CN105337919A - Method and device for carrying out Doppler estimation in high-speed mobile system - Google Patents
Method and device for carrying out Doppler estimation in high-speed mobile system Download PDFInfo
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- CN105337919A CN105337919A CN201410404395.1A CN201410404395A CN105337919A CN 105337919 A CN105337919 A CN 105337919A CN 201410404395 A CN201410404395 A CN 201410404395A CN 105337919 A CN105337919 A CN 105337919A
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Abstract
The objective of the invention lies in providing a method and device for carrying out Doppler estimation in a high-speed mobile system, especially an LTE system or other systems based on the OFDM. Compared with the prior art, the method comprises the steps: respectively carrying out the channel estimation of signals of a plurality of pieces of equipment according to receiving signals from the plurality of pieces of equipment, so as to obtain channel estimation values of the plurality of pieces of equipment; and jointly carrying out the Doppler estimation of the plurality of pieces of equipment based on a normalized post-processing/pre-processing method according to the channel estimation values. The method greatly enlarges a training signal sample, and can improve the accuracy of parameter estimation through a classical theory. Meanwhile, the method meets the demands for a shorter period. A combined Doppler estimation algorithm can improve the performance of the high-speed mobile system, and has no loss. The method can increase the number of pieces of access UE of one cell. The method saves the transmission power of a single piece of user equipment, and prolongs the service life of the user equipment.
Description
Technical field
The present invention relates to communication technical field, particularly relating to a kind of technology for carrying out Doppler's estimation in high-speed mobile system.
Background technology
Single UE (UserEquipment, subscriber equipment) Doppler estimation is used to obtain the frequency displacement caused by the movement of UE.
In existing system, training signal is used to estimate the fixing or variable cycle.For an example of fixed cycle, at the channel parameter h of n-th sample of time m
m(n), n=0,1 ..., N-1; M=0,1 ..., M-1, can be estimated by channel estimation method.If the time interval of training signal is less than channel coherency time, h
m+1(n) and h
mn the phase difference between () can be used to frequency displacement and estimate
frequency displacement can be defined as:
Wherein, []
*be the conjugate operation of plural number, arg () is the phase angle of plural number,
the frequency displacement of sample n, Δ
th
m+1(n) and h
mthe time interval between (n).Meanwhile,
all sample averages can improve frequency displacement estimate performance.
To the situation of variable period, the sampling interval can be adjusted, but basic conception is the same with the fixed cycle.Process can be as shown in Figure 1.
At the up direction of LTE (LongTermEvolution, Long Term Evolution) system, there are two kinds of training sequences.The first is DMRS (DedicateModulationReferenceSignal, demodulated reference signal), each TTI (TransmissionTimeInterval, Transmission Time Interval) comprises the user data be scheduled, and it also comprises DMRS.Therefore, eNB estimates the frequency displacement of each TTI, subsequently the estimated result of level and smooth multiple TTI.Another kind is SRS (SoundingReferenceSignal inquires after reference signal), and configuration UE is sent SRS in the periodicity that one comprises multiple TTI by eNB.Therefore, eNB should estimate frequency displacement by adjacent S RS, filters the skew that some cycle causes subsequently.
Usually, in a normal cell, the movement of various UE is assumed to be at random, as shown in Figure 2.The behavior of obvious UE can not be managed.Therefore, the frequency displacement of these UE is separate.Be difficult to estimate to obtain any information by the Doppler of associating.
Train in high-speed railways, moves with the speed exceeding speed per hour 300Km.Usually, the UE in these systems is by special base station coverage, and this base station only provides the service for high speed UE, is intended to solve the problem caused by speed.
Now need to introduce new technology.Such as, frequency hopping will be used with alternative frequency selection scheduling.Further, OneLogicalCell (common logic district) method will be provided to the switching reducing minizone, and more than one base station and a community are combined by it, as shown in Figure 3.
Algorithm for higher frequency displacement needs carefully to design.Especially, new Doppler estimation and channel estimating can be employed.
Strict configuration should be employed.In LTE system, due to the great change of environment, more strong detectable signal should be transmitted by by a certain UE.
As a conclusion to parameter estimation theories, two kinds of modes are had to carry out the performance of modified parameters estimation.The first is the SINR (SignalInterferenceNoiseRatio, Signal to Interference plus Noise Ratio) strengthening signal.The second collects more multisample.
More demand is had when high ferro.Due to channel variation faster, frequency displacement is more rapidly needed to estimate.Under the covering of a base station, doppler information only can be applied to the shorter duration of UE.
Traditional method is, in a certain cycle, a certain UE should be distributed in more training signal source, to strengthen the accuracy of estimation.But on the other hand, it means that less UE can access a base station.
Another kind of mode is that in system, all UE transmit training signal with higher power level.This plan has problems.First, large transmission power will cause the more background noises in neighbor cell, and it will reduce the throughput of whole system.Further, the maximum transmission power of UE is confined.When UE is at cell edge, be difficult to promote estimated accuracy by improving UE power.Last but be not the most unessential, this plan will life-span of waste battery.
In sum, the degeneration of systematic function is certainly existed when high ferro.
In PLL (Phase-LockedLoops, phase-locked loop) theory, maximumly detect frequency displacement and sample cycle is inversely proportional to.In other words, the shorter cycle can mate larger Doppler shift.Under high ferro coverage condition, cause huge frequency displacement by the high speed of train.More training signal is needed within the very short duration.As mentioned above, it means that less connection UE can access a base station equally.
Suppose in high-speed mobile system, as a row train of running at high speed, all subscriber equipmenies, its frequency displacement is identical.Although subscriber equipment can move in the compartment of this train, but consider the speed of train, the movement of subscriber equipment can be left in the basket and disregard.According to prior information, by all training signals of various user device transmissions, united frequency displacement can be estimated.
Summary of the invention
The object of this invention is to provide a kind of method and apparatus carrying out Doppler's estimation in high-speed mobile system.
According to an aspect of the present invention, provide a kind of method of carrying out Doppler's estimation in high-speed mobile system, wherein, the method comprises the following steps:
A, according to the Received signal strength being received from multiple subscriber equipment, carries out channel estimating to the signal of described multiple subscriber equipment respectively, to obtain the channel estimation value of described multiple subscriber equipment respectively;
B according to described channel estimation value, based on to after normalized/preprocess method, combine and Doppler's estimation carried out to described multiple subscriber equipment.
According to another aspect of the present invention, additionally provide a kind of method of carrying out Doppler's estimation in the high-speed mobile system of movement in opposite directions, wherein, the method comprises the following steps:
A follow the trail of all subscriber equipmenies in high-speed mobile system the base station of process;
B according to described subscriber equipment the different base station sequence of process, determine the moving direction of described subscriber equipment, so that described subscriber equipment is divided into two groups;
C, for wherein each organizes subscriber equipment, performs the method for carrying out Doppler's estimation as mentioned above in high-speed mobile system.
According to a further aspect of the invention, additionally provide the device that a kind of Doppler carried out in high-speed mobile system estimates, wherein, this device comprises:
Channel estimating apparatus, for according to the Received signal strength being received from multiple subscriber equipment, carries out channel estimating to the signal of described multiple subscriber equipment, respectively to obtain the channel estimation value of described multiple subscriber equipment respectively;
Doppler's estimation unit, for according to described channel estimation value, based on to after normalized/preprocess method, combine and Doppler's estimation carried out to described multiple subscriber equipment.
According to a further aspect of the invention, additionally provide a kind of eNB, comprise the device carrying out Doppler's estimation as mentioned above in high-speed mobile system.
According to a further aspect of the invention, additionally provide a kind of device carrying out Doppler's estimation in the high-speed mobile system of movement in opposite directions, wherein, this device comprises:
Follow-up mechanism, for follow the trail of all subscriber equipmenies in high-speed mobile system the base station of process;
Apparatus for grouping, for according to described subscriber equipment the different base station sequence of process, determine the moving direction of described subscriber equipment, so that described subscriber equipment is divided into two groups;
Final controlling element, for for wherein each organizes subscriber equipment, performs the method for carrying out Doppler's estimation as mentioned above in high-speed mobile system.
Compared with prior art, the present invention proposes a kind of method of carrying out Doppler's estimation in high-speed mobile system, especially LTE or other systems based on OFDM (OrthogonalFrequencyDivisionMultiplexing, orthogonal frequency division multiplexer).The present invention, according to the Received signal strength being received from multiple subscriber equipment, carries out channel estimating to described multiple subscriber equipment respectively, to obtain the channel estimation value of described multiple subscriber equipment respectively; According to described channel estimation value, based on to after normalized/preprocess method, combine and Doppler's estimation carried out to described multiple subscriber equipment; Substantially increase the sample of training signal, it can improve the accuracy of being carried out parameter Estimation by classical theory; Meanwhile, reach for more short-period demand.Doppler's algorithm for estimating of associating can improve the performance in high-speed mobile system, and does not have loss.The present invention can increase the quantity of the access UE of a community; Meanwhile, through-put power and the battery life of unique user equipment has been saved.
Further, the present invention also proposes a kind of method of carrying out Doppler's estimation in the high-speed mobile system of movement in opposite directions, follow the trail of all subscriber equipmenies in high-speed mobile system the base station of process; According to described subscriber equipment the different base station sequence of process, determine the moving direction of described subscriber equipment, so that described subscriber equipment is divided into two groups; For wherein each organizes subscriber equipment, perform the method for carrying out Doppler's estimation as mentioned above in high-speed mobile system, improve the accuracy that Doppler estimates, improve systematic function.
Accompanying drawing explanation
By reading the detailed description done non-limiting example done with reference to the following drawings, other features, objects and advantages of the present invention will become more obvious:
Fig. 1 illustrates in prior art the schematic diagram carrying out Doppler's estimation;
Fig. 2 illustrates in prior art another schematic diagram carrying out Doppler's estimation;
Fig. 3 illustrates in prior art another schematic diagram carrying out Doppler's estimation;
Fig. 4 illustrates the method flow diagram carrying out Doppler's estimation in high-speed mobile system according to one aspect of the invention;
Fig. 5 illustrates the schematic diagram carrying out Doppler's estimation in high-speed mobile system in accordance with a preferred embodiment of the present invention;
Fig. 6 illustrates the schematic diagram carrying out Doppler's estimation in high-speed mobile system according to another preferred embodiment of the present invention;
Fig. 7 illustrates the schematic diagram carrying out Doppler's estimation in high-speed mobile system according to another preferred embodiment of the present invention;
Fig. 8 illustrates the simulation result figure carrying out Doppler's estimation in high-speed mobile system according to another preferred embodiment of the present invention;
Fig. 9 illustrates the method flow diagram carrying out Doppler's estimation in the high-speed mobile system of movement in opposite directions according to a further aspect of the present invention;
Figure 10 illustrates the schematic diagram carrying out Doppler's estimation in the high-speed mobile system of movement in opposite directions in accordance with a preferred embodiment of the present invention;
Figure 11 illustrates the device schematic diagram carrying out Doppler's estimation in high-speed mobile system according to another aspect of the present invention;
Figure 12 illustrates the device schematic diagram carrying out Doppler's estimation in the high-speed mobile system of movement in opposite directions according to another aspect of the present invention.
In accompanying drawing, same or analogous Reference numeral represents same or analogous parts.
Embodiment
Below in conjunction with accompanying drawing, the present invention is described in further detail.
Fig. 4 illustrates the method flow diagram carrying out Doppler's estimation in high-speed mobile system according to one aspect of the invention.
In step S401, device 1, according to the Received signal strength being received from multiple subscriber equipment, carries out channel estimating to the signal of described multiple subscriber equipment respectively, to obtain the channel estimation value of described multiple subscriber equipment respectively.In step S402, device 1 according to described channel estimation value, based on to after normalized/preprocess method, combine and Doppler's estimation carried out to described multiple subscriber equipment.
At this, device 1 such as can be arranged in eNB.In the following description, for the sake of simplicity, sometimes for eNB.
Suppose in high-speed mobile system, as a row train of running at high speed, all subscriber equipmenies, its frequency displacement is identical.Although subscriber equipment can move in the compartment of this train, but consider the speed of train, the movement of subscriber equipment can be left in the basket and disregard.According to prior information, by all training signals of various user device transmissions, united frequency displacement can be estimated, as shown in Figure 5.In other words, the method substantially increases the sample of training signal, and it can improve the accuracy of being carried out parameter Estimation by classical theory.Meanwhile, reach for more short-period demand.Doppler's algorithm for estimating of associating can improve the performance in high ferro covering system, and does not have loss.
Particularly, in step S401, device 1 receives the Received signal strength from the multiple subscriber equipmenies in this high-speed mobile system, such as, LTE system inquire after the uplink pilot signal in reference signal and uplink demodulation reference signal, CDMA or W-CDMA system, the upper interline in TD-SCDMA system inserts pilot portion etc.; Subsequently, device 1, according to the Received signal strength being received from the plurality of subscriber equipment, carries out channel estimating to the signal of the plurality of subscriber equipment respectively, to obtain the channel estimation value of the plurality of subscriber equipment respectively.
Such as, l subscriber equipment is h at moment m at the channel estimation value of the n-th sample
m,l(n), n=0,1 ..., N-1; M=0,1 ..., M-1; L=0,1 ..., L-1, the average phase-shift between moment m and m+1 is:
Those skilled in the art will be understood that; the mode that the above-mentioned signal to multiple subscriber equipment carries out channel estimating is only citing; other signals to multiple subscriber equipment that are existing or that may occur from now on carry out the mode of channel estimating as being applicable to the present invention; also within scope should being included in, and this is contained at this with way of reference.
Preferably, in step S401, device 1, according to the upstream data being received from described multiple subscriber equipment, carries out channel estimating to the signal of described multiple subscriber equipment respectively, to obtain the channel estimation value of described multiple subscriber equipment respectively;
Wherein, described upstream data comprises following any one:
-inquire after reference signal and uplink demodulation reference signal;
-uplink pilot signal;
-upper interline inserts pilot portion.
Particularly, in LTE system, in step S401, device 1 inquires after reference signal and up DMRS (demodulated reference signal) according to what be received from the plurality of subscriber equipment, respectively channel estimating is carried out to the signal of the plurality of subscriber equipment, to obtain the channel estimation value of the plurality of subscriber equipment respectively.
In CDMA or W-CDMA system, in step S401, device 1, according to the uplink pilot signal being received from the plurality of subscriber equipment, carries out channel estimating to the signal of the plurality of subscriber equipment respectively, to obtain the channel estimation value of the plurality of subscriber equipment respectively.
In TD-SCDMA system, in step S401, device 1 inserts pilot portion according to the upper interline being received from the plurality of subscriber equipment, carries out channel estimating respectively, to obtain the channel estimation value of the plurality of subscriber equipment respectively to the signal of the plurality of subscriber equipment.
Those skilled in the art will be understood that above-mentioned upstream data is only citing, and other upstream datas that are existing or that may occur from now on, as being applicable to the present invention, within also should being included in scope, and are contained in this at this with way of reference.
Preferably, in step S401, device 1 according to the Received signal strength being received from described multiple subscriber equipment, based on inquiring after cycle reference signal and code division multiplexing, respectively channel estimating is carried out to the signal of described multiple subscriber equipment, to obtain the channel estimation value of described multiple subscriber equipment respectively.
Particularly, in step S401, the time interval that device 1 carries out channel estimating to the multiple subscriber equipmenies in this high-speed mobile system inquires after cycle reference signal, the reference signal of inquiring after of multiple subscriber equipment is transmitted on identical time and frequency resource, it is launched by different codes, is called as code division multiplexing.Therefore, device 1, as eNB, can estimate the channel estimation value of each subscriber equipment, as shown in Figure 6 respectively.
For other situations, multiple subscriber equipment is divided into several groups, and each group takies a running time-frequency resource.To at the subscriber equipment of identical group, it uses identical resource and code division multiplexing, as shown in Figure 7.Therefore, device 1, as eNB, can estimate the channel estimation value of each subscriber equipment in each group, and the channel estimation value in conjunction with the subscriber equipment in all groups calculates frequency displacement.
In step S402, device 1 according to described channel estimation value, based on to after normalized/preprocess method, combine and Doppler's estimation carried out to described multiple subscriber equipment.
Preferably, normalized method comprises post-processing approach, and wherein, in step S402, device 1 is combined and carried out Doppler's estimation to described multiple subscriber equipment, to obtain the frequency displacement of described multiple subscriber equipment; The frequency displacement of described multiple subscriber equipment is normalized, to obtain the normalization frequency displacement of described multiple subscriber equipment.
Particularly, in step S401, it is h at the channel estimation value of the n-th sample that device 1 calculates l subscriber equipment at moment m
m,l(n), n=0,1 ..., N-1; M=0,1 ..., M-1; L=0,1 ..., L-1, the average phase-shift between moment m and m+1 is:
Subsequently, in step S402, the frequency displacement that device 1 calculates l subscriber equipment is:
Then, the frequency displacement of the average multiple subscriber equipment of this device 1 is:
Now, device 1 calculates the normalization frequency displacement of the plurality of subscriber equipment and is:
Wherein, α
lthe SINR of l subscriber equipment.
At this, when the normalized post-processing approach of employing, first device 1 carries out Doppler's estimation to the plurality of subscriber equipment, obtains frequency displacement, then is normalized the frequency displacement of the plurality of subscriber equipment.
Preferably, normalized method comprises preprocess method, and wherein, in step S402, the channel estimation value of device 1 to described multiple subscriber equipment is normalized, to obtain normalization channel estimation value; According to described normalization channel estimation value, combine and Doppler's estimation is carried out to described multiple subscriber equipment, to obtain the normalization phase shift of described multiple subscriber equipment.
Particularly, in step S401, it is h at the channel estimation value of the n-th sample that device 1 calculates l subscriber equipment at moment m
m,l(n), n=0,1 ..., N-1; M=0,1 ..., M-1; L=0,1 ..., L-1, the average phase-shift between moment m and m+1 is:
Subsequently, in step S402, the average phase-shift that device 1 calculates multiple subscriber equipment is:
Then, device 1, according to this average phase-shift, is combined and is carried out Doppler's estimation to the plurality of subscriber equipment, to obtain Doppler frequency shift:
And then this device 1 is averaged to above-mentioned frequency displacement or filters;
Now, device 1 calculates and in the normalization phase shift of the plurality of subscriber equipment of moment m is:
Wherein, α
lthe SINR of l subscriber equipment.
At this, when the normalized preprocess method of employing, first device 1 is normalized the channel estimation value of the plurality of subscriber equipment, then according to normalized channel estimation value, carries out Doppler's estimation to the plurality of subscriber equipment.
Fig. 8 illustrates the simulation result that the Doppler under fading channel estimates.The line of asterisk mark is the MSE (MeanSquareError, mean square error) being estimated the estimation frequency displacement reported by unique user equipment.The line of circles mark is the MSE of the associating FOE (FrequencyOffsetEstimation, frequency deviation is estimated) obtained based on normalized post-processing approach.The ratio of gains based on the associating frequency deviation estimating method of normalized post-processing approach only uses unique user equipment to carry out the many 3dB of method of frequency deviation estimation.The line of warning triangle is the MSE of the associating FOE obtained based on normalized preprocess method, and other two lines of its slope ratio are larger.As can be seen here, adopt and can estimate frequency displacement more accurately based on normalized preprocess method.
At this, propose a kind of method of carrying out Doppler's estimation in high-speed mobile system, especially LTE or other systems based on OFDM.Device 1, according to the Received signal strength being received from multiple subscriber equipment, carries out channel estimating to the signal of described multiple subscriber equipment respectively, to obtain the channel estimation value of described multiple subscriber equipment respectively; According to described channel estimation value, based on to after normalized/preprocess method, combine and Doppler's estimation carried out to described multiple subscriber equipment; Substantially increase the sample of training signal, it can improve the accuracy of being carried out parameter Estimation by classical theory; Meanwhile, reach for more short-period demand.Doppler's algorithm for estimating of associating can improve the performance in high-speed mobile system, and does not have loss; The quantity of the access UE of a community can be increased; Meanwhile, through-put power and the battery life of unique user equipment has been saved.
Fig. 9 illustrates the method flow diagram carrying out Doppler's estimation in the high-speed mobile system of movement in opposite directions according to a further aspect of the present invention.
In step S901, device 2 follow the trail of all subscriber equipmenies in high-speed mobile system the base station of process; In step S902, device 2 according to described subscriber equipment the different base station sequence of process, determine the moving direction of described subscriber equipment, so that described subscriber equipment is divided into two groups; In step S903, device 2, for wherein each organizes subscriber equipment, performs the method for carrying out Doppler's estimation as mentioned above in high-speed mobile system.
Particularly, the high-speed mobile system such as two of this movement in opposite directions arranges the train of high-speed mobile in opposite directions, and this two row train is in relative direction, and the frequency displacement of the subscriber equipment on different train is different.Group technology as shown in Figure 10 can be adopted, to solve this problem.In step S901, device 2 follow the trail of all subscriber equipmenies in high-speed mobile system the base station of process, such as, when subscriber equipment switches between two base stations, intercommunication handover information between base station, device 2 then in this base station can according to this handover information, follow the trail of all subscriber equipmenies the base station of process.In step S902, device 2 according to described subscriber equipment the different base station sequence of process, determine the moving direction of described subscriber equipment, so that described subscriber equipment is divided into two groups.Such as, for tactic base station A, B, C, subscriber equipment a and b the base station sequence of process be A, B, C; And subscriber equipment c and d the base station sequence of process be C, B, A, then this subscriber equipment a and b is divided into one group, this subscriber equipment c and d is divided into one group.In step S903, device 2 is for wherein each organizes subscriber equipment, perform the method for carrying out Doppler's estimation as mentioned above in high-speed mobile system, to combine, frequency deviation estimation is carried out to this group subscriber equipment, as for subscriber equipment a and b, perform the method for carrying out Doppler's estimation as above in high-speed mobile system.
At this, device 2 such as can be arranged in eNB.
Preferably, in step S902, device 2 also according to the handover information about subscriber equipment being received from adjacent base station, determine described subscriber equipment the different base station sequence of process.
Particularly, when subscriber equipment switches between different base stations, intercommunication handover information between base station, device 2 then in this base station can according to the handover information about subscriber equipment being received from adjacent base station, determine subscriber equipment the different base station sequence of process, and then determine the moving direction of subscriber equipment, to be divided into groups by these subscriber equipmenies.
At this, propose a kind of method of carrying out Doppler's estimation in the high-speed mobile system of movement in opposite directions, device 2 follow the trail of all subscriber equipmenies in high-speed mobile system the base station of process; According to described subscriber equipment the different base station sequence of process, determine the moving direction of described subscriber equipment, so that described subscriber equipment is divided into two groups; For wherein each organizes subscriber equipment, perform the method for carrying out Doppler's estimation as mentioned above in high-speed mobile system, improve the accuracy that Doppler estimates, improve systematic function.
Figure 11 illustrates the device schematic diagram carrying out Doppler's estimation in high-speed mobile system according to another aspect of the present invention.Device 1 comprises channel estimating apparatus 1101 and Doppler's estimation unit 1102.
Channel estimating apparatus 1101, for according to the Received signal strength being received from multiple subscriber equipment, carries out channel estimating to the signal of described multiple subscriber equipment, respectively to obtain the channel estimation value of described multiple subscriber equipment respectively.Doppler's estimation unit 1102 for according to described channel estimation value, based on to after normalized/preprocess method, combine and Doppler's estimation carried out to described multiple subscriber equipment.
At this, device 1 such as can be arranged in eNB.In the following description, for the sake of simplicity, sometimes for eNB.
Suppose in high-speed mobile system, as a row train of running at high speed, all subscriber equipmenies, its frequency displacement is identical.Although subscriber equipment can move in the compartment of this train, but consider the speed of train, the movement of subscriber equipment can be left in the basket and disregard.According to prior information, by all training signals of various user device transmissions, united frequency displacement can be estimated, as shown in Figure 5.In other words, the method substantially increases the sample of training signal, and it can improve the accuracy of being carried out parameter Estimation by classical theory.Meanwhile, reach for more short-period demand.Doppler's algorithm for estimating of associating can improve the performance in high ferro covering system, and does not have loss.
Particularly, channel estimating apparatus 1101 receives the Received signal strength from the multiple subscriber equipmenies in this high-speed mobile system, such as, LTE system inquire after the uplink pilot signal in reference signal and uplink demodulation reference signal, CDMA or W-CDMA system, the upper interline in TD-SCDMA system inserts pilot portion etc.; Subsequently, channel estimating apparatus 1101, according to the Received signal strength being received from the plurality of subscriber equipment, carries out channel estimating to the signal of the plurality of subscriber equipment respectively, to obtain the channel estimation value of the plurality of subscriber equipment respectively.
Such as, l subscriber equipment is h at moment m at the channel estimation value of the n-th sample
m,l(n), n=0,1 ..., N-1; M=0,1 ..., M-1; L=0,1 ..., L-1, the average phase-shift between moment m and m+1 is:
Those skilled in the art will be understood that; the mode that the above-mentioned signal to multiple subscriber equipment carries out channel estimating is only citing; other signals to multiple subscriber equipment that are existing or that may occur from now on carry out the mode of channel estimating as being applicable to the present invention; also within scope should being included in, and this is contained at this with way of reference.
Preferably, channel estimating apparatus 1101, according to the upstream data being received from described multiple subscriber equipment, carries out channel estimating to the signal of described multiple subscriber equipment respectively, to obtain the channel estimation value of described multiple subscriber equipment respectively;
Wherein, described upstream data comprises following any one:
-inquire after reference signal and uplink demodulation reference signal;
-uplink pilot signal;
-upper interline inserts pilot portion.
Particularly, in LTE system, channel estimating apparatus 1101 inquires after reference signal and up DMRS (demodulated reference signal) according to what be received from the plurality of subscriber equipment, respectively channel estimating is carried out to the signal of the plurality of subscriber equipment, to obtain the channel estimation value of the plurality of subscriber equipment respectively.
In CDMA or W-CDMA system, channel estimating apparatus 1101, according to the uplink pilot signal being received from the plurality of subscriber equipment, carries out channel estimating to the signal of the plurality of subscriber equipment respectively, to obtain the channel estimation value of the plurality of subscriber equipment respectively.
In TD-SCDMA system, channel estimating apparatus 1101 inserts pilot portion according to the upper interline being received from the plurality of subscriber equipment, carries out channel estimating respectively, to obtain the channel estimation value of the plurality of subscriber equipment respectively to the signal of the plurality of subscriber equipment.
Those skilled in the art will be understood that above-mentioned upstream data is only citing, and other upstream datas that are existing or that may occur from now on, as being applicable to the present invention, within also should being included in scope, and are contained in this at this with way of reference.
Preferably, channel estimating apparatus 1101 is according to the Received signal strength being received from described multiple subscriber equipment, based on inquiring after cycle reference signal and code division multiplexing, respectively channel estimating is carried out to the signal of described multiple subscriber equipment, to obtain the channel estimation value of described multiple subscriber equipment respectively.
Particularly, the time interval that channel estimating apparatus 1101 carries out channel estimating to the multiple subscriber equipmenies in this high-speed mobile system inquires after cycle reference signal, the reference signal of inquiring after of multiple subscriber equipment is transmitted on identical time and frequency resource, it is launched by different codes, is called as code division multiplexing.Therefore, device 1, as eNB, can estimate the channel estimation value of each subscriber equipment, as shown in Figure 6 respectively.
For other situations, multiple subscriber equipment is divided into several groups, and each group takies a running time-frequency resource.To at the subscriber equipment of identical group, it uses identical resource and code division multiplexing, as shown in Figure 7.Therefore, device 1, as eNB, can estimate the channel estimation value of each subscriber equipment in each group, and the channel estimation value in conjunction with the subscriber equipment in all groups calculates frequency displacement.
Doppler's estimation unit 1102 for according to described channel estimation value, based on to after normalized/preprocess method, combine and Doppler's estimation carried out to described multiple subscriber equipment.
Preferably, normalized method comprises post-processing approach, and wherein, Doppler's estimation unit 1102 is combined and carried out Doppler's estimation to described multiple subscriber equipment, to obtain the frequency displacement of described multiple subscriber equipment; The frequency displacement of described multiple subscriber equipment is normalized, to obtain the normalization frequency displacement of described multiple subscriber equipment.
Particularly, channel estimating apparatus 1101 calculates l subscriber equipment at moment m is h at the channel estimation value of the n-th sample
m,l(n), n=0,1 ..., N-1; M=0,1 ..., M-1; L=0,1 ..., L-1, the average phase-shift between moment m and m+1 is:
Subsequently, Doppler's estimation unit 1102 calculates the frequency displacement of l subscriber equipment and is:
Then, the frequency displacement of the average multiple subscriber equipment of Doppler's estimation unit 1102 is:
Now, Doppler's estimation unit 1102 calculates the normalization frequency displacement of the plurality of subscriber equipment and is:
Wherein, α
lthe SINR of l subscriber equipment.
At this, when the normalized post-processing approach of employing, first device 1 carries out Doppler's estimation to the plurality of subscriber equipment, obtains frequency displacement, then is normalized the frequency displacement of the plurality of subscriber equipment.
Preferably, normalized method comprises preprocess method, and wherein, the channel estimation value of Doppler's estimation unit 1102 to described multiple subscriber equipment is normalized, to obtain normalization channel estimation value; According to described normalization channel estimation value, combine and Doppler's estimation is carried out to described multiple subscriber equipment, to obtain the normalization phase shift of described multiple subscriber equipment.
Particularly, channel estimating apparatus 1101 calculates l subscriber equipment at moment m is h at the channel estimation value of the n-th sample
m,l(n), n=0,1 ..., N-1; M=0,1 ..., M-1; L=0,1 ..., L-1, the average phase-shift between moment m and m+1 is:
Subsequently, Doppler's estimation unit 1102 calculates the average phase-shift of multiple subscriber equipment and is:
Then, Doppler's estimation unit 1102, according to this average phase-shift, is combined and is carried out Doppler's estimation to the plurality of subscriber equipment, to obtain Doppler frequency shift:
And then Doppler's estimation unit 1102 is averaged to above-mentioned frequency displacement or filters;
Now, Doppler's estimation unit 1102 calculates and in the normalization phase shift of the plurality of subscriber equipment of moment m is:
Wherein, α
lthe SINR of l subscriber equipment.
At this, when the normalized preprocess method of employing, first device 1 is normalized the channel estimation value of the plurality of subscriber equipment, then according to normalized channel estimation value, carries out Doppler's estimation to the plurality of subscriber equipment.
Fig. 8 illustrates the simulation result that the Doppler under fading channel estimates.The line of asterisk mark is the MSE (MeanSquareError, mean square error) being estimated the estimation frequency displacement reported by unique user equipment.The line of circles mark is the MSE of the associating FOE (FrequencyOffsetEstimation, frequency deviation is estimated) obtained based on normalized post-processing approach.The ratio of gains based on the associating frequency deviation estimating method of normalized post-processing approach only uses unique user equipment to carry out the many 3dB of method of frequency deviation estimation.The line of warning triangle is the MSE of the associating FOE obtained based on normalized preprocess method, and other two lines of its slope ratio are larger.As can be seen here, adopt and can estimate frequency displacement more accurately based on normalized preprocess method.
At this, propose a kind of method of carrying out Doppler's estimation in high-speed mobile system, especially LTE or other systems based on OFDM.Device 1, according to the Received signal strength being received from multiple subscriber equipment, carries out channel estimating to the signal of described multiple subscriber equipment respectively, to obtain the channel estimation value of described multiple subscriber equipment respectively; According to described channel estimation value, based on to after normalized/preprocess method, combine and Doppler's estimation carried out to described multiple subscriber equipment; Substantially increase the sample of training signal, it can improve the accuracy of being carried out parameter Estimation by classical theory; Meanwhile, reach for more short-period demand.Doppler's algorithm for estimating of associating can improve the performance in high-speed mobile system, and does not have loss; The quantity of the access UE of a community can be increased; Meanwhile, through-put power and the battery life of unique user equipment has been saved.
Figure 12 illustrates the device schematic diagram carrying out Doppler's estimation in the high-speed mobile system of movement in opposite directions according to another aspect of the present invention.Device 2 comprises follow-up mechanism 1201, apparatus for grouping 1202 and final controlling element 1203.
Follow-up mechanism 1201 follow the trail of all subscriber equipmenies in high-speed mobile system the base station of process; Apparatus for grouping 1202 according to described subscriber equipment the different base station sequence of process, determine the moving direction of described subscriber equipment, so that described subscriber equipment is divided into two groups; Final controlling element 1203, for wherein each organizes subscriber equipment, performs the method for carrying out Doppler's estimation as mentioned above in high-speed mobile system.
Particularly, the high-speed mobile system such as two of this movement in opposite directions arranges the train of high-speed mobile in opposite directions, and this two row train is in relative direction, and the frequency displacement of the subscriber equipment on different train is different.Group technology as shown in Figure 10 can be adopted, to solve this problem.Follow-up mechanism 1201 follow the trail of all subscriber equipmenies in high-speed mobile system the base station of process, such as, when subscriber equipment switches between two base stations, intercommunication handover information between base station, follow-up mechanism 1201 then in this base station can according to this handover information, follow the trail of all subscriber equipmenies the base station of process.Apparatus for grouping 1202 according to described subscriber equipment the different base station sequence of process, determine the moving direction of described subscriber equipment, so that described subscriber equipment is divided into two groups.Such as, for tactic base station A, B, C, subscriber equipment a and b the base station sequence of process be A, B, C; And subscriber equipment c and d the base station sequence of process be C, B, A, then this subscriber equipment a and b is divided into one group, this subscriber equipment c and d is divided into one group.Final controlling element 1203 is for wherein each organizes subscriber equipment, perform the method for carrying out Doppler's estimation as mentioned above in high-speed mobile system, to combine, frequency deviation estimation is carried out to this group subscriber equipment, as for subscriber equipment a and b, perform the method for carrying out Doppler's estimation as above in high-speed mobile system.
At this, device 2 such as can be arranged in eNB.
Preferably, apparatus for grouping 1202 also according to the handover information about subscriber equipment being received from adjacent base station, determine described subscriber equipment the different base station sequence of process.
Particularly, when subscriber equipment switches between different base stations, intercommunication handover information between base station, apparatus for grouping 1202 then in this base station can according to the handover information about subscriber equipment being received from adjacent base station, determine subscriber equipment the different base station sequence of process, and then determine the moving direction of subscriber equipment, to be divided into groups by these subscriber equipmenies.
At this, propose a kind of method of carrying out Doppler's estimation in the high-speed mobile system of movement in opposite directions, device 2 follow the trail of all subscriber equipmenies in high-speed mobile system the base station of process; According to described subscriber equipment the different base station sequence of process, determine the moving direction of described subscriber equipment, so that described subscriber equipment is divided into two groups; For wherein each organizes subscriber equipment, perform the method for carrying out Doppler's estimation as mentioned above in high-speed mobile system, improve the accuracy that Doppler estimates, improve systematic function.
It should be noted that the present invention can be implemented in the assembly of software and/or software restraint, such as, application-specific integrated circuit (ASIC) (ASIC), general object computer or any other similar hardware device can be adopted to realize.In one embodiment, software program of the present invention can perform to realize step mentioned above or function by processor.Similarly, software program of the present invention (comprising relevant data structure) can be stored in computer readable recording medium storing program for performing, such as, and RAM memory, magnetic or CD-ROM driver or floppy disc and similar devices.In addition, steps more of the present invention or function can adopt hardware to realize, such as, as coordinating with processor thus performing the circuit of each step or function.
In addition, a part of the present invention can be applied to computer program, such as computer program instructions, when it is performed by computer, by the operation of this computer, can call or provide according to method of the present invention and/or technical scheme.And call the program command of method of the present invention, may be stored in fixing or moveable recording medium, and/or be transmitted by the data flow in broadcast or other signal bearing medias, and/or be stored in the working storage of the computer equipment run according to described program command.At this, comprise a device according to one embodiment of present invention, this device comprises the memory for storing computer program instructions and the processor for execution of program instructions, wherein, when this computer program instructions is performed by this processor, trigger this plant running based on the aforementioned method according to multiple embodiment of the present invention and/or technical scheme.
To those skilled in the art, obviously the invention is not restricted to the details of above-mentioned one exemplary embodiment, and when not deviating from spirit of the present invention or essential characteristic, the present invention can be realized in other specific forms.Therefore, no matter from which point, all should embodiment be regarded as exemplary, and be nonrestrictive, scope of the present invention is limited by claims instead of above-mentioned explanation, and all changes be therefore intended in the implication of the equivalency by dropping on claim and scope are included in the present invention.Any Reference numeral in claim should be considered as the claim involved by limiting.In addition, obviously " comprising " one word do not get rid of other unit or step, odd number does not get rid of plural number.Multiple unit of stating in device claim or device also can be realized by software or hardware by a unit or device.First, second word such as grade is used for representing title, and does not represent any specific order.
Claims (15)
1. in high-speed mobile system, carry out a method for Doppler's estimation, wherein, the method comprises the following steps:
A, according to the Received signal strength being received from multiple subscriber equipment, carries out channel estimating to the signal of described multiple subscriber equipment respectively, to obtain the channel estimation value of described multiple subscriber equipment respectively;
B according to described channel estimation value, based on to after normalized/preprocess method, combine and Doppler's estimation carried out to described multiple subscriber equipment.
2. method according to claim 1, wherein, normalized method comprises post-processing approach, and wherein, described step b comprises:
-combine and Doppler's estimation is carried out to described multiple subscriber equipment, to obtain the frequency displacement of described multiple subscriber equipment;
-frequency displacement of described multiple subscriber equipment is normalized, to obtain the normalization frequency displacement of described multiple subscriber equipment.
3. method according to claim 1, wherein, normalized method comprises preprocess method, and wherein, described step b comprises:
-channel estimation value of described multiple subscriber equipment is normalized, to obtain normalization channel estimation value;
-according to described normalization channel estimation value, combine and Doppler's estimation is carried out to described multiple subscriber equipment, to obtain the normalization phase shift of described multiple subscriber equipment.
4. according to the method in any one of claims 1 to 3, wherein, described step a comprises:
-according to the upstream data being received from described multiple subscriber equipment, respectively channel estimating is carried out to the signal of described multiple subscriber equipment, to obtain the channel estimation value of described multiple subscriber equipment respectively;
Wherein, described upstream data comprises following any one:
-inquire after reference signal and uplink demodulation reference signal;
-uplink pilot signal;
-upper interline inserts pilot portion.
5. method according to any one of claim 1 to 4, wherein, described step a comprises:
-according to the Received signal strength being received from described multiple subscriber equipment, based on inquiring after cycle reference signal and code division multiplexing, respectively channel estimating is carried out to the signal of described multiple subscriber equipment, to obtain the channel estimation value of described multiple subscriber equipment respectively.
6. in the high-speed mobile system of movement in opposite directions, carry out a method for Doppler's estimation, wherein, the method comprises the following steps:
A follow the trail of all subscriber equipmenies in high-speed mobile system the base station of process;
B according to described subscriber equipment the different base station sequence of process, determine the moving direction of described subscriber equipment, so that described subscriber equipment is divided into two groups;
C, for wherein each organizes subscriber equipment, performs the method according to any one of claim 1 to 5.
7. method according to claim 6, wherein, described step B also comprises:
-according to being received from the handover information about subscriber equipment of adjacent base station, determine described subscriber equipment the different base station sequence of process.
8. the device that the Doppler carried out in high-speed mobile system estimates, wherein, this device comprises:
Channel estimating apparatus, for according to the Received signal strength being received from multiple subscriber equipment, carries out channel estimating to the signal of described multiple subscriber equipment, respectively to obtain the channel estimation value of described multiple subscriber equipment respectively;
Doppler's estimation unit, for according to described channel estimation value, based on to after normalized/preprocess method, combine and Doppler's estimation carried out to described multiple subscriber equipment.
9. device according to claim 8, wherein, normalized method comprises post-processing approach, and wherein, described Doppler's estimation unit is used for:
-combine and Doppler's estimation is carried out to described multiple subscriber equipment, to obtain the frequency displacement of described multiple subscriber equipment;
-frequency displacement of described multiple subscriber equipment is normalized, to obtain the normalization frequency displacement of described multiple subscriber equipment.
10. device according to claim 8, wherein, normalized method comprises preprocess method, and wherein, described Doppler's estimation unit is used for:
-channel estimation value of described multiple subscriber equipment is normalized, to obtain normalization channel estimation value;
-according to described normalization channel estimation value, combine and Doppler's estimation is carried out to described multiple subscriber equipment, to obtain the normalization phase shift of described multiple subscriber equipment.
Device according to any one of 11. according to Claim 8 to 10, wherein, described channel estimating apparatus is used for:
-according to the upstream data being received from described multiple subscriber equipment, respectively channel estimating is carried out to the signal of described multiple subscriber equipment, to obtain the channel estimation value of described multiple subscriber equipment respectively;
Wherein, described upstream data comprises following any one:
-inquire after reference signal and uplink demodulation reference signal;
-uplink pilot signal;
-upper interline inserts pilot portion.
Device according to any one of 12. according to Claim 8 to 11, wherein, described channel estimating apparatus is used for:
-according to the Received signal strength being received from described multiple subscriber equipment, based on inquiring after cycle reference signal and code division multiplexing, respectively channel estimating is carried out to the signal of described multiple subscriber equipment, to obtain the channel estimation value of described multiple subscriber equipment respectively.
13. 1 kinds of eNB, comprise the device according to any one of claim 8 to 12.
14. 1 kinds of devices carrying out Doppler's estimation in the high-speed mobile system of movement in opposite directions, wherein, this device comprises:
Follow-up mechanism, for follow the trail of all subscriber equipmenies in high-speed mobile system the base station of process;
Apparatus for grouping, for according to described subscriber equipment the different base station sequence of process, determine the moving direction of described subscriber equipment, so that described subscriber equipment is divided into two groups;
Final controlling element, for for wherein each organizes subscriber equipment, performs the method according to any one of claim 1 to 5.
15. devices according to claim 14, wherein, described apparatus for grouping also for:
-according to being received from the handover information about subscriber equipment of adjacent base station, determine described subscriber equipment the different base station sequence of process.
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