CN1385007A - Doppler spread estimation using channel autocorroelation function hypotheses - Google Patents
Doppler spread estimation using channel autocorroelation function hypotheses Download PDFInfo
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- CN1385007A CN1385007A CN 00813799 CN00813799A CN1385007A CN 1385007 A CN1385007 A CN 1385007A CN 00813799 CN00813799 CN 00813799 CN 00813799 A CN00813799 A CN 00813799A CN 1385007 A CN1385007 A CN 1385007A
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- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/01—Reducing phase shift
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- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/005—Control of transmission; Equalising
Abstract
A Doppler spread for a communications channel is measured by providing an estimate of the communications channel and generating an autocorrelation function for the estimate of the communications channel. One of a plurality of autocorrelation function hypotheses is selected to approximate the autocorrelation function for the estimate of the communications channel wherein each of the autocorrelation function hypotheses corresponds to a respective Doppler spread estimate hypothesis. One of the Doppler spread estimate hypotheses is selected corresponding to the selected autocorrelation function hypotheses as an estimate of the Doppler spread for the communications channel.
Description
FIELD OF THE INVENTION
The present invention relates to the communications field, more specifically, relate to the reception radio communication.
The background of invention
A kind of radio channel that is used for portable terminal in cellular radiotelephone communication systems may be difficult to operation.Particularly, the signal that is sent often by around Ambient, scattering, diffraction, the time-delay, and the decay.And because the object of the mobile and close portable terminal of portable terminal is mobile, the radio channel that is used for a portable terminal usually is not static.Can move apace when portable terminal uses in automobile, other vehicle also can move near portable terminal.
The characteristic of radio channel also may be owing to landform/building, weather, and/or the difference of other factor changes to another zone from a zone.Therefore radio signal may stand multipath fading, the influence of shadow zone and path loss along the propagation of radio channel.In these factors, multipath fading may be most important, and multipath fading can be declined by envelope, and Doppler's expansion and time delay are expanded and characterized.
Doppler frequency shift is the frequency displacement that radio signal is subjected to when portable terminal moves, and Doppler expansion is a kind of the measuring of the spectrum expansion that causes of the time rate of change by mobile radio channel.Therefore Doppler's expansion causes frequency dispersion, and the Doppler's expansion in frequency domain is closely related with the rate of change in the signal that is observed.Therefore the auto-adaptive time of used algorithm should be faster than the rate of change of channel in adaptive receiver, so that can accurately follow the tracks of the fluctuating in the received signal.
For example, depend on car speed, carrier frequency and other factor, a portable terminal in the DAMPS cellular radiotelephone communication systems may be subjected to 0Hz and expand to the Doppler in the 250Hz scope.The complexity that the knowledge of this radio channel rate of change can be used to improve the performance of receiver and/or reduce receiver.And a function that can be used as Doppler's expansion for the auto-adaptive parameter of an adaptive receiver is changed.Expand the fixedly way of the parameter of tracker and interpolation instead of the Doppler who expects under the worst situation, for example can make into, can be with these parameters as the function adaptively modifying of doppler information to improve performance.Equally, Doppler's extend information can be used for to mobile radio station can mobile friction speed receiver control adaptively.In other words, can use different receiver algorithms according to the mobile speed of portable terminal.
Therefore the estimation that can use Doppler to expand increases the performance of receiver.A function that can be used as Doppler's expansion changes the parameter of receiver adaptive algorithm, so that make adaptively, for example, the coherent detector optimization in the receiver.In addition, if the available words of Doppler's valuation can strengthen the handover procedure in the cellular mobile telephone system.Therefore can avoid the mobile terminal skip zone of a fast moving is switched to a Microcell.
For example, the U.S. Patent No. 4 of investing Koch, 723,303, title is " Methodof and Circuit Arrangement for Measuring the Quality ofRadio-Transmission Channels of a Radio-TransmissionSystem ", with the U.S. Patent No. 5 of investing Raith, 016,017, title is in " Methodof Controlling the Frequency of a Coherent Radio Receiver andApparatus for Carrying Out the Method ", and Doppler spread estimation has been discussed.Thereby the disclosure of each in these patents is incorporated in entirely this is for reference.
For example, paper at Lars Lindbom, title is " Adaptive Equalizationfor Fading Mobile Radio Channels ", (Techn, Lic.Thesis No.UPTEC 92124R, November 1992, Department of Technology, UppsalaUniversity, Uppsala Sweden) in, the method of coming estimation of Doppler expansion from a series of channel guess value has been discussed, thereby its disclosure has been incorporated in entirely this is for reference.In the paper of Lindbom,, comprise that in time the difference of value is used for the estimation of Doppler expansion between 2 with the difference of channel guess value.Yet these differences may be noises, so need average.As a result, this mean value can provide the valuation of Doppler's expansion of skew.
At titles such as list of references Karim Jamal is " Adaptive MSLE PerformanceOn The D-AMPS 1900 Channel " (IEEE Trans.Vehic.Technol., Vol.46, Aug.1997), with titles such as list of references M.Morelli be " Further ResultsIn Carrier Frequency Estimation for Transmissions Over FlatFading Channels " (IEEE Commun Letters, Vol.2, pp.327-330 has discussed other Doppler spread estimation technology in Dec.1998).
Although the whole bag of tricks more than was discussed, the needs of the technology of the improvement Doppler spread estimation method that still exists.
Summary of the invention
Therefore an object of the present invention is to provide the method and relevant system and receiver of improved estimation of communication channels Doppler expansion.
Another object of the present invention provides the method and relevant system and receiver of not too complicated estimation of Doppler expansion.
According to the present invention by providing the valuation of communication channel and producing the purpose that can reach these and other to the auto-correlation function of communication channel valuation.Choose one of multiple autocorroelation function hypotheses so that the auto-correlation function of approximate this communication channel valuation, wherein each autocorroelation function hypotheses is expanded the valuation hypothesis corresponding to separately Doppler.To expand valuation hypothesis then corresponding to the Doppler of selected autocorroelation function hypotheses and be elected to be valuation into Doppler's expansion of this communication channel.
This autocorroelation function hypotheses can be stored in according to Doppler of the present invention expand in the memory of estimator and with the auto-correlation function of communication channel valuation is made comparisons, immediate autocorroelation function hypotheses is accepted as the actual auto-correlation function valuation for communication channel.Like this, the Doppler corresponding to this immediate auto-correlation function can be expanded the valuation that hypothesis is used as actual Doppler's expansion of this communication channel.Therefore the computational complexity that is used for the estimating Doppler expansion can be lowered, and provides more accurate Doppler to expand valuation simultaneously.In addition, the number of used autocorroelation function hypotheses can be increased so that more accurate valuation to be provided, perhaps it be reduced to reduce number of computations and used memory sum.
In more detail, select one of autocorroelation function hypotheses can comprise be used for the communication channel valuation auto-correlation function and these a plurality of autocorroelation function hypotheses each compare.In addition, select one of autocorroelation function hypotheses can comprise one of these a plurality of autocorroelation function hypotheses of the most approaching approximate auto-correlation function that is used to estimate communication channel of selection.
And, select one of these autocorroelation function hypotheses to comprise and produce a plurality of error signals that correspond respectively to these a plurality of autocorroelation function hypotheses, wherein each error signal is illustrated in the difference between the auto-correlation function of each autocorroelation function hypotheses and communication channel valuation, error signal is compared, select the auto-correlation hypothesis so that the approximate auto-correlation function that is used to estimate communication channel.Particularly, can compare these error signals, so that option table is shown in these corresponding autocorroelation function hypotheses and is used to estimate the error signal of the minimum differentiation between the auto-correlation function of communication channel.In addition, before the comparison of these error signals that each error signal is average, so that average error signal to be provided, wherein error signal relatively comprised comparison to these average error signals.
Therefore according to method of the present invention, system and receiver can be used to provide valuation for Doppler's expansion of communication channel with lower complexity.
The accompanying drawing summary
Fig. 1 is a kind of communication system block diagram that comprises according to receiver of the present invention.
Fig. 2-the 4th is according to receiver block diagram of the present invention.
Fig. 5 expands the estimator block diagram according to a kind of Doppler of the present invention.
Fig. 6 is with the sketch that explains radio channel auto-correlation function on respect to the receiver of base station friction speed.
Fig. 7 is the abridged table with the auto-correlation function sample that explains storage map 6.
Describe in detail
Now will the present invention be described more fully with reference to the accompanying drawing that the preferred embodiment of the invention is shown from now on.Yet the present invention can be implemented with many different forms, should not be construed as limited to the embodiment that proposes at this; But these embodiments are provided and make that the open material of this part will be thorough and completely, and will fully scope of the present invention be conveyed to those skilled in the art.Same numerals belongs to same parts.
Fig. 1 illustrates according to transmitter T of the present invention and receiver R, and wherein data d is sent by radio channel C by transmitter T.The signal r that receives is the data d that is sent, the function of radio channel C and noise n.In the channel of flat fading:
R=hd+n (equation 1)
As discussed above like that, can and utilize the function of estimated Doppler's exaptation receiver to improve the performance of receiver by the estimating Doppler expansion.More specifically, can utilize estimated Doppler's expansion to estimate radio channel h more accurately.At common unsettled U.S. Patent application string number be _ _ _ _, Leonid Krasny etc., " DOPPLER SPREADESTIMATION SYSTEM ", 1999, the use (DocKet No.P10367-RCVR and 1280.00105) that Doppler expands estimator has been discussed in the file of submitting to March 22.The application of Krasny etc. is crossed to produce gives assignee of the present invention, and the application of Krasny etc. and the application have public inventor.In addition, the disclosure of the application of Krasny etc. is entirely introduced for reference at this.
Comprising various receiver Ra, Rb and the Rc that expand estimator according to Doppler of the present invention shown in Fig. 2-4.Particularly, the receiver Ra of Fig. 2 is adapted to and uses known aiming symbol, and this receiver comprises the antenna 21 of received signal r, radio receiver and converter 23a, channel estimator 25a, Doppler expand estimator 27a, known symbol square frame 29a and signal processor 31a.The antenna 21a r that receives radio signals, radio receiver and converter 23a be the radio signal r filtering that receives, and amplifies and be transformed into numeral sample for handling.More specifically, the radio signal that receives can be transformed into a kind of form that is suitable for handling, as comprehensive digital sample values.Channel estimator receives the radio signal be transformed and from the known symbol of known symbol square frame 29a.
Specifically be, known symbol square frame 29a can provide aiming symbol or other known reference symbols, as is included in the synchronizing symbol among the received signal r, can be used to the calculating channel valuation.And known symbol square frame 29a can comprise memory, stores known symbol therein, or comprises code generator, can found living known symbol.Channel estimator 25a is relevant with known symbol with the numeral sample that receives, and the valuation of being expanded the channel C of estimator 27a use by Doppler is provided.Doppler expands estimator and utilizes the expansion of channel guess value estimating Doppler, then estimated Doppler's expansion is sent to signal processor 31a.Below will discuss the operation that Doppler expands estimator in more detail.Signal processor 31a handles the signal be sampled so that extraction information, and signal processor 31a provides the feedback to channel estimator 25a, makes can improve channel guess value after Doppler expands valuation.
The receiver Rb of Fig. 3 is adapted to and does not use known aiming symbol.This receiver comprises the antenna 21b of received signal r, radio receiver and converter 23b, and channel estimator 25b, Doppler expand estimator 27b, symbol estimation device 29b and signal processor 31b.Except the known symbol square frame 29a that use symbol estimation device 29b replaces using in the receiver of Fig. 2, the receiver Ra of receiver Rb and Fig. 2 is similar.Symbol estimation device 29b can be used in the application of unknown symbols.For example, symbol estimation device 29b can use error detect and alignment technique, estimates the symbol that receives with high-grade precision.These estimated symbols can be used to estimate channel h by channel estimator 25b then.As following go through, Doppler expands estimator 27b and uses the expansion of channel guess value estimating Doppler.
In code division multiple access (CDMA) cellular system (as the IS-95 system), transmitter sends the known symbol stream that is called guidance code.Utilize different spread-spectrum codes on identical channel, to send guidance code simultaneously with other information-bearing symbol.The receiver Rc of Fig. 4 is provided at multispectral in a kind of like this cdma system and reins in the expansion valuation.The receiver Rc of Fig. 4 is adapted to the antenna 21c that uses known aiming symbol and this receiver to comprise received signal r, and radio receiver and converter 23c, channel estimator 25c, Doppler expand estimator 27c and signal processor 31c.In this cdma receiver, can be directly by not with the symbol estimation device 29b of the channel estimator 25c of the known symbol piece 29a of Fig. 1 or Fig. 2 to channel guess value, channel guess value is used for Doppler and expands valuation.
Therefore the receiver of Fig. 2-4 illustrates and comprises the various receivers of expanding estimator according to Doppler of the present invention.In every kind of receiver, channel guess value is provided for Doppler and expands estimator and expand valuation for calculating Doppler.Comprise that the receiver of expanding estimator according to Doppler of the present invention is not limited to the channel estimator of above discussion, person of skill in the art will appreciate that any channel guess value technology can be used to provide channel guess value.
Particularly, channel estimator can utilize the symbol that is illustrated in the data sample that receives during the time slot to be created in a channel guess value on the tdma slot.For example, the receiver Rb of Fig. 3 can comprise the symbol estimation device 296 to symbol estimation.Doppler expands estimator and can use the Doppler who calculates for current time slots for the channel guess value of current time slots to expand valuation then, signal processor can use this Doppler to expand valuation in for the calculating of follow-up time slot, as calculating the channel guess value for follow-up time slot.In other words, expand valuation for the Doppler of current time slots and can be used in signal processor, be updated in long-time section Doppler's valuation using in the follow-up calculating.For example, utilization is following wants averaging discussed in detail can upgrade long-time section Doppler's valuation.
When the symbol estimation device is used as discussed in reference to Figure 3, for the Doppler who is used to calculate this time slot expand valuation to be implemented cyclic redundancy check (CRC) by the symbol of valuation may be useful.If cyclic redundancy check passes through, channel guess value should be more accurate, and resulting Doppler expands valuation can be used to upgrade long-time section Doppler's valuation., if cyclic redundancy check failure, channel guess value may be insecure, and therefore utilizing Doppler based on potential insecure channel guess value to expand valuation, to upgrade a long-time section Doppler valuation may be undesirable.
Expanding valuation referring now to the Doppler of Fig. 5 discusses Doppler in more detail and expands valuation.For example, can be in company with foundation DAMPS or DAMPS
+The receiver of the mobile phone communication system of standard operation uses Doppler to expand estimator.At DAMPS
+In, known aiming symbol is provided.In DAMPS, utilize repeatedly demodulation, if in the position of the grade 1 of the demodulation first time by cyclic redundancy check (CRC), then they can be used as aiming symbol.Best, the phase place ambiguity between the guiding time slot is lowered to increase result's reliability.For example, list of references, T.Fulghum: " Channel Interpolation On Second PassDemodulation " (Tech.Rep.Tr/X 98:1230, Ericsson, RTP, NC, Feb.22, a kind of method of differentiating the phase place ambiguity has been discussed 1999), and it is for reference that its disclosure entirely is incorporated in this.
Suppose that aiming symbol is available, the phase place ambiguity between aiming symbol has been lowered to an acceptable level, and utilization can be found out auto-correlation function by auto-correlation calculator 51 from the channel guess value that aiming symbol obtains
Sample.Can utilize hypothesis comparator 53 with the sample of auto-correlation function and the different hypothesis (H of the actual auto-correlation function of different Doppler's expanding value then
1, H
2, H
3... H
k) compare, provide Error Calculation (e for the auto-correlation function sample of every kind of hypothesis relatively
1(m), e
2(m), e
3(m) ... e
k(m)).Can utilize averager 55 on several time slots, each Error Calculation to be averaged then, so that a plurality of mean error value (e separately to be provided
Av, 1, e
Av, 2, e
Av, 3... e
Av, k).Select the Doppler expansion corresponding by minimal error selector 57 then, provide by the Doppler of valuation and expand with the hypothesis that obtains minimum mean error value
In more detail, utilize now or in the future available technology can determine channel guess value, with the hypothesis (H of the corresponding different auto-correlation functions of different Doppler's expanding value
1, H
2, H
3... H
k) can be calculated and be stored in the memory.Particularly, can on the portable terminal speed different, determine actual radio channel and corresponding Doppler's expanding value with respect to the base station, and the auto-correlation function that can obtain each speed calculation.Shown in Figure 6 corresponding to radio channel that on friction speed, records and figure example (correlation is to τ) corresponding to the different autocorroelation function hypotheses of different Doppler's expanding value.
Represent each hypothesis H
kThe sample of each auto-correlation function can be stored in the memory that is used for supposing comparator 53, the hypothesis H shown in Fig. 5 is provided
1, H
2, H
3... H
kFor example, with the figure of the corresponding Fig. 6 of different τ values in the sample of each auto-correlation function can be stored in as shown in Figure 7 the memory.Though in 5 different hypothesis shown in the figure of Fig. 6, can use any number, can use the hypothesis of more number (k) so that higher accuracy is being provided aspect the valuation of Doppler's expanding value.And the hypothesis of less number (k) can provide calculating less, more uncomplicated operation and lower memory requirement.And, can change the sample number Z that is stored for each hypothesis according to expand the desirable accuracy class of valuation for Doppler.
Can use auto-correlation estimator 51, utilize the channel guess value on known domain to calculate for an auto-correlation function valuation that has the channel of frequency error:
In this equation,
Be comprise frequency error by the auto-correlation function of valuation,
It is the channel guess value on known domain (or aiming symbol).Note, when in received signal, frequency error being arranged, can directly influence channel guess value, can rotate by frequency error quantity, thereby influence the auto-correlation valuation.Frequency error is labeled as f
e, the rotation in channel guess value can be calculated as:
Wherein
Channel guess value when expression does not have frequency error.Therefore the auto-correlation function that has frequency error can be write as:
Perhaps:
Wherein
It is the auto-correlation valuation that does not have frequency error.
Can utilize, as at " Further Results InCarrier Frequency Estimation For Transmissions Over FlatFading Channels " (IEEE Commun.Letters such as list of references Morelli, Vol, 2, pp.327-330, Dec.1998) the known method calculated rate error of being discussed in, its disclosure are incorporated in entirely that this is for reference.Therefore the influence that can from channel guess value relevant, remove frequency error.
Do not have then frequency error relevant valuation can with the hypothesis comparator 53 different hypothesis (H
1, H
2, H
3... H
k) compare.
Suppose (H
1, H
2, H
3... H
k) can be determined and be stored in as above about in Fig. 6 and 7 memories of being discussed.Utilize the auto-correlation valuation of following formula calculating about each hypothesis
Error e
k(m):
In this equation, e
k(m) be by the auto-correlation function of valuation with as shown in the formula the true auto-correlation function R of the normalization that provides
H, kBetween the different samples of (m) k hypothesis with m the error that time slot is corresponding:
R
H, K(n)=J
0(2 π f
Doppler, kNT), (equation 8) be fdoppler wherein, and k is that k Doppler expands hypothesis.Error term e
kBeing utilized following equation upward averages several time slots at averager 55 (filter):
E wherein
Av, kBe and k the mean error that hypothesis is corresponding, M is the length of average window.In this example, piece on average is used to mean error.In addition, the averaging that can use other as move average or sliding window average.Like this, averaging reduces statistical error.
Minimal error selector 57 is determined minimum mean error e
Av, k, select the most approaching autocorroelation function hypotheses H that is similar to for the auto-correlation function of this receive channel
kDoppler expands and supposes that selector selection and the corresponding Doppler of selected autocorroelation function hypotheses expand hypothesis and expand as Doppler
Valuation.In other words, the minimum value e of mean error
Av, 1-e
Av, kBe used to select to obtain the autocorroelation function hypotheses of minimum average B configuration error (on the most minimum error selector 57), the Doppler corresponding with selected autocorroelation function hypotheses expands hypothesis is elected to be Doppler's expansion by following equation valuation (expanding on the hypothesis selector 59 Doppler):
In addition, can as in the list of references of Morelli etc. calculate the auto-correlation function that has frequency error discussing.Replace to seek frequency error and with it from being removed the auto-correlation function of valuation, we can get by the autocorrelative absolute value of valuation, obtain the envelope auto-correlation function to be:
This absolute value of auto-correlation function valuation then (not having frequency error) can be made comparisons as follows with the different hypothesis corresponding to the actual envelope auto-correlation function of different Doppler's expanding value:
Wherein,
Error term is used to determine to provide the hypothesis of minimal error as before in the valuation of Doppler's expanding value.
In the DAMPS system, can utilize known technology in a time slot, to remove the phase place ambiguity basically.Yet the phase place ambiguity of striding time slot may still exist.According to the present invention, can estimate being correlated with and making comparisons in the time slot with different hypothesis.Yet the error of striding time slot is by average.
Such as previously discussed, can change the number of hypothesis according to the complexity that desirable accuracy and Doppler expand estimator and receiver.More hypothesis number can provide higher accuracy and need more memory and calculating.Less hypothesis number can reduce using of memory and calculate and provide not too accurate Doppler to expand valuation.
Therefore expanding estimation method according to Doppler of the present invention can be realized with higher computational efficiency and good result.Particularly, use the envelope correlation function can provide near the performance level that does not need the other technologies of frequency estimation.
Doppler's valuation, according to the present invention, can, for example, utilize in the scope of DAMPS cellular radiotelephone system following descending time slot and transformat to implement: the PI/4-DQPSK that has the root raised cosine pulse shaping; The tdma frame of 20ms; 3 users with shared tdma frame.And, the time slot duration be 6.667ms one image duration each user can send twice.Transmission medium can be a kind of rayleigh fading channel, and this channel can utilize Jake decline model emulation.Can use the carrier frequency of a single aerial receiver and 1900 MHz.
In descending joint demodulation, no matter only need expand valuation, because no matter desirable base station of still disturbing is moving with portable terminal of fixing to a Doppler for desirable still interference signals.Supposing not have directapath is reasonable hypothesis.Thereby can utilize corresponding information estimating Doppler expansion with stronger user, this user is exactly desirable user in most cases.
In receiver, can suppose that desirable sync bit is known, the sample that receives can be used to the sequence of demodulation user profile coherently.Can be used to channel tracking based on the Kalman method of utilizing second-order autoregressive model (AR-2) to carry out channel guess value.As discussed above such, channel tracking depends on doppler information.Because doppler information can not know at the very start that tracker parameters can be set to higher Doppler's expansion of 100Hz at the beginning.Converge on actual Doppler's expansion because Doppler expands valuation, also should in adaptive receiver, change tracker parameters.
The present invention can be used as method or equipment is implemented.In addition, the present invention can take complete hardware embodiment, fully software implementation scheme, the perhaps form of the embodiment of combination of hardware.The present invention is described in the part about the block diagram of Fig. 1-5.Will be understood that the combination of each diagram square frame and square frame can realize with computer program instructions.These can represent that the program command of step can offer processor so that produce a kind of machine.
Therefore, the square frame in the block diagram is being used for realizing that the step combination support of specific function is used to realize that the various devices of specific function make up.Will be understood that the combination of each diagram square frame and square frame can realize function that these system implementations are special or step, the perhaps combination of specialized hardware and computer instruction with the system of specialized hardware-Ji.
In drawing and description, typical preferred embodiment of the present invention is disclosed.Though adopt special term, yet they are to be used on the meaning of general and description, the purpose that is not meant to limit, scope of the present invention is set forth in following claim.
Claims (57)
1. method that is used to estimate Doppler's expansion of communication channel, this method comprises:
Valuation to communication channel is provided;
Produce the auto-correlation function of the valuation of communication channel;
Select one of a plurality of autocorroelation function hypotheses to be similar to this auto-correlation function of communication channel valuation, wherein each of each these autocorroelation function hypotheses is expanded the valuation hypothesis corresponding to separately Doppler; With
Selection is expanded one of valuation hypothesis corresponding to these Doppler of selected autocorroelation function hypotheses and is expanded valuation as the Doppler of communication channel.
2. a foundation the process of claim 1 wherein and selects one of these autocorroelation function hypotheses to comprise that each is made comparisons with in the auto-correlation function of communication channel valuation and these a plurality of autocorroelation function hypotheses.
3. a foundation the process of claim 1 wherein and selects one of these autocorroelation function hypotheses to comprise that selection the most closely is similar to one of these a plurality of autocorroelation function hypotheses of the auto-correlation function of this communication channel valuation.
4. a foundation the process of claim 1 wherein and selects one of these autocorroelation function hypotheses to comprise:
Generation corresponds respectively to a plurality of error signals of these a plurality of autocorroelation function hypotheses, and wherein each error signal is represented the difference between the auto-correlation function of this each autocorroelation function hypotheses and this communication channel valuation; With
Relatively these error signals are so that select the auto-correlation hypothesis of the auto-correlation function that is similar to this communication channel valuation.
5. method according to claim 4, wherein relatively these error signals comprise that option table is shown in the error signal of minimum differentiation between the auto-correlation function of this corresponding autocorroelation function hypotheses and this communication channel valuation.
6. the method according to claim 5 wherein selects these error signals to comprise one minimum in these error signals of selection.
7. method according to claim 4, wherein carried out in the past at comparison error signal:
Each error signal is average, and so that average error signal to be provided, wherein relatively these error signals comprise these average error signal of comparison.
8. method according to claim 7, wherein each of average these error signals comprises that piece is average, a kind of during the average and sliding window of operation is average.
9. a foundation the process of claim 1 wherein that in these a plurality of autocorroelation function hypotheses each comprises a plurality of samples, and wherein the auto-correlation function for the communication channel valuation comprises a plurality of samples.
10. a foundation the process of claim 1 wherein that this communication channel comprises radio channel.
11. a foundation the process of claim 1 wherein that this auto-correlation function comprises a plurality of samples, and wherein produces this auto-correlation function and comprise the frequency error that reduces these a plurality of samples.
12. the method according to claim 1 also comprises:
Utilize the Doppler of this communication channel to expand second valuation that valuation provides this communication channel.
13. a foundation the process of claim 1 wherein that providing this communication channel valuation to comprise by this communication channel receives a plurality of data samples, wherein these data samples is used to produce these channel guess values, this method also comprises:
To being used to produce the data sample implementation cyclic redundancy check of channel guess value;
When these data samples pass through this cyclic redundancy check, utilize Doppler to expand valuation and upgrade long-time section Doppler valuation.
14. a foundation the process of claim 1 wherein and provides the valuation of this communication channel to comprise:
A plurality of aiming symbols on the received communication channel;
Reduce the phase place ambiguity between the aiming symbol; With
Utilize the aiming symbol that has reduced ambiguity that the valuation of this communication channel is provided.
15. a Doppler who is used for Doppler's expansion of estimation of communication channels expands estimator, this Doppler expands estimator and comprises:
Expand the corresponding a plurality of autocorroelation function hypotheses of valuation hypothesis with a plurality of Doppler separately;
Estimate the channel estimator of this communication channel;
Produce the auto-correlation generator of the auto-correlation function of this communication channel valuation;
Selection is similar to the autocorroelation function hypotheses tester of one of these autocorroelation function hypotheses of the auto-correlation function of this communication channel valuation; With
Select the Doppler corresponding to expand one of valuation and expand the hypothesis selector as the Doppler of a valuation of the Doppler of this communication channel expansion with selected autocorroelation function hypotheses.
16. the Doppler according to claim 15 expands estimator, wherein this hypothesis tester is with each is made comparisons in the auto-correlation function of this communication channel valuation and this a plurality of autocorroelation function hypotheses.
17. the Doppler according to claim 15 expands estimator, wherein this hypothesis tester selects the most closely to be similar to one of these a plurality of autocorroelation function hypotheses of the auto-correlation function of this communication channel valuation.
18. the Doppler according to claim 15 expands estimator, wherein this hypothesis tester produces a plurality of error signals that correspond respectively to these a plurality of autocorroelation function hypotheses, wherein each of these error signals is illustrated in the difference between the auto-correlation function of each autocorroelation function hypotheses and this communication channel valuation, and this hypothesis tester compares these error signals, is similar to the auto-correlation hypothesis of the auto-correlation function of this communication channel valuation with selection.
19. the Doppler according to claim 18 expands estimator, wherein is somebody's turn to do the error signal that the hypothesis tester is selected minimum differentiation between the auto-correlation function of this corresponding autocorroelation function hypotheses of expression and this communication channel valuation.
20. the Doppler according to claim 19 expands estimator, wherein this hypothesis tester is selected of minimum in these error signals.
21. the Doppler according to claim 18 expands estimator, wherein this hypothesis tester is with each averages in these error signals, and so that average error signal to be provided, this hypothesis tester compares these average error signal.
22. the Doppler according to claim 21 expands estimator, wherein this hypothesis tester utilizes piece average, and a kind of each in these error signals during the average and sliding window of operation is average averages.
23. the Doppler according to claim 15 expands estimator, wherein each in these a plurality of autocorroelation function hypotheses comprises a plurality of samples, and the auto-correlation function of this communication channel valuation comprises a plurality of samples.
24. the Doppler according to claim 15 expands estimator, wherein this communication channel comprises radio channel.
25. the Doppler according to claim 15 expands estimator, wherein this auto-correlation function comprises a plurality of samples, and this auto-correlation generator reduces the frequency error of a plurality of samples.
26. the Doppler according to claim 15 expands estimator, wherein this channel estimator utilizes the Doppler of this communication channel to expand second valuation that valuation provides this communication channel.
27. the Doppler according to claim 15 expands estimator, a plurality of data samples on this channel estimator received communication channel wherein, these data samples are used to estimate this communication channel, wherein this channel estimator is to being used to produce the data sample implementation cyclic redundancy check of channel guess value, and this Doppler expands estimator and also comprises:
Long-time section Doppler estimator, wherein when these data samples passed through this cyclic redundancy check, the valuation that utilizes this Doppler to expand is upgraded should long-time section Doppler's estimator.
28. the Doppler according to claim 15 expands estimator, a plurality of aiming symbols on this channel estimator received communication channel wherein, reduce the phase place ambiguity between the aiming symbol, and utilize the aiming symbol that has reduced ambiguity that the valuation of this communication channel is provided.
29. a method that is used for received communication, this method comprises:
Signal on the received communication channel, wherein this signal indication is from the data of distance transmitter;
Produce this communication channel valuation of received signal thereon;
Produce the auto-correlation function of this communication channel valuation;
One of a plurality of autocorroelation function hypotheses of valuation hypothesis are expanded in selection corresponding to each a plurality of Doppler, so that the auto-correlation function of approximate this communication channel valuation;
Selection is expanded valuation corresponding to the Doppler as this communication channel that the Doppler of selected autocorroelation function hypotheses expands in the valuation hypothesis; With
Reproduction is by the valuation of the data of this distance transmitter transmission.
30. the method according to claim 29 is wherein selected one of these autocorroelation function hypotheses to comprise the auto-correlation function of this communication channel valuation and each in these a plurality of autocorroelation function hypotheses is made comparisons.
31. the method according to claim 29 wherein selects one of these autocorroelation function hypotheses to comprise that selection the most closely is similar to one of these a plurality of autocorroelation function hypotheses of the auto-correlation function of this communication channel valuation.
32. the method according to claim 29 wherein selects one of these autocorroelation function hypotheses to comprise:
Generation corresponds respectively to a plurality of error signals of these a plurality of autocorroelation function hypotheses, and wherein each error signal is illustrated in the difference between the auto-correlation function of each autocorroelation function hypotheses and this communication channel valuation; With
These error signals are compared, be similar to the auto-correlation hypothesis of the auto-correlation function of this communication channel valuation with selection.
33. the method according to claim 32 wherein compares these error signals and comprises that option table is shown in the error signal of the minimum differentiation between the auto-correlation function of this corresponding autocorroelation function hypotheses and this communication channel valuation.
34. the method according to claim 33 wherein selects this error signal to comprise to select one of minimum in these error signals.
35. the method according to claim 32 was wherein carried out in the past in these error signals of comparison:
Each of these error signals is average, and so that average error signal to be provided, wherein relatively these error signals comprise these average error signal of comparison.
36. the method according to claim 35, wherein average each error signal comprises that piece is average, a kind of during the average and sliding window of operation is average.
37. the method according to claim 29, wherein each in these a plurality of autocorroelation function hypotheses comprises a plurality of samples, and wherein the auto-correlation function of this communication channel valuation comprises a plurality of samples.
38. the method according to claim 29, wherein this communication channel comprises radio channel.
39. the method according to claim 29, wherein this auto-correlation function comprises a plurality of samples, and produces this auto-correlation function and comprise the frequency error that reduces these a plurality of samples.
40. the method according to claim 29 also comprises:
Utilize the Doppler of this communication channel to expand second valuation that valuation provides this communication channel.
41. the method according to claim 29 wherein provides this communication channel valuation to comprise and receives a plurality of data samples on this communication channel, wherein this data sample is used to produce this channel guess value, this method also comprises:
To being used to produce these data samples implementation cyclic redundancy checks of channel guess value;
When these data samples pass through this cyclic redundancy check, utilize Doppler to expand valuation and upgrade long-time section Doppler valuation.
42. the method according to claim 29 wherein comprises aiming symbol from the data that distance transmitter receives, and produces this communication channel valuation and comprise:
Reduce the phase place ambiguity between these aiming symbols; With
Utilize these aiming symbols that reduced ambiguity that the communication channel valuation is provided.
43. a receiver comprises:
The radio receiver of the signal on the received communication channel and converter;
Channel estimator according to this communication channel of signal estimation that on this communication channel, receives;
Expand the corresponding a plurality of autocorroelation function hypotheses of valuation hypothesis with a plurality of Doppler separately;
Produce the auto-correlation generator of the auto-correlation function of this communication channel valuation;
The autocorroelation function hypotheses tester selects in these autocorroelation function hypotheses so that be similar to the auto-correlation function of this communication channel valuation; With
Doppler expands the hypothesis selector, and a Doppler as this communication channel who selects the Doppler corresponding to selected autocorroelation function hypotheses to expand in the valuation hypothesis expands valuation.
44. the receiver according to claim 43, wherein this hypothesis tester is made comparisons the auto-correlation function of this communication channel valuation and each in these a plurality of autocorroelation function hypotheses.
45. the receiver according to claim 43, wherein this hypothesis tester selects the most closely to be similar in these a plurality of autocorroelation function hypotheses of auto-correlation function of this communication channel valuation one.
46. receiver according to claim 43, wherein this hypothesis tester produces a plurality of error signals that correspond respectively to these a plurality of autocorroelation function hypotheses, each error signal is illustrated in the difference between the auto-correlation function of each correlation function hypothesis and this communication channel valuation, and this hypothesis tester compares these error signals, is similar to the auto-correlation hypothesis of the auto-correlation function of this communication channel valuation with selection.
47. the receiver according to claim 46, wherein this hypothesis tester option table is shown in the error signal of the minimum differentiation between the auto-correlation function of this corresponding autocorroelation function hypotheses and this communication channel valuation.
48. the receiver according to claim 47, wherein this hypothesis tester is selected one of minimum in these error signals.
49. the receiver according to claim 46, wherein this hypothesis tester averages each error signal, so that average error signal to be provided, wherein should compare these average error signal by the hypothesis tester.
50. the receiver according to claim 49, wherein this hypothesis tester utilizes piece average, and a kind of during the average and sliding window of operation is average averages each error signal.
51. the receiver according to claim 43, wherein each in these a plurality of autocorroelation function hypotheses comprises a plurality of samples, and the auto-correlation function of this communication channel valuation comprises a plurality of samples.
52. the receiver according to claim 43 also comprises:
Be connected Doppler and expand signal processor between estimator and the channel estimator, wherein this signal processor is expanded the operation that this channel estimator is revised in valuation according to the Doppler of this communication channel.
53. the receiver according to claim 43, wherein this communication channel comprises radio channel.
54. the receiver according to claim 43, wherein the auto-correlation function of this communication channel valuation comprises a plurality of samples, and this auto-correlation generator reduces the frequency error of these a plurality of samples.
55. the receiver according to claim 43, wherein this channel estimator utilizes this communication channel Doppler to expand second valuation that valuation provides this communication channel.
56. receiver according to claim 43, wherein the signal that receives on this communication channel comprises a plurality of data samples, this channel estimator utilizes these data samples to estimate this communication channel, wherein this channel estimator is to being used to produce the data sample implementation cyclic redundancy check of channel guess value, and this receiver also comprises:
Long-time section Doppler estimator, wherein when these data samples passed through this cyclic redundancy check, utilizing this Doppler to expand the valuation renewal should long-time section Doppler estimator.
57. receiver according to claim 43, wherein the signal that receives on this communication channel comprises a plurality of aiming symbols, this channel estimator reduces the phase place ambiguity between these aiming symbols, and this channel estimator utilization these aiming symbols of having reduced the phase place ambiguity provide the valuation of this communication channel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
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| US09/373,289 | 1999-08-12 | ||
| US09/373,289 US6680969B1 (en) | 1999-03-22 | 1999-08-12 | Methods for estimating doppler spreads including autocorrelation function hypotheses and related systems and receivers |
Publications (2)
| Publication Number | Publication Date |
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| CN1385007A true CN1385007A (en) | 2002-12-11 |
| CN1156999C CN1156999C (en) | 2004-07-07 |
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| CNB008137994A Expired - Fee Related CN1156999C (en) | 1999-08-12 | 2000-08-02 | Doppler spread estimation using channel autocorroelation function hypotheses |
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| JP (1) | JP4659317B2 (en) |
| CN (1) | CN1156999C (en) |
| AR (1) | AR025231A1 (en) |
| AU (1) | AU6755000A (en) |
| CO (1) | CO5300492A1 (en) |
| DE (1) | DE10084912T1 (en) |
| MY (1) | MY125793A (en) |
| WO (1) | WO2001013537A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004109949A1 (en) * | 2003-06-05 | 2004-12-16 | Huawei Technologies Co., Ltd. | Method for estimation of maximum doppler frequency |
| CN104980966A (en) * | 2014-04-04 | 2015-10-14 | 苹果公司 | Cell Measurements in Unlicensed Frequency Bands |
| CN106412980A (en) * | 2016-09-08 | 2017-02-15 | 璧垫兜 | LTE-oriented mobile terminal speed measurement method based on Doppler frequency shift measurement |
| CN115189785A (en) * | 2021-04-02 | 2022-10-14 | 中国移动通信集团终端有限公司 | Method, system and equipment for verifying Doppler spread of channel |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6922452B2 (en) | 2001-03-27 | 2005-07-26 | Telefonaktiebolaget L M Ericsson (Publ) | Method and apparatus for estimating Doppler spread |
| FI110725B (en) | 2001-04-20 | 2003-03-14 | Nokia Corp | Method of receiver synchronization and receiver |
| US6636574B2 (en) * | 2001-05-31 | 2003-10-21 | Motorola, Inc. | Doppler spread/velocity estimation in mobile wireless communication devices and methods therefor |
| ATE244968T1 (en) * | 2001-11-19 | 2003-07-15 | Cit Alcatel | SELECTION OF THE AUTOCORRELATION FUNCTION OF THE INTERFERENCE COMPONENTS IN THE RECEIVED MESSAGE SIGNAL |
| US7054394B2 (en) | 2002-02-18 | 2006-05-30 | Telefonaktiebolaget Lm Ericsson (Publ) | Doppler shift and spread estimation method and apparatus |
| US8027373B2 (en) | 2005-09-15 | 2011-09-27 | Qualcomm Incorporated | Quick detection of signaling in a wireless communication system |
| DE602008000755D1 (en) | 2008-01-11 | 2010-04-15 | Ntt Docomo Inc | Method, apparatus and system for channel estimation in two-way relay networks |
| EP2636158A4 (en) * | 2010-11-04 | 2016-02-17 | Ericsson Telefon Ab L M | A radio base station and a method therein for estimating a doppler spread |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4914699A (en) * | 1988-10-11 | 1990-04-03 | Itt Corporation | High frequency anti-jam communication system terminal |
| FR2708162B1 (en) * | 1993-07-20 | 1995-09-01 | Alcatel Mobile Comm France | Method for determining the optimal length of a data block in a time division multiple access (TDMA) communication system. |
| JPH11234190A (en) * | 1998-02-12 | 1999-08-27 | Oki Electric Ind Co Ltd | Maximum doppler frequency observation circuit, radio channel estimation circuit and object moving speed observation circuit |
-
2000
- 2000-07-13 MY MYPI20003214 patent/MY125793A/en unknown
- 2000-08-01 CO CO00057675A patent/CO5300492A1/en not_active Application Discontinuation
- 2000-08-02 DE DE10084912T patent/DE10084912T1/en not_active Withdrawn
- 2000-08-02 CN CNB008137994A patent/CN1156999C/en not_active Expired - Fee Related
- 2000-08-02 WO PCT/US2000/021081 patent/WO2001013537A1/en active Application Filing
- 2000-08-02 JP JP2001517721A patent/JP4659317B2/en not_active Expired - Fee Related
- 2000-08-02 AU AU67550/00A patent/AU6755000A/en not_active Abandoned
- 2000-08-11 AR ARP000104169 patent/AR025231A1/en unknown
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004109949A1 (en) * | 2003-06-05 | 2004-12-16 | Huawei Technologies Co., Ltd. | Method for estimation of maximum doppler frequency |
| CN100373801C (en) * | 2003-06-05 | 2008-03-05 | 华为技术有限公司 | Method for estimating Doppler limiting frequency |
| CN104980966A (en) * | 2014-04-04 | 2015-10-14 | 苹果公司 | Cell Measurements in Unlicensed Frequency Bands |
| CN104980966B (en) * | 2014-04-04 | 2018-11-09 | 苹果公司 | Wireless user equipment (ue) device and the method for executing cell measurement |
| CN106412980A (en) * | 2016-09-08 | 2017-02-15 | 璧垫兜 | LTE-oriented mobile terminal speed measurement method based on Doppler frequency shift measurement |
| CN106412980B (en) * | 2016-09-08 | 2020-03-03 | 赵涵 | Mobile terminal speed measurement method based on Doppler frequency shift measurement and oriented to LTE |
| CN115189785A (en) * | 2021-04-02 | 2022-10-14 | 中国移动通信集团终端有限公司 | Method, system and equipment for verifying Doppler spread of channel |
| CN115189785B (en) * | 2021-04-02 | 2023-10-27 | 中国移动通信集团终端有限公司 | Method, system and equipment for verifying Doppler spread of channel |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2001013537A1 (en) | 2001-02-22 |
| AU6755000A (en) | 2001-03-13 |
| JP2003507927A (en) | 2003-02-25 |
| CO5300492A1 (en) | 2003-07-31 |
| CN1156999C (en) | 2004-07-07 |
| AR025231A1 (en) | 2002-11-13 |
| MY125793A (en) | 2006-08-30 |
| JP4659317B2 (en) | 2011-03-30 |
| DE10084912T1 (en) | 2002-09-26 |
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