CN104025526B - Method and apparatus for antenna calibration - Google Patents
Method and apparatus for antenna calibration Download PDFInfo
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- CN104025526B CN104025526B CN201280065762.9A CN201280065762A CN104025526B CN 104025526 B CN104025526 B CN 104025526B CN 201280065762 A CN201280065762 A CN 201280065762A CN 104025526 B CN104025526 B CN 104025526B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/10—Monitoring; Testing of transmitters
- H04B17/11—Monitoring; Testing of transmitters for calibration
- H04B17/12—Monitoring; Testing of transmitters for calibration of transmit antennas, e.g. of the amplitude or phase
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/0082—Monitoring; Testing using service channels; using auxiliary channels
- H04B17/0085—Monitoring; Testing using service channels; using auxiliary channels using test signal generators
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/0202—Channel estimation
- H04L25/024—Channel estimation channel estimation algorithms
- H04L25/0256—Channel estimation using minimum mean square error criteria
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Abstract
Disclose the method and apparatus for calibrating antenna between multiple BS.There is provided a kind of method for being used to calibrate antenna between the first BS and the 2nd BS.This method includes：The first BS UL CSI are obtained based on the SRS sent from UE；The 2nd BS equivalent CSI of UL are obtained via the weighting SRS sent from the UE.Weighting SRS is weighted with the first BS DL CSI with the 2nd BS DL CSI ratio.This method further comprises：The equivalent CSI of UL of UL CSI and the 2nd BS based on the first BS, to calculate the fuzzy factor between the first BS and the 2nd BS.Then, the fuzzy factor can be used to calibrate antenna between the two BS.
Description
Technical field
Embodiments of the invention relate generally to communication system, and relate more particularly to be used between multiple base stations
Calibrate method, device, base station, user equipment and the computer program of antenna.
Background technology
This section introduces may help to promote each side being best understood to (multiple) present invention.Therefore, this part
Statement will be read and will be not understood to what belonging to prior art on or what does not belong to from this angle
In recognizing for prior art.
There is abbreviation in the present description and drawings and term is defined as follows.
3GPP third generation partner programs
BS base stations
CoMP cooperates with multiple spot
CSI channel condition informations
DL downlinks
FDD FDDs
ICI inter-cell interference
LTE Long Term Evolutions
LTE-A Long Term Evolutions-senior
SRS detection reference signals
TDD time division duplexs
UE user equipmenies
UL up-links
UTRAN universal terrestrial radio access networks
In senior (LTE-A) systems of LTE-, (it is one that it, which is also referred to as collaboration multiple spot (CoMP) transmission, for base station collaboration transmission
Kind to reduce inter-cell interference (ICI) and improve the promising technology of the system spectral efficiency in cellular network, especially
For multiaerial system.
There is two kinds of dual-modes, FDD (FDD) and time division duplex (TDD) in LTE and lte-a system.Channel
Reciprocity has been considered as TDD system relative to one of major advantage of FDD system because the up-link in TDD system and
Downlink shares identical frequency band.In other words, base station (BS) can be by via the instruction transmitted from user equipment (UE)
Practice sequence (for example, detection reference signal (SRS)) and carry out estimating uplink channel information, to predict downlink channel information.
However, the reciprocity between uplink channel and downlink channel in TDD system only for spatial channel by
Ensure, it is in actual system due to the mismatch of radio frequency (RF) chain used in the reception and transmission for each antenna
And it is invalid.
Fig. 1 is shown for illustrating the nonreciprocity between the uplink channel in TDD system and downlink channel
Signal mode.
As shown in Figure 1, for each antenna in BS or in UE, its RF chains include the Gao Gong for transmitting
Rate amplifier (HPA) and the low-noise amplifier (LNA) for reception.Transmission-reception switch is arranged in transmission with receiving
Between switch.Therefore, the equivalent channel between BS base band and UE base band includes HPA, spatial channel and LNA.As above
It is previously mentioned, spatial channel is ideally reciprocity.
The channel between j-th of antenna in i-th of antenna and the BS in UE is taken as example.OrderWithDifference table
Show the HPA of j-th of antenna in BS gain and LNA gain,WithThe HPA of i-th of antenna in expression UE increasing
The gain of benefit and LNA, and cijRepresent the spatial channel between j-th of antenna in i-th of the antenna and BS in UE.Such as
This, equivalent uplink channel and equivalent downlink channel can be expressed as：
OrderWithRefer to respectively in UE and the chain in BS and the gain ratio of reception chain.Such as
This, the relation between uplink channel and downlink channel can be expressed as：
WhereinIt is referred to as reciprocity error.
Because the property of RF chains can change with temperature, humidity etc., in order to fully utilize channel reciprocity, day
Line calibration is necessary.
Self calibration is a kind of popular antenna calibration method used in single cell system.Utilize such one kind side
The reciprocity error of each antenna in method, same BS is calibrated to same reference value.Fig. 2 is illustrated for two days in BS
The self-alignment method of line.
As shown in Figure 2, in block 201, generation calibration signal (for example=1).The calibration signal be transferred to as
Amplifier (that is, LNA and HPA) indicated in block 202, by be calibrated two antennas.Then, two signals (for example=
1.1 and 1.2) in block 203 received and be saved.This means the amplifier of the two antennas has different gains.
Afterwards, in block 204, the ratio between the gain of the amplifier of the two antennas is calculated and is saved.Illustrated
In example, the ratio is 1.1/1.2 ≈ 0.92.Then, the ratio can be used to calibrate the two antennas.Specifically, in block
In 205, first antenna can directly transmit data, and the second antenna can transmit number by being multiplied by the ratio (that is, 0.92)
According to.
Three or more antennas that method illustrated can be expanded in BS, wherein the gain of all antennas is calibrated
To reference value (for example, gain of first antenna).
However, in multi-cell cooperation system, for example, in CoMP system, plurality of BS be used as single super BS with
Mitigate inter-cell interference, the self calibration individually performed at each BS by the Gain Fuzzy between causing all cooperation BS, its
Systematic function is set seriously to deteriorate.
A kind of air interface calibration method between multiple BS has been proposed, to recover channel reciprocity.So
A kind of method in, user equipment (UE) via a limited number of bit by estimated downlink channel information feed back to by
The multiple BS being calibrated.Then, these BS are based on from these UE downlink channel informations fed back and estimated up
Link channel information, come the gain ratio of transmission-reception chain of all antennas for calibrating them.
However, due to channel estimation errors and feedback error, using air interface calibration method described above still
It is difficult to recover the channel reciprocity between the up-link and downlink in TDD CoMP systems.Further, these errors
Systematic function will greatly be influenceed.
The content of the invention
Therefore, it would be desirable to that there is provided the solution party for calibrating antenna between at least two base stations in the art
Case.It it would be desirable to there is provided a kind of method, theirs can be calibrated exactly by the BS in this method TDD CoMP systems
Antenna is without making system performance degradation.
In order to preferably solve one or more of focus above focus, in the first aspect of the present invention,
There is provided a kind of method for being used to calibrate antenna between first base station (BS) and the second base station BS.This method can include：Base
In from the training sequence transmitted by user equipment (UE), to obtain the first BS uplink traffic channel information；Via from the user
The training sequence being weighted that equipment is sent, to obtain the 2nd BS up-link equivalent channels information, wherein by using first
The ratio of BS downlink channel information and the 2nd BS downlink channel information weights the training sequence, obtaining this
The training sequence being weighted；And uplink traffic channel information and the 2nd BS up-link equivalent channel letter based on the first BS
Breath, to calculate the fuzzy factor between the first BS and the 2nd BS, wherein the fuzzy factor be used to calibrate the first BS and the 2nd BS
In at least one BS in antenna.
In certain embodiments, at least one BS in the first BS and the 2nd BS can include multiple antennas, and this is more
Individual antenna is calibrated by self-calibration process.
In certain embodiments, calculating fuzzy factor can include：Uplink traffic channel information based on the first BS and logical
Multiple user equipmenies and/or acquired the 2nd BS during multiple frames up-link equivalent channels information are crossed, is estimated to combine
Count the fuzzy factor.
In certain embodiments, the user equipment is that have the link with the first BS and the 2nd BS higher than predetermined threshold
Signal to noise ratio (SNR) edge customer equipment.
In certain embodiments, weighting the training sequence can include：With the first BS and the 2nd BS downlink channel
The amplitude and/or phase of the ratio of information weights the training sequence.
In the second aspect of the present invention the antenna school between two base stations is aided in there is provided a kind of user equipment that is used for
Accurate method.This method can include：Training sequence is transferred to two base stations；Estimate the downlink letter of two base stations
Road information；The training sequence is weighted with the ratio of the downlink channel information of two base stations；And by the instruction being weighted
Practice at least one base station for servicing the user equipment that sequence is transferred in two base stations.
In certain embodiments, the user equipment is that have the letter with the link of two base stations higher than predetermined threshold
The edge customer equipment made an uproar than (SNR).
In certain embodiments, the user equipment repeats the estimation, weighted sum transmission during multiple frames.
In certain embodiments, the estimation is based on from the training sequence transmitted by two base stations.
In the third aspect of the present invention there is provided a kind of device come implement the first aspect of the present invention method it is various
Embodiment.Specifically there is provided a kind of device for being used to calibrate antenna between the first BS and the 2nd BS.The device can be wrapped
Include：Acquiring unit, is configured as based on obtaining the first BS uplink channel from the training sequence transmitted by user equipment
Information, and obtain the 2nd BS up-link equivalent channel via the training sequence being weighted sent from the user equipment
Information, wherein being weighted by using the first BS downlink channel information with the ratio of the 2nd BS downlink channel information
The training sequence is to obtain the training sequence that this is weighted.The device may further include：Computing unit, is configured as being based on
First BS uplink traffic channel information and the 2nd BS up-link equivalent channels information, come calculate the first BS and the 2nd BS it
Between fuzzy factor, wherein the fuzzy factor be used for calibrate the first BS and the 2nd BS at least one BS in antenna.
In the fourth aspect of the present invention there is provided a kind of device come implement the second aspect of the present invention method it is various
Embodiment.Specifically the device of the antenna calibration between two base stations is aided in there is provided a kind of user equipment that is used for.The device
It can include：Transmission unit, is configured as training sequence being transferred to two base stations；Estimation unit, being configured as estimation should
The downlink channel information of two base stations；And weighted units, it is configured as being believed with the downlink channel of two base stations
The ratio of breath weights the training sequence；The training sequence that wherein transmission unit is configured to be weighted is transferred to
At least one base station for servicing the user equipment in two base stations.
There is provided a kind of device in the fifth aspect of the present invention, the device includes at least one processor and including meter
At least one memory of calculation machine program code.The memory and the computer program code are configured as：The device is promoted to hold
The embodiment of the method for row the first aspect of the present invention, or the method for the second aspect of the present invention embodiment.
There is provided a kind of computer program product in the sixth aspect of the present invention, the computer program product includes tool
There is at least one computer-readable recording medium for the computer readable program code part being stored thereon.This is computer-readable
Program code sections include：Embodiment or the second aspect of the present invention for the method that performs the first aspect of the present invention
The code instructions of the embodiment of method.
There is provided a kind of equipment in the seventh aspect of the present invention, the equipment includes：First party for implementing the present invention
The device of each step of each step of the method in face or the method for the second aspect of the present invention.
The specific embodiment of theme described in this specification can be carried out, to realize one in following advantages
Or multiple advantages.
Using the specific embodiment of the technology described in this specification, antenna can be calibrated between multiple BS.Enter
One step, by the feedback via weighting detection reference signal (SRS), because feedback error caused by quantization or limit bit can
To be ignored and feedback overhead can be reduced.Therefore, can be with as the fuzzy factor between multiple BS caused by self calibration
It is calibrated.Proposed solution can be used in TDD CoMP systems, to recover channel reciprocity without making system
Penalty.
When read in conjunction with the accompanying drawings, other feature and advantage of embodiments of the invention will also pass through following specific embodiment
Description be understood, the principle of embodiments of the invention has been illustrated by way of example in these accompanying drawings.
Brief description of the drawings
By way of example, according to following the detailed description and the accompanying drawings, it is above various embodiments of the present invention and its
His aspect, feature and benefit will become more fully substantially, in the accompanying drawings：
Fig. 1 is shown for illustrating the nonreciprocity between the uplink channel in TDD system and downlink channel
Signal mode；
Fig. 2 illustrates the self-alignment method for two antennas in BS；
Fig. 3 illustrates exemplary signal flow according to an embodiment of the invention；
Fig. 4 illustrates the comparison of the simulation result of various calibration methods；
Fig. 5 illustrates the exemplary process diagram of method 500 according to an aspect of the present invention；
Fig. 6 illustrates the exemplary process diagram of method 600 according to another aspect of the present invention；
Fig. 7 is can be configured as carrying out the device 700 of exemplary embodiment according to an aspect of the present invention to show
Meaning property block diagram；
Fig. 8 is can be configured as carrying out the device 800 of exemplary embodiment according to another aspect of the present invention
Schematic block diagram；
Fig. 9 is the schematic frame for being suitable for the BS and UE used in the exemplary embodiment according to the present invention is carried out
Figure；
Similar reference number in the various accompanying drawings element similar with sign instruction.
Embodiment
Below, the embodiment with reference to illustration is described to the principle and spirit of the present invention.It should be appreciated that all
These embodiments be only used for those skilled in the art more fully understand and further carry out the present invention and be presented, without
For limiting the scope of the present invention.For example, by as one embodiment a part illustrate or description feature can with it is another
Individual embodiment is used together, to produce further embodiment.For clearness, implement in this specification without description reality
All features of mode.Certainly it will be realized that in the exploitation of any such practical embodiments, many embodiment party should be made
Formula specifically determines to realize the specific objective of developer, limitation such as related to system and with business correlation, and this will be from
A kind of embodiment changes to another embodiment.Furthermore, it will be appreciated that such development be probably it is complicated and
Time-consuming, but those skilled in the art of the benefit for obtaining present disclosure will be still conventional task.
Disclosed theme is described referring now to accompanying drawing.Various structures, system and equipment only for explanation purpose
And be depicted schematically in the figures, and so as to obscure without describing this details well known to those skilled in the art
It is hard to understand.However, accompanying drawing is included to describe and explain the illustrated examples of disclosed theme.Word used herein and short
Language should be appreciated that and be interpreted as having contain consistent to the understanding of these words and phrase with those skilled in the relevant art
Justice.Used by the term or the uniformity of phrase to this paper, be not intended to imply to the specifically defined of the term or phrase, i.e.
The definition different from the common and conventional implication that those skilled in the art is understood.It is intended in term or phrase with special
The aspect of implication (that is, the implication different from the implication understood by technical staff), it is such it is specifically defined will in the description with
The mode of definition clearly illustrated, the mode of this definition is directly and explicitly provided for the specifically defined of the term or phrase.
As mentioned previously, in multi-cell cooperation system, the self calibration individually performed at each BS result in many
Gain Fuzzy between individual BS, it makes CoMP system performance seriously deteriorate.
In this disclosure in proposed solution, one or more UE can be chosen, to aid in or support
Calibration between multiple BS.Each UE can feed back its downlink channel information via training sequence (for example, SRS),
This will exclude the feedback caused by quantization or limit bit such as occurred in previously described air interface calibration method
Error.Specifically, each UE can be sent with the ratio of be calibrated two BS downlink channel information weighted
SRS.Then, the weighted SRS can be used to calculate the fuzzy factor between the two BS.
Consider the TDD CoMP for including being connected to B base station of CPU (CU) via low time delay back haul link
System, it is referred to as centralized CoMP system.It should be appreciated by those skilled in the art the proposed solution of present disclosure
Scheme can be used in the CoMP system of de-centralized.Above example is only used for illustrating.
In this illustration, each base station in the B base station is equipped with Nt antenna, and jointly serves M
The individual user equipment with single antenna.It is modernIndicate the descending of m-th UE
Chain channel matrix, whereinIt is Nt n dimensional vector ns, and indicates the descending chain between b-th of BS and m-th of UE
Path channels, αmbSign includes a wide range of decay of path loss and shadow fading,Sign includes the channel arrow of small range decline
Amount.
In this way, according to formula above (3), the relation between uplink channel and downlink channel can be expressed
For：
WhereinReciprocity error is indicated, and diag (x) represents the member with vector x
The diagonal matrix of element.
The purpose of antenna calibration between multiple BS is the ratio for obtaining the reciprocity error between different BS, and it can determine
Justice isThat is, the fuzzy factor between i-th BS and j-th of BS.Then, the mould
The paste factor can be used to adjustment by the power for the signal being transmitted, so that the reciprocity for compensating each antenna in multiple BS is missed
Imbalance between difference.
The definition of reciprocity error in formula (3), fuzzy factor between i-th of BS and j-th of BS can be by
Downlink channel and uplink channel between the two BS and UE are directly expressed as follows.
Wherein gMi, kK-th of antenna in i-th of BS is indicated to the channel between m-th of UE.
From equation (5), it can be seen that the fuzzy factor between two BS can the downlink based on the two BS and UE
Calculated with uplink ratios.
Fig. 3 illustrates exemplary signal flow according to an embodiment of the invention.In figure 3 in illustrated scene, I
Assume antenna in both the two BS (that is, BSi and BSj) by self calibration.In other words, it is each in same BS
Antenna and UE reciprocity error are identicals.Therefore, the calibration between two BS is actually equivalent to one in each BS
The calibration of antenna.Simplicity for illustrative, it is considered to which each BS only has individual antenna, and in B=2 base station (BSi
And BSj) between perform calibration.
Further, it will be assumed that a centralized CoMP system, wherein cooperation BS (for example, BSi310i and BSj310j)
It should be connected by back haul link with CPU (CU) 330.Under such framework, each UE320 is by its channel
Status information (CSI) feeds back to the local of it or service BS, and then CU collects CSI by back haul link from all BS.
Using the CSI of all users at CU, centralized CoMP system realizes the cooperation of global optimum between BS.However, this area
It will be appreciated by the skilled person that the proposed solution of present disclosure can be used in the CoMP system of de-centralized
In (for example, Distributed C oMP systems), and therefore the communication between BS and CU can be correspondingly adapted.
As shown in Figure 3, one or more UE320 are chosen, to support or aid in the first BSi310i and second
Antenna calibration between BSj310j.Two BS can communicate with CU330.Without loss of generality, it is assumed that UE320 by
BSj310j is serviced.Therefore, the link between UE320 and BSj310j can be referred to as link-local, and UE320 and BSi340i
Between link can be referred to as cross link.
At step S301, training sequence (for example, downlink reference signal (DL RS)) is transferred to by BSi and BSj
UE320.When receiving the training sequence, at step S303, UE320 can estimate that downlink is believed according to the RS of reception
Channel state information (DL CSI).Channel estimation can be implemented by various known technologies, such as least squares error
(LSE), least mean-square error (MMSE) and the MMSE of modification.
For example, based on MMSE estimations, real downlink channel can be expressed as：
WhereinEstimative downlink channel is indicated, andIndicate noise.
Then, UE320 can calculate the two DL CSI ratio.Specifically, UE can calculate will be calibrated two
The ratio of BS downlink small range channel is as follows：
DefinitionWherein AijAnd θijThe amplitude and phase of DL CSI ratio are indicated respectively.
Meanwhile, at step S302, uplink sounding reference signal (UL SRS, be denoted as sm) is transferred to by UE320
BS310i and 310j.When receiving the UL SRS, at step S304, each BS in BS can according to the SRS of reception come
Estimating uplink channel condition information (UL CSI).Similarly, estimate that real uplink channel can based on such as MMSE
To be expressed as：
WhereinEstimative uplink channel is indicated, andIndicate noise.
In certain embodiments, estimative UL CSI can be transferred at step S305 via back haul link
CU330。
DL CSI ratio is had calculated that, at step S306, UE320 can be incited somebody to action during next uplink frame
SRS transmission is weighted at least one BS in two BS.
In certain embodiments, SRS can be weighted with the amplitude and/or phase of DL CSI ratio.For example, it is contemplated that arriving
The signal being transmitted will can be only with phase (that is, exp (the i θ of the ratio by power normalization, SRSij) sm) weight.Typically
For, weighting SRS can be expressed as Aijexp(iθij)sm.Such weighting will not affect that the SRS's between multiple UE is orthogonal
Property.
For simplicity, UE320 can broadcast weighting SRS to by be calibrated two BS, because SRS will be used for by BS
Other functions besides channel estimation.
Afterwards, at step S307, BS (for example, service Bsj) can be obtained by channel estimation：
By simplifying above formula (9), observation equation (10) can be obtained：
WhereinSign observation noise, and it
Variance can be expressed as：
As seen from observation equation (10), UL CSI and j-th of BS that can be at least based on i-th of BS UL be equivalent
CSI, to obtain the fuzzy factor λ between the two BSij.In other words, depending on λijDefinition (that is, cross link with it is local
The reciprocity error ratio of link), for higher accuracy, λijCan be by UL CSI and link-local based on cross link
UL equivalent CSI calculate.
Therefore, continued with Fig. 3, at step S308, the equivalent CSI of estimative UL can be transferred to by BS310i and 310j
CU330。
Alternatively, the estimative UL CSI transmitted in step S305 can be in step S308 together with equivalent CSI
It is transmitted.
Then, at step S309, having been obtained for these UL CSI and UL equivalent CSI, CU can be based on sight above
Equation (10) is surveyed to calculate fuzzy factor.Multiple observation equatioies can be used to the jointly ambiguous estimation factor.
In one embodiment, multiple user equipmenies can be chosen so as to support calibration, and it can be referred to as multi-user school
It is accurate.
In another embodiment, multiple uplink frames of unique user equipment can be used to support calibration, and it can
To be referred to as many Frame Alignment FAs.
In yet another embodiment, multiple uplink frames of multiple user equipmenies can be used to support calibration, and it can
To be referred to as many Frame Alignment FAs of multi-user.
No matter using which kind of mode as above, multiple (for example, M) observation equatioies can be obtained, they can be combined
For：
yTra=hTraλij+wTra (12)
Wherein And
wTraCovariance be：
By using the parameter Estimation based on weighted least squares (WLS), fuzzy factor can be acquired as：
And evaluated error can be expressed as：
As seen from formula (15), the modulus of evaluated error and UE small range fading channelIt is relevant.Therefore, when
When being calibrated using multi-user,It is statistical iteration；When using many Frame Alignment FAs,With temporal correlation.If UE
Slowly move and channel is in deep fading, then the evaluated error of many Frame Alignment FAs will significantly increase.Got over it is apparent that obtaining
The observation equation of many statistical iterations, fuzzy factor can be estimated more exactly.
Further, according to observation equation (10), its SNR can be expressed as：
Its conditional (a) assumes that edge SNR is much larger than 1.Therefore, from formula (15) it can be seen thatIt is UE and two
The harmonic average of up-link SNR and downlink SNR between BS.Therefore, the minimum uplink SNR of cross link is (i.e.,) account for leading.In order to reduce observation error, the mode of full blast is to increase the SNR of cross link.In other words, when
When selecting UE as holder for calibration, the cell of the high SNR (that is, close to real cell edge) with cross link
Edge UE should be selected for aiding in the calibration between multiple BS.In certain embodiments, selected holder UE is tool
Have it is higher than predetermined threshold, with by the SNR of the link of each BS in the BS being calibrated edge UE.
It will be understood to those skilled in the art that can also be using other parameter estimation algorithms, such as least square
(LS), the consistent LS of random sample (Ransac LS), least square intermediate value (LMedS) etc..
Continued with Fig. 3, obtained fuzzy factor, the fuzzy factor can be transferred to by CU330 at step S310
In BS310i and 310j any one or both.Then at step S311, BSi and/or BSj can use the fuzzy of reception
The factor calibrates its respective antenna.
In certain embodiments, any one BS in BS can be selected as reference, and then another BS can
It is calibrated based on the fuzzy factor.In some other embodiments, the BS that the gain of its RF chain is relatively low can be chosen to make
For the reference.In a further embodiment, two BS can be calibrated based on the fuzzy factor, and may need to use
In the algorithm that gain ratio is distributed between BS.
In this way, discussing the mechanism of antenna calibration between two BS of proposal on Fig. 3.Those skilled in the art
Member will be understood that the calibration between two BS can be easily extended to more than two BS.Specifically, when there is B ＞ 2 will be by school
During the base station of standard, i-th of BS can be selected as reference.Calibration process is every time in i-th of BS and remaining (B-1) individual BS
A BS between be performed.After the calibration process (B-1) of execution above is secondary, B all BS have been calibrated.Ability
The technical staff in domain will be understood that B-1 calibration can also be carried out simultaneously.
Using embodiments of the invention, antenna can be calibrated between multiple BS.Further, by via weighting
SRS feedback, feedback error can be eliminated caused by quantization or limit bit and feedback overhead can be reduced.Cause
This, the fuzzy factor between multiple BS as caused by self calibration can be calculated exactly and therefore antenna can be by accurately
Calibration.Proposed solution can be used in TDD CoMP systems, to recover channel reciprocity without making systematicness
It can deteriorate.
Emulation has been carried out, to assess the performance of antenna calibration according to an embodiment of the invention.Form I summarizes one
As environmental simulation parameter.
Form I：Simulation parameter
Fig. 4 illustrates the comparison of the simulation result of various calibration methods.
As shown in Figure 4, it illustrates the simulation result of following scheme：Ideal calibration, the calibration via training
(that is, via the calibration of the weighting SRS using 30 UE), only phase ideal calibration, using normalized pilot tone calibration (i.e.,
Via phase weighting SRS calibration), the calibration (that is, each BS self calibration) in non-CoMP (NC) and BS.Trunnion axis table
Show the cell edge SNR in units of dB, and vertical axis represents average per-user speed.
As seen from Fig. 4, the gap between top line and bottom line is as caused by the ambiguity between BS.According to this
The embodiment of invention via the calibration of training is in close proximity to ideal calibration；Using normalized pilot tone calibration closely
In the ideal calibration of only phase.It is therefore proposed that calibration method can almost entirely regenerate the performance.
In following description, proposed mechanism will be described in detail on illustrated example embodiment in accompanying drawing.
Fig. 5 illustrates the exemplary process diagram of method 500 according to an aspect of the present invention.Depending on TDD CoMP systems
The framework (that is, centralized CoMP or the CoMP of de-centralized) of system, method 500 can be by the base station that is cooperated in the CoMP system
Entity in (for example, eNB) is held to perform, or by multiple entities among the BS and CU being distributed in the CoMP system
OK.Method 500 can be performed to calibrate antenna between multiple BS.As an example, it regard reference as example
Two BS (the first BS and the 2nd BS) and a holder UE carry out discussion method 500.2nd BS just serving UE, i.e. the 2nd BS with
Link between UE is link-local, and the link between the first BS and UE is cross link.
As shown in Figure 5, method 500 can start at step S501 and continue to S502.In step
At S502, if the BS being calibrated is included into multiple antennas, the plurality of antenna can be calibrated by self-calibration process.Should be certainly
Calibration process can be performed according to technology that is any of or further developing, such as hardware self calibration, feedback self-correcting
It is accurate.The present invention is not limited in this.
Then, at step S503, it can obtain the two BS's based on the training sequence (that is, SRS) sent from UE
Uplink channel state information (UL CSI).As described earlier, fuzzy factor λijCalculating can at least based on intersect
The equivalent CSI of UL CSI and link-local UL of link.Therefore, at the step of the example, it is only necessary to obtain the first BS
UL CSI.However, the two BS UL CSI can be estimated for other purposes.
Method 500 can continue to S504., can be based on the training being weighted sent from UE at step S504
Sequence (that is, weight SRS) obtains the two BS equivalent CSI of up-link.Similarly, in the step S504 of this example
Place, it is only necessary to obtain link-local or the 2nd BS equivalent CSI of UL.
As described in together with step S303 and S306 in Fig. 3, can by using the first BS downlink CSI (DL
CSI SRS) is weighted with the 2nd BS downlink CSI ratio, to obtain weighting SRS.In certain embodiments, SRS can be with
Weighted by the amplitude and/or phase of the ratio with DL CSI.For example, it is contemplated that to the signal transmitted will be by power normalization
, SRS can be weighted only with the phase of the ratio.
Then, at step S505, the UL equivalent CSI of CSI and UL have been obtained, UL that can be at least based on the first BS
CSI and the 2nd BS equivalent CSI of UL, to calculate the fuzzy factor between two BS.UL CSI that can be based on the first BS and logical
The 2nd BS equivalent CSI of UL for crossing multiple UE and/or being obtained during multiple frames, carry out the Combined estimator fuzzy factor.It is fuzzy because
The calculating of son may be referred to the description above for the step S309 in Fig. 3, and the description being therefore described in detail is omitted herein.
Afterwards, the fuzzy factor of calculating can be used to calibrate antenna between the two BS.For example, the first BS can be by
Reference is selected as, and the 2nd BS adjusts the gain of its RF chain in transmission based on fuzzy factor.
Fig. 6 illustrates the exemplary process diagram of method 600 according to another aspect of the present invention.Method 600 can be by
The entity in user equipment in TDD CoMP systems is performed.In order to for example, will with the identical scene of method 500 come
Discussion method 600, i.e. two BS (the first BS and the 2nd BS) and a holder UE are used as example.2nd BS is just serving UE,
That is the link between the 2nd BS and UE is link-local, and the link between the first BS and UE is cross link.
As shown in Figure 6, method 600 can start at step S601 and continue to S602.In step
At S602, UE can be by SRS transmission to by the BS being calibrated.On the other hand, at step S603, UE can be respectively from will be by school
Each BS in accurate BS receives pilot signal or reference signal (RS).UE can estimate the two BS DLCSI and calculating
The two DL CSI ratio.
Then, at step S604, UE can weight its SRS with the two DL CSI of calculating ratio.One
In a little embodiments, SRS can be weighted with the amplitude and/or phase of DL CSI ratio.
Finally, at step S605, UE can by weight SRS transmission to serviced in the two BS UE at least one
BS.As mentioned previously, fuzzy factor λijCalculating can be at least based on cross link UL CSI and link-local UL
Equivalent CSI.Therefore, weighting SRS transmission only can be given the 2nd BS, i.e. its local BS by UE.It is preferred that, UE will can be weighted
SRS is broadcasted to two BS, because SRS can be further used for other purposes by these BS.
Therefore, via the SRS weighted with DL CSI ratio, UE can feed back DL CSI exactly, and it can be used to
The ambiguous estimation factor.
In certain embodiments, multiple UE (for example, 30 or more) can be chosen so as to support antenna calibration.These
Each UE in UE is able to carry out method 600 and calibrated with auxiliary antenna.High SNR with cross link is (that is, close to really small
Area edge) those cell edges UE can be selected for aiding in the calibration between multiple BS.In other words, selected branch
Hold thing UE with it is higher than predetermined threshold, with by the SNR of the link of each BS in the BS being calibrated edge UE.
In some other embodiments, multiple uplink frames of unique user equipment can be used to support calibration.
If UE is quickly moved, the performance of many Frame Alignment FAs may increase due to the channel of time-varying.UE can be in multiple frame phases
Between repetition methods 600.
In a further embodiment, multiple uplink frames of multiple user equipmenies can be used to support calibration.
Fig. 7 is can be configured as carrying out the device 700 of exemplary embodiment according to an aspect of the present invention to show
Meaning property block diagram.Device 700 can be merged in BS or eNB, and is configured as performing the side of the exemplary embodiment of the present invention
Method.Alternatively, device 700 can be distributed among various network elements (such as BS and CU), to perform the example of the present invention
The method of property embodiment.
As shown in Figure 7, device 700 can include acquiring unit 701 and computing unit 702.
Acquiring unit 701 can be configured as：The first BS UL CSI are obtained based on the training sequence sent from UE, and
And the 2nd BS equivalent CSI of UL are obtained via the training sequence being weighted sent from the UE.By using the first BS DL
The amplitude and/or phase of CSI and the 2nd BS DL CSI ratio weight the training sequence, and obtain the training sequence of weighting
Row.
Computing unit 702 can be configured as：The equivalent CSI of UL of UL CSI and the 2nd BS at least based on the first BS, come
Calculate the fuzzy factor between the first BS and the 2nd BS.Then, the fuzzy factor of calculating can be used between the two BS
Calibrate antenna.
Computing unit 702 can be configured to：UL CSI based on the first BS and by multiple UE and/or many
The equivalent CSI of UL of the 2nd acquired BS during individual frame, carry out the Combined estimator fuzzy factor.
It should be appreciated that the unit 701-702 included in device 700 is arranged to carry out the exemplary implementation of the present invention
Example.Therefore, operation and feature above with reference to described by Fig. 3 and 5 is also applied to device 700 and unit therein, and it
Detailed description be omitted herein.
Fig. 8 is can be configured as carrying out the device 800 of exemplary embodiment according to another aspect of the present invention
Schematic block diagram.Device 800 can be merged in UE, and the method for being configured as the exemplary embodiment of the execution present invention.
As shown in Figure 8, device 800 can include estimation unit 801, weighted units 802 and transmission unit 803.
Estimation unit 801 can be configured as estimating at least two BS DL CSI.The estimation is based on from transmitted by BS
Training sequence (RS).
Weighted units 802 can be configured as, and SRS is weighted with two BS DL CSI ratio.The ratio be based on by
The DL CSI that estimation unit 801 is estimated are calculated.
Transmission unit 803 can be configured as, by SRS or weighting SRS transmission to by the BS being calibrated.
It should be appreciated that the unit 801-803 included in device 800 is arranged to carry out the exemplary implementation of the present invention
Example.Therefore, device 800 and unit therein, and they are also applied to above with reference to the operations described of Fig. 3 and 6 and feature
Detailed description be omitted herein.
Fig. 9 illustrates the BS901's for being suitable for being used in the exemplary embodiment according to the present invention is carried out and UE902
Simplified block diagram.In fig .9, wireless network is adapted to (be referred to as LTE-LAN BS in the above example via BS901
(or eNB)) with UE902 (being referred to as LTE-LAN UE in the above example) communication.UE902 includes data processor
(DP) 903, the memory (MEM) 904 coupled to DP903 and the suitable RF transmitters TX and receiver coupled to DP903
RX905 (it need not be embodied in same component).MEM904 storage programs (PROG) 906.TX/RX905 be used for
BS901 two-way wireless communication.Note, TX/RX905 has at least one antenna to promote communication；Multiple antennas can be adopted
With for multiple-input and multiple-output MIMO communications, UE902 can have multiple TX and/or RX in this case.
BS901 includes data processor (DP) 907, the memory (MEM) 908 coupled to DP907 and is coupled to
DP907 suitable RF transmitters TX and receiver RX909.MEM608 storage programs (PROG) 910.TX/RX909 be used for
UE902 two-way wireless communication.Note, TX/RX909 has at least one antenna to promote communication, but BS will in practice
Generally there are several antennas.BS901 may further include the communication interface 911 for being docked with other network elements.Communication
Interface 911 can be for the X2 interface with other BS two-way communications.Alternatively or additionally, communication interface 911 can be
With CU back haul link.BS1100 can be coupled to one or more external networks or system via data path, such as
Internet.
BS901 can be coupled to one or more external networks or system, such as internet via data path.
At least one in PROG906 and 910 is assumed including following programmed instruction, when these programmed instruction are by correlation
When the DP903 of connection and 907 is performed so that UE902 and BS901 can be according to the sheet such as discussed herein together with method 500 or 600
The exemplary embodiment of invention is operated.
In general, UE902 various embodiments can include, but are not limited to, cell phone, with radio communication energy
The personal digital assistant (PDA) of power, the portable computer with wireless communication ability, the image with wireless communication ability are adopted
Collection equipment (such as digital camera), the game station with wireless communication ability, the music with wireless communication ability are deposited
Internet device and be incorporated to the combination of these functions just that storage and playback device, allowance wireless Internet are accessed and browsed
Portable units or terminal.
Embodiments of the invention can by can by UE902 and BS901 DP903, one or more of 907 perform
Computer software implement, or implement by hardware or by the combination of software and hardware.
MEM904 and 908 can be suitable for any types of local technical environment, and can use it is any suitable
Data storage technology is implemented, and is used as non-limiting example, such as memory devices based on semiconductor, magnetic memory device
With system, optical memory devices and system, read-only storage and removable memory.Although only one MEM is illustrated in
In BS901 or UE902, but there may be several physically different memory cells in BS901 or UE902.DP903 and
907 can be suitable for any types of local technical environment, and as nonrestrictive example, can include：General meter
In calculation machine, special-purpose computer, microprocessor, digital signal processor (DSP) and processor based on polycaryon processor framework
One or more.In UE902 and BS901 any one or both can have multiple processors, such as, in the time
On by making the dedicated IC chip of the synchronous clock control of primary processor.
The example of the present invention is described by reference to method, the block diagram of the diagram of device (that is, system) and flow chart above
Property embodiment.It will be understood that, each block of block diagram and flow chart illustration, and the block of block diagram and flow chart illustration combination, respectively
It can be implemented by the various devices including computer program instructions.These computer program instructions can be loaded into general meter
To produce a kind of machine in calculation machine, special-purpose computer or other programmable data processing units so that in the computer or
These instructions performed in other programmable data processing units of person are created for specified in implementing procedure segment or multiple pieces
Function device.
Aforementioned computer program instruction can be such as subroutine and/or function.Meter in one embodiment of the present of invention
Calculation machine program product includes at least one computer-readable recording medium, and foregoing computer program instructions are stored in the computer
On readable storage medium storing program for executing.Computer-readable recording medium can be, for example, (random access is stored by light compact disk or such as RAM
Device) or ROM (read-only storage) electronic memory device.
Although this specification includes many specific implementation details, these implementation details are not construed as to appointing
The scope of what embodiment or to the limitation for the scope that may require protection, but be interpreted to being specific to particular implementation
Specific embodiment feature description.Some features in this manual described in the context of the embodiment of separation are also
Can be combined implementation in single embodiment.Conversely, various features described in the context of single embodiment can be with
Discretely or with any appropriate sub-portfolio it is carried out in various embodiments.Although in addition, feature may be described above
For with some combinations, and even initially so it is claimed, still, it is desirable to one or many in the combination of protection
Individual feature can be removed from the combination in some cases, and combination claimed can be pointed at sub-portfolio or
The deformation of sub-portfolio.
It shall also be noted that embodiment described above provides to describe the present invention rather than the limitation present invention, and
And will be understood that, as the skilled person easily understood, without departing from the spirit and scope of the present invention, can be with
By modifications and variations.Such modifications and variations are considered in the present invention and scope of the following claims.This hair
Bright protection domain is limited to the appended claims.In addition, any reference number in reference number in claim
It is not construed as limitations on claims.Verb " comprising " and its paradigmatic use are not excluded for except claim
The presence of element or step outside middle those stated element or steps.Indefinite article " one " before element or step
Or " one " is not excluded for the presence of multiple such element or steps.
Claims (16)
1. a kind of method for being used to calibrate antenna between first base station BS and the 2nd BS, including：
The uplink traffic channel information of the first BS is obtained based on the training sequence sent from user equipment；
The equivalent letter of up-link of the 2nd BS is obtained via the training sequence being weighted sent from the user equipment
Road information, wherein by using the downlink channel information and the downlink channel information of the 2nd BS of the first BS
Ratio weights the training sequence that the training sequence is weighted to obtain；And
The equivalent letter of the up-link of the uplink traffic channel information and the 2nd BS at least based on the first BS
Road information, to calculate the fuzzy factor between the first BS and the 2nd BS, wherein the fuzzy factor is used for calibration
The antenna at least one BS in first BS and the 2nd BS.
2. according to the method described in claim 1, wherein at least one BS in first BS and the 2nd BS is including more
Individual antenna, and the multiple antenna is calibrated by self-calibration process.
3. method according to claim 1 or 2, wherein calculating fuzzy factor includes：Based on by multiple user equipmenies and/
Or the first BS being acquired during multiple frames the uplink traffic channel information and the 2nd BS it is described up
Link equivalent channels information, carrys out fuzzy factor described in Combined estimator.
4. method according to claim 1 or 2, wherein the user equipment be have it is higher than predetermined threshold with it is described
The edge customer equipment of the signal to noise ratio snr of first BS and the 2nd BS link.
5. method according to claim 1 or 2, wherein weighting the training sequence includes：It is descending with the first BS
The amplitude and/or phase of the ratio of link channel information and the 2nd BS downlink channel information are described to weight
Training sequence.
6. a kind of method for aiding in the antenna calibration between two base stations for user equipment, including：
Training sequence is transferred to described two base stations；
The downlink channel information of described two base stations is estimated based on the training sequence sent from described two base stations；
The training sequence is weighted with the ratio of the downlink channel information of described two base stations；And
The training sequence being weighted is transferred to at least one base station for just servicing the user equipment in described two base stations.
7. method according to claim 6, the user equipment be have it is higher than predetermined threshold with described two bases
The edge customer equipment of the signal to noise ratio snr for the link stood.
8. the method according to claim 6 or 7, wherein the user equipment repeats the estimation during multiple frames, added
Power and the transmission of the training sequence of weighting.
9. a kind of device for being used to calibrate antenna between first base station BS and the 2nd BS, including：
Acquiring unit, is configured as obtaining the up-link letter of the first BS from user equipment based on the training sequence sent
Road information, and obtain via the training sequence being weighted sent from the user equipment the up-link of the 2nd BS
Equivalent channels information, wherein the downlink channel of the downlink channel information and the 2nd BS by using the first BS
The ratio of information weights the training sequence that the training sequence is weighted to obtain；And
Computing unit, is configured as the uplink traffic channel information at least based on the first BS and the institute of the 2nd BS
Up-link equivalent channels information is stated, to calculate the fuzzy factor between the first BS and the 2nd BS, wherein the mould
The paste factor be used to calibrate the antenna at least one BS in the first BS and the 2nd BS.
10. device according to claim 9, wherein at least one BS in first BS and the 2nd BS is including more
Individual antenna, and the multiple antenna is calibrated by self-calibration process.
11. the device according to claim 9 or 10, wherein the computing unit is configured to：Based on by many
The uplink traffic channel information and the 2nd BS of individual user equipment and/or the first BS obtained during multiple frames
The up-link equivalent channels information, carry out fuzzy factor described in Combined estimator.
12. the device according to claim 9 or 10, wherein the user equipment be have it is higher than predetermined threshold with institute
State the edge customer equipment of the signal to noise ratio snr of the first BS and the 2nd BS link.
13. the device according to claim 9 or 10, wherein the training sequence being weighted is by with the first BS
The amplitude and/or phase of the ratio of downlink channel information and the 2nd BS downlink channel information is weighted.
14. a kind of be used to user equipment aid in the device of the antenna calibration between two base stations, including：
Transmission unit, is configured as training sequence being transferred to described two base stations；
Estimation unit, is configured as estimating the descending of described two base stations based on the training sequence sent from described two base stations
Link channel information；And
Weighted units, are configured as weighting the training with the ratio of the downlink channel information of described two base stations
Sequence；
The training sequence that wherein described transmission unit is configured to be weighted is transferred in described two base stations just
Service at least one base station of the user equipment.
15. device according to claim 14, the user equipment be have it is higher than predetermined threshold with it is described two
The edge customer equipment of the signal to noise ratio snr of the link of base station.
16. the device according to claims 14 or 15, wherein the user equipment repeated during multiple frames the estimation,
The training sequence transmission of weighted sum weighting.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2012/080834 WO2014032271A1 (en) | 2012-08-31 | 2012-08-31 | Method and apparatus for antenna calibration |
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| CN104025526B true CN104025526B (en) | 2017-10-10 |
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Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DK2730123T3 (en) | 2011-07-07 | 2020-03-02 | Ericsson Telefon Ab L M | Handover decision in serving base station based on a first and second type of mobility mechanism |
| CN106464458A (en) * | 2014-03-18 | 2017-02-22 | 华为技术有限公司 | Method of correcting reciprocity between UEs, and device and communication system |
| WO2015161429A1 (en) * | 2014-04-22 | 2015-10-29 | 华为技术有限公司 | Joint channel correction method, apparatus and management device |
| US10236999B2 (en) | 2014-06-13 | 2019-03-19 | Nokia Solutions And Networks Oy | Method, apparatus and computer program for antenna calibration |
| CN106664588B (en) * | 2014-07-02 | 2020-08-21 | 瑞典爱立信有限公司 | Method and network node for calibrating beamforming for uplink measurements |
| CN106576272B (en) * | 2014-07-02 | 2020-09-25 | 瑞典爱立信有限公司 | Method and apparatus for obtaining accurate measurement results of a communication device |
| WO2016029434A1 (en) * | 2014-08-29 | 2016-03-03 | Nec Corporation | Method and apparatus for antenna calibration in tdd systems |
| CN105991177B (en) * | 2015-02-11 | 2019-11-08 | 电信科学技术研究院 | A kind of method and device of antenna calibration |
| CN105044490B (en) * | 2015-06-25 | 2018-06-12 | 电子科技大学 | A kind of antenna array calibration method of the spatial domain small sample based on compressed sensing |
| US9590708B1 (en) * | 2015-08-25 | 2017-03-07 | Motorola Mobility Llc | Method and apparatus for equal energy codebooks for antenna arrays with mutual coupling |
| CN110383719B (en) * | 2017-03-16 | 2021-08-13 | 华为技术有限公司 | Hardware impairment parameter determination for downlink channel state information estimation |
| CN108880702B (en) * | 2017-05-10 | 2022-03-25 | 中兴通讯股份有限公司 | Antenna correction method and device for FDD system and base station |
| WO2020183670A1 (en) * | 2019-03-13 | 2020-09-17 | 三菱電機株式会社 | Calibration device and terminal device |
| CN111521969B (en) * | 2020-04-17 | 2022-07-05 | 西北工业大学 | Passive indoor positioning method based on Wi-Fi |
| EP4200996A1 (en) * | 2020-08-24 | 2023-06-28 | Telefonaktiebolaget LM Ericsson (publ) | Ue selection for ue aided antenna calibration |
| CN112911704B (en) * | 2021-01-21 | 2022-04-05 | 北京邮电大学 | CSI indoor fingerprint positioning method and device based on dynamic fusion characteristics |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101753185A (en) * | 2008-12-15 | 2010-06-23 | 大唐移动通信设备有限公司 | Method, device and system for realizing multi-cell multi-antenna calibration |
| CN101873281A (en) * | 2010-07-15 | 2010-10-27 | 西安电子科技大学 | Reciprocity loss compensation method of 2*2 TDD-MIMO system channel |
| CN102064919A (en) * | 2009-11-13 | 2011-05-18 | 中兴通讯股份有限公司 | Method and device for correcting channel quality information |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20070032548A (en) * | 2005-09-16 | 2007-03-22 | 삼성전자주식회사 | Apparatus and method for calibrating channel in wireless communication system using multiple antennas |
| CN101807978B (en) * | 2010-03-12 | 2012-11-21 | 北京航空航天大学 | Transceiver antenna calibration error-based multipoint coordinated robust pre-coding method |
| CN102149123B (en) * | 2011-04-15 | 2013-12-04 | 北京邮电大学 | Scheme and device for calibrating antennae among base stations in cooperative multi-point system and base station |
-
2012
- 2012-08-31 WO PCT/CN2012/080834 patent/WO2014032271A1/en active Application Filing
- 2012-08-31 CN CN201280065762.9A patent/CN104025526B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101753185A (en) * | 2008-12-15 | 2010-06-23 | 大唐移动通信设备有限公司 | Method, device and system for realizing multi-cell multi-antenna calibration |
| CN102064919A (en) * | 2009-11-13 | 2011-05-18 | 中兴通讯股份有限公司 | Method and device for correcting channel quality information |
| CN101873281A (en) * | 2010-07-15 | 2010-10-27 | 西安电子科技大学 | Reciprocity loss compensation method of 2*2 TDD-MIMO system channel |
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