CN102014098A - Method and device for measuring and calculating maximum Doppler frequency offset - Google Patents

Abstract

The embodiment of the invention discloses a method and a device for measuring and calculating the maximum Doppler frequency offset, which solve the problem that the estimation of the maximum Doppler frequency offset has overlarge limit to the resource scheduling of a time domain and a frequency domain and the multiuser resource distribution strategy. The method disclosed in the embodiment of the invention comprises the steps of: estimating a first maximum Doppler frequency offset fd1 of a measured frequency on the frequency domain; judging whether the movement speed of a mobile terminal is in a high-speed interval or a low-speed interval according to the first maximum Doppler frequency offset fd1; if the movement speed of the mobile terminal is in the high-speed interval, determining the first maximum Doppler frequency offset fd1 to be the measured and calculated maximum Doppler frequency offset; or else, estimating a second maximum Doppler frequency offset fd2 of the measured frequency on the frequency domain and determining the second maximum Doppler frequency offset fd2 to be the measured and calculated maximum Doppler frequency offset. By using the estimation of a frequency domain channel, which is less limited by the resource scheduling of the time domain and the frequency domain and the multiuser resource distribution strategy, the method and the device for measuring and calculating the maximum Doppler frequency offset are suitable for a system which needs frequency hopping scheduling, such as LTE (Long Term Evolution) and the like, or a multi-carrier system.

Description

A kind of measuring and calculating maximum Doppler frequency offset method and apparatus

Technical field

The present invention relates to the mobile communication technology field, be specifically related to a kind of measuring and calculating maximum Doppler frequency offset method and apparatus.

Background technology

Become fading channel when the related channel of mobile communication system is generally multipath, change at random all can take place in the amplitude of its received signal and phase place in time.Usually, adopt the Doppler frequency deviation of fading channel to reflect the speed that the parameter of mobile communication transmission channel changes, the translational speed of portable terminal is fast more, and Doppler frequency deviation is big more, and channel parameter changes fast more.

Because Doppler frequency deviation and maximum Doppler frequency offset and other parameters are (for example, the translational speed of portable terminal, direction and carrier frequency etc.) there is certain mathematical relationship, therefore, by certain measuring method, the maximum Doppler frequency offset that estimates the mobile communication transmission channel is the steps necessary of Doppler frequency deviation when calculating practical application.

For some Frequency Division Multiplexing system (for example, OFDM), the frequency domain characteristic estimation maximum Doppler frequency offset that can change according to signal promptly, uniformly-spaced be chosen the estimated value of pilot signal on the same sub-carrier, as Fig. 1, (for example, T uniformly-spaced ₀Time) choose subcarrier f _2cOn pilot signal R ₂₁, R ₂₂And R ₂₃Deng, statistics certain hour scope is interior (for example, from t ₁Constantly to t ₅(for example, the pilot signal R of sampled point constantly) ₂₁, R ₂₂And R ₂₃Deng), to t ₁Constantly to t ₅Sampled point constantly carries out fast Fourier transform (FFT, Fast Fourier Transform), through behind the FFT, gets the peak frequency point that power peak is higher than noise gate, and this peak frequency point is exactly the maximum Doppler frequency offset that estimates.

The present inventor is through discovering: above-mentioned prior art has special requirement to sampling instant and the shared sub-carrier resources of pilot signal when the estimation maximum Doppler frequency offset.That is to say that within the timing statistics that satisfies the requirement of FFT sampling number, sampling instant must have this user's pilot signal, and this user's pilot signal (sampled point) must be positioned on the identical sub-carrier resources, can not frequency hopping, for example, at t ₂Because can't collect pilot signal, then scheme two just can not be implemented constantly; If in communication process, the user is at subcarrier f _2c, f _3cAnd f _4cBetween frequency hopping, then can not add up subcarrier f _2cOn pilot signal R ₂₁, subcarrier f _3cOn pilot signal R ₃₁With subcarrier f _4cOn pilot signal R ₄₁Carry out FFT etc. the pilot signal on the different sub carrier.Therefore, prior art is excessive for the scheduling of resource and the restriction of multi-user's resource allocation policy of time-domain and frequency-domain, needs the system of frequency hopping scheduling to be difficult in fact realize such as LTE or the like.

Summary of the invention

The embodiment of the invention provides a kind of estimation maximum Doppler frequency offset method and apparatus, and this method and apparatus is not subjected to the constraint of correlation time or pilot signal subcarrier of living in.

The method of the measuring and calculating maximum Doppler frequency offset that the embodiment of the invention provides comprises:

Estimation is by the first maximum Doppler frequency offset f of measured frequency on frequency domain _D1

According to the described first maximum Doppler frequency offset f _D1The translational speed of judgement portable terminal is between high velocity or is between low regime;

If the translational speed of described portable terminal is between high velocity, then determine with the described first maximum Doppler frequency offset f _D1As the maximum Doppler frequency offset that calculates, otherwise estimation is by the second maximum Doppler frequency offset f of measured frequency on frequency domain _D2And determine with the described second maximum Doppler frequency offset f _D2As the maximum Doppler frequency offset that calculates.

The device of the measuring and calculating maximum Doppler frequency offset that the embodiment of the invention provides comprises:

Estimation block is used for estimating by the first maximum Doppler frequency offset f of measured frequency on frequency domain _D1With the second maximum Doppler frequency offset f _D2

Judge module is used for according to the described first maximum Doppler frequency offset f _D1The translational speed of judgement portable terminal is between high velocity or is between low regime;

The maximum Doppler frequency offset determination module is used for determining with the described first maximum Doppler frequency offset f when described judge module judges that the translational speed of described portable terminal is between high velocity _D1As the maximum Doppler frequency offset that calculates, perhaps, when described judge module judges that the translational speed of described portable terminal is between low regime, determine the second maximum Doppler frequency offset f that estimates with described estimation block _D2As the maximum Doppler frequency offset that calculates.

The embodiment of the invention is by estimating on frequency domain by first maximum Doppler frequency offset of measured frequency, judge that with described first maximum Doppler frequency offset translational speed of portable terminal is between high velocity or is between low regime, when being between high velocity, the translational speed of described portable terminal determines as the maximum Doppler frequency offset that calculates with described first maximum Doppler frequency offset, otherwise estimation is also determined with described second maximum Doppler frequency offset as the maximum Doppler frequency offset that calculates by second maximum Doppler frequency offset of measured frequency on frequency domain.Effectively utilized the pilot signal of big correlation time and the pilot signal of less correlation time favorable factor to the estimation result, the scope and the resolution of the estimation precision and the frequence estimation of maximum Doppler frequency offset have been improved, simultaneously, in computational process, use the also less restriction that is subjected to time-domain and frequency-domain scheduling of resource and multi-user's resource allocation policy of estimation of frequency domain channel, be applicable to the system or the multicarrier system that need the frequency hopping scheduling such as LTE etc. more.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, to do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below, apparently, accompanying drawing in describing below only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.

Fig. 1 is prior art is estimated maximum Doppler frequency offset on time domain a relevant schematic diagram;

Fig. 2 is the method basic procedure schematic diagram of the measuring and calculating maximum Doppler frequency offset that provides of the embodiment of the invention;

Fig. 3 is the relevant schematic diagram of calculating maximum Doppler frequency offset on frequency domain that the embodiment of the invention provides;

Fig. 4 is the device basic logical structure schematic diagram of the measuring and calculating maximum Doppler frequency offset that provides of the embodiment of the invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that is obtained under the creative work prerequisite.

The method basic procedure of the calculating maximum Doppler frequency offset of the embodiment of the invention can mainly comprise with reference to figure 2:

Step S201, estimation is by the first maximum Doppler frequency offset f of measured frequency on frequency domain _D1

Prior art is to obtain by the time domain channel estimated value when the estimation maximum Doppler frequency offset, and the evaluation method on this time domain is not suitable for the multicarrier system of use OFDM modulation systems such as LTE.For fear of this defective of prior art, the embodiment of the invention adopts the channel estimation value estimation maximum Doppler frequency offset on the frequency domain.

Because the correlation time of pilot signal is all influential to the measuring and calculating scope and the estimation precision of frequency, be in particular in: correlation time is big more, and it is more little that maximum detection is calculated frequency, but estimation precision can be better when the portable terminal translational speed is low; Correlation time is more little, and it is big more that maximum detection is calculated frequency, but the frequency resolution that calculates is lower, and measuring and calculating is inaccurate when the portable terminal translational speed is low.In embodiments of the present invention, time-parameters t _cCan set, be used for defining the pilot signal size of correlation time.For example, Long Term Evolution (LTE) technology frequency is the carrier frequency of 2.5GHz, and maximum Doppler frequency offset was 289Hz when then the translational speed of portable terminal was 120km/h, and corresponding pilot tone is about 1.1ms correlation time.Can set 1.1ms is a time-parameters that is used to define pilot signal size correlation time, with this standard, because up demodulated pilot signal (DMRS in the LTE system, DeModulation Reference Signals) be 0.5ms correlation time, and then DMRS can be called the pilot signal of correlation time less than setting-up time parameter (1.1ms).

In order to obtain bigger measuring and calculating scope, the embodiment of the invention can be T with correlation time ₁Pilot signal insert by measured frequency, this correlation time T ₁Less than parameter t sometime _c, adopt this pilot signal to estimate the first maximum Doppler frequency offset f _D1, its idiographic flow comprises:

Step S2011, calculating synchronization t different sub carrier frequency domain channel estimated value H (t) respectively is described correlation time of T in correlation time ₁Auto-correlation function value R (t)=H with 0 o'clock described correlation time ^*(t) H (t+T ₁) and R (0)=H ^*(t) H (t).

By pilot signal estimation frequency domain channel estimated value is known technology, does not do herein and gives unnecessary details.In embodiments of the present invention, if having a n+1 subcarrier, and with number 0,1,2......n-1, n represent, then calculating synchronization t different sub carrier frequency domain channel estimated value H (t) is described correlation time of T in correlation time ₁Comprise calculating with the auto-correlation function value of 0 o'clock described correlation time: R ₀(T ₁)=H ₀ ^*(t) H ₀(t+T ₁), R ₁(T ₁)=H ₁ ^*(t ₀) H ₁(t ₀+ T ₁) ..., R _n(T ₁)=H _n ^*(t) H _n(t+T ₁) and R ₀(0)=H ₀ ^*(t) H ₀(t), R ₁(0)=H ₁ ^*(t) H ₁(t) ..., R _n(0)=H _n ^*(t) H _n(t).

Step S2012, asking for pilot signal correlation time respectively is T ₁With the desired value E[H that is 0 the different frequency domain channel of different sub carrier constantly estimated values correlation time ^*(t) H (t+T ₁)] and E[H ^*(t) H (t)], wherein,

$E\left[H^{*}\left(t\right)H(t+T_1)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p(t_q+T_1)}{n\×s},$

$E\left[H^{*}\left(t\right)H\left(t\right)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p\left(t_q\right)}{n\×s},$ Described subscript p identifies the described different sub carrier and the different moment respectively with subscript q.

Pilot signal correlation time is T among the embodiment ₁The desired value calculating formula of the different estimated values of different sub carrier frequency domain channel constantly

$\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H}_p^{*}\left(t_q\right)H_p(t_q+T_1)}{n\×s}...........................\left(1\right)$

Launching back reality is: $E\left[H^{*}\left(t\right)H(t+T_1)\right]=$ $\left\{\right[H_0^{*}\left(t_0\right)H_0(t_0+T_1)+H_1^{*}\left(t_0\right)H_1(t_0+T_1)+...+H_n^{*}\left(t_0\right)H_n(t_0+T_1)]+$ $[H_0^{*}\left(t_1\right)H_0(t_1+T_1)+H_1^{*}\left(t_1\right)H_1(t_1+T_1)+...+H_n^{*}\left(t_1\right)H_n(t_1+T_1)]+...+$ $[H_0^{*}\left(t_{s-1}\right)H_0(t_{s-1}+T_1)+H_1^{*}\left(t_{s-1}\right)H_1(t_{s-1}+T_1)+...+H_n^{*}\left(t_{s-1}\right)H_n(t_{s-1}+T_1)]+$ ${[H}_0^{*}\left(t_s\right)H_0(t_s+T_1)+H_1^{*}\left(t_s\right)H_1(t_s+T_1)+...+H_n^{*}\left(t_s\right)H_n(t_s+T_1)\left]\right\}\÷(n\×s),$ It is similar that pilot signal is that the desired value calculating formula of 0 different estimated values of different sub carrier frequency domain channel is constantly launched the back correlation time, repeats no more.

Can learn from the desired value calculating formula of the foregoing description frequency domain channel estimated value, owing in computational process, in fact comprised t ₀To t _sTherefore subcarrier 0, also can use the method measuring and calculating maximum Doppler frequency offset even need carry out the system of frequency hopping communications to the frequency domain channel estimated value of subcarrier n constantly.For example, on frequency domain, calculating in the relevant schematic diagram of maximum Doppler frequency offset that the embodiment of the invention shown in Figure 3 provides, suppose that the user jumps to another frequency m from a communication frequency (carrier frequency) 0, because the desired value calculating formula E[H of frequency domain channel estimated value ^*(t) H (t+T ₁)] comprised the estimated value to frequency domain channel at frequency m place

And H _m(t _s+ T ₁), therefore, user's frequency hopping is not subjected to the constraint of technical solution of the present invention.In other words, the less restriction that is subjected to time-domain and frequency-domain scheduling of resource and multi-user's resource allocation policy of estimation maximum Doppler frequency offset on frequency domain that the embodiment of the invention provides relatively is fit to the system such as the scheduling of LTE or the like needs frequency modulation.

Step S2013 is to 2 π f _D1T ₁Zero Bessel function J for independent variable ₀(2 π f _D1T ₁) reflect and penetrate, promptly get the first maximum Doppler frequency offset f that estimates _D1, wherein,

$J_0\left(2\mathrm{\π}{f}_{d1}{T}_1\right)=\frac{E\left[H^{*}\left(t\right)H(t+T_1)\right]}{E\left[H^{*}\left(t\right)H\left(t\right)\right]}.$

Step S202 is according to the described first maximum Doppler frequency offset f _D1The translational speed of judgement portable terminal is between high velocity or is between low regime.

As previously mentioned, the maximum Doppler frequency offset measuring and calculating of adopting portable terminal that correlation time, less pilot signal moved low speed to produce is inaccurate.In embodiment provided by the invention, the translational speed that can suppose portable terminal in advance is higher, therefore can adopt pilot signal (for example, be the up demodulated pilot signal DMRS of 0.5ms correlation time in the LTE system) the estimation first maximum Doppler frequency offset f of correlation time less than a certain setting-up time parameter _D1(evaluation method such as step S2011 are to step S2013) is then according to the first maximum Doppler frequency offset f that estimates _D1The translational speed of judgement portable terminal is between high velocity or is between low regime.If being the translational speed of portable terminal, the result who judges is between high velocity, then the higher hypothesis of the translational speed of portable terminal is set up, adopt correlation time higher less than the first maximum Doppler frequency offset precision that a certain setting-up time parameter estimates, can be used as by the maximum Doppler frequency offset of measured frequency, otherwise, need estimation again.

In embodiments of the present invention, can judge that the translational speed of portable terminal be between high velocity or is between low regime with following method:

A, at first set a translational speed that is used to define portable terminal and be between high velocity or be in speed parameter u between low regime _b

B, then according to the first maximum Doppler frequency offset f that estimates _D1Calculate the translational speed of portable terminal correspondence;

In embodiments of the present invention, can be according to calculating formula

u＝vf _m/f _c...........................................(2)

Calculate the translational speed of portable terminal correspondence, wherein, u is the translational speed of portable terminal, and v is the light velocity in the vacuum, f _cBe carrier frequency, f _mThe first maximum general frequency deviation f that reins in that estimates to step S2013 for step S2011 _D1

C, if the translational speed u of portable terminal correspondence greater than the speed parameter u of described setting _b, the translational speed of then judging portable terminal is to be between high velocity, otherwise, judge that the translational speed of portable terminal is to be between low regime.

From calculating formula (2) as can be seen, the translational speed of portable terminal is to be proportional to the maximum Doppler frequency offset that produced with this translational speed, therefore, can also judge that the translational speed of portable terminal be between high velocity or is between low regime with following another kind of method:

A, the first maximum Doppler frequency offset f that relatively estimates _D1With the speed parameter u that sets _bCorresponding maximum Doppler frequency offset f _pBoth sizes;

B, if the maximum Doppler frequency offset f that estimates _mGreater than the speed parameter u that sets _bCorresponding maximum Doppler frequency offset f _p, the translational speed u that then judges portable terminal is between high velocity, otherwise, judge that the translational speed u of portable terminal is between low regime.

Step S203 if the translational speed of described portable terminal is between high velocity, then determines with the described first maximum Doppler frequency offset f _D1As the maximum Doppler frequency offset that calculates, otherwise estimation is by the second maximum Doppler frequency offset f of measured frequency on frequency domain _D2And determine with the described second maximum Doppler frequency offset f _D2As the maximum Doppler frequency offset that calculates.

In fact, step S203 is in the first maximum Doppler frequency offset f of back to estimating between low regime in the translational speed of judging portable terminal _D1The correction of being done.In other words, prior translational speed to portable terminal is in the hypothesis that (therefore needs to adopt the pilot signal estimation maximum Doppler frequency offset of correlation time less than a certain setting-up time parameter) between high velocity to be false, according to the explanation of preamble, must adopt estimate the second maximum Doppler frequency offset f again correlation time greater than the pilot signal of a certain setting-up time parameter _D2In embodiments of the present invention, can be T with correlation time ₂Pilot signal insert by measured frequency, this correlation time T ₂Greater than parameter t sometime _c(for example, the LTE system medium frequency that preamble is mentioned is the carrier frequency of 2.5GHz, and maximum Doppler frequency offset was 289Hz when the translational speed of portable terminal was 120km/h, corresponding pilot tone 1.1ms correlation time) adopts this pilot signal to estimate the second maximum Doppler frequency offset f _D2, its idiographic flow comprises:

Step S2031, calculating synchronization t different sub carrier frequency domain channel estimated value H (t) respectively is described correlation time of T in correlation time ₂Auto-correlation function value R (t)=H with 0 o'clock described correlation time ^*(t) H (t+T ₂) and R (0)=H ^*(t) H (t).

By pilot signal estimation frequency domain channel estimated value is known technology, does not do herein and gives unnecessary details.In embodiments of the present invention, if having a n+1 subcarrier, and with number 0,1,2......n-1, n represent, then calculating synchronization t different sub carrier frequency domain channel estimated value H (t) is described correlation time of T in correlation time ₂Comprise calculating with the auto-correlation function value of 0 o'clock described correlation time: R ₀(T)=H ₀ ^*(t) H ₀(t+T ₂), R ₁(T ₂)=H ₁ ^*(t ₀) H ₁(t ₀+ T ₂) ..., R _n(T ₂)=H _n ^*(t) H _n(t+T ₂) and R ₀(0)=H ₀ ^*(t) H ₀(t), R ₁(0)=H ₁ ^*(t) H ₁(t) ..., R _n(0)=H _n ^*(t) H _n(t).

Step S2032, asking for pilot signal correlation time respectively is T ₂With the desired value E[H that is 0 the different frequency domain channel of different sub carrier constantly estimated values correlation time ^*(t) H (t+T ₂)] and E[H ^*(t) H (t)], wherein,

$E\left[H^{*}\left(t\right)H(t+T_2)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p(t_q+T_2)}{n\×s},$

$E\left[H^{*}\left(t\right)H\left(t\right)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p\left(t_q\right)}{n\×s},$

Described subscript p identifies the described different sub carrier and the different moment respectively with subscript q.

Pilot signal correlation time is T among the embodiment ₂The desired value calculating formula of the different estimated values of different sub carrier frequency domain channel constantly

$\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H}_p^{*}\left(t_q\right)H_p(t_q+T_1)}{n\×s}...........................\left(1\right)$

Launching back reality is: $E\left[H^{*}\left(t\right)H(t+T_1)\right]=$ $\left\{\right[H_0^{*}\left(t_0\right)H_0(t_0+T_1)+H_1^{*}\left(t_0\right)H_1(t_0+T_1)+...+H_n^{*}\left(t_0\right)H_n(t_0+T_1)]+$ $[H_0^{*}\left(t_1\right)H_0(t_1+T_1)+H_1^{*}\left(t_1\right)H_1(t_1+T_1)+...+H_n^{*}\left(t_1\right)H_n(t_1+T_1)]+...+$ $[H_0^{*}\left(t_{s-1}\right)H_0(t_{s-1}+T_1)+H_1^{*}\left(t_{s-1}\right)H_1(t_{s-1}+T_1)+...+H_n^{*}\left(t_{s-1}\right)H_n(t_{s-1}+T_1)]+$ ${[H}_0^{*}\left(t_s\right)H_0(t_s+T_1)+H_1^{*}\left(t_s\right)H_1(t_s+T_1)+...+H_n^{*}\left(t_s\right)H_n(t_s+T_1)\left]\right\}\÷(n\×s),$ It is similar that pilot signal is that the desired value calculating formula of 0 different estimated values of different sub carrier frequency domain channel is constantly launched the back correlation time, repeats no more.

Can learn from the desired value calculating formula of the foregoing description frequency domain channel estimated value, owing in computational process, in fact comprised t ₀To t _sTherefore subcarrier 0, also can use the method estimation maximum Doppler frequency offset even need carry out the system of frequency hopping communications to the frequency domain channel estimated value of subcarrier n constantly.For example, in Fig. 3, suppose that the user jumps to another frequency m from a communication frequency (carrier frequency) 0, because the desired value calculating formula E[H of frequency domain channel estimated value ^*(t) H (t+T ₂)] comprised the estimated value to frequency domain channel at frequency m place

And H _m(t _s+ T ₂), therefore, user's frequency hopping is not subjected to the constraint of technical solution of the present invention.In other words, the less restriction that is subjected to time-domain and frequency-domain scheduling of resource and multi-user's resource allocation policy of estimation maximum Doppler frequency offset on frequency domain that the embodiment of the invention provides relatively is fit to the system such as the scheduling of LTE or the like needs frequency modulation.

Step S2013 is to 2 π f _D2T ₂Zero Bessel function J for independent variable ₀(2 π f _D2T ₂) reflect and penetrate, promptly get the second maximum Doppler frequency offset f that estimates _D2, wherein,

$J_0\left(2\mathrm{\π}{f}_{d2}{T}_2\right)=\frac{E\left[H^{*}\left(t\right)H(t+T_2)\right]}{E\left[H^{*}\left(t\right)H\left(t\right)\right]}.$

As one embodiment of the invention, can be the speed parameter u of setting with the translational speed 30km/h of portable terminal in the LTE system (carrier frequency is 2.6GHz) _b, the maximum Doppler frequency offset f that it is corresponding _pBe 72Hz.In embodiments of the present invention, if the first maximum Doppler frequency offset f to estimate less than a certain setting-up time parameter (for example, be the up demodulated pilot signal DMRS of 0.5ms correlation time in the LTE system) correlation time _D1Greater than 72Hz, perhaps, if the first maximum Doppler frequency offset f to estimate less than a certain setting-up time parameter correlation time _D1The translational speed of corresponding mobile terminal is greater than 30km/h, and the translational speed of then judging portable terminal is to be between high velocity, the first maximum Doppler frequency offset f that estimates _D1Comparatively accurate, can be used as by the maximum Doppler frequency offset of measured frequency.

Still the translational speed 30km/h with portable terminal in the LTE system (carrier frequency is 2.6GHz) is the speed parameter u of setting _b, its corresponding maximum Doppler frequency offset f _pFor 72Hz comes description of step S203 as an example.If the first maximum Doppler frequency offset f that estimate less than the pilot signal (for example, be the up demodulated pilot signal DMRS of 0.5ms correlation time in the LTE system) of a certain setting-up time parameter correlation time _D1Less than 72Hz, perhaps, if the first maximum Doppler frequency offset f to estimate less than the pilot signal of a certain setting-up time parameter correlation time _D1The translational speed of corresponding mobile terminal is less than 30km/h, then can adopt in the LTE system minimum correlation time is the monitoring pilot signal (SRS of 2ms, Sounding Reference Signals) estimation second maximum Doppler frequency offset, and with this second maximum Doppler frequency offset f that estimates _D2As by the maximum Doppler frequency offset of measured frequency.

By above explanation as can be known, the embodiment of the invention with correlation time less relatively pilot signal at first maximum Doppler frequency offset is estimated roughly, and be at a high speed or estimation again after between low regime with the translational speed that the estimation result distinguishes portable terminal, effectively utilized the pilot signal of big correlation time and the pilot signal of less correlation time favorable factor to the estimation result, and the also less restriction that is subjected to time-domain and frequency-domain scheduling of resource and multi-user's resource allocation policy of the estimation of frequency domain channel on frequency domain.

See also Fig. 4, a kind of device of calculating maximum Doppler frequency offset that the embodiment of the invention provides.For convenience of explanation, only show the part relevant with the embodiment of the invention.This device comprises:

Estimation block 41 is used for estimating by the first maximum Doppler frequency offset f of measured frequency on frequency domain _D1With the second maximum Doppler frequency offset f _D2

Judge module 42 is used for the first maximum Doppler frequency offset f according to described estimation block 41 estimations _D1The translational speed of judgement portable terminal is between high velocity or is between low regime, and it comprises:

First judging unit 421 is used for the first maximum Doppler frequency offset f that estimates according to described estimation block 41 _D1Calculate the translational speed of portable terminal correspondence, judge that the translational speed of portable terminal is to be between high velocity in the translational speed of portable terminal correspondence during greater than a default speed parameter, during less than a default speed parameter, judge that the translational speed of portable terminal is to be between low regime in the translational speed of portable terminal correspondence; Perhaps

Second judging unit 422 is used for the first maximum Doppler frequency offset f that more described estimation block 41 estimates _D1With the described default corresponding maximum Doppler frequency offset f of speed parameter _pSize, at the described first maximum Doppler frequency offset f _D1Maximum Doppler frequency offset f greater than described default speed parameter correspondence _pThe time, judge that the translational speed of portable terminal is to be between high velocity, at the described first maximum Doppler frequency offset f _D1Maximum Doppler frequency offset f less than described default speed parameter correspondence _pThe time, judge that the translational speed of portable terminal is to be between low regime;

Maximum Doppler frequency offset determination module 43 is used for determining with the described first maximum Doppler frequency offset f when described judge module 42 judges that the translational speed of described portable terminal is between high velocity _D1As the maximum Doppler frequency offset that calculates, perhaps, when described judge module 42 judges that the translational speed of described portable terminal is between low regime, determine the second maximum Doppler frequency offset f that estimates with described estimation block _D2As the maximum Doppler frequency offset that calculates.

Described estimation block 41 comprises:

First pilot signal is inserted submodule 411, and being used for to be T correlation time ₁Pilot signal insert by measured frequency, described correlation time T ₁Less than parameter t sometime _c

Described estimation block 41 further comprises:

The first estimation submodule 413, be T the correlation time that is used to adopt described first pilot signal to insert the submodule insertion ₁Pilot signal on frequency domain, estimate by the first maximum Doppler frequency offset f of measured frequency _D1, it comprises:

The first auto-correlation function computing unit 4131, being used for calculating respectively synchronization t different sub carrier frequency domain channel estimated value H (t) is described correlation time of T in correlation time ₁Auto-correlation function value R (t)=H with 0 o'clock described correlation time ^*(t) H (t+T ₁) and R (0)=H ^*(t) H (t);

First desired value is asked for unit 4132, is used for calculating the gained auto-correlation function values according to the described first auto-correlation function computing unit 4121, and asking for pilot signal correlation time respectively is T ₁With the desired value E[H that is 0 the different frequency domain channel of different sub carrier constantly estimated values correlation time ^*(t) H (t+T ₁)] and E[H ^*(t) H (t)], wherein,

$E\left[H^{*}\left(t\right)H(t+T_1)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p(t_q+T_1)}{n\×s},$

$E\left[H^{*}\left(t\right)H\left(t\right)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p\left(t_q\right)}{n\×s},$ Described subscript p identifies the described different sub carrier and the different moment respectively with subscript q;

Unit 4133 is penetrated in first reflection, is used for 2 π f _D1T ₁Zero Bessel function J for independent variable ₀(2 π f _D1T ₁) reflect and penetrate, promptly get the first maximum Doppler frequency offset f that estimates _D1, wherein,

$J_0\left(2\mathrm{\π}{f}_{d1}{T}_1\right)=\frac{E\left[H^{*}\left(t\right)H(t+T_1)\right]}{E\left[H^{*}\left(t\right)H\left(t\right)\right]}.$

In order when described judge module 42 judges that the translational speed of described portable terminal is between low regime, further to estimate the second maximum Doppler frequency offset f _D2, described estimation block 41 comprises:

Second pilot signal is inserted submodule 412, and being used for to be T correlation time ₂Pilot signal insert by measured frequency, described correlation time T ₂Less than the described t of parameter sometime _c

Described estimation block 41 further comprises:

The second estimation submodule 414, be T the correlation time that is used to adopt described second pilot signal to insert submodule 412 insertions ₂Pilot signal on frequency domain, estimate by the second maximum Doppler frequency offset f of measured frequency _D2, it comprises:

The second auto-correlation function computing unit 4141, being used for calculating respectively synchronization t different sub carrier frequency domain channel estimated value H (t) is described correlation time of T in correlation time ₂Auto-correlation function value R (t)=H with 0 o'clock described correlation time ^*(t) H (t+T ₂) and R (0)=H ^*(t) H (t);

Second desired value is asked for unit 4142, is used for calculating the gained auto-correlation function values according to the described second auto-correlation function computing unit 4141, and asking for pilot signal correlation time respectively is T ₂With the desired value E[H that is 0 the different frequency domain channel of different sub carrier constantly estimated values correlation time ^*(t) H (t+T ₂)] and E[H ^*(t) H (t)], wherein,

$E\left[H^{*}\left(t\right)H(t+T_2)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p(t_q+T_2)}{n\×s},$

$E\left[H^{*}\left(t\right)H\left(t\right)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p\left(t_q\right)}{n\×s},$ Described subscript p identifies the described different sub carrier and the different moment respectively with subscript q;

Unit 4143 is penetrated in second reflection, is used for 2 π f _D2T ₂Zero Bessel function J for independent variable ₀(2 π f _D2T ₂) reflect and penetrate, promptly get the second maximum Doppler frequency offset f that estimates _D2, wherein,

$J_0\left(2\mathrm{\π}{f}_{d2}{T}_2\right)=\frac{E\left[H^{*}\left(t\right)H(t+T_2)\right]}{E\left[H^{*}\left(t\right)H\left(t\right)\right]}.$

One of ordinary skill in the art will appreciate that all or part of step in the whole bag of tricks of the foregoing description is to instruct relevant hardware to finish by program, this program can be stored in the computer-readable recording medium, storage medium can comprise: read-only memory (ROM, Read Only Memory), random access memory (RAM, RandomAccess Memory), disk or CD etc.

More than the method and apparatus of the measuring and calculating maximum Doppler frequency offset that the embodiment of the invention provided is described in detail, used specific case herein principle of the present invention and execution mode are set forth, the explanation of above embodiment just is used for helping to understand method of the present invention and core concept thereof; Simultaneously, for one of ordinary skill in the art, according to thought of the present invention, the part that all can change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.

Claims (13)

1. a method of calculating maximum Doppler frequency offset is characterized in that, comprising:

Estimation is by the first maximum Doppler frequency offset f of measured frequency on frequency domain _D1

According to the described first maximum Doppler frequency offset f _D1The translational speed of judgement portable terminal is between high velocity or is between low regime;

If the translational speed of described portable terminal is between high velocity, then determine with the described first maximum Doppler frequency offset f _D1As the maximum Doppler frequency offset that calculates, otherwise estimation is by the second maximum Doppler frequency offset f of measured frequency on frequency domain _D2And determine with the described second maximum Doppler frequency offset f _D2As the maximum Doppler frequency offset that calculates.

2. calculate the method for maximum Doppler frequency offset according to claim 1, it is characterized in that, described on frequency domain the estimation by the first maximum Doppler frequency offset f of measured frequency _D1Comprise:

To be correlation time T ₁Pilot signal insert by measured frequency, described correlation time T ₁Less than parameter t sometime _c

Adopting described correlation time is T ₁Pilot signal on frequency domain, estimate by the first maximum Doppler frequency offset f of measured frequency _D1

3. as the method for measuring and calculating maximum Doppler frequency offset as described in the claim 2, it is characterized in that described employing described correlation time is T ₁Pilot signal on frequency domain, estimate by the first maximum Doppler frequency offset f of measured frequency _D1Comprise:

Calculating synchronization t different sub carrier frequency domain channel estimated value H (t) respectively is described correlation time of T in correlation time ₁Auto-correlation function value R (t)=H with 0 o'clock described correlation time ^*(t) H (t+T ₁) and R (0)=H ^*(t) H (t);

Asking for pilot signal correlation time respectively is T ₁With the desired value E[H that is 0 the different frequency domain channel of different sub carrier constantly estimated values correlation time ^*(t) H (t+T ₁)] and E[H ^*(t) H (t)], wherein,

$E\left[H^{*}\left(t\right)H(t+T_1)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p(t_q+T_1)}{n\×s},$

$E\left[H^{*}\left(t\right)H\left(t\right)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p\left(t_q\right)}{n\×s},$ Described subscript p identifies the described different sub carrier and the different moment respectively with subscript q;

To with 2 π f _D1T ₁Zero Bessel function J for independent variable ₀(2 π f _D1T ₁) reflect and penetrate, promptly get the first maximum Doppler frequency offset f that estimates _D1, wherein,

$J_0\left(2\mathrm{\π}{f}_{d1}{T}_1\right)=\frac{E\left[H^{*}\left(t\right)H(t+T_1)\right]}{E\left[H^{*}\left(t\right)H\left(t\right)\right]}.$

4. as the method for measuring and calculating maximum Doppler frequency offset as described in the claim 3, it is characterized in that, described on frequency domain estimation by the second maximum Doppler frequency offset f of measured frequency _D2Comprise:

To be correlation time T ₂Pilot signal insert by measured frequency, described correlation time T ₂Less than the described t of parameter sometime _c

Adopting described correlation time is T ₂Pilot signal on frequency domain, estimate by the second maximum Doppler frequency offset f of measured frequency _D2

5. as the method for measuring and calculating maximum Doppler frequency offset as described in the claim 4, it is characterized in that described employing described correlation time is T ₂Pilot signal on frequency domain, estimate by the second maximum Doppler frequency offset f of measured frequency _D2Comprise:

Calculating synchronization t different sub carrier frequency domain channel estimated value H (t) respectively is described correlation time of T in correlation time ₂Auto-correlation function value R (t)=H with 0 o'clock described correlation time ^*(t) H (t+T ₂) and R (0)=H ^*(t) H (t);

Asking for pilot signal correlation time respectively is T ₂With the desired value E[H that is 0 the different frequency domain channel of different sub carrier constantly estimated values correlation time ^*(t) H (t+T ₂] and E[H ^*(t) H (t)], wherein,

$E\left[H^{*}\left(t\right)H(t+T_2)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p(t_q+T_2)}{n\×s},$

$E\left[H^{*}\left(t\right)H\left(t\right)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p\left(t_q\right)}{n\×s},$ Described subscript p identifies the described different sub carrier and the different moment respectively with subscript q;

To with 2 π f _D2T ₂Zero Bessel function J for independent variable ₀(2 π f _D2T ₂) reflect and penetrate, promptly get the second maximum Doppler frequency offset f that estimates _D2, wherein,

$J_0\left(2\mathrm{\π}{f}_{d2}{T}_2\right)=\frac{E\left[H^{*}\left(t\right)H(t+T_2)\right]}{E\left[H^{*}\left(t\right)H\left(t\right)\right]}.$

6. calculate the method for maximum Doppler frequency offset according to claim 1, it is characterized in that, described according to the described first maximum Doppler frequency offset f _D1The translational speed of judgement portable terminal is between high velocity or is between low regime and comprises:

According to the first maximum Doppler frequency offset f that estimates _D1Calculate the translational speed of portable terminal correspondence;

If the translational speed of portable terminal correspondence is greater than a default speed parameter, the translational speed of then judging portable terminal is to be between high velocity, otherwise, judge that the translational speed of portable terminal is to be between low regime.

7. as the method for measuring and calculating maximum Doppler frequency offset as described in the claim 6, it is characterized in that, described according to the described first maximum Doppler frequency offset f _D1The translational speed of judgement portable terminal is between high velocity or is between low regime and comprises:

The more described first maximum Doppler frequency offset f _D1With the described default corresponding maximum Doppler frequency offset f of speed parameter _pSize;

If the described first maximum Doppler frequency offset f _D1Maximum Doppler frequency offset f greater than described default speed parameter correspondence _p, the translational speed of then judging portable terminal is to be between high velocity, otherwise, judge that the translational speed of portable terminal is to be between low regime.

8. a device of calculating maximum Doppler frequency offset is characterized in that, comprising:

Estimation block is used for estimating by the first maximum Doppler frequency offset f of measured frequency on frequency domain _D1With the second maximum Doppler frequency offset f _D2

Judge module is used for according to the described first maximum Doppler frequency offset f _D1The translational speed of judgement portable terminal is between high velocity or is between low regime;

The maximum Doppler frequency offset determination module is used for determining with the described first maximum Doppler frequency offset f when described judge module judges that the translational speed of described portable terminal is between high velocity _D1As the maximum Doppler frequency offset that calculates, perhaps, when described judge module judges that the translational speed of described portable terminal is between low regime, determine the second maximum Doppler frequency offset f that estimates with described estimation block _D2As the maximum Doppler frequency offset that calculates.

9. as the device of measuring and calculating maximum Doppler frequency offset as described in the claim 8, it is characterized in that described estimation block comprises:

First pilot signal is inserted submodule, and being used for to be T correlation time ₁Pilot signal insert by measured frequency, described correlation time T ₁Less than parameter t sometime _c

10. as the device of measuring and calculating maximum Doppler frequency offset as described in the claim 9, it is characterized in that described estimation block also comprises:

The first estimation submodule, be T the correlation time that is used to adopt described first pilot signal to insert the submodule insertion ₁Pilot signal on frequency domain, estimate by the first maximum Doppler frequency offset f of measured frequency _D1, it comprises:

The first auto-correlation function computing unit, being used for calculating respectively synchronization t different sub carrier frequency domain channel estimated value H (t) is described correlation time of T in correlation time ₁Auto-correlation function value R (t)=H with 0 o'clock described correlation time ^*(t) H (t+T ₁) and R (0)=H ^*(t) H (t);

First desired value is asked for the unit, is used for calculating the gained auto-correlation function value according to the described first auto-correlation function computing unit, and asking for pilot signal correlation time respectively is T ₁With the desired value E[H that is 0 the different frequency domain channel of different sub carrier constantly estimated values correlation time ^*(t) H (t+T ₁)] and E[H ^*S (t) H (t)], wherein,

$E\left[H^{*}\left(t\right)H(t+T_1)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p(t_q+T_1)}{n\×s},$

$E\left[H^{*}\left(t\right)H\left(t\right)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p\left(t_q\right)}{n\×s},$ Described subscript p identifies the described different sub carrier and the different moment respectively with subscript q;

The unit is penetrated in first reflection, is used for 2 π f _D1T ₁Zero Bessel function J for independent variable ₀(2 π f _D1T ₁) reflect and penetrate, promptly get the first maximum Doppler frequency offset f that estimates _D1, wherein,

$J_0\left(2\mathrm{\π}{f}_{d1}{T}_1\right)=\frac{E\left[H^{*}\left(t\right)H(t+T_1)\right]}{E\left[H^{*}\left(t\right)H\left(t\right)\right]}.$

11. the device as measuring and calculating maximum Doppler frequency offset as described in the claim 10 is characterized in that described estimation block comprises:

Second pilot signal is inserted submodule, and being used for to be T correlation time ₂Pilot signal insert by measured frequency, described correlation time T ₂Less than the described t of parameter sometime _c

12. the device as measuring and calculating maximum Doppler frequency offset as described in the claim 11 is characterized in that described estimation block also comprises:

The second estimation submodule, be T the correlation time that is used to adopt described second pilot signal to insert the submodule insertion ₂Pilot signal on frequency domain, estimate by the second maximum Doppler frequency offset f of measured frequency _D2, it comprises:

The second auto-correlation function computing unit, being used for calculating respectively synchronization t different sub carrier frequency domain channel estimated value H (t) is described correlation time of T in correlation time ₂Auto-correlation function value R (t)=H with 0 o'clock described correlation time ^*(t) H (t+T ₂) and R (0)=H ^*(t) H (t);

Second desired value is asked for the unit, is used for calculating the gained auto-correlation function value according to the described second auto-correlation function computing unit, and asking for pilot signal correlation time respectively is T ₂With the desired value E[H that is 0 the different frequency domain channel of different sub carrier constantly estimated values correlation time ^*(t) H (t+T ₂)] and E[H ^*(t) H (t)], wherein,

$E\left[H^{*}\left(t\right)H(t+T_2)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p(t_q+T_2)}{n\×s},$

$E\left[H^{*}\left(t\right)H\left(t\right)\right]=\frac{\underset{q=0}{\overset{s}{\mathrm{\Σ}}}\underset{p=0}{\overset{n}{\mathrm{\Σ}}}{H_p}^{*}\left(t_q\right)H_p\left(t_q\right)}{n\×s},$ Described subscript p identifies the described different sub carrier and the different moment respectively with subscript q;

The unit is penetrated in second reflection, is used for 2 π f _D2T ₂Zero Bessel function J for independent variable ₀(2 π f _D2T ₂) reflect and penetrate, promptly get the second maximum Doppler frequency offset f that estimates _D2, wherein,

$J_0\left(2\mathrm{\π}{f}_{d2}{T}_2\right)=\frac{E\left[H^{*}\left(t\right)H(t+T_2)\right]}{E\left[H^{*}\left(t\right)H\left(t\right)\right]}.$

13. the device as measuring and calculating maximum Doppler frequency offset as described in the claim 8 is characterized in that described judge module comprises:

First judging unit is used for the first maximum Doppler frequency offset f that estimates according to described estimation block _D1Calculate the translational speed of portable terminal correspondence, judge that the translational speed of portable terminal is to be between high velocity in the translational speed of portable terminal correspondence during greater than a default speed parameter, during less than a default speed parameter, judge that the translational speed of portable terminal is to be between low regime in the translational speed of portable terminal correspondence; Perhaps

Second judging unit is used for the first maximum Doppler frequency offset f that more described estimation block estimates _D1With the described default corresponding maximum Doppler frequency offset f of speed parameter _pSize, at the described first maximum Doppler frequency offset f _D1Maximum Doppler frequency offset f greater than described default speed parameter correspondence _pThe time, judge that the translational speed of portable terminal is to be between high velocity, at the described first maximum Doppler frequency offset f _D1Maximum Doppler frequency offset f less than described default speed parameter correspondence _pThe time, judge that the translational speed of portable terminal is to be between low regime.

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