 3, this method includes：
Step 301：Receive the first baseband signal；
Step 302：It is determined from least one multistage nonlinear terms of the second baseband signal of transmission, it is described with being leaked to
Self-interference signal in first baseband signal is corresponding, k rank nonlinear terms, and non-linear to k ranks using predeterminated frequency offset
Item carries out frequency spectrum shift, obtains interference signal, k is positive integer；
Step 303：Calculate the first frequency offset between the first baseband signal and interference signal；
Step 304：According to first frequency offset and predeterminated frequency offset, respectively at least one multistage nonlinear terms
In each multistage nonlinear terms carry out frequency spectrum shift；
Step 305：Signal reconstruction is carried out using at least one multistage nonlinear terms after frequency spectrum shift, obtains reconstruct letter
Number；
Step 306：Interference elimination is carried out using the first baseband signal of reconstruction signal pair.
In step 301, the frequency range of the first baseband signal received can be located at the communication protocols such as LTE, WCDMA, WiFi
The frequency range of support.
In the embodiment of the present application, the first baseband signal got can be the output signal of radio-frequency transmitter.First base
Band signal can be expressed as：Rx+d+N0, wherein Rx is it is expected the signal that receives, can also be referred to as useful signal, d the
The self-interference signal that two baseband signal X are generated after the Baseband Receiver access of radio-frequency transmitter, N0For white noise.In order to reduce
The influence of signal Rx that self-interference signal d receives expectation, can by self-interference reconfigurable circuit pair the second baseband signal X into
Row reconstruct, obtains reconstruction signal d ', and the influence for the signal that self-interference signal receives expectation is reduced to pass through d '.
In step 302, while receiving the first baseband signal, by the k rank nonlinear terms of the second baseband signal of transmission
Carry out frequency spectrum shift.
The value of k can be selected according to actual conditions, generally by the multistage nonlinear terms of the second baseband signal to first
Baseband signal interferes the multistage nonlinear terms of most serious as k rank nonlinear terms.
For example, in LTE system, for the carrier aggregation scene of Band 4 and Band 17, the reception of Band 4 is believed
In number, the X of Band 173Caused by interfere most serious, at this point it is possible to by the 3 rank nonlinear terms of Band 17 according to default frequency
Rate offset carries out frequency spectrum shift, and by the X after frequency spectrum shift3As interference signal.
Certainly, k can also take other values, such as 2,4,5 etc., specifically can be no longer superfluous herein determines according to actual conditions
It states.
Optionally, interference signal predeterminated frequency offset can carry out frequency spectrum shift and according to Timing Synchronization according to
Deviation carries out the k rank nonlinear terms X after time delay processingk.The Timing Synchronization deviation is that the first baseband signal is believed with the second base band
Time deviation between number.
In step 303, can be determined according to the first baseband signal and interference signal got the first baseband signal with
First frequency offset between interference signal.
The method that segmentation cross product may be used in the embodiment of the present application determines between the first baseband signal and interference signal
First frequency offset.Specifically, can first obtain in the same period L sampled point the first baseband signal and L
The interference signal of sampled point；Then it determines the segmentation cross product between the first baseband signal and interference signal, and determines segmentation cross product
Argument main value；First frequency offset is finally determined according to argument main value.
Specifically, the segmentation cross product between the first baseband signal and the interference signal can be determined according to following formula
Zm：
Wherein, RxData (n) is the first baseband signal,For the conjugated signal of interference signal；L believes for the first base band
Number or interference signal sampled point quantity.
Then according to segmentation cross product ZmFirst frequency offset △ f (m) are determined by following formula：
Wherein, Arg (Zm) it is segmentation cross product ZmArgument main value, FsFor the sampling of the first baseband signal or interference signal
Frequency, Arg () are to take argument operation.FsValue can be selected according to actual conditions.For example, in LTE system, Fs's
Value can be 30.72M/s.
It should be noted that in the embodiment of the present application, the first baseband signal and interference can also be determined according to following formula
Segmentation cross product Z between signalm：
Then the first frequency offset between the first baseband signal and interference signal is determined by formula (2).
Optionally, in order to obtain more accurate first frequency offset, the first baseband signal and the interference is being determined
After frequency offset between signal, it is also necessary to carry out smothing filtering to first frequency offset.
In the embodiment of the present application, frequency offset can be multiplied with default weighted value and obtain weighted frequency offset；So
Weighted frequency offset and the sum of the first frequency offset after last smothing filtering are determined as second frequency offset afterwards.
Wherein, default weighted value can be the number for being less than 1 more than 0.
For example, second frequency offset can be determined in the embodiment of the present application by following formula：
Wherein,For second frequency offset,It is inclined for the first frequency after last smothing filtering
Shifting amount, factor are default weighted value.Can be 0.
Further, in the embodiment of the present application, the m times corresponding default weighted value of first frequency offset determined
Factor can be determined by following formula：
Wherein, MminFor first threshold, MmaxFor second threshold, and the first threshold is less than the second threshold.Citing
For, MminCan be 10, MmaxCan be 100.
Smothing filtering, this Shen are carried out to first frequency offset it should be noted that can also realize by other means
Please embodiment this is not limited.
Electricity is generated to nonlinear terms in self-interference reconfigurable circuit according to second frequency offset and predeterminated frequency offset
The output signal on road carries out frequency spectrum shift, can more accurately realize and be corrected to unpredictable frequency departure.
In step 304, according to first frequency offset between the first baseband signal and the interference signal and default
Frequency offset to each multistage nonlinear terms at least one multistage nonlinear terms for being generated by the second baseband signal into
Unpredictable frequency departure is corrected in row frequency spectrum shift, realization.
Specifically, the sum of first frequency offset and predeterminated frequency offset can be utilized, respectively to described at least one
Each multistage nonlinear terms in multistage nonlinear terms carry out frequency spectrum shift.For example, first frequency offset and predeterminated frequency
The sum of offset is 30MHz, then can be by the frequency of each multistage nonlinear terms at least one multistage nonlinear terms
Spectrum moves 30MHz.For example, the sum of first frequency offset and predeterminated frequency offset are -10MHz, then it can be by described at least
Frequency spectrum shift-the 10MHz of each multistage nonlinear terms in one multistage nonlinear terms.
For example, as shown in figure 4, being a kind of spectrum diagram provided by the embodiments of the present application.The first base band is believed in Fig. 4
It is expected that the center frequency point of the signal received is 2140MHz in number, the center frequency point of self-interference signal is 2130MHz, interference letter
Number center frequency point be 2100MHz.In order to eliminate the self-interference signal in the first baseband signal, first frequency offset is determined
It is 30MHz with the sum of predeterminated frequency offset.At this time by after the frequency spectrum shift frequency spectrum shift amount of interference signal, interference signal
Center frequency point can be aligned with the center frequency point of self-interference signal in the first baseband signal, so as to eliminate self-interference signal.
Specifically, as shown in figure 5, being a kind of spectrum diagram provided by the embodiments of the present application.In Fig. 5, interference signal is removed by frequency spectrum
After shifting, it is 2130MHz that center frequency point can be aligned with the center frequency point of self-interference signal in the first baseband signal.
Further, it if having carried out smothing filtering to first frequency offset, can also utilize by after smothing filtering
The sum of second frequency offset and predeterminated frequency offset of acquisition, respectively to every at least one multistage nonlinear terms
One multistage nonlinear terms carries out frequency spectrum shift.
In step 305, it determines reconstruction signal, and is removed by the second base band from the first baseband signal according to reconstruction signal
Self-interference signal caused by signal.
Specifically, being carried out certainly to the first baseband signal after last interference elimination treatment first with adaptive prediction algorithm
Adaptive prediction obtains system of polynomials corresponding with each multistage nonlinear terms at least one multistage nonlinear terms
Number.
Wherein, adaptive prediction algorithm can be LMS (Least mean square, lowest mean square root) algorithm, RLS
(Recursive Least Squares, recurrence minimum quadratic power, also known as least square method of recursion) algorithm, LS (Least
Square, least square method) algorithm etc., these algorithms belong to the algorithm of comparative maturity, belong to the relatively well known technology in this field,
The detailed process of these algorithms is no longer deeply unfolded in this.
Then the coefficient of each multistage nonlinear terms after frequency spectrum shift is set according to the multinomial coefficient of acquisition, and will
All multistage nonlinear terms provided with multinomial coefficient are as reconstruction signal.
Finally, within step 306, first baseband signal is subtracted each other with the reconstruction signal, acquisition disappears by interference
Except treated the first baseband signal, to eliminate the self-interference signal in the first baseband signal.
The embodiment of the present application provides a kind of interference blanking unit, and implementation can refer to above description, and details are not described herein.
It is a kind of interference blanking unit structural schematic diagram provided by the embodiments of the present application as shown in Fig. 6 (a).
The device can execute method flow shown in Fig. 3.
Referring to Fig. 6 (a), interference blanking unit 600 includes：Nonlinear terms generative circuit 601, frequency spectrum shift circuit 602, letter
Number reconfigurable circuit 603, interference cancellation circuit 604, frequency discriminator 605, loop filter 606.
Nonlinear terms generative circuit 601, for generating at least one multistage nonlinear terms according to the second baseband signal；
Frequency spectrum shift circuit 602, for being determined from least one multistage nonlinear terms and being leaked to the first base band
The corresponding k ranks nonlinear terms of self-interference signal in signal, and the k ranks nonlinear terms are carried out using predeterminated frequency offset
Frequency spectrum shift, obtains interference signal, and k is positive integer；
Frequency discriminator 605, for calculating the first frequency offset between first baseband signal and the interference signal；
The frequency spectrum shift circuit 602 is additionally operable to according to the first frequency offset and the predeterminated frequency offset,
Frequency spectrum shift is carried out to each multistage nonlinear terms at least one multistage nonlinear terms respectively；
Signal reconstruction circuit 603, for carrying out signal using at least one multistage nonlinear terms after frequency spectrum shift
Reconstruct obtains reconstruction signal；
Interference cancellation circuit 604, for carrying out interference elimination to first baseband signal using the reconstruction signal.
Optionally, the frequency discriminator 605 is specifically used for：
The first frequency between first baseband signal and the interference signal is calculated in a manner of being segmented cross product
Offset.
Optionally, the frequency discriminator 605 is specifically used for：
The segmentation cross product Z between first baseband signal and the interference signal is determined according to following formulam：
Wherein, RxData (n) is first baseband signal,For the conjugated signal of the interference signal；L is institute
State the quantity of the sampled point of the first baseband signal or the interference signal；
According to the segmentation cross product ZmThe first frequency offset △ f (m) are determined by following formula：
Wherein, Arg (Zm) it is the segmentation cross product ZmArgument main value, FsFor first baseband signal or described dry
Disturb the sample frequency of signal.
Optionally,
Frequency spectrum shift circuit 602 is specifically used for：It is right respectively using the sum of first frequency offset and predeterminated frequency offset
Each multistage nonlinear terms at least one multistage nonlinear terms carry out frequency spectrum shift；Alternatively, described device further includes ring
Path filter 606, the loop filter 606 are used to carry out smothing filtering to first frequency offset, and it is inclined to obtain second frequency
Shifting amount；Then frequency spectrum shift circuit is specifically used for：Using the sum of second frequency offset and predeterminated frequency offset, respectively at least
Each multistage nonlinear terms in one multistage nonlinear terms carry out frequency spectrum shift.
Optionally, the loop filter 606 is specifically used for：
First frequency offset is multiplied with default weighted value and obtains weighted frequency offset；By weighted frequency offset with
The sum of first frequency offset after last smothing filtering is determined as second frequency offset.
It is a kind of interference blanking unit structural representation provided by the embodiments of the present application as shown in Fig. 6 (b) in conjunction with Fig. 6 (a)
Figure.
Optionally, in Fig. 6 (b), signal reconstruction circuit 603 includes that multinomial coefficient generative circuit 6031 and finite impulse are rung
Answer filter 6032；
Multinomial coefficient generative circuit 6031, after using adaptive prediction algorithm to last interference elimination treatment
First baseband signal carries out adaptive prediction, obtains multistage non-linear with each at least one multistage nonlinear terms
The corresponding multinomial coefficient of item；
Wherein, adaptive prediction algorithm can be LMS algorithm, RLS algorithm, LS algorithms etc., these algorithms, which belong to, to be compared into
Ripe algorithm belongs to the relatively well known technology in this field, the detailed process of these algorithms is no longer deeply unfolded herein.
Finite impulse response filter 6032, the system of polynomials for obtaining the generation of multinomial coefficient generative circuit 6031
Number；Obtain at least one multistage nonlinear terms after 602 frequency spectrum shift of frequency spectrum shift circuit；Utilize the multinomial
The coefficient of at least one multistage nonlinear terms is arranged in coefficient, by least one multistage nonlinear terms provided with coefficient
It is exported as reconstruction signal.
Optionally, finite impulse response filter 6032 are additionally operable to carry out delay process to the reconstruction signal, and export
Reconstruction signal after delay process so that reconstruction signal after delay process in the time domain with the self-interference in the first baseband signal
Signal alignment.
Optionally, in Fig. 6 (b), signal reconstruction circuit 603 further includes low-pass filter 6033, the low-pass filter
6033 are coupled between frequency spectrum shift circuit 602 and finite impulse response filter 6032；
Low-pass filter 6033, for more to each at least one multistage nonlinear terms after time delay processing
Rank nonlinear terms are filtered, and eliminate the noise in each multistage nonlinear terms.
Optionally, in Fig. 6 (b), signal reconstruction circuit 603 further includes delayer 6034, and the delayer 6034 is coupled in
Between low-pass filter 6033 and limit impulse response filter 6032；
Delayer 6034, for at least one multistage nonlinear terms after 602 frequency spectrum shift of frequency spectrum shift circuit
In each multistage nonlinear terms carry out delay process so that each multistage nonlinear terms after delay process are in the time domain
It is aligned with the self-interference signal in the first baseband signal.
It should be noted that finite impulse response filter 6032 can not have to carry out at delay reconstruction signal at this time
Reason.
The transmitting signal of communication equipment may interfere the reception signal of the equipment, generally be known as this interference certainly
Interference.There are many scenes existing for self-interference, such as：Interfering between different communication standard, same communication standard different frequency range
Between interfere, the interference etc. in same frequency range.
The second baseband signal that the transmitting terminal of communication equipment is sent is passed through after uplink transmitting path, due to radio-frequency devices
The factors such as non-linear, the first baseband signal band that the second baseband signal can receive the receiving terminal of the communication equipment is from dry
It disturbs.It is influenced caused by the first baseband signal to eliminate self-interference, the second baseband signal can be utilized to obtain reconstruction signal, from
And eliminate self-interference in the first baseband signal.
In conjunction with the description of front, as shown in fig. 7, be a kind of communication equipment provided by the embodiments of the present application, including：
Any one interference blanking unit 702, receiver 703, processor 701, memory 704 as described above.
The interference blanking unit 702 is coupling between the receiver 703 and the processor 701；The reception
Machine is for receiving the first baseband signal；The processor is for generating the second baseband signal；
The interference blanking unit 702 is used to carry out letter according to second baseband signal for the interference blanking unit
Number reconstruct, obtain reconstruction signal, and interference elimination is carried out to first baseband signal using the reconstruction signal.
It should be noted that processor 701 can be communication processor, baseband processor, baseband chip or including base
SOC (System on a Chip, system on chip) chip including provided with processor, memory 704 are coupled to processor 701, deposit
Reservoir 704 is implemented for storing the relevant instruction of communication protocol, processor 701 by reading the instruction stored in memory 704
Including modulation /demodulation, channel coding/decoding, interleaving/deinterleaving, the related algorithms such as encryption/decryption, to being connect by receiver 703
The baseband signal received such as is decrypted, demodulates at the operations, or the operations such as to sent original signal is encrypted, modulates,
Generate baseband signal.
In communication equipment provided by the present application, interference blanking unit can first determine the first baseband signal and interference signal
Between first frequency offset then utilize first frequency to unpredictable first frequency offset in acquisition system
The second baseband signal of offset pair carries out signal reconstruction, can be with the self-interference in the first baseband signal to obtain center frequency point
The reconstruction signal of the center frequency point alignment of signal, the factors such as non-linear to overcome due to radio-frequency devices lead to the weight obtained
The problem of structure signal inaccuracy.Then reconstruction signal is subtracted from the first baseband signal received, to eliminate self-interference, to
So that the quality for receiving signal gets a promotion.
Although the preferred embodiment of the application has been described, created once a person skilled in the art knows basic
Property concept, then additional changes and modifications may be made to these embodiments.So it includes excellent that the following claims are intended to be interpreted as
It selects embodiment and falls into all change and modification of the application range.
Obviously, those skilled in the art can carry out the application essence of the various modification and variations without departing from the application
God and range.In this way, if these modifications and variations of the application belong to the range of the application claim and its equivalent technologies
Within, then the application is also intended to include these modifications and variations.
Claims (9)
1. a kind of interference elimination method, which is characterized in that including：
Receive the first baseband signal；
It is determined from least one multistage nonlinear terms of the second baseband signal of transmission, and is leaked to first baseband signal
In self-interference signal it is corresponding, k rank nonlinear terms, and using predeterminated frequency offset to the k ranks nonlinear terms into line frequency
Spectrum is moved, and interference signal is obtained, and k is positive integer；
Calculate the first frequency offset between first baseband signal and the interference signal；
Using the sum of the first frequency offset and the predeterminated frequency offset, respectively to described at least one multistage non-thread
Property item in each multistage nonlinear terms carry out frequency spectrum shift；Alternatively, smothing filtering is carried out to the first frequency offset,
Second frequency offset is obtained, using the sum of the second frequency offset and the predeterminated frequency offset, respectively to described
Each multistage nonlinear terms at least one multistage nonlinear terms carry out frequency spectrum shift；
Signal reconstruction is carried out using at least one multistage nonlinear terms after frequency spectrum shift, obtains reconstruction signal；And
Interference elimination is carried out to first baseband signal using the reconstruction signal.
2. the method as described in claim 1, which is characterized in that described to calculate first baseband signal and the interference signal
Between first frequency offset, including：
The first frequency offset between first baseband signal and the interference signal is calculated in a manner of being segmented cross product
Amount.
3. method as claimed in claim 2, which is characterized in that described to calculate the first base band letter in a manner of being segmented cross product
The first frequency offset number between the interference signal, including：
The segmentation cross product Z between first baseband signal and the interference signal is determined according to following formulam：
Wherein, RxData (n) is first baseband signal,For the conjugated signal of the interference signal；L is described the
The quantity of the sampled point of one baseband signal or the interference signal；
According to the segmentation cross product ZmThe first frequency offset △ f (m) are determined by following formula：
Wherein, Arg (Zm) it is the segmentation cross product ZmArgument main value, FsBelieve for first baseband signal or the interference
Number sample frequency.
4. the method as described in claim 1, which is characterized in that it is described that smothing filtering is carried out to the first frequency offset,
Second frequency offset is obtained, including：
The first frequency offset is multiplied with default weighted value and obtains weighted frequency offset；
The weighted frequency offset and the sum of the first frequency offset after last smothing filtering are determined as described second
Frequency offset.
5. a kind of interference blanking unit, which is characterized in that including：
Nonlinear terms generative circuit, for generating at least one multistage nonlinear terms according to the second baseband signal；
Frequency spectrum shift circuit, for determining and being leaked in the first baseband signal from least one multistage nonlinear terms
The corresponding k ranks nonlinear terms of self-interference signal, and frequency spectrum is carried out to the k ranks nonlinear terms using predeterminated frequency offset and is removed
It moves, obtains interference signal, k is positive integer；
Frequency discriminator, for calculating the first frequency offset between first baseband signal and the interference signal；
The frequency spectrum shift circuit is additionally operable to utilize the sum of the first frequency offset and the predeterminated frequency offset, point
Other each multistage nonlinear terms at least one multistage nonlinear terms carry out frequency spectrum shift；Alternatively, loop filtering
Device obtains second frequency offset for carrying out smothing filtering to the first frequency offset；The frequency spectrum shift circuit,
For utilizing the sum of the second frequency offset and the predeterminated frequency offset, respectively to described at least one multistage non-thread
Property item in each multistage nonlinear terms carry out frequency spectrum shift；
Signal reconstruction circuit is obtained for carrying out signal reconstruction using at least one multistage nonlinear terms after frequency spectrum shift
Obtain reconstruction signal；
Interference cancellation circuit, for carrying out interference elimination to first baseband signal using the reconstruction signal.
6. device as claimed in claim 5, which is characterized in that the frequency discriminator is specifically used for：
The first frequency offset between first baseband signal and the interference signal is calculated in a manner of being segmented cross product
Amount.
7. device as claimed in claim 6, which is characterized in that the frequency discriminator is specifically used for：
The segmentation cross product Z between first baseband signal and the interference signal is determined according to following formulam：
Wherein, RxData (n) is first baseband signal,For the conjugated signal of the interference signal；L is described the
The quantity of the sampled point of one baseband signal or the interference signal；
According to the segmentation cross product ZmThe first frequency offset △ f (m) are determined by following formula：
Wherein, Arg (Zm) it is the segmentation cross product ZmArgument main value, FsBelieve for first baseband signal or the interference
Number sample frequency.
8. device as claimed in claim 5, which is characterized in that the loop filter is specifically used for：
The first frequency offset is multiplied with default weighted value and obtains weighted frequency offset；
The weighted frequency offset and the sum of the first frequency offset after last smothing filtering are determined as described second
Frequency offset.
9. a kind of communication equipment, which is characterized in that including：
Such as claim 5 to 8 any one of them interference blanking unit, receiver, processor, the interference blanking unit coupling
Between the receiver and the processor；
The receiver is for receiving the first baseband signal；
The processor is for generating the second baseband signal；
The interference blanking unit is used to carry out signal reconstruction according to second baseband signal, obtains reconstruction signal, and utilize
The reconstruction signal carries out interference elimination to first baseband signal.
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| CN110087326B (en) * | 2019-05-31 | 2022-06-17 | 中国联合网络通信集团有限公司 | Method and device for reducing harmonic interference |
| CN110649991B (en) * | 2019-09-26 | 2021-11-09 | 中国人民解放军陆军工程大学 | Signal reconstruction method based on out-of-band nonlinear component convolution inversion |
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