CN104639490B - A kind of Combined estimator and the compensation method of frequency dependence IQ imbalance and channel - Google Patents
A kind of Combined estimator and the compensation method of frequency dependence IQ imbalance and channel Download PDFInfo
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Abstract
The invention belongs to wireless communication technology fields, in particular to a kind of method of joint channel estimation and frequency dependence IQ (In-phase Quadrature, IQ) imbalance compensation in wireless communication system.This hair by channel and introduces receiving end frequency dependence IQ imbalance, obtains receiving signal and its frequency-domain expression by sending training sequence；Initiation parameter αR、βR、hIAnd hQ；Obtain response H of the channel h [n] on frequency domainkWith the conjugation h of channel h [n]*The response of [n] on frequency domainObtain βR、αR、hI=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3] estimated value；These steps of originally transmitted signal are recovered to realize.The unbalanced parameter of IQ and estimation channel that the present invention is separated simultaneously, the IQ imbalance parameter estimated is used to carry out unified compensation as preset parameter, it no longer needs to carry out duplicate parameter Estimation to IQ imbalance parameter, relative to previous IQ imbalance compensation method IQ imbalance is considered mostly as a whole with channel, reduces the expense of system-computed.Meanwhile total algorithm of the invention relates generally to linear operation, complexity is low.
Description
Technical field
The invention belongs to wireless communication technology fields, in particular to a kind of joint channel estimation and frequency in wireless communication system
The method of rate correlation IQ (In-phase Quadrature, IQ) imbalance compensation.
Background technique
Wireless communication usually requires carrier modulation, in view of the imperfection of analog device in practice, AFE(analog front end) (FE,
Front-end same phase) can produce during modulation /demodulation with orthogonal (IQ, In-phase Quadrature) two paths of signals
The imbalance of raw signal, i.e. the amplitude of IQ two-way local oscillation signal is no longer identical, and phase difference is also not equal to (IQ is uneven), to lead
System performance decline is caused, this is even more serious in the higher system of carrier frequency (such as millimeter-wave communication system), is especially working as
High frequency communication system is reduced cost using high order modulation or radio-frequency front-end and uses inexpensive Direct Conversion structure
In the case of.In general, it can be used to reduce the unbalanced influence of IQ there are also the technology of analog domain, such as wiring technique uses
Different circuit topological structure etc., but these technologies often will increase equipment size, power consumption and cost, and cannot be effective
It is uneven that IQ is eliminated on ground.In contrast, estimation is carried out to IQ imbalance by Digital Signal Processing in numeric field and compensation is not required to
Various tradeoffs or compromise are done as analog domain, there is huge advantage.Therefore, IQ imbalance compensation is carried out in digital baseband
It is necessary and crucial.
Cause the unbalanced reason of IQ to be divided into two kinds: one is with the independent IQ imbalance (frequency- of frequency
Independent I/Q mismatch), this imbalance is that the local oscillation signal inaccuracy generated due to frequency mixer is caused, and is mixed
Local oscillation signal phase difference is not 90 ° in device or amplitude difference causes IQ two paths of signals that cannot occur orthogonal demodulation, it is this not
Each frequency component is mutually indepedent in the effect and signal of balance.Another IQ is uneven and frequency dependence, i.e. IQ are unbalanced
Effect is different according to the difference of the frequency content in signal, and this uneven generation stems primarily from circuit device in IQ two-way
The difference of filter freguency response in the gap of part Frequency Response, such as two branches, amplifier, digital analog converter (DAC,
Digital-to-Analog Converter) or analog-digital converter (ADC, Analog-to-Digital Converter) output
Difference etc., these can all cause I Q two-way that the unmatched situation with frequency dependence occurs.
Currently, common some IQ imbalance compensation schemes, it is roughly divided into two kinds: blind estimate or non-blind algorithm for estimating.
About blind estimate algorithm, for example, with Interference Cancellation (IC, Interference Cancellation) and blind source separating (BSS,
Blind Source Separation) based on backoff algorithm, pass through influence of the analysis IQ imbalance to signal statistics
To compensate IQ imbalance.This method does not need any known sequence, does not need to estimate IQ imbalance parameter yet, but usually
Need a large amount of symbol and longer adaptive iteration process, destruction of the synchronous signal statistical property vulnerable to multipath.And for
Non-blind algorithm for estimating, is based on signal detection theory, and IQ imbalance parameter can also be estimated by sending known training sequence.
It generally can be by based on system-level algorithm and using traditional least square (LS, Least Squares), expectation maximization
Criterion such as (EM, Expectation Maximization), realization are accurately and rapidly estimated and are compensated to IQ imbalance.It is this
Compensation scheme is smaller than blind estimate operand, it is easy to accomplish, therefore be widely used.But common non-blind algorithm for estimating is faced with dependence
In perfect channel estimation, there is particular requirement to which applicability is limited, can not be by IQ imbalance parameter and channel point to training sequence
The problems such as leaving or effective compensation can not being carried out to frequency dependence IQ imbalance.For appeal problem, study a kind of general
The method of joint channel estimation and frequency dependence IQ imbalance compensation has important practical significance.
Summary of the invention
The present invention provides Combined estimator and the compensation method of a kind of frequency dependence IQ imbalance and channel, specific as follows:
S1, it enables the training sequence x [n] that length is N pass through channel h [n], considers that frequency dependence IQ in receiving end is unbalanced and draw
Enter, receiving end receives the frequency domain presentation of signal are as follows:Wherein, XkPass through N for x [n]s
Frequency-region signal after the FFT of point,For the conjugated signal x of x [n]*[n] passes through NsFrequency-region signal after the FFT of point, HkFor letter
Road h [n] passes through NsFrequency domain response after the FFT of point,For the conjugation h of channel h [n]*[n] passes through NsFrequency domain after the FFT of point
Response, 0≤k≤Ns- 1,For noise,0≤Ns≤ N and NsFor integer, Ak、BkFor with receiving end frequency
Rate correlation IQ imbalance parameter alphaR、βR、hI=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3] associated parameter, physical relationship
Expression formula is as follows:
HI·kWith HQ·kRespectively hIWith hQNsPoint FFT:
The parameter alphaR、βR、hIAnd hQBetween mutually indepedent, αRAnd βRIndicate influence of the IQ imbalance in receiving end to signal is received,
hI=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3] it is to consider that one kind of IQ imbalance frequency dependence is equivalently represented,
Parameter alpha described in S2, initialization S1R、βR、hIAnd hQ, enable αR=1, βR=0, hI=[1,0,0], hQ=[1,0,0]；
S3, the channel h [n] described in S1 carry out maximal possibility estimation, obtain response H of the channel h [n] on frequency domainkAnd letter
The conjugation h of road h [n]*The response of [n] on frequency domain
S4, by H described in S3kWithIt substitutes into described in S1In, to βREstimated
Meter, obtains βREstimated value；
S5, by β described in S4REstimated value substitute intoObtain αREstimated value；
S6, by H described in S3kWithβ described in S4REstimated value and S5 described in αREstimated value substitute into S1 described inIn, the successively h described in S1 by way of iterationI=[hI1,hI2,hI3] and hQ=
[hQ1,hQ2,hQ3] estimated, obtain hI=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3] estimated value；
The unbalanced all parameters of S7, the frequency dependence IQ for obtaining estimation substitute into described in S1In, channel is estimated by maximum-likelihood criterion, obtained estimated value conduct
Finally determining channel estimation；
S8, send information sequence, by channel and the unbalanced influence of IQ, obtain receiving signal, using described in S7 finally
Determining channel estimation compensates the reception signal, recovers the signal not influenced by receiving end IQ imbalanceAfter removing channel effect using obtained channel estimation, it can obtainI.e.
Recover originally transmitted signal.
Further, N described in S1s=512.
Further, to channel h [n] progress maximal possibility estimation, specific step is as follows described in S3:
S31, channel frequency domain response is subjected to Fourier expansion.Enable FK, nIndicate correspond to k-th of subcarrier FFT arrange to
Amount, i.e.,(0≤k≤Ns- 1,0≤n≤N), h is the column vector for indicating channel time domain impact, there is Hk
=Fk TH,Then received frequency-region signal can indicate are as follows:
S32, according to maximum-likelihood criterion, the maximum-likelihood estimator for obtaining h isTo described
In h and h*Differential is taken respectively and result is set 0, is obtained about h and h*Equation group beWherein,
a1、b1And c1For known quantity；
S33, the equation group according to S32 acquire the estimated value of channel time domain impact h；
S34, response H of the channel h on frequency domain is calculatedkWith the conjugation h of channel h*Response on frequency domain
Further, to β described in S4REstimated, the specific steps are as follows:
S41, by H described in S3kWithIt substitutes into described in S1In, keep αR=
1、hI=[1,0,0] and hQThe value of=[1,0,0] is constant；
S42, according to S1, have:
S43, according to maximum-likelihood criterion, obtain βRMaximum-likelihood estimator be
S44, described in S43Middle βRAnd βR *It takes differential and result is set 0, obtain about βRAnd βR *Equation group；
Solving equations described in S45, simultaneous S44, obtain βR=(a2·b2 *-a2 *·c2)/(b2·b2 *-c2·c2 *), i.e.,
Obtain βREstimated value.
The beneficial effects of the present invention are:
The present invention is applicable in frequency independence IQ imbalance and frequency dependence IQ imbalance compensation, in frequency independence IQ
The lower h of imbalanceI=[1,0,0], hQ=[1,0,0], it is only necessary to consider αR、βR.The present invention be suitable for simultaneously SC-FDE system and
Ofdm system, inventive algorithm are based on training sequence, but to training sequence without particular requirement, suitable under many various criterions
Communication system has good invention value and practical significance.
The unbalanced parameter of IQ and estimation channel that the present invention is separated simultaneously, with the IQ imbalance parameter estimated
Unified compensation is carried out as preset parameter, no longer needs to carry out duplicate parameter Estimation to IQ imbalance parameter, relative to previous
IQ imbalance compensation method mostly considers IQ imbalance with channel as a whole, reduces the expense of system-computed.Together
When, total algorithm of the invention relates generally to linear operation, and complexity is low.
Detailed description of the invention
Fig. 1 is present system model structure.
Fig. 2 is receiving end frequency dependence IQ unbalanced construction figure of the present invention.
Fig. 3 is inventive algorithm flow chart.
Fig. 4 is inventive algorithm bit error rate (BER) performance chart.
Specific embodiment
Below with reference to embodiment and attached drawing, the technical solution that the present invention will be described in detail.
Consider that IQ is uneven, the system model of SC-FDE and OFDM are as shown in Figure 1.The two process is closely similar, only FFT
The difference of module position, but the application purpose difference of its FFT/IFFT causes them to have the difference of essence.For OFDM, IFFT/
Signal progress multi-carrier modulation is converted parallel transmission by FFT module, and essence is a kind of modulation.And for SC-FDE, FFT and
IFFT is successively carried out in receiving end, carries out equalization operation between, is that the distortion generated by channel is put into frequency domain more
It mends, essence is the equilibrium of receiving end.
Assuming that original data stream is symbolic blocks u=[u [nN], u [nN+ that u [n] obtains that length is N after serioparallel exchange
1],…,u[(n+1)N-1]]Τ, wherein n=1,2 ....Then, it is prelisted by a square matrix Γ to the symbolic blocks u
Code:For OFDM, Γ=ΙN, ΙNIndicate N rank unit matrix.N rank FFT matrix is indicated for SC-FDE, Γ=F, F:Wherein 0≤k, n≤N-1.
By frequency-region signalIt is transformed into time domain:Wherein, FΗIndicate N rank IFFT matrix.The intubating length before x
For NcpCyclic prefix (Cyclic Prefix, CP) formation length be NsNew sequence:Wherein, NsThe matrix of × NTo add CP matrix, Ns=N+Ncp, 0m×nIndicate the null matrix of m × n.After parallel-serial conversion,
Become sequence of scalars x [n],Wherein, n=kNs+l-1。
Ignore the unbalanced influence of transmitting terminal IQ, by channel and influence of noise, in the signal that receiving end receives are as follows:
Fig. 2 is receiving end frequency dependence IQ unbalanced construction figure of the present invention.
Consider then to be received signal by the unbalanced interference of receiving end frequency independence IQ first
Distortion, which occurs, to be become:Wherein, αR=cos (Δ φR)-j
εR sin(ΔφR), βR=εR cos(ΔφR)+j sin(ΔφR), by αR≈ 1, βR≈ 0 can
Know, variance and σw 2It is approximately equal.
The influence h of the frequency response difference of branchI、hQCome equivalently represented, consideration IQ imbalance frequency dependence, reception signal
Finally are as follows:Wherein,HI·kAnd HQ·kRespectively hIAnd hQNsThe FFT of point.
It is the N of channel h [n]sPoint FFT, i.e. channel frequency domain response (CFR, channel frequency response), k are indicated k-th
Subcarrier.It is h*The N of [n]sPoint FFT.Similarly, XkIt is x [n], x respectively*The N of [n]sPoint FFT and AWGN to
The N of amountsPoint FFT.After IQ imbalance obtains compensation, frequency domain MMSE equalizing coefficient EkWith YkIt is multiplied, channel shadow can be removed
It rings.
As shown in figure 3, to estimate IQ imbalance parameter, consider to receive unknown ginseng in signal frequency domain expression formula first
The case where amount, wherein including channel frequency domain response Hk、αR、βR、hI=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3], between parameter
Independently of each other, it is contemplated that have α for frequency dependence IQ imbalance parameter in actual conditionsR≈ 1, βR≈ 0, hI≈ [1,0,0], hQ
≈ [1,0,0], then might as well be using these parameters as known quantity processing, and unknown parameter only has channel at this time, thus maximum can be used
Likelihood criterion estimates it, and the channel estimation made at this time therefore is cannot function as final under ideal assumed condition
Channel estimation value.It after obtaining channel estimation, is classified as and has estimated parameter, select next parameter β to be estimatedR, at this time will be to
Estimate parameter βRAs unknown quantity, remaining parameter is substituted into as known quantity and is received in signal frequency domain expression formula, then to βRCarry out maximum seemingly
So estimation, obtains its estimated value, and replace βRInitial value, then by βRIt is classified as and has estimated parameter.Pass through the side of this iteration
Formula is then based on maximum-likelihood criterion and carries out to it so that receiving parameter only to be estimated in signal frequency domain expression formula is unknown quantity
Estimation, until obtaining the estimated value of all parameters.At this point, the estimated value of all parameters is brought into expression formula, again to channel
Estimated, so that its estimated value is more acurrate.It is real in signal to receiving finally by obtained IQ imbalance parameter and channel
The information sequence part for needing to transmit carries out IQ imbalance compensation and channel equalization, to recover originally transmitted signal.
S1, it enables the training sequence x [n] that length is N pass through channel h [n], considers that frequency dependence IQ in receiving end is unbalanced and draw
Enter, receiving end receives the frequency domain presentation of signal are as follows:Wherein, XkPass through N for x [n]s
Frequency-region signal after the FFT of point,For the conjugated signal x of x [n]*[n] passes through NsFrequency-region signal after the FFT of point, HkFor letter
Road h [n] passes through NsFrequency domain response after the FFT of point,For the conjugation h of channel h [n]*[n] passes through NsFrequency domain after the FFT of point
Response, 0≤k≤Ns- 1,For noise,0≤Ns≤ N and NsFor integer, Ak、BkFor with receiving end frequency
Related IQ imbalance parameter alphaR、βR、hI=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3] associated parameter, physical relationship table
It is as follows up to formula:
HI·kWith HQ·kRespectively hIWith hQNsPoint FFT:
The parameter alphaR、βR、hIAnd hQBetween mutually indepedent, αRAnd βRIndicate IQ imbalance in receiving end to the shadow for receiving signal
It rings, hI=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3] it is to consider that one kind of IQ imbalance frequency dependence is equivalently represented,
Parameter alpha described in S2, initialization S1R、βR、hIAnd hQ, enable αR=1, βR=0, hI=[1,0,0], hQ=[1,0,0]；
S3, the channel h [n] described in S1 carry out maximal possibility estimation, obtain response H of the channel h [n] on frequency domainkAnd letter
The conjugation h of road h [n]*The response of [n] on frequency domainIt is specific as follows:
S31, for the ease of processing, channel frequency domain response is subjected to Fourier expansion, then received frequency-region signal is expressed as wherein, FK, nIndicate the FFT column vector for corresponding to k-th of subcarrier, i.e. (0≤k≤Ns- 1,0≤n≤N), h is the column vector for indicating channel time domain impact, there is Hk=Fk TH,
S32, according to maximum-likelihood criterion, the maximum-likelihood estimator for obtaining h is
To the h and h in described*Differential is taken respectively and result is set 0, is obtained about h and h*Equation group be
Wherein, a1、b1And c1For known quantity；
S33, the equation group according to S32 acquire the estimated value of channel time domain impact h；
S34, response H of the channel h on frequency domain is calculatedkWith the conjugation h of channel h*Response on frequency domain
S4, by H described in S3kWithIt substitutes into described in S1In, to βREstimated
Meter, obtains βREstimated value, specifically:
S41, by H described in S3kWithIt substitutes into described in S1In, keep αR=
1、hI=[1,0,0] and hQThe value of=[1,0,0] is constant；
S42, according to S1, have:
S43, according to maximum-likelihood criterion, obtain βRMaximum-likelihood estimator be
S44, described in S43Middle βRAnd βR *It takes differential and result is set 0, obtain about βRAnd βR *Equation group；
Solving equations described in S45, simultaneous S44, obtain βR=(a2·b2 *-a2 *·c2)/(b2·b2 *-c2·c2 *), i.e.,
Obtain βREstimated value.
S5, by β described in S4REstimated value substitute intoObtain αREstimated value；
S6, except currently wait estimate parameter in addition to, by all obtained estimates of parameters and the parameter also do not estimated
Initial value substitutes into the frequency-domain expression for receiving signal, obtains the estimated value of parameter to be estimated by maximum-likelihood criterion, with obtaining
Estimated value replace current value, be included in obtained estimates of parameters, then in the same way never
It selects next Parameter to be estimated in the parameter of processing to be estimated, until estimating all parameters.Iteration in this way
Mode can be successively to hI=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3] estimated.By H described in S3kWithDescribed in S4
βREstimated value and S5 described in αREstimated value substitute into S1 described inIn, pass through iteration
The mode successively h described in S1I=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3] estimated, obtain hI=[hI1,hI2,hI3] and
hQ=[hQ1,hQ2,hQ3] estimated value；
The unbalanced all parameters of S7, the frequency dependence IQ for obtaining estimation substitute into described in S1In, channel is estimated by maximum-likelihood criterion, obtained estimated value conduct
Finally determining channel estimation；
S8, send information sequence, by channel and the unbalanced influence of IQ, obtain receiving signal, using described in S7 finally
Determining channel estimation compensates the reception signal, recovers the signal not influenced by receiving end IQ imbalanceThe signalIgnore noise item.Channel effect is removed using obtained channel estimation
Later, it can obtainRecover originally transmitted signal.
Fig. 4 is the system model structure, the IQ imbalance model structure of Fig. 2 and the algorithm flow of Fig. 3 using Fig. 1, application
Into specific communication system, bit error rate (BER) performance curve of the inventive algorithm emulated in SC-FDE system
Figure.Wherein, Fig. 4 (a) and Fig. 4 (b) are illustrated respectively in sighting distance (LOS) channel model that IEEE 802.15.ad standard channel defines
With bit signal-to-noise ratio E different in non line of sight (NLOS) channel modelb/N0(dB) performance chart.The analogue system of this example is to belong to
In high-frequency high-speed ultra-wideband communication system, its main simulation parameter is: carrier frequency 60GHz, bit rate 1.76Gbps,
16QAM modulation, the roll-off factor for sending and receiving roll-off filter is 0.25, system bandwidth 2.16GHz, receiving end frequency phase
Pass IQ imbalance parameter is εR=1dB, Δ φR=50, hI=[1.02,0.04,0.03], hQ[1.03,0.02,0.012], physics
Layer frame structure is using frame format defined in 802.11ad standard.Lead code is mainly used for interblock interference, automatic growth control, frequency
Estimation, synchronous, channel estimation and modulation system expression etc. partially, by short training sequence (STF, Short Training Field)
It is formed with channel estimation sequence (CEF, Channel Estimation Field).From Fig. 4 it will be seen that not to IQ
When balanced compensated, the poor performance of system, and to IQ imbalance compensation after, system performance improves apparent.
Claims (4)
1. Combined estimator and the compensation method of a kind of frequency dependence IQ imbalance and channel, which comprises the steps of:
S1, it enables the training sequence x [n] that length is N pass through channel h [n], considers the unbalanced introducing of receiving end frequency dependence IQ,
The frequency domain presentation of receiving end reception signal are as follows:Wherein, XkPass through N for x [n]sPoint
Frequency-region signal after FFT,For the conjugated signal x of x [n]*[n] passes through NsFrequency-region signal after the FFT of point, HkFor channel h
[n] passes through NsFrequency domain response after the FFT of point,For the conjugation h of channel h [n]*[n] passes through NsFrequency domain after the FFT of point is rung
It answers, 0≤k≤Ns- 1,For noise, 0≤Ns≤ N and NsFor integer, Ak、BkFor with receiving end frequency dependence IQ imbalance parameter
αR、βR、hI=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3] associated parameter, physical relationship expression formula is as follows:
HI·kWith HQ·kRespectively hIWith hQNsPoint FFT:
The parameter alphaR、βR、hIAnd hQBetween mutually indepedent, αRAnd βRIndicate influence of the IQ imbalance in receiving end to signal is received, hI
=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3] it is to consider that one kind of IQ imbalance frequency dependence is equivalently represented,
Parameter alpha described in S2, initialization S1R、βR、hIAnd hQ, enable αR=1, βR=0, hI=[1,0,0], hQ=[1,0,0]；
S3, the channel h [n] described in S1 carry out maximal possibility estimation, obtain response H of the channel h [n] on frequency domainkWith channel h [n]
Conjugation h*The response of [n] on frequency domain
S4, by H described in S3kWithIt substitutes into described in S1In, to βREstimated, is obtained
To βREstimated value；
S5, by β described in S4REstimated value substitute intoObtain αREstimated value；
S6, by H described in S3kWithβ described in S4REstimated value and S5 described in αREstimated value substitute into S1 described inIn, the successively h described in S1 by way of iterationI=[hI1,hI2,hI3] and hQ=
[hQ1,hQ2,hQ3] estimated, obtain hI=[hI1,hI2,hI3] and hQ=[hQ1,hQ2,hQ3] estimated value；
The unbalanced all parameters of S7, the frequency dependence IQ for obtaining estimation substitute into described in S1
In, channel is estimated by maximum-likelihood criterion, obtained estimated value is as finally determining channel estimation；
S8, information sequence is sent, by channel and the unbalanced influence of IQ, obtains reception signal, using finally being determined described in S7
Channel estimation the reception signal is compensated, recover the signal not influenced by receiving end IQ imbalanceAfter removing channel effect using obtained channel estimation, it can obtainIt is i.e. extensive
It appears again originally transmitted signal.
2. Combined estimator and the compensation method of a kind of frequency dependence IQ imbalance and channel according to claim 1, special
Sign is: N described in S1s=512.
3. Combined estimator and the compensation method of a kind of frequency dependence IQ imbalance and channel according to claim 1, special
Sign is: carrying out maximal possibility estimation to channel h [n] described in S3, specific step is as follows:
S31, channel frequency domain response is subjected to Fourier expansion, enables FK, nIndicate the FFT column vector for corresponding to k-th of subcarrier, i.e.,(0≤k≤Ns- 1,0≤n≤N), h is the column vector for indicating channel time domain impact, there is Hk=Fk T·
H,Then received frequency-region signal can indicate are as follows:
S32, according to maximum-likelihood criterion, the maximum-likelihood estimator for obtaining h is
To institute
It statesIn h and h*Differential is taken respectively and result is set 0, is obtained about h and h*Equation group beIts
In, a1、b1And c1For known quantity；
S33, the equation group according to S32 acquire the estimated value of channel time domain impact h；
S34, response H of the channel h on frequency domain is calculatedkWith the conjugation h of channel h*Response on frequency domain
4. Combined estimator and the compensation method of a kind of frequency dependence IQ imbalance and channel according to claim 1, special
Sign is: to β described in S4REstimated, the specific steps are as follows:
S41, by H described in S3kWithIt substitutes into described in S1In, keep αR=1, hI=
[1,0,0] and hQThe value of=[1,0,0] is constant；
S42, according to S1, have:
S43, according to maximum-likelihood criterion, obtain βRMaximum-likelihood estimator be
S44, described in S43Middle βRAnd βR *It takes differential and result is set 0, obtain about βRAnd βR *Equation group；
Solving equations described in S45, simultaneous S44, obtain βR=(a2·b2 *-a2 *·c2)/(b2·b2 *-c2·c2 *) to get arrive βR
Estimated value.
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| CN104935537A (en) * | 2015-06-17 | 2015-09-23 | 电子科技大学 | Joint estimation compensation improving method of transmitter-receiver IQ imbalance and channel |
| CN106161304B (en) * | 2016-04-01 | 2019-03-12 | 电子科技大学 | A kind of transmitting terminal IQ imbalance compensation method of joint channel estimation |
| TWI664844B (en) * | 2017-11-15 | 2019-07-01 | 元智大學 | Joint estimation and compensation method for solving radio frequency imperfection factor |
| CN109873671B (en) * | 2017-12-04 | 2020-08-04 | 中国航天科工集团第四研究院指挥自动化技术研发与应用中心 | Frequency response characteristic unbalance measurement method, optical transmitter and measurement system |
| CN108616469B (en) * | 2018-05-11 | 2020-10-02 | 东南大学 | Method and device for estimating and compensating IQ imbalance of receiving end of SC-FDE system |
| CN109104201B (en) * | 2018-08-06 | 2020-08-18 | 中科威发半导体（苏州）有限公司 | Frequency correlation IQ mismatch calibration and compensation method based on FFT operation |
| CN110380996B (en) * | 2019-07-12 | 2021-06-08 | 电子科技大学 | Frequency-dependent IQ imbalance compensation method in SC-FDE system |
| US11012273B1 (en) | 2019-12-31 | 2021-05-18 | Hughes Network Systems, Llc | Compensating for frequency-dependent I-Q phase imbalance |
| CN113556302B (en) * | 2021-07-19 | 2023-12-05 | 上海擎昆信息科技有限公司 | IQ imbalance correction method and device for transmitter |
| CN115021772B (en) * | 2022-05-27 | 2023-05-26 | 电子科技大学 | I/Q imbalance iterative estimation and compensation method suitable for frequency correlation |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103152308A (en) * | 2013-03-04 | 2013-06-12 | 北京科技大学 | Joint estimation method of frequency offset, DC (Direct Current) and imbalance of orthogonal frequency division multiplexing system |
| CN103312640A (en) * | 2013-06-30 | 2013-09-18 | 电子科技大学 | Channel estimation and IQ (In-phase Quadrature) imbalance united compensation method |
| CN103746947A (en) * | 2014-01-07 | 2014-04-23 | 电子科技大学 | Phase noise estimation method |
Family Cites Families (1)
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| CN103152308A (en) * | 2013-03-04 | 2013-06-12 | 北京科技大学 | Joint estimation method of frequency offset, DC (Direct Current) and imbalance of orthogonal frequency division multiplexing system |
| CN103312640A (en) * | 2013-06-30 | 2013-09-18 | 电子科技大学 | Channel estimation and IQ (In-phase Quadrature) imbalance united compensation method |
| CN103746947A (en) * | 2014-01-07 | 2014-04-23 | 电子科技大学 | Phase noise estimation method |
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