CN106850495B - For the estimation of IQ imbalance and compensation method of initial phase offset and device - Google Patents
For the estimation of IQ imbalance and compensation method of initial phase offset and device Download PDFInfo
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- H04L27/00—Modulated-carrier systems
- H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
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Abstract
The present invention provides a kind of for the estimation of IQ imbalance and compensation method of initial phase offset and device, the estimation of IQ imbalance and compensation method for initial phase offset is the following steps are included: step S1, synchronizes detection to reception signal and obtain frame start position；Step S2 receives the initial phase of signal according to the time domain phase estimation of the time domain phase and local signal that receive signal, then carries out initial phase compensation to reception signal；Step S3 carries out the estimation of IQ imbalance and compensation using the reception signal after compensation initial phase.This invention removes the influences of receiver local oscillator time error and signal transmission time bring initial phase offset, improve the accuracy of IQ imbalance estimation, after compensating IQ amount of unbalance, finally improve the performance for receiving signal.
Description
Technical field
The present invention relates to the estimation of the IQ imbalance of OFDM wireless system and compensation, more particularly to for initial phase offset
The estimation of IQ imbalance and compensation method, and be related to using the estimation of IQ imbalance and compensation method for initial phase offset
Device.
Background technique
The WLAN of IEEE802.11 standard use Direct Conversion transmitter/receiver, Direct Conversion transmitter/receiver without
Intermediate frequency, directly by signal from base-band frequency conversion to radio frequency/radio frequency is converted to base band.Ideal Direct Conversion transmitter/receiver is in frequency conversion I
Road and the road Q signal have the property of complete orthogonal same amplitude.But in fact, due to device, Direct Conversion transmitting/reception
Machine is difficult to reach perfect condition, can generate the deviation of the road I, Q amplitude and phase, so as to cause demodulation performance deterioration, i.e., so-called
IQ imbalance problem.So that Direct Conversion transmitter/receiver is applied, it must just be compensated, it is uneven to eliminate IQ
Influence to system.
Summary of the invention
The technical problem to be solved by the present invention is to need to provide a kind of IQ imbalance estimation for initial phase offset
And compensation method, reach and accurately estimate IQ unbalanced error and carry out correct IQ imbalance compensation, and improves receiving end
The purpose of demodulation performance, and the IQ imbalance for being related to using this for initial phase offset estimates and the device of compensation method.
In this regard, the present invention provides a kind of estimation of IQ imbalance and compensation method for initial phase offset, including following
Step:
Step S1 synchronizes detection to reception signal and obtains frame start position；
Step S2 receives the initial phase of signal according to the time domain phase estimation of the time domain phase and local signal that receive signal
Then position carries out initial phase compensation to reception signal；
Step S3 carries out the estimation of IQ imbalance and compensation to the reception signal after compensation initial phase.
A further improvement of the present invention is that in the step S2, including following sub-step:
Step S201 is completed after synchronizing detection to signal is received, and is navigated to the long instruction sequence for receiving signal, is then used and receive
It is poor that the time-domain signal phase of time-domain signal phase and the long instruction sequence of local signal that Chief Signal Boatswain instructs sequence is carried out by sampled point one by one
It is worth operation, finally seeks the average value of these phase difference values as the initial phase for receiving signal；
Step S202 after estimating the initial phase for receiving signal, carries out initial phase to the long instruction sequence for receiving signal
Compensation.
A further improvement of the present invention is that including following sub-step in the step S3:
It is uneven to carry out IQ using the energy feature or time domain specification of the reception signal after compensation initial phase by step S301
Estimation；
Step S302 carries out IQ imbalance compensation to signal is received after the estimation of IQ imbalance.
A further improvement of the present invention is that passing through formula in the step S201
Ψx(t)_LTS) seek the initial phase for receiving signalWherein, NLTSIndicate the time-domain sampling points of long instruction sequence,
Ψx(t)_LTSIndicate the phase of the time-domain signal sampling instant t of the long instruction sequence of local signal,It indicates to receive Chief Signal Boatswain instruction
The phase of the time-domain signal sampling instant t of sequence.
A further improvement of the present invention is that estimating the initial phase for receiving signal in the step S202Afterwards, lead to
Cross formulaTo the long instruction sequence for receiving signalIt compensates.
A further improvement of the present invention is that the estimation of IQ imbalance includes to IQ amplitude imbalance in the step S301
Estimate and IQ unbalance in phase is estimated, wherein if utilizing the reception signal after compensation initial phaseEnergy
Feature carries out the estimation of IQ imbalance, then passes through formulaEstimate
Meter receives the IQ amplitude imbalance of signal, wherein and E () is summation,Sequence is instructed to receive Chief Signal Boatswain
The road I energy,To receive the road the Q energy that Chief Signal Boatswain instructs sequence；Pass through formulaEstimation receives the IQ unbalance in phase of signal, and wherein arcsin is to ask
Arcsine,To receive the road I and the road the Q sum of products that Chief Signal Boatswain instructs sequence.
A further improvement of the present invention is that in the step S301, if utilizing the reception signal after compensation initial phaseTemporal signatures carry out the estimation of IQ imbalance, then first seek IQ imbalance associated expression, formula isWherein, x (t) _ LTS is this
The complex signal of the long instruction sequential sampling moment t of earth signal, x*(t) _ LTS is the complex signal of the long instruction sequential sampling moment t of local signal
Conjugation,To receive the complex signal that Chief Signal Boatswain instructs sequential sampling moment t；Then according to IQ imbalance associated expression
μrAnd vrEstimate IQ amplitude imbalance αrWith IQ unbalance in phase θr, formula is Wherein, η=- μr/vr *, Gain=(- b ± sqrt
(b2- 4))/2,vr *For vrConjugation, real (η) are the real part of η, and imag (η) is the void of η
Portion, arctan are tangent of negating.
A further improvement of the present invention is that passing through formula in the step S302To reception signalCarry out IQ imbalance compensation, wherein μr' and vr' it is respectively IQ width
Spend imbalance αrWith unbalance in phase θrThe plural number constituted by formula.
A further improvement of the present invention is that in the step S1, using the short training sequence and local signal for receiving signal
Short training sequence carry out sliding related operation, by similarity degree obtain receive signal short training sequence starting point, and then derive
The initial position of signal frame is received out, this process is thick synchronizing process；According to the frame start position that thick synchronizing process obtains, obtain
It takes and receives Chief Signal Boatswain instruction sequence Position Approximate, sequence is then instructed with reception Chief Signal Boatswain by the long instruction sequence of local signal and is slided
Related operation obtains the starting point for receiving the long instruction sequence of signal, and then the starting of corrected received signal frame by similarity degree
Position, this process are smart synchronizing process.
The present invention also provides a kind of for the IQ imbalance estimation of initial phase offset and compensation device, uses institute as above
The estimation of IQ imbalance and compensation method for initial phase offset stated, and include:
Synchronization module utilizes the signal autocorrelation of the short training sequence for receiving signal and local signal and long instruction sequence, inspection
The frame header position for receiving signal is measured, then determines the position for receiving each data field in signal；
Initial phase estimation and compensating module instruct sequence time domain specification using long, by the long instruction sequence of local signal and connect
The phase difference for receiving Chief Signal Boatswain instruction sequence, estimates initial phase, then compensates this initial phase to reception Chief Signal Boatswain and instructs sequence
On column；
The estimation of IQ imbalance and compensating module, it is special using the energy response or time domain of the long instruction sequence after compensation initial phase
Property, estimation receives the IQ amplitude imbalance and IQ unbalance in phase of signal, and carries out IQ imbalance compensation to the entire signal that receives；
Channel estimation and parsing module do channel using long instruction sequence to the reception signal after completion IQ imbalance compensation
Estimation carries out balancing operational and parsing to data field is received.
Compared with prior art, the beneficial effects of the present invention are: the long instruction sequence of selection carries out initial phase estimation and IQ
Imbalance estimation, realizes the estimation and compensation method for receiving signal initial phase, the long instruction sequence after compensating initial phase, tool
Have that IQ two paths of signals energy is equal, energy response of quadrature in phase, and the compensated reception signal of initial phase is in each time domain
Sampled point IQ imbalance time domain specification having the same.Using its energy response or time domain specification, the estimation of IQ imbalance is realized,
After estimating the estimation of IQ imbalance, IQ imbalance compensation is carried out to signal is received.The present invention is uneven for the IQ of initial phase offset
Weighing apparatus estimation and compensation are very accurate, can effectively improve the demodulation performance of receiving end.To sum up, this invention removes receiver local oscillators
The influence of time error and signal transmission time bring initial phase offset improves the accuracy of IQ imbalance estimation,
After compensating IQ amount of unbalance, the performance for receiving signal is finally improved.
Detailed description of the invention
Fig. 1 is the workflow schematic diagram of an embodiment of the present invention.
Specific embodiment
With reference to the accompanying drawing, preferably embodiment of the invention is described in further detail.
Firstly, explaining to some terms, WLAN is Wireless Local Area Network line local area network,
OFDM is Orthogonal Frequency Division Multiplexing orthogonal frequency division multiplexing, STS short
Training symbol Short training sequence, abbreviation short training sequence symbol；LTS is long training symbol long instruction
Practice sequence symbol, referred to as long instruction sequence symbol；BPSK is Binary Phase Shift Keying bi-phase shift keying symbol tune
System, QPSK are Quaternary Phase Shift Keying quadriphase PSK symbol-modulated.
This example considers ideal WLAN model, it is assumed that baseband complex signal is x (t)=xI(t)+i*xQ(t), Direct Conversion is sent out
Penetrating machine I, Q road local oscillation signal is aI(t)=cos (wct),aQ(t)=sin (wcT), wherein t is the time, and i is imaginary part, wcFor
The angular frequency for the carrier frequency that radio frequency uses.
Then emitting radiofrequency signal isWherein x*(t) be x (t) conjugation,
Channel response from transmitting terminal to receiving end is denoted as h (t), and interchannel noise is Gaussian noise n (t), then Direct Conversion
The radiofrequency signal that receiver receives is represented by Wherein t is the time,Indicate convolution algorithm.
The road Direct Conversion Receiver I and the road Q local oscillation signal are bI(t)=cos (wct),bQ(t)=- sin (wct).Assuming that
Direct Conversion Receiver is expressed as y (t)=y for what radiofrequency signal was transformed to complex baseband signalI(t)+i*yQ(t), then having Wherein, LPF was low-pass filter, will be containedHigh frequency section is eliminated by filter.
Y can similarly be derivedQ(t)=i*LPF { bQ(t)rRF(t) }=i*xQ(t)。
In ideal communication channel h (t)=1 and in the case where ignore noise, receiving end baseband signal and transmitting terminal baseband signal
Relationship is as followsPassing through local oscillator by formula explanation is aI(t)=cos
(wct),aQ(t)=sin (wcT) transmitter and local oscillator is bI(t)=cos (wct),bQ(t)=- sin (wcT) receiver,
The baseband signal received can be regarded as the baseband signal of transmitting.
But in a practical situation, it will lead to the road I and the road Q after frequency conversion since the local oscillator of Direct Conversion Receiver is undesirable
The imbalance of signal generation amplitude and phase, i.e. two-way amplitude be not identical, phase phase difference is not 90.Then Direct Conversion Receiver I
Road and the road Q local oscillation signal bI(t)=cos (wct),bQ(t)=- sin (wcT) become bI(t)=(1+ αr)cos(wct-θr/ 2), bQ
(t)=- (1- αr)sin(wct+θr/ 2), wherein αrIndicate receiver IQ amplitude imbalance amount,Unit is dB.WithIt is the road receiver I and the road Q amplitude gain respectively.θrIt indicates to receive
Machine IQ unbalance in phase amount, be the road receiver I and the road Q phase difference and ideal 90 degree of deviation.
Formula at this timeBecome Wherein μr、vrIt is by IQ amplitude imbalance αrWith IQ unbalance in phase θrThe correlated expression of composition
Formula.
At this time receive signalConjugate x comprising emitting signal*(t), i.e., by the interference of conjugate, cause to connect
Performance is received to be affected.Work as αr=0, θrWhen=0, there is μr=1, vr=0, this is precisely the reception mode on ideal I road and the road Q.
IEEE 802.11a/p/g/n/ac standard is encoded in frequency domain, by the Symbol duration of 0.4us, passes through IDFT
Time-domain signal is transformed to be transmitted.For BPSK, QPSK modulation system, the road I of transmitting terminal baseband signal x (t) and the road Q tool
Have that energy is equal, mean value zero, and orthogonal relationship, i.e.,E(xI(t))=E (xQ(t))
=0, E (xI(t)*xQ(t))=0.Wherein xI(t) be x (t) real part, xQ(t) be x (t) imaginary part, E () be summation.
The long instruction sequence LTS modulation system of 802.11 a/p/g/n/ac of IEEE is BPSK, according to formula The long instruction sequence LTS for then receiving signal y (t) hasE(yI(t))=E
(yI(t))=0, E (yI(t)*yQ(t))=0.If receiver IQ amplitude imbalance is αr, IQ unbalance in phase is θr, then not by IQ
Reception model after balance influence is The road I be The road Q beAt this time have That is, to signal is receivedIt is long
The road I and the road Q signal for instructing sequence substitute intoWithIQ can then be acquired
Amplitude imbalance αrWith IQ unbalance in phase θr。
Another situation, since IQ imbalance is receiver bring, the influence to each sampled point of time domain is the same.
As it was noted above, if receiver IQ amplitude imbalance is αr, IQ unbalance in phase is θr, then reception after being influenced by IQ imbalance
Model isWhen knowing two adjacent transmitting training sequences and corresponding received training sequence,
Parameter μ can be obtained by way of solving equationsrAnd vr.Same selection long training sequence, if x (t) and x (t+1) are to send
Long instruction two points of sequence, corresponding reception value is y (t) and y (t+1), by equation groupWithSimultaneous solution can obtainWherein need to guarantee that denominator is not 0 in formula, long instruction sequence
The time-domain signal condition that be able to satisfy denominator just not be 0.Also to ensure that stability, can choose multiple data points.When
Find out IQ disequilibrium assemblage at associated expression μrAnd vr, then IQ amplitude imbalance α can be acquiredrWith IQ unbalance in phase θr。
Compensation IQ imbalance mode is, according to the IQ amplitude imbalance α acquiredrWith IQ unbalance in phase θr, combination IQ injustice
Weigh expression formulaIQ imbalance is connect
Receive modelIQ imbalance compensation is carried out, compensation factor isIt is after then compensatingAfter carrying out IQ imbalance compensationEliminate conjugate x*
(t) interference.
In the equipment of practical application, the above-mentioned two methods estimation IQ provided is uneven and carries out compensated effect simultaneously
It is bad.This is because transmitter and receiver passes through local oscillator Time Inconsistency, in addition signal transmission is also required to a period of time, this is just
Result in formulaIt does not set up strictly.
Assuming that the initial time of transmitting x (t) transmission is t=τ0, the carrier frequency used is f, receives signal y (t) and receives
Initial time to transmitting signal is t=τ1, according to the transport property of electromagnetic wave, then y (t) and x (t) have an initial phase
Offset, sending and receiving end baseband signal relationship is expressed as follows again: y (t)=ei*Ψ* x (t), wherein For to being rounded under x.Initial phase Ψ is equivalent to the entire signal relative transmission signal that receives and carries out
The rotation of angle Ψ.
To normally receiving for process, initial phase Ψ can be balanced out by channel estimation and balanced two steps, because
This does not influence to receive, and is usually not considered.
When y (t) by initial phase and IQ are unbalanced influence when, initial phase on IQ imbalance estimation be influential.
As initial phase Ψ, the road I of y (t) and the road the Q following y of expression formulaI(t)=cos (Ψ) xI(t)-sin(Ψ)xQ(t),yQ(t)
=sin (Ψ) xI(t)+cos(Ψ)xQ(t), then by formula E (xI(t)xQ(t))=0,E(xI
(t))=E (xI=0 and y (t)=e (t))i*Ψ* x (t) cannot get formula E (yI(t)yQ(t))=0,E(yI(t))=E (yI(t)) condition=0 set up, then formulaWithIt is same invalid, therefore there are errors for the estimation of IQ imbalance.
Likewise, receiving signal no longer has formulaCharacteristic, concrete form becomesSo simultaneous WithBecause how uncertain
Unknown quantity Ψ, therefore estimate that IQ imbalance estimates that there are errors.
Therefore, this example first carries out initial phase estimation to signal is received, and then carries out initial phase compensation to reception signal,
Reception data after compensation initial phase meet formulaIQ unbalanced method energy to provide
It is enough correctly to estimate IQ imbalance, then corresponding IQ imbalance compensation is carried out, promote receptivity.
That is, this example is in system of the IEEE802.11 based on ofdm communication, for straight Conversion Receiver in fact
The road IQ imbalance problem considers the adverse effect that initial phase estimates traditional IQ imbalance, proposes a kind of compensation initial phase
After offset, then the method for carrying out IQ imbalance estimation, IQ imbalance compensation is then carried out, achievees the purpose that promote receptivity.
This example is by taking IEEE 802.11a system receives example scenario as an example.Transmitter, receiver local oscillator time difference
The rotation for needing the time that signal is caused to have phase Ψ, that is, so-called initial phase are transmitted with signal.Receive signal time domain letter
Road response is h (t), and noise is white Gaussian noise n (t), receiver IQ amplitude imbalance αrWith IQ unbalance in phase θr, combine IQ
Uneven expression formula IQ is uneven
Receive modelForm is expressed as follows again
As shown in Figure 1, this example provides a kind of estimation of IQ imbalance and compensation method for initial phase offset, including with
Lower step:
Step S1 synchronizes detection to reception signal and obtains frame start position；
Step S2 receives the initial phase of signal according to the time domain phase estimation of the time domain phase and local signal that receive signal
Then position carries out initial phase compensation to reception signal；
Step S3 carries out the estimation of IQ imbalance and compensation to the reception signal after compensation initial phase.
In brief, the step S1 synchronizes detection to receiving signal to realize, the step S2 is in order to realize
Estimation and compensation to initial phase, the step S3 is in order to realize the estimation of IQ imbalance and compensation, as shown in Figure 1.
Wherein, it in step S1 described in this example, is slided using the short training sequence for receiving signal with local signal short training sequence
Dynamic related operation, the starting point for receiving signal short training sequence is obtained by similarity degree, and then is derived and received rising for signal frame
Beginning position, this process are thick synchronizing process；According to the frame start position that thick synchronizing process obtains, obtains and receive Chief Signal Boatswain instruction sequence
Column are general, then carry out sliding related operation with Chief Signal Boatswain instruction sequence is received by the long instruction sequence of local signal, pass through similar journey
Degree obtains the starting point for receiving the long instruction sequence of signal, and then the initial position of revise signal frame, this process are that essence synchronized
Journey.
Specifically, in the synchronous detection of the step S1, according to signal IQ two paths of data is received, by the phase of certain window
After closing detection, frame start position is obtained.The thick synchronizing process of the present invention is using reception signal short training sequence and local signal short training sequence
Column carry out sliding related operation, judge its similarity degree, and crosscorrelation is distinguished on the concrete operations road Shi Dui IQ, and take flat after correlation
Square accumulated value.Used formula is as follows, Cτ=CI,I_ideal+
CI,Q_ideal+CQ,I_ideal+CQ,Q_idealAnd PointSTS=Max (Cτ), whereinIndicate that receiving signal with time τ is starting
Real part,Indicate that receiving signal with time τ is the imaginary part originated, xI(t) _ STS indicates local signal short training sequence STS letter
Number real part, xQ(t) _ STS indicates local signal short training sequence STS signal imaginary part, and ∑ () indicates cumulative, and Max () expression is asked
Maximum value, PointSTSIndicate the initial position of short training sequence STS on reception signal.
Short training sequence STS's has synchronized 10 peak values, is obtained according to peak value and receives signal short training sequence STS starting point, so
After derive receive signal frame start position, realize thick synchronizing process.It is repositioned on the position for receiving Chief Signal Boatswain instruction sequence, is used
Length instruction sequence and local long instruction sequence are received, thick synchronizing process is repeated and realizes that essence is synchronous, after instructing sequence related operation according to length
Two peak values also can determine out the starting point for receiving signal frame.The final signal frame starting point that receives is obtained with smart synchronizing process
Result subject to.
Certainly, it is that frame start position, this example list one in order to obtain that a pair reception signal, which synchronizes detection, described in this example
The preferred method of kind, in practical applications, it is not limited to a kind of this synchronization detecting method, as long as obtaining frame start position i.e.
It can.
In step S2 described in this example, including following sub-step:
Step S201 is completed after synchronizing detection to signal is received, and is navigated to the long instruction sequence for receiving signal, is then used and receive
The time domain phase of the long instruction sequence of the time domain phase and local signal of the long instruction sequence of signal carries out difference fortune by sampled point one by one
It calculates, finally seeks the average value of these phase difference values as the initial phase for receiving signal；
Step S202 after estimating the initial phase for receiving signal, carries out initial phase to the long instruction sequence for receiving signal
Compensation.
In step S201 described in this example, estimated according to the time domain phase and local signal time domain phase that receive signal initial
Phase.This example is completed after synchronizing detection to signal is received, and is navigated to the long instruction sequence LTS for receiving signal, is then used and receive long instruction
The time domain phase of sequence LTS and the time domain phase of locally known long instruction sequence LTS temporally carry out difference point by point, finally ask these
Phase difference value is averaged.
In step s 201, pass through formulaSeek the first of the reception signal
Beginning phaseWherein, NLTSIndicate the time-domain sampling points of long instruction sequence, Ψx(t)_LTSIndicate the time-domain signal of local long instruction sequence
The phase of sampling instant t,Indicate to receive the phase of the time-domain signal sampling instant t of long instruction sequence in signal.
In the step S202, the initial phase for receiving signal is estimatedAfterwards, pass through formula To the long instruction sequence for receiving signalIt compensates.
Include following sub-step in step S3 described in this example:
Step S301 carries out the estimation of IQ imbalance using the compensated energy feature for receiving signal or time domain specification；
Step S302 carries out IQ imbalance compensation to signal is received after the estimation of IQ imbalance.
In step S301 described in this example, the estimation of IQ imbalance includes estimating IQ amplitude imbalance and to IQ unbalance in phase
Estimation, wherein if utilizing compensated reception signalEnergy feature carry out the estimation of IQ imbalance, then pass through public affairs
FormulaEstimation receives the IQ amplitude imbalance of signal,
In, E () is summation,To receive the road the I energy that Chief Signal Boatswain instructs sequence,
To receive the road the Q energy that Chief Signal Boatswain instructs sequence；Pass through formulaEstimation connects
The IQ unbalance in phase of the collection of letters number, wherein arcsin is sine of negating,To receive signal
The road I of long instruction sequence and the road the Q sum of products.
In addition, this example can also estimate IQ imbalance associated expression to compensated reception signal time domain specification；Cause
This, in step S301 described in this example, if utilizing the reception signal after compensation initial phaseTemporal signatures carry out
The estimation of IQ imbalance, then first seek IQ imbalance associated expression, formula is Wherein, x (t) _ LTS is answering for local long instruction sequential sampling moment t
Signal, x*(t) _ LTS is the complex signal conjugation of local long instruction sequential sampling moment t,Sequence is instructed to receive Chief Signal Boatswain
The complex signal of column sampling instant t.Then according to IQ imbalance associated expression μrAnd vrEstimate IQ amplitude imbalance αrWith IQ phase
Uneven θr, formula is Wherein, η=-
μr/vr *, Gain=(- b ± sqrt (b2- 4))/2,vr *For vrConjugation, real (η) are η's
Real part, imag (η) are the imaginary part of η, and arctan is tangent of negating.
In step S302 described in this example, pass through formulaTo reception signalCarry out IQ
Imbalance compensation, wherein
μr' and vr' it is IQ amplitude imbalance αrWith unbalance in phase θrIt is IQ amplitude imbalance α by the plural number that formula is constitutedrNot with phase
Balance θrThe plural number constituted by formula.
After step S3 realizes the estimation of IQ imbalance and compensation, by compensated reception dataIt is sent into receiving module
Processor, routinely process carries out channel estimation and parsing data.
Therefore, this example also provides a kind of for the IQ imbalance estimation of initial phase offset and compensation device, uses such as
The upper estimation of IQ imbalance and compensation method for initial phase offset, and include:
Synchronization module, by receiving the short training sequence of signal and local signal and the signal autocorrelation of long instruction sequence, inspection
The frame header position for receiving signal is measured, then determines the position for receiving each data field in signal；
Initial phase estimation and compensating module instruct sequence time domain specification using long, by the long instruction sequence of local signal and connect
The phase difference for receiving Chief Signal Boatswain instruction sequence, estimates initial phase, then compensates this initial phase to reception Chief Signal Boatswain and instructs sequence
On column；
The estimation of IQ imbalance and compensating module, it is special using the energy response or time domain of the long instruction sequence after compensation initial phase
Property, estimation receives the IQ amplitude imbalance and IQ unbalance in phase of signal, and carries out IQ imbalance compensation to the entire signal that receives；
Channel estimation and parsing module do channel using long instruction sequence to the reception signal after completion IQ imbalance compensation
Estimation carries out balancing operational and parsing to data field is received.
Synchronization module described in this example synchronizes detection to reception signal for realizing step S1's to obtain start of frame bits
It sets, synchronization module mainly utilizes the autocorrelation of short training sequence and long instruction sequence, detects the frame header position for receiving signal, then
Determine the position for receiving each data field in signal.
The estimation of initial phase described in this example and compensating module are estimated and are compensated for realizing the initial phase of step S2.Initially
Phase estimation and compensating module by local length instruction sequence and receive the long phase for instructing sequence mainly using long instruction sequence time domain specification
Potential difference estimates initial phase, then compensates this initial phase onto reception signal.
The estimation of IQ imbalance described in this example and compensating module method one, the main road the IQ energy response using long instruction sequence,
The unbalanced situation of energy that Chief Signal Boatswain instructs the road sequence IQ is received by statistics, IQ amplitude imbalance is estimated and IQ phase is uneven
Weighing apparatus.Then the IQ amount of unbalance estimated is compensated onto reception signal.
The estimation of IQ imbalance described in this example and compensating module method two, it is mainly special using the long instruction sequence time domain of leading the inside
Property and IQ imbalance to time domain effect of signals the characteristics of, pass through local long instruction sequence and receive long instruction two receiving point simultaneous of sequence
Equation estimates IQ amplitude imbalance and IQ unbalance in phase.Then the IQ amount of unbalance estimated is compensated onto reception signal.
Channel estimation and parsing module described in this example are incited somebody to action for realizing after step S3 realizes the estimation of IQ imbalance and compensation
Compensated reception data are sent into receiving module processor, and routinely process carries out channel estimation and parsing data.
The long instruction sequence progress initial phase estimation of this example selection and the estimation of IQ imbalance, realize based on reception signal to first
The estimation and compensation method of beginning phase, the long instruction sequence after compensating initial phase, have IQ two paths of signals energy is equal, phase just
The energy response of friendship, and the compensated reception signal of initial phase is in each point IQ imbalance time domain specification having the same.Benefit
With its energy response or time domain specification, the estimation of IQ imbalance is realized, after estimation IQ imbalance estimation, carry out IQ to signal is received
Imbalance compensation.Estimate the present invention is based on the IQ imbalance for receiving signal and compensation is very accurate, receiving end can be effectively improved
Demodulation performance.
It is noted that according to this example provide ofdm system for initial phase offset IQ imbalance estimation with
Compensation method when the method carries out signal reception, between synchronization module and channel estimation and parsing module, increases by one
Initial phase estimation and compensating module are further added by the estimation of IQ imbalance and compensating module, can reach it is following the utility model has the advantages that
Compared with existing IQ imbalance estimation method, receiver local oscillator time error and signal transmission time bring initial phase are eliminated
The influence of position offset, improves the accuracy of IQ imbalance estimation, after compensating IQ amount of unbalance, finally improves reception letter
Number performance.
The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be said that
Specific implementation of the invention is only limited to these instructions.For those of ordinary skill in the art to which the present invention belongs, exist
Under the premise of not departing from present inventive concept, a number of simple deductions or replacements can also be made, all shall be regarded as belonging to of the invention
Protection scope.
Claims (6)
1. a kind of estimation of IQ imbalance and compensation method for initial phase offset, which comprises the following steps:
Step S1 synchronizes detection to reception signal and obtains frame start position；
Step S2 receives the initial phase of signal according to the time domain phase estimation of the time domain phase and local signal that receive signal,
Then initial phase compensation is carried out to reception signal；
Step S3 carries out the estimation of IQ imbalance and compensation to the reception signal after compensation initial phase；
The step S2 includes following sub-step:
Step S201 is completed after synchronizing detection to signal is received, and is navigated to the long instruction sequence for receiving signal, is then used and receive signal
The time-domain signal phase of long instruction sequence and the time-domain signal phase of the long instruction sequence of local signal carry out difference fortune by sampled point one by one
It calculates, finally seeks the average value of these phase difference values as the initial phase for receiving signal；
Step S202 after estimating the initial phase for receiving signal, carries out initial phase compensation to the long instruction sequence for receiving signal；
The step S3 includes following sub-step:
Step S301 carries out IQ imbalance using the energy feature or time domain specification of the reception signal after compensation initial phase and estimates
Meter；
Step S302 carries out IQ imbalance compensation to signal is received after the estimation of IQ imbalance；
In the step S301, the estimation of IQ imbalance includes estimating IQ amplitude imbalance and estimating IQ unbalance in phase,
In, if utilizing the reception signal after compensation initial phaseEnergy feature carry out the estimation of IQ imbalance, then pass through
FormulaEstimation receives the IQ amplitude imbalance of signal,
In, E () is summation,To receive the road the I energy that Chief Signal Boatswain instructs sequence,
To receive the road the Q energy that Chief Signal Boatswain instructs sequence；Pass through formulaEstimation is received
The IQ unbalance in phase of signal, wherein arcsin is sine of negating,To receive Chief Signal Boatswain
Instruct the road I and the road the Q sum of products of sequence；
In the step S302, pass through formulaTo reception signalIt is uneven to carry out IQ
Compensation, whereinμr' and vr′
Respectively IQ amplitude imbalance αrWith unbalance in phase θrThe plural number constituted by formula.
2. the estimation of IQ imbalance and compensation method according to claim 1 for initial phase offset, which is characterized in that
In the step S201, pass through formulaSeek the initial phase for receiving signalWherein, NLTSIndicate the time-domain sampling points of long instruction sequence, Ψx(t)_LTSIndicate that the time-domain signal of the long instruction sequence of local signal is adopted
The phase of sample moment t,Indicate the phase of the time-domain signal sampling instant t of reception Chief Signal Boatswain instruction sequence.
3. the estimation of IQ imbalance and compensation method according to claim 2 for initial phase offset, which is characterized in that
In the step S202, the initial phase for receiving signal is estimatedAfterwards, pass through formula To the long instruction sequence for receiving signalIt compensates.
4. the estimation of IQ imbalance and compensation method according to claim 3 for initial phase offset, which is characterized in that
In the step S301, if utilizing the reception signal after compensation initial phaseTemporal signatures to carry out IQ uneven
Estimation, then first seek IQ imbalance associated expression, formula is Wherein, x (t) _ LTS is the long instruction sequential sampling moment t of local signal
Complex signal, x*(t) _ LTS is the complex signal conjugation of the long instruction sequential sampling moment t of local signal,To receive signal
The complex signal of long instruction sequential sampling moment t；Then according to IQ imbalance associated expression μrAnd vrEstimate IQ amplitude imbalance αrWith
IQ unbalance in phase θr, formula is Its
In, η=- μr/vr *, Gain=(- b ± sqrt (b2- 4))/2,vr *For vrConjugation, real
(η) is the real part of η, and imag (η) is the imaginary part of η, and arctan is tangent of negating.
5. the estimation of IQ imbalance and compensation method according to any one of claims 1 to 4 for initial phase offset,
It is characterized in that, carrying out sliding related fortune to local signal short training sequence using signal short training sequence is received in the step S1
It calculates, the starting point for receiving signal short training sequence is obtained by similarity degree, crosscorrelation is distinguished on the concrete operations road Shi Dui IQ, and takes
Square accumulated value after correlation, used formula is as follows, Cτ=CI,I_ideal+CI,Q_ideal+CQ,I_ideal+CQ,Q_idealAnd PointSTS
=Max (Cτ), whereinIndicate that receiving signal with time τ is the real part originated,Indicate that receiving signal with time τ is
The imaginary part of starting, xI(t) _ STS indicates local signal short training sequence STS signal real part, xQ(t) _ STS indicates local signal short training
Sequence STS signal imaginary part, ∑ () indicate cumulative, and Max () indicates maximizing, PointSTSIt indicates to receive short training on signal
The initial position of sequence STS and then the initial position for deriving reception signal frame, this process are thick synchronizing process；According to thick same
The frame start position that step process obtains obtains and receives Chief Signal Boatswain instruction sequence location, and then local signal is long instructs sequence and receive letter
Number long instruction sequence carries out sliding related operation, passes through similarity degree and obtains the starting point for receiving the long instruction sequence of signal, Jin Erxiu
The positive initial position for receiving signal frame, this process are smart synchronizing process；The essence synchronizing process, which navigates to, receives Chief Signal Boatswain instruction
The position of sequence instructs sequence with locally long using long instruction sequence is received, it is smart synchronous to repeat thick synchronizing process realization.
6. a kind of for the IQ imbalance estimation of initial phase offset and compensation device, which is characterized in that wanted using such as right
The estimation of IQ imbalance and compensation method described in 1 to 5 any one for initial phase offset are asked, and includes:
Synchronization module is detected using the signal autocorrelation of the short training sequence for receiving signal and local signal and long instruction sequence
The frame header position of signal is received, then determines the position for receiving each data field in signal；
Initial phase estimation and compensating module instruct sequence time domain specification using long, instruct sequence by local signal length and receive and believe
The phase difference of number long instruction sequence, estimates initial phase, then compensates this initial phase to receiving in Chief Signal Boatswain instruction sequence；
The estimation of IQ imbalance and compensating module instruct the energy response or time domain specification of sequence using the length after compensation initial phase,
Estimation receives the IQ amplitude imbalance and IQ unbalance in phase of signal, and carries out IQ imbalance compensation to the entire signal that receives；
Channel estimation and parsing module do channel estimation using long instruction sequence to the reception signal after completion IQ imbalance compensation,
Balancing operational and parsing are carried out to data field is received.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1649276A (en) * | 2004-01-30 | 2005-08-03 | 三星电子株式会社 | Method and device for compensating phase error in base station system |
| CN101222142A (en) * | 2008-01-30 | 2008-07-16 | 湖南大学 | An Unbalance Compensation and Ant Colony Optimization Method for Static Var Compensator |
| US8126086B2 (en) * | 2008-01-31 | 2012-02-28 | Agilent Technologies, Inc. | System and method for in-phase/quadrature-phase (I/Q) mismatch measurement and compensation |
| CN104584502A (en) * | 2012-09-21 | 2015-04-29 | 意法爱立信有限公司 | Loopback technique for IQ imbalance estimation for calibration in OFDM systems |
| CN104991231A (en) * | 2015-05-26 | 2015-10-21 | 芜湖航飞科技股份有限公司 | Intermediate-frequency cancellation technology |
-
2017
- 2017-01-11 CN CN201710018193.7A patent/CN106850495B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1649276A (en) * | 2004-01-30 | 2005-08-03 | 三星电子株式会社 | Method and device for compensating phase error in base station system |
| CN101222142A (en) * | 2008-01-30 | 2008-07-16 | 湖南大学 | An Unbalance Compensation and Ant Colony Optimization Method for Static Var Compensator |
| US8126086B2 (en) * | 2008-01-31 | 2012-02-28 | Agilent Technologies, Inc. | System and method for in-phase/quadrature-phase (I/Q) mismatch measurement and compensation |
| CN104584502A (en) * | 2012-09-21 | 2015-04-29 | 意法爱立信有限公司 | Loopback technique for IQ imbalance estimation for calibration in OFDM systems |
| CN104991231A (en) * | 2015-05-26 | 2015-10-21 | 芜湖航飞科技股份有限公司 | Intermediate-frequency cancellation technology |
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