CN103581072B - Frequency offset estimation method and device for multi-carrier system - Google Patents
Frequency offset estimation method and device for multi-carrier system Download PDFInfo
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Abstract
The invention provides a frequency offset estimation method for a multi-carrier system. The frequency offset estimation method comprises the following steps: detecting subframes in PUSCH (Physical Uplink Shared Channel), performing advanced Nf samplings and normal sampling to OFDM (Orthogonal Frequency Division Multiplexing) symbols in the subframes to obtain roughly estimated phase difference; calculating the two pilot carrier OFDM symbols in the subframes to obtain the actuary phase difference of the corresponding user; determining the frequency offset value of the user according to the actuary phase difference and/or roughly estimated phase difference. The invention further provides a frequency offset estimation device for the multi-carrier system. The frequency offset estimation method and the frequency offset estimation device for the multi-carrier system can improve the estimated accuracy and range of the phase offset in high-speed movement demodulation, thereby helping to improve the demodulation performance.
Description
Technical field
The present invention relates to wireless communication technology field, specifically, the present invention relates to a kind of frequency deviation of multicarrier system is estimated
Meter method and device.
Background technology
In recent years, society to the dependence communicating and requires more and more higher.The criterion of communication system efficiency is exactly mainly
The availability of frequency spectrum and power utilization.Particularly in the case of wireless communication, higher to the utilization rate of two indices, especially
The availability of frequency spectrum.Then, various communication technology with high spectral efficiency is continuously developed out, OFDM
（Orthogonal Frequency Division Multiplexing, OFDM）It is that a kind of special multicarrier is adjusted
Technology processed, it improves the availability of frequency spectrum further using the orthogonality of intercarrier, and can resist arrowband interference and how resist through declining
Fall.OFDM can increase the width of code element by multiple orthogonal subcarriers by serial data parallel transmission, reduces single code element
The frequency band taking, the frequency selective fading that opposing multipath causes, can effectively overcome intersymbol interference, reduce system to equilibrium skill
The requirement of art.
OFDM is a kind of Multicarrier Transmission Technology, breaks a channel into some orthogonal sub-channels, high-speed data signal is changed
Become parallel low speed sub-data flow, modulate and be transmitted on each of the sub-channels.Orthogonal signalling can be by adopting in receiving terminal
Separated with correlation technique, so can reduce interfering ICI between subchannel.Signal bandwidth on every sub-channels is little
Flatness of can regarding as in the correlation bandwidth of channel, therefore every sub-channels declines, such that it is able to eliminate intersymbol interference.
The bandwidth being additionally, since every sub-channels is only the sub-fraction of former channel width, and channel equalization becomes relatively easy.Due to
General ofdm system is all using CP（Cyclic Prefix, Cyclic Prefix）So that it can be completely eliminated under certain condition
The intersymbol interference that the multipath transmisstion of signal causes, is completely eliminated the destruction to intercarrier orthogonality for the multipath transmisstion, therefore OFDM system
System has good anti-multipath jamming ability.
But, compared to single-carrier system, OFDM/OFDMA（Orthogonal Frequency Division
Multiplexing/Orthogonal Frequency Division Multiple Access, OFDM/orthogonal
Frequency division multiple access）System is more sensitive to carrier wave frequency deviation.Carrier wave frequency deviation destroys the orthogonality between OFDM subcarrier, severe jamming
Demodulating process, causes performance drastically to decline.Commercial system（As LTE）In often require that higher frequency offset estimation accuracy to ensure to be
The receptivity of system.
Therefore, for existing multicarrier system it is necessary to propose a kind of efficient multi-user's frequency deviation estimating method and dress
Put, to solve the problems, such as that in existing high-speed motion demodulation, phase ambiguity and deviation are larger.
Content of the invention
The purpose of the present invention aims to provide a kind of multi-user's frequency deviation estimating method and the device of multicarrier system, to improve height
The estimated accuracy of phase deviation and scope in speed motion demodulation, thus be favorably improved demodulation performance.
On the one hand, embodiment of the present invention provides a kind of multi-user's frequency deviation estimating method of multicarrier system, including following
Step：Subframe in detection Physical Uplink Shared Channel PUSCH, carries out N in advance to the OFDM symbol in described subframefIndividual sampling
And normal sample, to obtain rough calculation phase contrastRow operation is entered to two Pilot OFDM symbols in described subframe, right to obtain
Answer the actuarial phase contrast of userAccording to actuarial phase contrastAnd/or rough calculation phase contrastDetermine the frequency deviation value of described user
On the other hand, embodiment of the present invention also provides a kind of multi-user's frequency deviation estimation device of multicarrier system, including：
First detection module, for detecting the subframe in Physical Uplink Shared Channel PUSCH, the OFDM symbol of antithetical phrase frame in is shifted to an earlier date
NfIndividual sampling and normal sample, to obtain rough calculation phase contrastSecond detection module, for two pilot tones OFDM of antithetical phrase frame in
Symbol enters row operation, to obtain the actuarial phase contrast of corresponding userProcessing module, for according to actuarial phase contrastAnd/or
Rough calculation phase contrastDetermine the frequency deviation value of user
A kind of multi-user's frequency deviation estimating method of multicarrier system and device that the present invention provides, can improve high-speed motion
The estimated accuracy of phase deviation and scope in demodulation, thus be favorably improved demodulation performance.Further it is proposed that above-mentioned side
Case, the change very little to existing system, do not interfere with the compatibility of equipment, and realize simple, efficiently.
The aspect that the present invention adds and advantage will be set forth in part in the description, and these will become from the following description
Obtain substantially, or recognized by the practice of the present invention.
Brief description
The above-mentioned and/or additional aspect of the present invention and advantage will become from the description to embodiment below in conjunction with the accompanying drawings
Substantially with easy to understand, wherein：
Fig. 1 shows the subframe structure schematic diagram of PUSCH channel in LTE system of the prior art；
Fig. 2 shows the subframe knot that PUSCH channel is carried out with the thick evaluation method of frequency deviation according to an embodiment of the present invention
Structure schematic diagram.；
Fig. 3 shows the subframe knot that PUSCH channel is carried out with frequency deviation essence evaluation method according to an embodiment of the present invention
Structure schematic diagram；
Fig. 4 shows the schematic flow sheet of the frequency deviation estimating method of multicarrier system according to an embodiment of the present invention；
Rough calculation phase contrast is obtained in multi-user's frequency deviation estimating method that Fig. 5 shows according to an embodiment of the present invention's
Schematic flow sheet；
Rough calculation phase contrast is obtained in multi-user's frequency deviation estimating method that Fig. 6 shows according to an embodiment of the present invention's
Subframe structure schematic diagram；
Actuarial phase contrast is obtained in multi-user's frequency deviation estimating method that Fig. 7 shows according to an embodiment of the present invention's
Schematic flow sheet；
It is based on rough calculation phase contrast in multi-user's frequency deviation estimating method that Fig. 8 shows according to an embodiment of the present inventionWith
Actuarial phase contrastJudge frequency deviation valueSchematic flow sheet；
Fig. 9 shows the frequency deviation value according to an embodiment in Fig. 8Judgement schematic flow sheet；
It is based on rough calculation phase contrast in multi-user's frequency deviation estimating method that Figure 10 shows according to another embodiment of the present inventionWith actuarial phase contrastJudge frequency deviation valueSchematic flow sheet；
Figure 11 shows the frequency deviation value according to embodiment another in Figure 10Judgement schematic flow sheet；
Figure 12 shows the structure of multi-user's frequency deviation estimation device of multicarrier system according to an embodiment of the present invention
Schematic diagram.
Specific embodiment
Embodiments of the present invention are described below in detail, the example of described embodiment is shown in the drawings, wherein ad initio
To the element that same or similar label represents same or similar element or has same or like function eventually.Below by ginseng
The embodiment examining Description of Drawings is exemplary, is only used for explaining the present invention, and is not construed as limiting the claims.
Those skilled in the art of the present technique are appreciated that unless expressly stated, singulative " " used herein, "
Individual ", " described " and " being somebody's turn to do " may also comprise plural form.It is to be further understood that arranging used in the description of the present invention
Diction " inclusion " refers to there is described feature, integer, step, operation, element and/or assembly, but it is not excluded that existing or adding
Other features one or more, integer, step, operation, element, assembly and/or their group.It should be understood that when we claim unit
Part is " connected " or during " coupled " to another element, and it can be directly connected or coupled to other elements, or can also exist
Intermediary element.Additionally, " connection " used herein or " coupling " can include wirelessly connecting or coupling.Wording used herein
"and/or" includes one or more associated any cell and all combinations of listing item.
Those skilled in the art of the present technique are appreciated that unless otherwise defined, all terms used herein（Including technology art
Language and scientific terminology）There is the general understanding identical meaning with the those of ordinary skill in art of the present invention.Also should
It is understood by, those terms defined in such as general dictionary should be understood that the meaning having with the context of prior art
The consistent meaning of justice, and unless defined as here, will not be explained with idealization or excessively formal implication.
Fig. 1 shows a kind of subframe structure schematic diagram of the PUSCH channel in LTE system.PUSCH channel in LTE system
Typically adopt the radio frames of a 10ms, the subframe of 10 1ms can be divided into, a subframe can have 2 time slots again.As Fig. 1
Shown, the subframe structure of PUSCH channel in LTE system.Each slot length is 0.5ms and can be divided into 7 OFDM symbol, its
In：3 OFDM data symbol in left side, 3, right side OFDM data symbol, middle 1 Pilot OFDM symbols.In the setting of no frequency hopping
In, when needing offset estimation, current way is made by two frequency pilot signs of same subframe, calculates both phase contrasts,
It is assumed to beDue to two pilot symbol interval 0.5ms, then the frequency deviation of this user isIt can be seen that it is estimated
Meter scope is ± 1000Hz.And in high motion scenes, user's frequency deviation is possible to exceed this scope, thus causing phase mode
Paste, and then affect demodulation performance.
Fig. 2 shows the subframe knot that PUSCH channel is carried out with the thick evaluation method of frequency deviation according to an embodiment of the present invention
Structure schematic diagram.As shown in Fig. 2 the thick evaluation method of frequency deviation can include：
S11, estimation range is divided into some segments.For example, the span of each segment is 2KHz.
S12, complete frequency deviation rough estimate using CP, determine which segment is this user's frequency deviation be in.For example, it is OFDM using CP
Some samplings at symbol end, intercept some samplings of CP, and sampling conjugate multiplication corresponding with OFDM symbol is simultaneously tied being multiplied
Fruit is added up, thus the phase contrast between being sampledAnd then, can be permissible according to the persistent period of this OFDM symbol
It is scaled frequency deviation value.Merge to estimate result with essence below, determine frequency deviation segment merely with rough estimate value herein.
Fig. 3 shows the subframe knot that PUSCH channel is carried out with frequency deviation essence evaluation method according to an embodiment of the present invention
Structure schematic diagram.As shown in figure 3, frequency deviation essence evaluation method can include：S22, two Pilot OFDM symbols of antithetical phrase frame in are carried out
Computing, to obtain actuarial phase contrastFor example, complete essence using frequency pilot sign to estimate, this estimation range can be set to ± 1KHz,
And it is finally completed offset estimation with reference to the segment determining in S12.For example, first, respectively the OFDM of time slot 0 and time slot 1 is led
Frequency symbol passes through FFT to frequency domain；Then, the reception pilot tone of this user is taken out respectively by demapping；Then, reception is led
Frequency division is not taken advantage of with respective pilot frequency sequence conjugation, has now actually obtained channel estimation in frequency domain result；Remember, during by two
The channel estimation results corresponding subcarrier conjugate multiplication of gap, and by multiplied result add up just can get time slot 0 frequency pilot sign and when
Phase contrast between gap 1 frequency pilot signSubsequently, the phase contrast by obtaining with reference to frequency deviation rough estimateEstimate with frequency deviation essence and obtain
Phase contrastAccording to formula below（1）Calculate frequency offset estimation result：
Wherein, TosRepresent the persistent period of an OFDM symbol.
It follows that a kind of efficient multi-user's frequency deviation estimating method that the present invention provides, existing high speed fortune can be solved
Phase ambiguity and the larger problem of deviation in dynamic demodulation.
Further, estimate to preferably realize multi-user, above-mentioned method of estimation can be optimized, by user
Frequency domain data separates and can realize multi-user's offset estimation, will not interfere with each other between each user.Another according to the present invention
Method of estimation, estimates the positive and negative values only with rough estimate result in merging process in rough estimate and essence, and takes protective measure, thus estimate
Scope can only achieve ± 1～± 2KHz, and this estimation range not only uses enough, and can effectively overcome in above-mentioned estimation scheme
The big shortcoming of rough estimate result error.
Fig. 4 shows the schematic flow sheet of the frequency deviation estimating method of multicarrier system according to an embodiment of the present invention.
As shown in figure 4, the frequency deviation estimating method of multicarrier system may include steps of：
Subframe in S21, detection Physical Uplink Shared Channel PUSCH, the OFDM symbol of antithetical phrase frame in carries out N in advancefIndividual
Sampling and normal sample, to obtain rough calculation phase contrast
S22, two Pilot OFDM symbols of antithetical phrase frame in enter row operation, to obtain the actuarial phase contrast of corresponding user
S23, according to actuarial phase contrastAnd/or rough calculation phase contrastDetermine the frequency deviation value of user
It is understood that in the present description, normal sample is not include CP, and samples in advance, includes
CP, therefore N in advancefIndividual sampling demodulation refers to so should be the N including in this OFDM symbolfIndividual CP sampled point is simultaneously given up
Corresponding N at endingfIndividual just frequently with point.
It is understood that the sequencing that step S21 and step S22 are not carried out, step S21 both can be first carried out
Execution step S22 again, can first carry out step S22 execution step S21 more again.
Further, step S21, can include：Any one or more OFDM symbol of antithetical phrase frame in carry out N in advancefIndividual
Sampling and normal sample, and carry out user after transforming to frequency domain respectively and separate, to obtain specific user or all user's rough calculation phases
Potential difference
For example, it is assumed that this frame only comprises two users, wherein user 1 takies PRB is 0 to 49, and the PRB that user 2 takies is
50 to 99, if only requiring, rough calculation phase difference estimation is carried out to user 1, the data of PRB numbering 0 to 49 after time-frequency conversion is taken out
Carry out the rough estimate of user 1；In the same manner, only require process user 2 when then directly PRB is numbered be 50 to 99 data take out used
The rough estimate at family 2；If system requirements all carries out rough calculation phase difference estimation to whole users, a time-frequency conversion also only need to be carried out, that is,
The data of PRB numbering 0 to 49 is taken out the rough estimate carrying out user 1, the data of PRB numbering 50 to 99 is taken out simultaneously and carry out user
2 rough estimate.
Rough calculation phase contrast is obtained in multi-user's frequency deviation estimating method that Fig. 5 shows according to an embodiment of the present invention
Schematic flow sheet.As shown in figure 5, executing S21, that is, any one or more OFDM symbol of antithetical phrase frame in carry out N in advancefIndividual adopt
Sample and normal sample, and carry out user after transforming to frequency domain respectively and separate, to obtain specific user or all user's rough calculation phase places
DifferenceMay include steps of：
S211, N in advance is carried out to OFDM symbolfIndividual sampling demodulation, to obtain the first sampled result, and to OFDM symbol
Carry out normal sample demodulation, to obtain the second sampled result；
S212, fast Fourier transform FFT, followed by phase compensation are carried out to the first sampled result, to obtain first
Transformation results, and FFT process is carried out to the second sampled result, to obtain the second transformation results；
For example for the first sampled result it is assumed that system bandwidth is 20M and be advanced by 100 sampled points, then need into
The FFT that 2048 points of row is it is assumed that transformation results are [a0,a1,...,a2047]T, knowable to the principle according to FFT, compensation sequence is
Exp (j2 π * 100*n/2048) wherein n=0,1 ..., 2047, that is, after phase compensation, data is bn=an*exp(j2π*100*n/
2048) wherein n=0,1 ..., 2047.
S213, user's demapping process is carried out to the first transformation results and the second transformation results, to obtain the first hits
According to the second sampled data；
S214, multiple correlation computing is carried out to the first sampled data and the second sampled data, obtain rough calculation phase contrast
For example, multiple correlation computing can be following manner：Will the corresponding subcarrier of sampled data and normal sample number in advance
Carry out conjugate multiplication according to corresponding subcarrier and multiplied result added up, shift to an earlier date sampled data and normal sample number to obtain
According between rough calculation phase contrastFor example, it is assumed that the first sampled data is c=[c1,c2...cN], the second sampled data be c '=
[c′1,c′2...c′N], then rough calculation phase contrast is
For example, when an OFDM symbol of antithetical phrase frame in carries out phase contrast rough calculation, then to the first sampled data and second
The result that sampled data carries out multiple correlation computing is exactly final rough calculation phase contrast；When multiple OFDM symbol of antithetical phrase frame in are carried out
During phase contrast rough calculation, then the result of the multiple correlation computing to each OFDM symbol is needed to average, and by the meansigma methodss obtaining
As final rough calculation phase contrast.
Rough calculation phase contrast is obtained in multi-user's frequency deviation estimating method that Fig. 6 shows according to an embodiment of the present invention's
Subframe structure schematic diagram.As shown in fig. 6, below scheme is the concrete processing procedure to step described in above-mentioned Fig. 5：
First, execute S211, N in advance is carried out to OFDM symbolfIndividual sampling demodulation, to obtain the first sampled result, and
And normal sample demodulation is carried out to OFDM symbol, to obtain the second sampled result.For example, it is possible to be OFDM symbol ending using CP
Partial some samplings and the fundamental characteristics of FFT, sampling in advance completes frequency deviation rough estimate.For example, as shown in Fig. 2 typically
In ofdm system, CP can be dropped completely, and OFDM symbol is carried out obtaining the reception number of specific user after FFT demapping
According to, and in the present invention, as shown in fig. 6, time domain data is shifted to an earlier date NfIndividual sampling, that is, contain NfIndividual CP sampling is simultaneously correspondingly given up
Abandon the corresponding sampling in OFDM symbol.
Then, execute S212, FFT, followed by phase compensation are carried out to the first sampled result, to obtain the first conversion
As a result, and to the second sampled result carry out FFT process, to obtain the second transformation results.For example, as shown in Fig. 2 sampling is tied
Fruit carries out FFT and compensates the phase deviation that each subcarrier is caused of sampling in advance.
Then, execute S213, user's demapping process is carried out to the first transformation results and the second transformation results, to obtain
First sampled data and the second sampled data.For example, as shown in Fig. 2 the result demapping after converting and compensating is obtained this use
The sampled data in advance at family.General frequency deviation can not possibly be bigger than subcarrier spacing, and in particular cases frequency deviation may compare subcarrier spacing
Greatly.In the scene that frequency deviation and subcarrier spacing differ greatly, now with normally demodulate the corresponding subcarrier of user data obtaining
Phase contrast be 2 π fNfTs.For example, for LTE system, sampling interval TsFor 1/30720000 second it is assumed that in advance 100 sampling
During point, then between two groups of samplings, difference 1/307200 second, it is further assumed that frequency deviation f to be estimated is 1000Hz, will result in this timePhase deviation；Conversely, measurement obtains this phase deviation then can inverse wait to estimate frequency
F partially.
Then, execute S214, multiple correlation computing is carried out to the first sampled data and the second sampled data, obtain rough calculation phase
Potential differenceFor example, as shown in Fig. 2 corresponding subcarrier carries out complex conjugate multiplication to two above demapping result, and will be multiplied
Result adds up and can obtain both phase contrasts, is finally calculated frequency deviation rough estimate result.
Actuarial phase contrast is obtained in multi-user's frequency deviation estimating method that Fig. 7 shows according to an embodiment of the present invention's
Schematic flow sheet.As shown in fig. 7, executing S22, that is, the two of antithetical phrase frame in Pilot OFDM symbols enter row operation, to obtain correspondence
The actuarial phase contrast of userCan include：
S221, two Pilot OFDM symbols are sampled respectively, to obtain the first pilot samples result and the second pilot tone
Sampled result；
S222, FFT process is carried out to the first pilot samples result and the second pilot samples result, to obtain the first pilot tone change
Change result and the second pilot tone transformation results；
S223, user's demapping process is carried out to the first pilot tone transformation results and the second pilot tone transformation results, to obtain
One receives pilot tone and the second reception pilot tone；
S224, first is received pilot tone and second and receive pilot tone and respective pilot frequency sequence conjugate multiplication, to obtain first
Channel estimation in frequency domain result and the second channel estimation in frequency domain result；
S225, the first frequency pilot sign channel estimation in frequency domain result and the second frequency pilot sign channel estimation in frequency domain result are carried out
Multiple correlation computing, obtains actuarial phase contrast
For example, multiple correlation computing can be following manner：By corresponding for the first channel estimation in frequency domain result subcarrier and
The corresponding subcarrier of two channel estimation in frequency domain results carries out conjugate multiplication and multiplied result is added up, during obtaining this two
Actuarial phase contrast between the OFDM symbol of the pilot tone in gapFor example, it is assumed that the first sampled data is c=[c1,c2...cN],
Second sampled data is c '=[c '1,c′2...c′N], then actuarial phase contrast is
It is based on rough calculation phase contrast in multi-user's frequency deviation estimating method that Fig. 8 shows according to an embodiment of the present invention
With actuarial phase contrastJudge frequency deviation valueSchematic flow sheet.As shown in figure 8, execution S23, that is, according to actuarial phase contrast
And/or rough calculation phase contrastDetermine the frequency deviation value of userCan include：
S231, according to frequency offset estimation range arrange merge threshold value φ=(2-n) π, wherein, frequency offset estimation range be ± nkHz
(0<n<2)；
For example, it is assumed that system operation is on 2.6GHz, user's highest movement speed is 450km/h, then maximum Doppler frequency
It is 1084Hz partially, estimation range can be set as -1100Hz to 1100Hz, then merging threshold value is φ=(2-1.1) π=0.9 π.
S232, when actuarial phase contrastAbsolute value be less than merge threshold value φ when, determine that frequency deviation value is actuarial phase contrastI.e. frequency deviation value
S233, when actuarial phase contrastAbsolute value be more than or equal to and merge threshold value φ, and actuarial phase contrastWith rough calculation
Phase contrastWhen symbol is different, determine that frequency deviation value is rough calculation phase contrastNumerical symbol and 2 π product and actuarial phase contrastSum, i.e. frequency deviation value
Fig. 9 shows the frequency deviation value according to an embodiment in Fig. 8Judgement schematic flow sheet.For example, according to estimation model
Enclose requirement setting and merge threshold value it is assumed that required scope is ± nkHz (0<n<2), then merging threshold value is φ=(2-n) π.As Fig. 9 institute
Show, first, comparison is smart to estimate whether result exceedes merging threshold value, just needs when a threshold is exceeded to merge with rough estimate result, otherwise ties
Bundle；When both need to merge, whether needing to compare rough estimate result and essence, to estimate result sign identical, just needs to close when different
And, otherwise terminate；Finally, when both signs are different, essence estimates result to be needed to adjust 2 π, and adjustment direction depends on rough estimate and ties
The sign of fruit.
It is based on rough calculation phase contrast in multi-user's frequency deviation estimating method that Figure 10 shows according to another embodiment of the present inventionWith actuarial phase contrastJudge frequency deviation valueSchematic flow sheet.As shown in Figure 10, execute S23, that is, according to actuarial phase contrastAnd/or rough calculation phase contrastDetermine the frequency deviation value of userCan include：
S231, according to frequency offset estimation range arrange merge threshold value φ=(2-n) π, wherein, frequency offset estimation range be ± nkHz
(0<n<2)；
S232 ', when actuarial phase contrastWith rough calculation phase contrastWhen symbol is identical, determine that frequency deviation value is actuarial phase contrastI.e. frequency deviation value
S233, when actuarial phase contrastAbsolute value be more than or equal to and merge threshold value φ, and actuarial phase contrastWith rough calculation
Phase contrastWhen symbol is different, determine that frequency deviation value is rough calculation phase contrastNumerical symbol and 2 π product and actuarial phase contrastSum, i.e. frequency deviation value
It is understood that step S23 both can be according only to actuarial phase contrastDetermine the frequency deviation value of userMay be used again
With according only to rough calculation phase contrastDetermine the frequency deviation value of userCan be combined with actuarial phase contrastWith rough calculation phase contrast
Figure 11 shows the frequency deviation value according to embodiment another in Figure 10Judgement schematic flow sheet.For example, according to estimating
Meter area requirement setting merges threshold value it is assumed that required scope is ± nkHz (0<n<2), then merging threshold value is φ=(2-n) π.As figure
Shown in 11, first, whether comparing rough estimate result and essence, to estimate result sign identical, when both signs are identical, directly determines
Frequency deviation value is actuarial phase contrastI.e. frequency deviation valueWhen both signs are different, comparison is smart to estimate whether result exceedes conjunction
And threshold value, just need when a threshold is exceeded to merge with rough estimate result, otherwise terminate；Finally, when needing to merge, essence estimates result to be needed
Adjust 2 π, adjustment direction depends on the sign of rough estimate result.
It follows that a kind of multi-user's frequency deviation estimating method of multicarrier system of present invention offer, can improve at a high speed
The estimated accuracy of phase deviation and scope in motion demodulation, thus be favorably improved demodulation performance.
Figure 12 shows the structure of multi-user's frequency deviation estimation device of multicarrier system according to an embodiment of the present invention
Schematic diagram.As shown in figure 12, the present invention provides a kind of multi-user's frequency deviation estimation device of multicarrier system, including：First detection
Module 101, for detecting the subframe in Physical Uplink Shared Channel PUSCH, the OFDM symbol of antithetical phrase frame in carries out N in advancefIndividual
Sampling and normal sample, to obtain rough calculation phase contrastSecond detection module 102, for two pilot tones OFDM of antithetical phrase frame in
Symbol enters row operation, to obtain the actuarial phase contrast of corresponding userProcessing module 103, for according to actuarial phase contrast
And/or rough calculation phase contrastDetermine the frequency deviation value of user
As a kind of embodiment, first detection module is further used for：Any one or more OFDM symbol of antithetical phrase frame in
Number carry out N in advancefIndividual sampling and normal sample, and carry out user after transforming to frequency domain respectively and separate, with obtain specific user or
All user's rough calculation phase contrasts
As a kind of embodiment, first detection module 101 is further used for：N in advance is carried out to OFDM symbolfIndividual sampling
Demodulation, to obtain the first sampled result, and carries out normal sample demodulation to OFDM symbol, to obtain the second sampled result；Right
First sampled result carries out fast Fourier transform, followed by phase compensation, to obtain the first transformation results, and to second
Sampled result carries out FFT process, to obtain the second transformation results；User's solution is carried out to the first transformation results and the second transformation results
Mapping is processed, to obtain the first sampled data and the second sampled data；First sampled data and the second sampled data are carried out multiple
Related operation, obtains rough calculation phase contrast
As a kind of embodiment, the second detection module 102 is further used for：Two Pilot OFDM symbols are carried out respectively
Sampling, to obtain the first pilot samples result and the second pilot samples result；First pilot samples result and the second pilot tone are adopted
Sample result carries out FFT process, to obtain the first pilot tone transformation results and the second pilot tone transformation results；To the first pilot tone transformation results
Carry out user's demapping process with the second pilot tone transformation results, to obtain the first reception pilot tone and the second reception pilot tone；By first
Receive pilot tone and second and receive pilot tone and respective pilot frequency sequence conjugate multiplication, to obtain the first channel estimation in frequency domain result and the
Two channel estimation in frequency domain results；To the first frequency pilot sign channel estimation in frequency domain result and the second frequency pilot sign channel estimation in frequency domain knot
Fruit carries out multiple correlation computing, obtains actuarial phase contrast
As a kind of embodiment, processing module 103 is further used for：Arranged according to frequency offset estimation range and merge threshold value φ
=(2-n) π, wherein, frequency offset estimation range is ± nkHz (0<n<2)；When actuarial phase contrastAbsolute value be less than merge threshold value
φ, frequency deviation valueWhen actuarial phase contrastAbsolute value be more than or equal to and merge threshold value φ, and actuarial phase contrastWith thick
Calculate phase contrastWhen symbol is different, frequency deviation value
As another embodiment, processing module 103 is further used for：Arranged according to frequency offset estimation range and merge threshold value
φ=(2-n) π, wherein, frequency offset estimation range is ± nkHz (0<n<2)；When actuarial phase contrastWith rough calculation phase contrastSymbol
When number identical, frequency deviation valueWhen actuarial phase contrastAbsolute value be more than or equal to and merge threshold value φ, and actuarial phase contrast
With rough calculation phase contrastWhen symbol is different, frequency deviation value
It follows that a kind of multi-user's frequency deviation estimation device of multicarrier system of present invention offer, can improve at a high speed
The estimated accuracy of phase deviation and scope in motion demodulation, thus be favorably improved demodulation performance.
Those skilled in the art of the present technique are appreciated that the present invention can relate to execute in operation described herein
The equipment of one or more operation.Described equipment can specially design for required purpose and manufacture, or can also include
Known device in general purpose computer, described general purpose computer has and activates or reconstruct with being stored in its interior procedure Selection.This
The computer program of sample can be stored in equipment（For example, computer）In computer-readable recording medium or be stored in be suitable to store electronics refer to
Order is simultaneously coupled in any kind of medium of bus respectively, and described computer-readable medium is including but not limited to any kind of
Disk（Including floppy disk, hard disk, CD, CD-ROM and magneto-optic disk）, memorizer immediately（RAM）, read only memory（ROM）, electricity can compile
Journey ROM, electrically erasable ROM（EPROM）, electrically erasable ROM（EEPROM）, flash memory, magnetic card or light card.Readable
Medium is included for by equipment（For example, computer）Readable form storage or any mechanism of transmission information.For example, readable
Medium includes memorizer immediately（RAM）, read only memory（ROM）, magnetic disk storage medium, optical storage medium, flash memory device, with
The signal that electricity, light, sound or other forms are propagated（Such as carrier wave, infrared signal, digital signal）Deng.
Those skilled in the art of the present technique be appreciated that can be realized with computer program instructions these structure charts and/or
Each frame in block diagram and/or flow graph and the combination of the frame in these structure charts and/or block diagram and/or flow graph.Can be by this
The processor that a little computer program instructions are supplied to general purpose computer, special purpose computer or other programmable data processing methods comes
Generate machine, thus by the instruction that the processor of computer or other programmable data processing methods executes create for
The method realizing specifying in the frame of structure chart and/or block diagram and/or flow graph or multiple frame.
Those skilled in the art of the present technique be appreciated that the various operations having discussed in the present invention, method, in flow process
Step, measure, scheme can be replaced, changed, combined or deleted.Further, there is discussed in the present invention each
Kind of operation, method, other steps in flow process, measure, scheme can also be replaced, changed, reset, decomposed, combined or deleted.
Further, of the prior art have and the step in the various operations disclosed in the present invention, method, flow process, measure, side
Case can also be replaced, changed, reset, decomposed, combined or deleted.
The above is only some embodiments of the present invention it is noted that ordinary skill people for the art
For member, under the premise without departing from the principles of the invention, some improvements and modifications can also be made, these improvements and modifications also should
It is considered as protection scope of the present invention.
Claims (10)
1. a kind of frequency deviation estimating method of multicarrier system is it is characterised in that comprise the following steps：
Subframe in detection Physical Uplink Shared Channel PUSCH, carries out N in advance to the OFDM symbol in described subframefIndividual sampling and
Normal sample, to obtain rough calculation phase contrastIncluding：N in advance is carried out to any one or more OFDM symbol in described subframef
Individual sampling and normal sample, and carry out user after transforming to frequency domain respectively and separate, to obtain specific user or all user's rough calculations
Phase contrast
Row operation is entered to two Pilot OFDM symbols in described subframe, to obtain the actuarial phase contrast of corresponding user
According to actuarial phase contrastAnd/or rough calculation phase contrastDetermine the frequency deviation value of described user
2. frequency deviation estimating method as claimed in claim 1 is it is characterised in that to any one or more OFDM in described subframe
Symbol carries out N in advancefIndividual sampling and normal sample, and carry out user after transforming to frequency domain respectively and separate, to obtain specific user
Or all user's rough calculation phase contrastsIncluding：
N in advance is carried out to described OFDM symbolfIndividual sampling demodulation, to obtain the first sampled result, and enters to described OFDM symbol
Row normal sample demodulates, to obtain the second sampled result；
Fast Fourier transform FFT, followed by phase compensation are carried out to the first sampled result, to obtain the first transformation results,
And FFT process is carried out to the second sampled result, to obtain the second transformation results；
User's demapping process is carried out to the first transformation results and the second transformation results, is adopted with obtaining the first sampled data and second
Sample data；
Multiple correlation computing is carried out to the first sampled data and the second sampled data, obtains rough calculation phase contrast
3. as described frequency deviation estimating method arbitrary in claim 1-2 it is characterised in that to two pilot tones in described subframe
OFDM symbol enters row operation, to obtain the actuarial phase contrast of corresponding userIncluding：
Two Pilot OFDM symbols are sampled respectively, to obtain the first pilot samples result and the second pilot samples result；
FFT process is carried out to the first pilot samples result and the second pilot samples result, with obtain the first pilot tone transformation results and
Second pilot tone transformation results；
User's demapping process is carried out to the first pilot tone transformation results and the second pilot tone transformation results, to obtain the first reception pilot tone
With the second reception pilot tone；
First is received pilot tone and second and receives pilot tone and respective pilot frequency sequence conjugate multiplication, estimated with obtaining the first frequency domain channel
Meter result and the second channel estimation in frequency domain result；
Multiple correlation fortune is carried out to the first frequency pilot sign channel estimation in frequency domain result and the second frequency pilot sign channel estimation in frequency domain result
Calculate, obtain actuarial phase contrast
4. frequency deviation estimating method as claimed in claim 1 is it is characterised in that according to actuarial phase contrastAnd/or rough calculation phase place
DifferenceDetermine the frequency deviation value of described userIncluding：
Arranged according to frequency offset estimation range and merge threshold value φ=(2-n) π, wherein, frequency offset estimation range is ± nkHz (0 ＜ n ＜
2)；
When actuarial phase contrastAbsolute value be less than merge threshold value φ, described frequency deviation value
When actuarial phase contrastAbsolute value be more than or equal to and merge threshold value φ, and actuarial phase contrastWith rough calculation phase contrastSymbol
When number different, described frequency deviation value
5. frequency deviation estimating method as claimed in claim 1 is it is characterised in that according to actuarial phase contrastAnd/or rough calculation phase place
DifferenceDetermine the frequency deviation value of described userAlso include：
Arranged according to frequency offset estimation range and merge threshold value φ=(2-n) π, wherein, frequency offset estimation range is ± nkHz (0 ＜ n ＜
2)；
When actuarial phase contrastWith rough calculation phase contrastWhen symbol is identical, described frequency deviation value
When actuarial phase contrastAbsolute value be more than or equal to and merge threshold value φ, and actuarial phase contrastWith rough calculation phase contrastSymbol
When number different, described frequency deviation value
6. a kind of frequency deviation estimation device of multicarrier system is it is characterised in that include：
First detection module, for detecting the subframe in Physical Uplink Shared Channel PUSCH, to the OFDM symbol in described subframe
Carry out N in advancefIndividual sampling and normal sample, to obtain rough calculation phase contrastIt is further used for：To any one in described subframe
Or multiple OFDM symbol carries out N in advancefIndividual sampling and normal sample, and carry out user after transforming to frequency domain respectively and separate, to obtain
Take specific user or all user's rough calculation phase contrasts
Second detection module, for entering row operation to two Pilot OFDM symbols in described subframe, to obtain corresponding user's
Actuarial phase contrast
Processing module, for according to actuarial phase contrastAnd/or rough calculation phase contrastDetermine the frequency deviation value of described user
7. frequency deviation estimation device as claimed in claim 6 is it is characterised in that described first detection module is further used for：
N in advance is carried out to described OFDM symbolfIndividual sampling demodulation, to obtain the first sampled result, and enters to described OFDM symbol
Row normal sample demodulates, to obtain the second sampled result；
Fast Fourier transform, followed by phase compensation are carried out to the first sampled result, to obtain the first transformation results, and
FFT process is carried out to the second sampled result, to obtain the second transformation results；
User's demapping process is carried out to the first transformation results and the second transformation results, is adopted with obtaining the first sampled data and second
Sample data；
Multiple correlation computing is carried out to the first sampled data and the second sampled data, obtains rough calculation phase contrast
8. if described frequency deviation estimation device arbitrary in claim 6-7 is it is characterised in that described second detection module is further
For：
Two Pilot OFDM symbols are sampled respectively, to obtain the first pilot samples result and the second pilot samples result；
FFT process is carried out to the first pilot samples result and the second pilot samples result, with obtain the first pilot tone transformation results and
Second pilot tone transformation results；
User's demapping process is carried out to the first pilot tone transformation results and the second pilot tone transformation results, to obtain the first reception pilot tone
With the second reception pilot tone；
First is received pilot tone and second and receives pilot tone and respective pilot frequency sequence conjugate multiplication, estimated with obtaining the first frequency domain channel
Meter result and the second channel estimation in frequency domain result；
Multiple correlation fortune is carried out to the first frequency pilot sign channel estimation in frequency domain result and the second frequency pilot sign channel estimation in frequency domain result
Calculate, obtain actuarial phase contrast
9. frequency deviation estimation device as claimed in claim 6 is it is characterised in that described processing module is further used for：
Arranged according to frequency offset estimation range and merge threshold value φ=(2-n) π, wherein, frequency offset estimation range is ± nkHz (0 ＜ n ＜
2)；
When actuarial phase contrastAbsolute value be less than merge threshold value φ, described frequency deviation value
When actuarial phase contrastAbsolute value be more than or equal to and merge threshold value φ, and actuarial phase contrastWith rough calculation phase contrastSymbol
When number different, described frequency deviation value
10. frequency deviation estimation device as claimed in claim 6 is it is characterised in that described processing module is further used for：
Arranged according to frequency offset estimation range and merge threshold value φ=(2-n) π, wherein, frequency offset estimation range is ± nkHz (0 ＜ n ＜
2)；
When actuarial phase contrastWith rough calculation phase contrastWhen symbol is identical, described frequency deviation value
When actuarial phase contrastAbsolute value be more than or equal to and merge threshold value φ, and actuarial phase contrastWith rough calculation phase contrastSymbol
When number different, described frequency deviation value
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| CN107306163B (en) | 2016-04-22 | 2019-06-28 | 富士通株式会社 | Processing unit, method and the receiver of pilot tone frequency deviation |
| CN110943820B (en) * | 2016-08-12 | 2023-11-10 | 华为技术有限公司 | Signal transmitting device, signal detecting device and method |
| CN109150784A (en) * | 2017-06-28 | 2019-01-04 | 大唐移动通信设备有限公司 | A kind of frequency deviation estimating method and device |
| CN108712234B (en) * | 2018-05-23 | 2021-02-26 | 电子科技大学 | Frequency offset detection method under interleaved multiple access technology combined with coordinate descent method |
| CN113141324B (en) * | 2020-01-19 | 2022-08-09 | 普天信息技术有限公司 | Channel estimation method and device |
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