CN103581072A - 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, particularly, the present invention relates to a kind of frequency deviation estimating method and device of multicarrier system.
Background technology
In recent years, society is more and more higher to the dependence of communication and requirement.The criterion of communication system efficiency is exactly mainly the availability of frequency spectrum and power utilization.Particularly the in the situation that of radio communication, higher to the utilance of two indexs, the availability of frequency spectrum especially.So, various communication technology with high spectral efficiency is constantly developed, OFDM(Orthogonal Frequency Division Multiplexing, OFDM) be a kind of special multi-carrier modulation technology, it utilizes the orthogonality of intercarrier further to improve the availability of frequency spectrum, and can resist arrowband to disturb and anti-multipath faidng.The subcarrier of OFDM by a plurality of quadratures is by serial data parallel transmission, can increase the width of code element, reduce the frequency band that single code element takies, the frequency selective fading that opposing multipath causes, can effectively overcome intersymbol interference, the requirement of reduction system to balancing technique.
OFDM is a kind of Multicarrier Transmission Technology, and channel is divided into some orthogonal sub-channels, converts high-speed data signal to parallel low speed sub data flow, is modulated on every sub-channels and transmits.Orthogonal signalling can, by adopting correlation technique to separate at receiving terminal, can reduce the phase mutual interference ICI between subchannel like this.Signal bandwidth on every sub-channels is less than the correlation bandwidth of channel, and therefore the flatness of can regarding as on every sub-channels declines, thereby can eliminate intersymbol interference.And because the bandwidth of every sub-channels is only the sub-fraction of former channel width, it is relatively easy that channel equalization becomes.Because general ofdm system all adopts CP(Cyclic Prefix, Cyclic Prefix), the intersymbol interference that makes it multipath transmisstion of erasure signal causes completely under certain condition, eliminate the destruction of multipath transmisstion to intercarrier orthogonality completely, so ofdm system has good anti-multipath interference performance.
But, than single-carrier system, OFDM/OFDMA(Orthogonal Frequency Division Multiplexing/Orthogonal Frequency Division Multiple Access, OFDM/OFDM) system is more responsive to carrier wave frequency deviation.Carrier wave frequency deviation has destroyed the orthogonality between OFDM subcarrier, severe jamming demodulating process, cause performance sharply to decline.The frequency offset estimation accuracy of often having relatively high expectations in commercial system (as LTE) is to guarantee the receptivity of system.
Therefore, for existing multicarrier system, be necessary to propose a kind of efficient multi-user's frequency deviation estimating method and device, to solve phase ambiguity and the larger problem of deviation in existing high-speed motion demodulation.
Summary of the invention
Object of the present invention aims to provide a kind of multi-user's frequency deviation estimating method and device of multicarrier system, to improve estimated accuracy and the scope of phase deviation in high-speed motion demodulation, thereby contributes to improve 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, comprises the following steps: detect the subframe in Physical Uplink Shared Channel PUSCH, the OFDM symbol in described subframe is shifted to an earlier date to N
findividual sampling and normal sampling, to obtain rough calculation phase difference
two pilot tone OFDM symbols in described subframe are carried out to computing, to obtain the actuarial phase difference of respective user
according to actuarial phase difference
and/or rough calculation phase difference
determine described user's frequency deviation value
On the other hand, embodiment of the present invention also provides a kind of multi-user's frequency deviation estimation device of multicarrier system, comprising: first detection module, for detection of the subframe in Physical Uplink Shared Channel PUSCH, shifts to an earlier date N to the OFDM symbol in subframe
findividual sampling and normal sampling, to obtain rough calculation phase difference
the second detection module, carries out computing for two pilot tone OFDM symbols in subframe, to obtain the actuarial phase difference of respective user
processing module, for according to actuarial phase difference
and/or rough calculation phase difference
determine user's frequency deviation value
Multi-user's frequency deviation estimating method and the device of a kind of multicarrier system provided by the invention, can improve estimated accuracy and the scope of phase deviation in high-speed motion demodulation, thereby contribute to improve demodulation performance.In addition, the such scheme that the present invention proposes, very little to the change of existing system, can not affect the compatibility of equipment, and realize simple, efficient.
The aspect that the present invention is additional and advantage in the following description part provide, and these will become obviously from the following description, or recognize by practice of the present invention.
Accompanying drawing explanation
Above-mentioned and/or the additional aspect of the present invention and advantage obviously and are easily understood becoming in the description of execution mode below in conjunction with accompanying drawing, wherein:
Fig. 1 shows the subframe structure schematic diagram of PUSCH channel in LTE system of the prior art;
Fig. 2 show according to an embodiment of the present invention PUSCH channel is carried out to the subframe structure schematic diagram of the thick evaluation method of frequency deviation.；
Fig. 3 show according to an embodiment of the present invention PUSCH channel is carried out to the subframe structure schematic diagram of frequency deviation essence evaluation method;
Fig. 4 shows the schematic flow sheet of the frequency deviation estimating method of multicarrier system according to an embodiment of the present invention;
Fig. 5 shows in multi-user's frequency deviation estimating method according to an embodiment of the present invention and obtains rough calculation phase difference
schematic flow sheet;
Fig. 6 shows in multi-user's frequency deviation estimating method according to an embodiment of the present invention and obtains rough calculation phase difference
subframe structure schematic diagram;
Fig. 7 shows in multi-user's frequency deviation estimating method according to an embodiment of the present invention and obtains actuarial phase difference
schematic flow sheet;
Fig. 8 shows in multi-user's frequency deviation estimating method according to an embodiment of the present invention based on rough calculation phase difference
with actuarial phase difference
judgement frequency deviation value
schematic flow sheet;
Fig. 9 shows according to the frequency deviation value of an execution mode in Fig. 8
judgement schematic flow sheet;
Figure 10 shows in multi-user's frequency deviation estimating method of another execution mode according to the present invention based on rough calculation phase difference
with actuarial phase difference
judgement frequency deviation value
schematic flow sheet;
Figure 11 shows according to the frequency deviation value of another execution mode in Figure 10
judgement schematic flow sheet;
Figure 11 shows the judgement frequency deviation value according to another execution mode in Figure 10
judgement schematic flow sheet;
Figure 12 shows the structural representation of multi-user's frequency deviation estimation device of multicarrier system according to an embodiment of the present invention.
Embodiment
Describe embodiments of the present invention below in detail, the example of described execution mode is shown in the drawings, and wherein same or similar label represents same or similar element or has the element of identical or similar functions from start to finish.Below by the execution mode being described with reference to the drawings, be exemplary, only for explaining the present invention, and can not be interpreted as limitation of the present invention.
Unless those skilled in the art of the present technique are appreciated that specially statement, singulative used herein " ", " one ", " described " and " being somebody's turn to do " also can comprise plural form.Should be further understood that, the wording of using in specification of the present invention " comprises " and refers to and have described feature, integer, step, operation, element and/or assembly, but do not get rid of, do not exist or adds one or more other features, integer, step, operation, element, assembly and/or their group.Should be appreciated that, when we claim element to be " connected " or " coupling " when another element, it can be directly connected or coupled to other elements, or also can have intermediary element.In addition, " connection " used herein or " coupling " can comprise wireless connections or couple.Wording "and/or" used herein comprises arbitrary unit of listing item and all combinations that one or more is associated.
Those skilled in the art of the present technique are appreciated that unless otherwise defined, all terms used herein (comprising technical term and scientific terminology) have with the present invention under the identical meaning of the general understanding of those of ordinary skill in field.Should also be understood that such as those terms that define in general dictionary and should be understood to have the consistent meaning of meaning in the context with prior art, unless and definition as here, can not explain by idealized or too formal implication.
Fig. 1 shows the subframe structure schematic diagram of the PUSCH channel in a kind of LTE system.In LTE system, PUSCH channel generally adopts the radio frames of a 10ms, can be divided into again the subframe of 10 1ms, and a subframe can have 2 time slots.As shown in Figure 1, the subframe structure of PUSCH channel in LTE system.Each slot length is that 0.5ms also can be divided into 7 OFDM symbols, wherein: 3, left side OFDM data symbol, 3, right side OFDM data symbol, middle 1 pilot tone OFDM symbol.In arranging without frequency hopping, when needs frequency deviation is estimated, current way is two frequency pilot signs by same subframe, calculates both phase differences, is assumed to be
due to two pilot symbol interval 0.5ms, this user's frequency deviation is
visible its estimation range is ± 1000Hz.And in high-speed motion scene, user's frequency deviation likely surpasses this scope, thus the phase ambiguity of causing, and then affect demodulation performance.
Fig. 2 show according to an embodiment of the present invention PUSCH channel is carried out to the subframe structure schematic diagram of the thick evaluation method of frequency deviation.As shown in Figure 2, the thick evaluation method of frequency deviation can comprise:
S11, estimation range is divided into some segments.For example, the span of each segment is 2KHz.
S12, use CP complete frequency deviation rough estimate, determine this user's frequency deviation is in which segment.For example, utilizing CP is some samplings at OFDM symbol end, some sampling of intercepting CP, and with sampling conjugate multiplication corresponding in OFDM symbol and multiplied result is added up, thus the phase difference between being sampled
and then, can be scaled frequency deviation value according to the duration of this OFDM symbol.In order to estimate result with essence below, merge, only utilize rough estimate value to determine frequency deviation segment herein.
Fig. 3 show according to an embodiment of the present invention PUSCH channel is carried out to the subframe structure schematic diagram of frequency deviation essence evaluation method.As shown in Figure 3, frequency deviation essence evaluation method can comprise: S22, two pilot tone OFDM symbols in subframe are carried out to computing, to obtain actuarial phase difference
for example, use frequency pilot sign to complete essence and estimate, can be made as ± 1KHz of this estimation range, and finally complete frequency deviation estimation in conjunction with segment definite in S12.For example, first, respectively the OFDM frequency pilot sign of time slot 0 and time slot 1 is transformed to frequency domain by FFT; Then, by demapping, take out respectively this user's reception pilot tone; Then, by receiving pilot tone, take advantage of with pilot frequency sequence conjugation separately respectively, be now actually and obtained channel estimation in frequency domain result; Remembering, by the corresponding subcarrier conjugate multiplication of the channel estimation results of two time slots, and multiplied result is being added up and just can obtain the phase difference between time slot 0 frequency pilot sign and time slot 1 frequency pilot sign
subsequently, by the phase difference obtaining in conjunction with frequency deviation rough estimate
estimate with frequency deviation essence the phase difference obtaining
according to following formula (1), calculate frequency offset estimation result:
Wherein, T
osthe duration that represents an OFDM symbol.
Hence one can see that, and a kind of efficient multi-user's frequency deviation estimating method provided by the invention can solve phase ambiguity and the larger problem of deviation in existing high-speed motion demodulation.
Further, in order better to realize multi-user, estimate, can be optimized above-mentioned method of estimation, by the separation of user's frequency domain data, can realize multi-user's frequency deviation and estimate, between each user, can not interfere with each other.According to another method of estimation of the present invention; in estimating merging process, rough estimate and essence only adopt the positive negative value of rough estimate result; and take safeguard measure; thereby can only reach ± 1～± 2KHz of estimation range; this estimation range is not only enough used, and can effectively overcome the large shortcoming of rough estimate result error in above-mentioned estimation scheme.
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 can comprise the steps:
Subframe in S21, detection Physical Uplink Shared Channel PUSCH, shifts to an earlier date N to the OFDM symbol in subframe
findividual sampling and normal sampling, to obtain rough calculation phase difference
S22, two pilot tone OFDM symbols in subframe are carried out to computing, to obtain the actuarial phase difference of respective user
S23, according to actuarial phase difference
and/or rough calculation phase difference
determine user's frequency deviation value
Be understandable that, in the present invention's description, normal sampling is not comprise CP, and sampling in advance has comprised CP, therefore shifts to an earlier date N
fso it be the N having comprised in this OFDM symbol that individual sampling demodulation refers to
findividual CP sampled point has also been given up the corresponding N of ending place
findividual normal employing point.
Be understandable that, the sequencing that step S21 and step S22 do not carry out, both can first perform step S21 and perform step S22 again, can first perform step again S22 and perform step S21 again.
Further, step S21, can comprise: any or a plurality of OFDM symbol in subframe are shifted to an earlier date to N
findividual sampling and normal sampling, and carry out user's separation after transforming to respectively frequency domain, to obtain specific user or all user's rough calculation phase differences
For example, suppose that this frame only comprises two users, wherein user 1 to take PRB be 0 to 49, the PRB that user 2 takies is 50 to 99, if only require user 1 is carried out to rough calculation phase difference estimation, the data of PRB numbering 0 to 49 after time-frequency conversion are taken out to the rough estimate of carrying out user 1; In like manner, only require that while processing user 2, directly PRB being numbered to 50 to 99 data takes out the rough estimate of carrying out user 2; If system requirements all carries out rough calculation phase difference estimation to whole users, also only need carry out one time time-frequency conversion, the data that are about to PRB numbering 0 to 49 are taken out the rough estimate of carrying out user 1, the data of PRB numbering 50 to 99 are taken out to the rough estimate of carrying out user 2 simultaneously.
Fig. 5 shows in multi-user's frequency deviation estimating method according to an embodiment of the present invention and obtains rough calculation phase difference
schematic flow sheet.As shown in Figure 5, carry out S21, any or a plurality of OFDM symbol in subframe are shifted to an earlier date to N
findividual sampling and normal sampling, and carry out user's separation after transforming to respectively frequency domain, to obtain specific user or all user's rough calculation phase differences
can comprise the steps:
S211, OFDM symbol is shifted to an earlier date to N
findividual sampling demodulation, to obtain the first sampled result, and to the demodulation of normally sampling of OFDM symbol, to obtain the second sampled result;
S212, the first sampled result is carried out to fast Fourier transform FFT, carry out thereafter phase compensation, to obtain the first transformation results, and the second sampled result is carried out to FFT processing, to obtain the second transformation results;
For example, for the first sampled result, supposing the system bandwidth is 20M and has shifted to an earlier date 100 sampled points, needs to carry out the FFT conversion of 2048, supposes that transformation results is for [a
0, a
1..., a
2047]
t, according to the known compensation sequence of the principle of FFT, be wherein n=0 of exp (j2 π * 100*n/2048), 1 ..., 2047, after phase compensation, data are b
n=a
n* exp (j2 π * 100*n/2048) n=0 wherein, 1 ..., 2047.
S213, the first transformation results and the second transformation results are carried out to the processing of user's demapping, to obtain the first sampled data and the second sampled data;
S214, the first sampled data and the second sampled data are carried out to multiple correlation computing, obtain rough calculation phase difference
For example, multiple correlation computing can be following mode: by shifting to an earlier date subcarrier corresponding to sampled data, carry out conjugate multiplication and multiplied result is added up with normal subcarrier corresponding to sampled data, to obtain sampled data and normally the rough calculation phase difference between sampled data in advance
for example, suppose that the first sampled data is c=[c
1, c
2... c
n], the second sampled data be c '=[c '
1, c '
2... c '
n], rough calculation phase difference is
For example, when an OFDM symbol in subframe carries out phase difference rough calculation, the result of the first sampled data and the second sampled data being carried out to multiple correlation computing is exactly final rough calculation phase difference; When a plurality of OFDM symbols in subframe carry out phase difference rough calculation, need the result of the multiple correlation computing of each OFDM symbol to average, and using the mean value obtaining as final rough calculation phase difference.
Fig. 6 shows in multi-user's frequency deviation estimating method according to an embodiment of the present invention and obtains rough calculation phase difference
subframe structure schematic diagram.As shown in Figure 6, following flow process is the concrete processing procedure to step described in above-mentioned Fig. 5:
First, carry out S211, OFDM symbol is shifted to an earlier date to N
findividual sampling demodulation, to obtain the first sampled result, and to the demodulation of normally sampling of OFDM symbol, to obtain the second sampled result.For example, can utilize CP is the fundamental characteristics of some samplings and the FFT conversion of OFDM symbol ending, the frequency deviation of having sampled in advance rough estimate.For example, as shown in Figure 2, in general ofdm system, CP can be abandoned completely, OFDM symbol is carried out obtaining specific user's reception data after FFT conversion demapping, and in the present invention, as shown in Figure 6, time domain data is shifted to an earlier date to N
findividual sampling, has comprised N
findividual CP sampling has also correspondingly been given up the correspondence sampling in OFDM symbol.
Then, carry out S212, the first sampled result is carried out to FFT, carry out thereafter phase compensation, to obtain the first transformation results, and the second sampled result is carried out to FFT processing, to obtain the second transformation results.For example, as shown in Figure 2, sampled result is carried out to FFT conversion and compensated the phase deviation of sampling in advance each subcarrier being caused.
Then, carry out S213, the first transformation results and the second transformation results are carried out to the processing of user's demapping, to obtain the first sampled data and the second sampled data.For example, as shown in Figure 2, the result demapping after converting and compensating is obtained to this user's sampled data in advance.General frequency deviation can not be larger than subcarrier spacing, and in particular cases frequency deviation may be larger than subcarrier spacing.In the scene that frequency deviation and subcarrier spacing differ greatly, the phase difference of the corresponding subcarrier of user data now obtaining with normal demodulation is 2 π fN
ft
s.For example, for LTE system, sampling interval T
sbe 1/30720000 second, while supposing to shift to an earlier date 100 sampled points, between two groups of samplings, differ 1/307200 second, then suppose that frequency deviation f to be estimated is 1000Hz, in this time, will cause
phase deviation; Otherwise measuring this phase deviation can inverse frequency deviation f to be estimated.
Then, carry out S214, the first sampled data and the second sampled data are carried out to multiple correlation computing, obtain rough calculation phase difference
for example, as shown in Figure 2, the corresponding subcarrier of above two demapping results is carried out to complex conjugate and multiply each other, and by the cumulative phase difference that can obtain both of multiplied result, finally calculate frequency deviation rough estimate result.
Fig. 7 shows in multi-user's frequency deviation estimating method according to an embodiment of the present invention and obtains actuarial phase difference
schematic flow sheet.As shown in Figure 7, carry out S22, two pilot tone OFDM symbols in subframe are carried out to computing, to obtain the actuarial phase difference of respective user
can comprise:
S221, two pilot tone OFDM symbols are sampled respectively, to obtain the first pilot samples result and the second pilot samples result;
S222, the first pilot samples result and the second pilot samples result are carried out to FFT processing, to obtain the first pilot tone transformation results and the second pilot tone transformation results;
S223, the first pilot tone transformation results and the second pilot tone transformation results are carried out to the processing of user's demapping, to obtain the first reception pilot tone and second, receive pilot tone;
S224, the first reception pilot tone and second is received to pilot tone and pilot frequency sequence conjugate multiplication separately, to obtain the 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 to multiple correlation computing, obtain actuarial phase difference
For example, multiple correlation computing can be following mode: subcarrier and subcarrier corresponding to the second channel estimation in frequency domain result that the first channel estimation in frequency domain result is corresponding carry out conjugate multiplication and multiplied result is added up, to obtain the actuarial phase difference between the OFDM symbol of the pilot tone in these two time slots
for example, suppose that the first sampled data is c=[c
1, c
2... c
n], the second sampled data be c '=[c '
1, c '
2... c '
n], actuarial phase difference is
Fig. 8 shows in multi-user's frequency deviation estimating method according to an embodiment of the present invention based on rough calculation phase difference
with actuarial phase difference
judgement frequency deviation value
schematic flow sheet.As shown in Figure 8, carry out S23, according to actuarial phase difference
and/or rough calculation phase difference
determine user's frequency deviation value
can comprise:
S231, according to frequency offset estimation range, arrange and merge the π of threshold value φ=(2-n), wherein, frequency offset estimation range is ± nkHz (0<n<2);
For example, supposing the system runs on that 2.6GHz is upper, and user's highest movement speed is 450km/h, and maximum Doppler frequency offset is 1084Hz, can be by be set as-1100Hz to 1100Hz of estimation range, merge threshold value and be π=0.9 π of φ=(2-1.1).
S232, when actuarial phase difference
absolute value be less than while merging threshold value φ, determine that frequency deviation value is actuarial phase difference
it is frequency deviation value
S233, when actuarial phase difference
absolute value be more than or equal to and merge threshold value φ, and actuarial phase difference
with rough calculation phase difference
when symbol is different, determine that frequency deviation value is rough calculation phase difference
numerical symbol and product and the actuarial phase difference of 2 π
sum, i.e. frequency deviation value
Fig. 9 shows according to the frequency deviation value of an execution mode in Fig. 8
judgement schematic flow sheet.For example, according to estimation range, require merging threshold value is set, suppose that required scope is for ± nkHz (0<n<2), merge threshold value and be the π of φ=(2-n).As shown in Figure 9, first, more smartly estimate result and whether surpass and merge threshold value, when surpassing threshold value, just need to merge with rough estimate result, otherwise finish; When both need to merge, whether need to comparing rough estimate result and essence, to estimate result sign identical, just needs to merge, otherwise finish when different; Finally, when both signs are different, essence is estimated result need to adjust 2 π, adjusts the sign that direction depends on rough estimate result.
Figure 10 shows in multi-user's frequency deviation estimating method of another execution mode according to the present invention based on rough calculation phase difference
with actuarial phase difference
judgement frequency deviation value
schematic flow sheet.As shown in figure 10, carry out S23, according to actuarial phase difference
and/or rough calculation phase difference
determine user's frequency deviation value
can comprise:
S231, according to frequency offset estimation range, arrange and merge the π of threshold value φ=(2-n), wherein, frequency offset estimation range is ± nkHz (0<n<2);
S232 ', when actuarial phase difference
with rough calculation phase difference
when symbol is identical, determine that frequency deviation value is actuarial phase difference
it is frequency deviation value
S233, when actuarial phase difference
absolute value be more than or equal to and merge threshold value φ, and actuarial phase difference
with rough calculation phase difference
when symbol is different, determine that frequency deviation value is rough calculation phase difference
numerical symbol and product and the actuarial phase difference of 2 π
sum, i.e. frequency deviation value
Be understandable that, step S23 both can be only according to actuarial phase difference
determine user's frequency deviation value
again can be only according to rough calculation phase difference
determine user's frequency deviation value
can also be in conjunction with actuarial phase difference
with rough calculation phase difference
Figure 11 shows according to the frequency deviation value of another execution mode in Figure 10
judgement schematic flow sheet.For example, according to estimation range, require merging threshold value is set, suppose that required scope is for ± nkHz (0<n<2), merge threshold value and be the π of φ=(2-n).As shown in figure 11, first, whether comparison rough estimate result and essence are estimated result sign identical, when both signs are identical, directly determine that frequency deviation value is actuarial phase difference
it is frequency deviation value
when both signs are different, more smartly estimate result and whether surpass and merge threshold value, when surpassing threshold value, just need to merge with rough estimate result, otherwise finish; Finally, when needs merge, essence is estimated result need to adjust 2 π, adjusts the sign that direction depends on rough estimate result.
Hence one can see that, and multi-user's frequency deviation estimating method of a kind of multicarrier system provided by the invention can improve estimated accuracy and the scope of phase deviation in high-speed motion demodulation, thereby contributes to improve demodulation performance.
Figure 12 shows the structural representation of multi-user's frequency deviation estimation device of multicarrier system according to an embodiment of the present invention.As shown in figure 12, the invention provides a kind of multi-user's frequency deviation estimation device of multicarrier system, comprising: first detection module 101, for detection of the subframe in Physical Uplink Shared Channel PUSCH, shifts to an earlier date N to the OFDM symbol in subframe
findividual sampling and normal sampling, to obtain rough calculation phase difference
the second detection module 102, carries out computing for two pilot tone OFDM symbols in subframe, to obtain the actuarial phase difference of respective user
processing module 103, for according to actuarial phase difference
and/or rough calculation phase difference
determine user's frequency deviation value
As a kind of execution mode, first detection module is further used for: any or a plurality of OFDM symbol in subframe are shifted to an earlier date to N
findividual sampling and normal sampling, and carry out user's separation after transforming to respectively frequency domain, to obtain specific user or all user's rough calculation phase differences
As a kind of execution mode, first detection module 101 is further used for: OFDM symbol is shifted to an earlier date to N
findividual sampling demodulation, to obtain the first sampled result, and to the demodulation of normally sampling of OFDM symbol, to obtain the second sampled result; The first sampled result is carried out to fast Fourier transform, carry out thereafter phase compensation, to obtain the first transformation results, and the second sampled result is carried out to FFT processing, to obtain the second transformation results; The first transformation results and the second transformation results are carried out to the processing of user's demapping, to obtain the first sampled data and the second sampled data; The first sampled data and the second sampled data are carried out to multiple correlation computing, obtain rough calculation phase difference
As a kind of execution mode, the second detection module 102 is further used for: two pilot tone OFDM symbols are sampled respectively, to obtain the first pilot samples result and the second pilot samples result; The first pilot samples result and the second pilot samples result are carried out to FFT processing, to obtain the first pilot tone transformation results and the second pilot tone transformation results; The first pilot tone transformation results and the second pilot tone transformation results are carried out to the processing of user's demapping, to obtain the first reception pilot tone and second, receive pilot tone; The first reception pilot tone and second is received to pilot tone and pilot frequency sequence conjugate multiplication separately, to obtain the first channel estimation in frequency domain result and the second channel estimation in frequency domain result; 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 to multiple correlation computing, obtain actuarial phase difference
As a kind of execution mode, processing module 103 is further used for: according to frequency offset estimation range, arrange and merge the π of threshold value φ=(2-n), wherein, frequency offset estimation range is ± nkHz (0<n<2); When actuarial phase difference
absolute value be less than and merge threshold value φ, frequency deviation value
when actuarial phase difference
absolute value be more than or equal to and merge threshold value φ, and actuarial phase difference
with rough calculation phase difference
when symbol is different, frequency deviation value
As another kind of execution mode, processing module 103 is further used for: according to frequency offset estimation range, arrange and merge the π of threshold value φ=(2-n), wherein, frequency offset estimation range is ± nkHz (0<n<2); When actuarial phase difference
with rough calculation phase difference
when symbol is identical, frequency deviation value
when actuarial phase difference
absolute value be more than or equal to and merge threshold value φ, and actuarial phase difference
with rough calculation phase difference
when symbol is different, frequency deviation value
Hence one can see that, and multi-user's frequency deviation estimation device of a kind of multicarrier system provided by the invention can improve estimated accuracy and the scope of phase deviation in high-speed motion demodulation, thereby contributes to improve demodulation performance.
Those skilled in the art of the present technique are appreciated that the present invention can relate to for carrying out the equipment of the one or more operation of operation described in the application.Described equipment can be required object specialized designs and manufacture, or also can comprise the known device in all-purpose computer, and described all-purpose computer has storage procedure Selection within it and activates or reconstruct.Such computer program (for example can be stored in equipment, computer), in computer-readable recording medium or be stored in the medium of any type that is suitable for store electrons instruction and is coupled to respectively bus, described computer-readable medium includes but not limited to the dish (comprising floppy disk, hard disk, CD, CD-ROM and magneto optical disk) of any type, memory (RAM), read-only memory (ROM), electrically programmable ROM, electric erasable ROM(EPROM immediately), electrically erasable ROM(EEPROM), flash memory, magnetic card or light card.Computer-readable recording medium comprises for any mechanism with for example, by the storage of the readable form of equipment (, computer) or transmission information.For example, computer-readable recording medium comprises memory (RAM) immediately, read-only memory (ROM), magnetic disk storage medium, optical storage medium, flash memory device, the signal (such as carrier wave, infrared signal, digital signal) propagated with electricity, light, sound or other form etc.
Those skilled in the art of the present technique are appreciated that and can realize each frame in these structure charts and/or block diagram and/or flow graph and the combination of the frame in these structure charts and/or block diagram and/or flow graph with computer program instructions.The processor that these computer program instructions can be offered to all-purpose computer, special purpose computer or other programmable data processing methods generates machine, thereby the instruction of carrying out by the processor of computer or other programmable data processing methods has created for the frame of implementation structure figure and/or block diagram and/or flow graph or the method for a plurality of frame appointments.
Those skilled in the art of the present technique be appreciated that step in the various operations discussed in the present invention, method, flow process, measure, scheme can by alternately, change, combination or delete.Further, have other steps in the various operations discussed in the present invention, method, flow process, measure, scheme also can by alternately, change, reset, decompose, combination or delete.Further, of the prior art have with the present invention in step in disclosed various operations, method, flow process, measure, scheme also can by alternately, change, reset, decompose, combination or delete.
The above is only part execution mode of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.
Claims (12)
1. a frequency deviation estimating method for multicarrier system, is characterized in that, comprises the following steps:
Detect the subframe in Physical Uplink Shared Channel PUSCH, the OFDM symbol in described subframe is shifted to an earlier date to N
findividual sampling and normal sampling, to obtain rough calculation phase difference
Two pilot tone OFDM symbols in described subframe are carried out to computing, to obtain the actuarial phase difference of respective user
According to actuarial phase difference
and/or rough calculation phase difference
determine described user's frequency deviation value
2. frequency deviation estimating method as claimed in claim 1, is characterized in that, the OFDM symbol in described subframe is shifted to an earlier date to N
findividual sampling and normal sampling, to obtain rough calculation phase difference, comprising:
Any or a plurality of OFDM symbol in described subframe are shifted to an earlier date to N
findividual sampling and normal sampling, and carry out user's separation after transforming to respectively frequency domain, to obtain specific user or all user's rough calculation phase differences
3. frequency deviation estimating method as claimed in claim 2, is characterized in that, any or a plurality of OFDM symbol in described subframe are shifted to an earlier date to N
findividual sampling and normal sampling, and carry out user's separation after transforming to respectively frequency domain, to obtain specific user or all user's rough calculation phase differences
comprise:
Described OFDM symbol is shifted to an earlier date to N
findividual sampling demodulation, to obtain the first sampled result, and to the demodulation of normally sampling of described OFDM symbol, to obtain the second sampled result;
The first sampled result is carried out to fast Fourier transform FFT, carry out thereafter phase compensation, to obtain the first transformation results, and the second sampled result is carried out to FFT processing, to obtain the second transformation results;
The first transformation results and the second transformation results are carried out to the processing of user's demapping, to obtain the first sampled data and the second sampled data;
The first sampled data and the second sampled data are carried out to multiple correlation computing, obtain rough calculation phase difference
4. as the frequency deviation estimating method as described in arbitrary in claim 1-3, it is characterized in that, two pilot tone OFDM symbols in described subframe are carried out to computing, to obtain the actuarial phase difference of respective user
comprise:
Two pilot tone OFDM symbols are sampled respectively, to obtain the first pilot samples result and the second pilot samples result;
The first pilot samples result and the second pilot samples result are carried out to FFT processing, to obtain the first pilot tone transformation results and the second pilot tone transformation results;
The first pilot tone transformation results and the second pilot tone transformation results are carried out to the processing of user's demapping, to obtain the first reception pilot tone and second, receive pilot tone;
The first reception pilot tone and second is received to pilot tone and pilot frequency sequence conjugate multiplication separately, to obtain the first channel estimation in frequency domain result and the second channel estimation in frequency domain result;
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 to multiple correlation computing, obtain actuarial phase difference
5. frequency deviation estimating method as claimed in claim 1, is characterized in that, according to actuarial phase difference
and/or rough calculation phase difference
determine described user's frequency deviation value
comprise:
According to frequency offset estimation range, arrange and merge the π of threshold value φ=(2-n), wherein, frequency offset estimation range is ± nkHz (0<n<2);
When actuarial phase difference
absolute value be less than and merge threshold value φ, described frequency deviation value
When actuarial phase difference
absolute value be more than or equal to and merge threshold value φ, and actuarial phase difference
with rough calculation phase difference
when symbol is different, described frequency deviation value
6. frequency deviation estimating method as claimed in claim 1, is characterized in that, according to actuarial phase difference
and/or rough calculation phase difference
determine described user's frequency deviation value
also comprise:
According to frequency offset estimation range, arrange and merge the π of threshold value φ=(2-n), wherein, frequency offset estimation range is ± nkHz (0<n<2);
When actuarial phase difference
with rough calculation phase difference
when symbol is identical, described frequency deviation value
When actuarial phase difference
absolute value be more than or equal to and merge threshold value φ, and actuarial phase difference
with rough calculation phase difference
when symbol is different, described frequency deviation value
7. a frequency deviation estimation device for multicarrier system, is characterized in that, comprising:
First detection module, for detection of the subframe in Physical Uplink Shared Channel PUSCH, shifts to an earlier date N to the OFDM symbol in described subframe
findividual sampling and normal sampling, to obtain rough calculation phase difference
The second detection module, carries out computing for two pilot tone OFDM symbols in described subframe, to obtain the actuarial phase difference of respective user
Processing module, for according to actuarial phase difference
and/or rough calculation phase difference
determine described user's frequency deviation value
8. frequency deviation estimation device as claimed in claim 7, is characterized in that, described first detection module is further used for:
Any or a plurality of OFDM symbol in described subframe are shifted to an earlier date to N
findividual sampling and normal sampling, and carry out user's separation after transforming to respectively frequency domain, to obtain specific user or all user's rough calculation phase differences
9. frequency deviation estimation device as claimed in claim 8, is characterized in that, described first detection module is further used for:
Described OFDM symbol is shifted to an earlier date to N
findividual sampling demodulation, to obtain the first sampled result, and to the demodulation of normally sampling of described OFDM symbol, to obtain the second sampled result;
The first sampled result is carried out to fast Fourier transform, carry out thereafter phase compensation, to obtain the first transformation results, and the second sampled result is carried out to FFT processing, to obtain the second transformation results;
The first transformation results and the second transformation results are carried out to the processing of user's demapping, to obtain the first sampled data and the second sampled data;
The first sampled data and the second sampled data are carried out to multiple correlation computing, obtain rough calculation phase difference
10. as the frequency deviation estimation device as described in arbitrary in claim 7-9, it is characterized in that, described the second detection module is further used for:
Two pilot tone OFDM symbols are sampled respectively, to obtain the first pilot samples result and the second pilot samples result;
The first pilot samples result and the second pilot samples result are carried out to FFT processing, to obtain the first pilot tone transformation results and the second pilot tone transformation results;
The first pilot tone transformation results and the second pilot tone transformation results are carried out to the processing of user's demapping, to obtain the first reception pilot tone and second, receive pilot tone;
The first reception pilot tone and second is received to pilot tone and pilot frequency sequence conjugate multiplication separately, to obtain the first channel estimation in frequency domain result and the second channel estimation in frequency domain result;
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 to multiple correlation computing, obtain actuarial phase difference
11. frequency deviation estimation devices as claimed in claim 7, is characterized in that, described processing module is further used for:
According to frequency offset estimation range, arrange and merge the π of threshold value φ=(2-n), wherein, frequency offset estimation range is ± nkHz (0<n<2);
When actuarial phase difference
absolute value be less than and merge threshold value φ, described frequency deviation value
When actuarial phase difference
absolute value be more than or equal to and merge threshold value φ, and actuarial phase difference
with rough calculation phase difference
when symbol is different, described frequency deviation value
12. frequency deviation estimation devices as claimed in claim 7, is characterized in that, described processing module is further used for:
According to frequency offset estimation range, arrange and merge the π of threshold value φ=(2-n), wherein, frequency offset estimation range is ± nkHz (0<n<2);
When actuarial phase difference
with rough calculation phase difference
when symbol is identical, described frequency deviation value
When actuarial phase difference
absolute value be more than or equal to and merge threshold value φ, and actuarial phase difference
with rough calculation phase difference
when symbol is different, described frequency deviation value
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| CN104158772A (en) * | 2014-06-27 | 2014-11-19 | 厦门大学 | Carrier frequency synchronization method for wireless communication network |
| CN104158772B (en) * | 2014-06-27 | 2017-04-26 | 厦门大学 | Carrier frequency synchronization method for wireless communication network |
| US10623128B2 (en) | 2016-04-22 | 2020-04-14 | Fujitsu Limited | Apparatus and method for processing a frequency offset of a pilot and receiver |
| CN107733561A (en) * | 2016-08-12 | 2018-02-23 | 华为技术有限公司 | Sender unit, signal supervisory instrument and method |
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| CN108712234A (en) * | 2018-05-23 | 2018-10-26 | 电子科技大学 | A kind of frequency deviation detection method under the interlacing multi-address technology of combination coordinate descent |
| 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 |
| CN113141324A (en) * | 2020-01-19 | 2021-07-20 | 普天信息技术有限公司 | Channel estimation method and device |
| CN111464471A (en) * | 2020-04-02 | 2020-07-28 | 宁波艾欧迪互联科技有限公司 | Frequency offset calculation method of NR PUSCH |
| CN111464471B (en) * | 2020-04-02 | 2023-04-11 | 宁波大学 | Frequency offset calculation method of NR PUSCH |
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