CN101997800A - Method and device for estimating carrier frequency offset - Google Patents

Abstract

The invention relates to the field of communication and discloses a method and device for estimating the carrier frequency offset. In the invention, the frequency offset is added to a local training sequence according to the step length in a receiving end, the detection amplitude (or the power) can be acquired by training sequence data received by the frequency offset-added local training sequence correlation, and the carrier frequency offset of the local training sequence correlation can be detected through the combined amplitude (or the power). By using the frequency offset-added local training sequence and the received training sequence to estimate the carrier frequency offset, the detection range of the carrier offset is wider and the detection precision is higher. In addition, the detection method for the carrier frequency offset is irrelevant with the mode of the system, thus the invention is free from being limited in the modulation mode of the system and can be applied to various communication systems, GSM (Global System for Mobile Communications), CDMA(Code Division Multiple Access) 2000/CDMA95, WCDMA(Wideband Code Division Multiple Access), TD-SCDMA(Time Division-Synchronization Code Division Multiple Access) and the like.

Description

The method of estimation of carrier wave frequency deviation and device thereof

Technical field

The present invention relates to the communications field, particularly the carrier wave frequency deviation detection technique in the communications field.

Background technology

In various carrier communication systems, the carrier frequency of receiving terminal carrier frequency very possible and transmitting terminal is inconsistent, at this moment, usually can be by the information detection receiving terminal of transmitting terminal emission and the carrier wave frequency deviation between the transmitting terminal at receiving terminal, and adjust the carrier frequency of receiving terminal, thereby the frequency of locking receiving terminal, the reliable transmission of assurance communication.Such as at global system for mobile communications (Global System for Mobile communication, abbreviation " GSM ") in the system, the frequency stability of system requirements mobile phone terminal reaches 0.1ppm, the deviation of the carrier frequency of mobile phone terminal detection of handset that must continue and base station like this, and adjust the radio-frequency (RF) local oscillator of mobile phone terminal, thereby guarantee that the carrier frequency of mobile phone and the carrier frequency of base station remain in the 0.1ppm.Can be 5450456 United States Patent (USP) referring to the patent No. about the detection technique of carrier wave frequency deviation.

At present, the method for estimation of Chang Yong carrier wave frequency deviation has following two kinds:

(1) in general carrier wave digital communication system, the capital regularly sends various training sequences (pilot frequency sequence), in receiving terminal, can do synchronously by these training sequences, channel estimating, Nonlinear Transformation in Frequency Offset Estimation etc., the method for estimation of general carrier wave frequency deviation is: 2 sections pilot frequency sequences on the different time are detected its time domain respectively impact respective phase; Calculate its frequency departure by its phase difference and time difference.

(2) carry out frequency offset estimating by demodulated data,, calculate frequency deviation according to phase deviation as the phase deviation of statistics demodulated data on constellation diagram.

Yet the present inventor finds that if adopt aforesaid way (1) to carry out the estimation of carrier frequency, detection range is big inadequately, in 2 sections pilot tone institute interlude sections, its impact the respective phase difference need

In, this will limit the detection range of its frequency offset estimating, and performance is with rapid deterioration when frequency deviation surpasses this scope.And, adopt its performance of method of estimation of aforesaid way (1) usually poor, so its accuracy of detection will be controlled within the specific limits, need very long detection time.And for detect frequency deviation (being the frequency deviation estimating method of aforesaid way (2)) by the phase deviation on the constellation diagram, under the situation of using high order modulation as 16QAM (quadrature amplitude modulation) etc., the performance of system will rapid deterioration, and its detection range is also smaller, system need can re-use frequency deviation region control earlier this method and further improve frequency stability within the specific limits by additive method.And above-mentioned dual mode is under high speed moving state of terminal, and its performance all will worsen.

Summary of the invention

The object of the present invention is to provide a kind of method of estimation and device thereof of carrier wave frequency deviation, enlarge the detection range of carrier wave frequency deviation, improve the accuracy of detection of carrier wave frequency deviation.

For solving the problems of the technologies described above, embodiments of the present invention provide a kind of method of estimation of carrier wave frequency deviation, comprise following steps:

Known local training sequence is added frequency deviation by step-length, obtained adding the local training sequence of frequency deviation;

According to the synchronizing information of current multipath k, the training sequence that receives is correlated with detected amplitude or detection power after obtaining to be correlated with the local training sequence that has added frequency deviation;

Calculate carrier wave frequency deviation according to detected amplitude that obtains or detection power.

Embodiments of the present invention also provide a kind of estimation unit of carrier wave frequency deviation, comprising:

Frequency deviation is added module, is used for known local training sequence is added frequency deviation by step-length, has obtained adding the local training sequence of frequency deviation;

Correlation module is used for the synchronizing information according to current multipath k, and the training sequence that receives is correlated with the local training sequence that has added frequency deviation, detected amplitude or detection power after obtaining to be correlated with;

The frequency offset calculation module is used for calculating carrier wave frequency deviation according to detected amplitude that obtains or detection power.

Embodiment of the present invention compared with prior art, the main distinction and effect thereof are:

In receiving terminal, local training sequence is added frequency deviation by step-length, the training sequence data that arrives by the local training sequence correlation reception of having added frequency deviation again, obtain detected amplitude (perhaps power), detect its carrier wave frequency deviation by the amplitude (perhaps power) after merging.The local training sequence that has added frequency deviation by utilization carries out the estimation of carrier wave frequency deviation with the training sequence that receives, and the scope that can make carrier wave frequency deviation detect is bigger, and the higher detection precision is arranged.And, because the detection method of carrier wave frequency deviation is not related with the pattern of system, therefore need not to be confined to the modulating mode of its system, go for various communication systems, GSM, CDMA (code division multiple access) 2000/CDMA95, WCDMA (Wideband Code Division Multiple Access (WCDMA)), TD-SCDMA (TD SDMA) or the like.

Further, before calculating carrier wave frequency deviation, earlier the power of current multipath k is adjudicated,, then utilize local training sequence that has added frequency deviation and the training sequence that receives to carry out the estimation of carrier wave frequency deviation again if the power of current multipath k is greater than presetting thresholding.Owing to earlier whether can satisfy frequency offset estimating to the power of current multipath require to adjudicate, therefore the synchronizing information detected amplitude or the detection power of this multipath that obtains possess certain reference value, have guaranteed the accuracy of the carrier wave frequency deviation that calculates.

Further, the detected amplitude or the detection power that are used to calculate carrier wave frequency deviation are multipath, multicycle, detected amplitude after the merging of many code channels or detection power, can further improve the accuracy of detection of carrier wave frequency deviation, make under situations such as high-speed mobile, also can guarantee the accuracy of the carrier wave frequency deviation that detects.

Description of drawings

Fig. 1 is the method for estimation flow chart according to the carrier wave frequency deviation of first embodiment of the invention;

Fig. 2 is the method for estimation flow chart according to the carrier wave frequency deviation of second embodiment of the invention;

Fig. 3 is the estimation unit schematic diagram according to the carrier wave frequency deviation of third embodiment of the invention.

Embodiment

In the following description, in order to make the reader understand the application better many ins and outs have been proposed.But, persons of ordinary skill in the art may appreciate that even without these ins and outs with based on the many variations and the modification of following each execution mode, also can realize each claim of the application technical scheme required for protection.

For making the purpose, technical solutions and advantages of the present invention clearer, embodiments of the present invention are described in further detail below in conjunction with accompanying drawing.

First embodiment of the invention relates to a kind of method of estimation of carrier wave frequency deviation, and idiographic flow as shown in Figure 1.

In step 110, whether the power of adjudicating current multipath k can be used for the detected carrier frequency deviation.Specifically, after system obtains smart synchronizing information or carries out channel estimating, the synchronizing information and the power information of multipath on each code channel will be obtained.At this moment, multipath power is adjudicated, if the power of current multipath k is greater than presetting thresholding, illustrate that then this multipath k can satisfy the requirement of frequency offset estimating, enter step 120, preset thresholding if be less than or equal to, illustrate that then this multipath k does not satisfy the requirement of frequency offset estimating, process ends.

Then, in step 120, known local training sequence is added frequency deviation by step-length.Specifically, be step-length according to Δ f, by following formula known local training sequence is added frequency deviation by step-length:

m＝-M，-M+1，-M+2，...-1，0，1，2...M；n＝1，2，...N。

Wherein, ± Δ f*M is the frequency deviation detection range, such as, need the frequency deviation region of detection to be ± 10Khz, step delta f is 1Khz, M can be set to 10 so.

Be immobile phase biased (can be set to 0) that Δ t is the time interval between two chips in the training sequence, N is the length of training sequence, and x (n) is known local training sequence, y _m(n) for having added the training sequence of frequency deviation.

In addition, the mode that is appreciated that the interpolation frequency deviation in the present embodiment is a concrete realization example, in actual applications, can also add frequency deviation to local training sequence by step-length by other modes.Such as, according to formula

N=1,2 ... N.Add frequency deviation, m can be revised as: m=-M, and-M+1 ,-M+2 ...-1,1,2...M; Perhaps m=0,1,2 ... M or the like.And Δ f can be with different under the different situation of m value, as y _m(n) can be revised as:

Δ f (m) is the frequency deviation step factor relevant with m.

Then, in step 130,, the training sequence that receives is correlated with detected amplitude or detection power after obtaining to be correlated with the local training sequence that has added frequency deviation according to the synchronizing information of current multipath k.

Specifically, according to the synchronizing information of multipath k, to the training sequence that receives with the local training sequence y that has added frequency deviation _m(n) relevant, obtain the correlation magnitude (or power) on the synchronous points.Such as the signal that receives is RecPilot (n), n=1, and 2 ... N is the training sequence that receives on multipath k synchronous points.Then can be correlated with the detected amplitude after obtaining to be correlated with by following formula with the local training sequence that has added frequency deviation to the training sequence that receives:

${\mathrm{AbsCorr}}_k\left(m\right)=|\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{RecPilot}\left(n\right)*y_m\left(n\right)|$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, AbsCorr _k(m) be the detected amplitude after relevant.

Perhaps, can be correlated with the detection power after obtaining to be correlated with by following formula with the local training sequence that has added frequency deviation to the training sequence that receives:

${\mathrm{AbsCorr}}_k\left(m\right)={[\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{RecPilot}\left(n\right)*y_m\left(n\right)]}^2$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, AbsCorr _k(m) be the detection power after relevant.

In addition, be appreciated that the calculating detected amplitude in the present embodiment or the mode of detection power are a concrete realization example.In actual applications, also can obtain detected amplitude or detection power after relevant by other various conversion examples.

Detected amplitude after acquisition is relevant or power (detected amplitude or all available AbsCorr of power after relevant _k(m) expression, AbsCorr _k(m) can be regarded as the expression correlated results) after, step 140 entered, according to the AbsCorr that obtains _k(m) calculate carrier wave frequency deviation.

It will be understood by those skilled in the art that and obtaining AbsCorr _k(m) after, can calculate carrier wave frequency deviation by variety of way, such as, according to the AbsCorr that obtains _k(m) the maximum value calculation carrier wave frequency deviation in perhaps, calculates the detected amplitude of acquisition or the difference of detection power, according to the Difference Calculation carrier wave frequency deviation that calculates.Exemplifying 3 kinds of modes below describes.

(1) directly at AbsCorr _k(m) look for maximum in, draw

Make

Maximum, at this moment, according to formula

Can calculate the value of frequency departure det ectf.

(2) at AbsCorr _k(m) look for maximum in, draw

Make

Maximum, and

With

In look for maximum or appoint and look for a value, establish it and be

According to formula

Can calculate the value of frequency departure detectf.Wherein, the plus-minus symbol " ± " in the formula by

With Front and back position decision, if

Greater than

Then get "+", otherwise, get "-".The calculating of γ can have several different methods, and is as follows:

$\mathrm{\γ}=\frac{\mathrm{\δ}}{(\mathrm{AbsC}{\mathrm{orr}}_k\left(\stackrel{\‾}{m}\right)+\mathrm{Abs}{\mathrm{Corr}}_k\left(\stackrel{=}{m}\right))+\mathrm{\ϵ}}$ Or

$\mathrm{\γ}=\frac{\mathrm{\δ}}{{\mathrm{AbsCorr}}_k\left(\stackrel{\‾}{m}\right)+\mathrm{\ϵ}}$ Or

$\mathrm{\γ}=\frac{\mathrm{\δ}}{{\mathrm{AbsCorr}}_k\left(\stackrel{=}{m}\right)+\mathrm{\ϵ}}$ Or

M can get arbitrary value in [M, M], or

Wherein

Be AbsCorr _kDetected average power when mean value (m) or channel estimating synchronous detecting.

Wherein, δ is the constant correction value.ε is the constant correction value, can be 0.Certainly, the computational methods of other γ can also be arranged, not give unnecessary details one by one at this.In addition, what deserves to be mentioned is, when in step 120,130, onlying demand AbsCorr _k(1) and AbsCorr _k(1) time, whole steps will further be simplified, and can pass through AbsCorr _k(1) and AbsCorr _kThe value of (1) two point is directly calculated det ectf with top method.

(3) calculate AbsCorr _k(m) difference DifAbsCorr _k(t), such as, according to formula DifAbsCorr _k(t)=AbsCorr _k(t)-AbsCorr _k(t-1), t=-M+1 ,-M+1 ...-1,0,1,2...M; Perhaps, according to formula DifAbsCorr _k(t)=AbsCorr _k(t-1)-AbsCorr _k(t), t=-M+1 ,-M+1 ...-1,0,1,2...M calculates AbsCorr _k(m) difference DifAbsCorr _k(t).

For DifAbsCorr _k(t) calculating only need be at AbsCorr _k(m) near the point the maximum calculates just passablely, there is no need whole calculating, also belongs to this scope of patent protection.

Theory can draw, DifAbsCorr _k(t) at AbsCorr _k(m) be that straight line distributes basically near the maximum, so we need calculate a and b in the parameter in its straight line y=ax+b equation, in the accounting equation method of a and b have multiple, as at AbsCorr _k(m) get 2 points in, directly solve an equation, can draw a and b; Perhaps carry out linear regression, calculate a and b, can also use other method, will be not described in detail here.After drawing a and b, we can calculate ax+b=0, obtain x, and x* Δ f is exactly the frequency offset estimating value of being asked.

Certainly, in actual applications, can also pass through AbsCorr _k(m) signal carries out curve fitting, AbsCorr _k(m) theory can be derived as the Cos distribution.

Be not difficult to find that the local training sequence that has added frequency deviation by utilization carries out the estimation of carrier wave frequency deviation with the training sequence that receives in the present embodiment, the scope that can make carrier wave frequency deviation detect is bigger.In many communication systems, as usually using DCXO (digitally controlled crystal oscillator) in the GSM mobile handset, frequency stability is merely able to be controlled at ± 15PPM in, perhaps initial frequency deviation reaches ± 30K, its frequency deviation of detection of using the frequency deviation estimating method in the present embodiment also can settle at one go.And the frequency deviation estimating method in the present embodiment has the higher detection precision, not only can be used in the thick frequency offset estimating of search phase, also can be used in the smart frequency offset estimating of tracking phase.And, because the detection method of carrier wave frequency deviation is not related with the pattern of system, therefore need not to be confined to the modulating mode of its system, go for various communication systems, as gsm system, cdma system and various 3G system (as TD-SCDMA, WCDMA, CDMA2000), Long Term Evolution (Long Term Evolution is called for short " LTE "), WiMax, various digital broadcast television systems in the Satellite Communication System, even can be used on terminal or the base station.

In addition, before calculating carrier wave frequency deviation, earlier the power of current multipath k is adjudicated,, then utilize local training sequence that has added frequency deviation and the training sequence that receives to carry out the estimation of carrier wave frequency deviation again if the power of current multipath k is greater than presetting thresholding.Owing to earlier whether can satisfy frequency offset estimating to the power of current multipath require to adjudicate, therefore the synchronizing information detected amplitude or the detection power of this multipath that obtains possess certain reference value, have guaranteed the accuracy of the carrier wave frequency deviation that calculates.

Second embodiment of the invention relates to a kind of method of estimation of carrier wave frequency deviation.Second execution mode improves on the basis of first execution mode, main improvements are: if the power that many multipaths are arranged is greater than presetting thresholding, then according to the synchronizing information of each multipath, obtain detected amplitude or detection power after each multipath relevant respectively.

If what obtain is detected amplitude, detected amplitude on each multipath that then will obtain merges, obtain the detected amplitude after multipath merges, detected amplitude after again multipath being merged is carried out the merging of the detected amplitude of a plurality of training sequence cycle and many code channels again, the detected amplitude after obtaining multipath, multicycle, many code channels and merging.

If what obtain is detection power, detection power on each multipath that then will obtain merges, obtain the detection power after multipath merges, detection power after again multipath being merged is carried out the merging of the detection power of a plurality of training sequence cycle and many code channels again, the detection power after obtaining multipath, multicycle, many code channels and merging.

In the step of calculating carrier wave frequency deviation, calculate carrier wave frequency deviation according to detected amplitude or detection power after multipath, multicycle, the merging of many code channels.

Idiographic flow in step 210, is adjudicated the power of each multipath as shown in Figure 2, obtains greater than each multipath that presets thresholding.

Then, in step 220, be step-length according to Δ f, respectively known local training sequence is added frequency deviation, this step is identical with step 120, does not repeat them here.

Then, in step 230, to the training sequence that receives with the local training sequence y that has added frequency deviation _m(n) relevant, amplitude (or power) AbsCorr after obtaining to be correlated with _k(m), this step is identical with step 130, does not repeat them here.

Then, in step 240, to each multipath, multicycle, the AbsCorr of many code channels _k(m) merge.Specifically, if detect many multipaths are arranged power greater than the frequency offset estimating thresholding, detected AbsCorr on each multipath _k(m) amplitude combines and is made as MutiPathAbsCorr (m), can obtain MutiPathAbsCorr (m) by following formula:

$\mathrm{MutiPathAbsCorr}\left(m\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\mathrm{\α}\left(k\right)*\mathrm{AbsCo}{\mathrm{rr}}_k\left(m\right)$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, M are the parameter that the frequency deviation region of detection as required is provided with, AbsCorr _k(m) be detected amplitude or detection power after k bar multipath relevant, K is many through quantity for what participate in merging, and α (k) be the function of k, can obtain according to various merging method, as etc. amplitude merge maximum likelihood ratio merging or the like.

In order to improve precision, can merge again MutiPathAbsCorr (m) in many training sequences cycle, and for merging (as the TD-SCDMA system in the many code channels of cdma system, the training sequence of training sequence Middleamble wherein behind the Shift that includes Basic Middleamnble on each code channel, can detect the training sequence behind the Shift of Middleamble and merge this moment).Specifically can adopt following formula to carry out the merging of multicycle, many code channels:

$\mathrm{CombAbsCorr}\left(m\right)=\underset{s=1}{\overset{S}{\mathrm{\Σ}}}\mathrm{\β}\left(s\right)*\mathrm{MutiPathAbsCor}{r}_s\left(m\right)$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, CombAbsCorr (m) they are detected amplitude or detection power (if the AbsCorr after multipath, multicycle, the merging of many code channels _k(m) expression detected amplitude, then CombAbsCorr (m) is the detected amplitude after multipath, multicycle, the merging of many code channels; If AbsCorr _k(m) expression detection power, then CombAbsCorr (m) is the detection power after multipath, multicycle, the merging of many code channels); S is the periodicity of the training sequence of participation merging and the summation of code channel number.β (s) is the function of s, and is similar with α (k), can obtain β (s) according to various merging method.

It will be understood by those skilled in the art that multipath, many code channels and multiply periodic merge order can exchange, and merge as carrying out the multicycle earlier, carry out multipath again and merge and carry out many code channels merging etc. again, being combined in this and giving unnecessary details no longer one by one of various merge orders.Certainly,, then can save some merging (as many code channels or multiply periodic merging), to reduce amount of calculation if the precision that detects can meet the demands.

In step 250, ask frequency deviation according to CombAbsCorr (m), this step is similar with step 140.Be that example describes still in 3 kinds of frequency offset calculation modes that exemplify in first execution mode.

(1) directly in CombAbsCorr (m), looks for maximum, draw Make

Maximum, the time, according to formula Can calculate the value of frequency departure detectf.

(2) in CombAbsCorr (m), look for maximum, draw

Make

Maximum, and With

In look for maximum or appoint and look for a value, establish it and be

According to formula

Can calculate the value of frequency departure detectf.Wherein, the plus-minus symbol " ± " in the formula by

With

Front and back position decision.The calculating of γ can have several different methods, and is as follows:

$\mathrm{\γ}=\frac{\mathrm{\δ}}{\left(\mathrm{CombAbsCorr}\left(\stackrel{\‾}{m}\right)\mathrm{CombAbsCorr}\left(\stackrel{=}{m}\right)\right)+\mathrm{\ϵ}}$ Or

$\mathrm{\γ}=\frac{\mathrm{\δ}}{\mathrm{CombAbsCorr}\left(\stackrel{\‾}{m}\right)+\mathrm{\ϵ}}$ Or

$\mathrm{\γ}=\frac{\mathrm{\δ}}{\mathrm{CombAbsCorr}\left(\stackrel{=}{m}\right)+\mathrm{\ϵ}}$ Or

M can get arbitrary value in [M, M], or

Wherein

Detected average power during for the mean value of CombAbsCorr (m) or channel estimating synchronous detecting.

Wherein, δ is the constant correction value.ε is the constant correction value, can be 0.Certainly, the computational methods of other γ can also be arranged, not give unnecessary details one by one at this.In addition, what deserves to be mentioned is, when in step 220,230,240, onlying demand CombAbsCorr (1) and CombAbsCorr (1), whole steps will further be simplified, and can pass through the value of CombAbsCorr (1) and (1) two point of CombAbsCorr and directly calculate detectf with top method.

(3) the difference DifCombAbsCorr (t) of calculating CombAbsCorr (m), such as, according to formula DifCombAbsCorr (t)=CombAbsCorr (t)-CombAbsCorr (t-1), t=-M+1 ,-M+1 ...-1,0,1,2...M;

Perhaps, DifCombAbsCorr (t)=CombAbsCorr (t-1)-CombAbsCorr (t), t=-M+1 ,-M+1 ...-1,0,1,2...M, the difference DifCombAbsCorr (t) of calculating CombAbsCorr (m).

For the calculating of DifCombAbsCorr (t), only need calculate just passablely near the point CombAbsCorr (m) maximum, there is no need whole calculating, also belong to this scope of patent protection.

Theory can draw, DifCombAbsCorr (t) is that straight line distributes basically near the maximum of CombAbsCorr (m), so we need calculate a and b in the parameter in its straight line y=ax+b equation, the method of a and b has multiple in the accounting equation, as in CombAbsCorr (m), getting 2 points, directly solve an equation, can draw a and b; Perhaps carry out linear regression, calculate a and b, can also use other method, will be not described in detail here.After drawing a and b, we can calculate ax+b=0, obtain x, and x* Δ f is exactly the frequency offset estimating value of being asked.

Certainly, in actual applications, can also be by CombAbsCorr (m) signal be carried out curve fitting, CombAbsCorr (m) theory can be derived as Cos and distribute.。

In addition, be appreciated that, in actual applications, multipath, many code channels, perhaps the detected amplitude (or power) in the multicycle can not merge (as first execution mode), perhaps only carries out part and merges, as just merging between the multipath, perhaps on the many code channels of multipath, merging or the like.Do not have for some communication system (as the GSM communication system) can think that code channel number is 1 under the situation of notion of code channel, need not merge between the code channel, therefore can be suitable for the method for estimation of the carrier wave frequency deviation in the present embodiment yet.

In the present embodiment, because being used to calculate the detected amplitude or the detection power of carrier wave frequency deviation is multipath, multicycle, detected amplitude after the merging of many code channels or detection power, therefore can further improve the accuracy of detection of carrier wave frequency deviation, make under situations such as high-speed mobile, also can guarantee the accuracy of the carrier wave frequency deviation that detects.

Need to prove that each method execution mode of the present invention all can be realized in modes such as software, hardware, firmwares.No matter the present invention be with software, hardware, or the firmware mode realize, instruction code can be stored in the memory of computer-accessible of any kind (for example permanent or revisable, volatibility or non-volatile, solid-state or non-solid-state, fixing or removable medium or the like).Equally, memory can for example be programmable logic array (Programmable Array Logic, be called for short " PAL "), random access memory (Random Access Memory, be called for short " RAM "), programmable read only memory (Programmable Read Only Memory, be called for short " PROM "), read-only memory (Read-Only Memory, be called for short " ROM "), Electrically Erasable Read Only Memory (Electrically Erasable Programmable ROM, be called for short " EEPROM "), disk, CD, digital versatile disc (Digital Versatile Disc is called for short " DVD ") or the like.

Third embodiment of the invention relates to a kind of estimation unit of carrier wave frequency deviation.The estimation unit of this carrier wave frequency deviation comprises as shown in Figure 3:

Frequency deviation is added module, is used for known local training sequence is added frequency deviation by step-length, has obtained adding the local training sequence of frequency deviation.Need to prove, when specific implementation, in order to reduce operand, can be directly calculate good interpolation the local sequence of frequency deviation preserve, that is to say this frequency deviation is added module also can in a disguised form be interpreted as it is the module of preserving the local sequence of having added frequency deviation.

Correlation module is used for the synchronizing information according to current multipath k, and the training sequence that receives is correlated with the local training sequence that has added frequency deviation, detected amplitude or detection power after obtaining to be correlated with.

The frequency offset calculation module is used for calculating carrier wave frequency deviation according to detected amplitude that obtains or detection power.

Judging module is used for the power of current multipath k is adjudicated, if the power of current multipath k greater than presetting thresholding, then indicates frequency deviation to add module known local training sequence is added frequency deviation by step-length.

Wherein, frequency deviation is added module and by following formula known local training sequence is added frequency deviation by step-length:

m＝-M，-M+1，-M+2，...-1，0，1，2...M；n＝1，2，...N

Wherein, ± Δ f*M is the frequency deviation detection range, Biased for immobile phase, Δ t is the time interval between two chips in the training sequence, and N is the length of training sequence, and x (n) is a training sequence, y _m(n) for having added the training sequence of frequency deviation.

Correlation module is correlated with the local training sequence that has added frequency deviation to the training sequence that receives by following formula, the detected amplitude after obtaining to be correlated with:

${\mathrm{AbsCorr}}_k\left(m\right)=|\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{RecPilot}\left(n\right)*y_m\left(n\right)|$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, AbsCorr _k(m) be the detected amplitude after relevant, RecPilot (n), n=1,2 ... the training sequence of N on the synchronous points of multipath k, receiving.

Perhaps, correlation module is correlated with the local training sequence that has added frequency deviation to the training sequence that receives by following formula, the detection power after obtaining to be correlated with:

${\mathrm{AbsCorr}}_k\left(m\right)={[\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{RecPilot}\left(n\right)*y_m\left(n\right)]}^2$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, AbsCorr _k(m) be the detection power after relevant, RecPilot (n), n=1,2 ... the training sequence of N on the synchronous points of described multipath k, receiving.

The frequency offset calculation module is according to detected amplitude that obtains or the maximum value calculation carrier wave frequency deviation in the detection power.Perhaps, the frequency offset calculation module is calculated the detected amplitude of acquisition or the difference of detection power, according to the Difference Calculation carrier wave frequency deviation that calculates.

Be not difficult to find that first execution mode is and the corresponding method execution mode of present embodiment, present embodiment can with the enforcement of working in coordination of first execution mode.The correlation technique details of mentioning in first execution mode is still effective in the present embodiment, in order to reduce repetition, repeats no more here.Correspondingly, the correlation technique details of mentioning in the present embodiment also can be applicable in first execution mode.

Four embodiment of the invention relates to a kind of estimation unit of carrier wave frequency deviation.The 4th execution mode improves on the basis of the 3rd execution mode, and main improvements are: the estimation unit of carrier wave frequency deviation also comprises:

Merge module, be used for the detected amplitude on each multipath is merged, obtain the detected amplitude after multipath merges, detected amplitude after again multipath being merged is carried out the merging of the detected amplitude of a plurality of training sequence cycle and many code channels again, the detected amplitude after obtaining multipath, multicycle, many code channels and merging; Perhaps, merging module merges the detection power on each multipath, obtain the detection power after multipath merges, detection power after again multipath being merged is carried out the merging of the detection power of a plurality of training sequence cycle and many code channels again, the detection power after obtaining multipath, multicycle, many code channels and merging.

This detected amplitude or detection power that merges after module indication frequency offset calculation module merges according to multipath, multicycle, many code channels is calculated carrier wave frequency deviation.

Specifically, detected amplitude or the detection power that merges on each multipath that module will obtain by following formula merges:

$\mathrm{MutiPathAbsCorr}\left(m\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\mathrm{\α}\left(k\right)*\mathrm{AbsCo}{\mathrm{rr}}_k\left(m\right)$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, M are the parameter that the frequency deviation region of detection as required is provided with, AbsCorr _k(m) be detected amplitude or detection power after k bar multipath relevant, MutiPathAbsCorr (m) is detected amplitude or the detection power of multipath after merging, and K is for participating in the many through quantity of merging.The merging of detected amplitude or detection power that detected amplitude after afterwards, the merging module merges the multipath that obtains by following formula again or detection power are carried out a plurality of training sequence cycle and many code channels:

$\mathrm{CombAbsCorr}\left(m\right)=\underset{s=1}{\overset{S}{\mathrm{\Σ}}}\mathrm{\β}\left(s\right)*\mathrm{MutiPathAbsCor}{r}_s\left(m\right)$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, CombAbsCorr (m) they are detected amplitude or the detection power after multipath, multicycle, the merging of many code channels; S is the periodicity of the training sequence of participation merging and the summation of code channel number.

Be not difficult to find that second execution mode is and the corresponding method execution mode of present embodiment, present embodiment can with the enforcement of working in coordination of second execution mode.The correlation technique details of mentioning in second execution mode is still effective in the present embodiment, in order to reduce repetition, repeats no more here.Correspondingly, the correlation technique details of mentioning in the present embodiment also can be applicable in second execution mode.

Need to prove, each unit of mentioning in each equipment execution mode of the present invention all is a logical block, physically, a logical block can be a physical location, it also can be the part of a physical location, can also realize that the physics realization mode of these logical blocks itself is not most important with the combination of a plurality of physical locations, the combination of the function that these logical blocks realized is the key that just solves technical problem proposed by the invention.In addition, for outstanding innovation part of the present invention, above-mentioned each the equipment execution mode of the present invention will not introduced not too close unit with solving technical problem relation proposed by the invention, and this does not show that there is not other unit in the said equipment execution mode.

Though pass through with reference to some of the preferred embodiment of the invention, the present invention is illustrated and describes, but those of ordinary skill in the art should be understood that and can do various changes to it in the form and details, and without departing from the spirit and scope of the present invention.

Claims (14)

1. the method for estimation of a carrier wave frequency deviation is characterized in that, comprises following steps:

Known local training sequence is added frequency deviation by step-length, obtained adding the local training sequence of frequency deviation;

According to the synchronizing information of current multipath k, the training sequence that receives is correlated with the described local training sequence that has added frequency deviation, obtain described detected amplitude or detection power after relevant;

Detected amplitude or detection power according to described acquisition are calculated carrier wave frequency deviation.

2. the method for estimation of carrier wave frequency deviation according to claim 1 is characterized in that, before entering described step to known local training sequence interpolation frequency deviation, also comprises following steps:

Power to current multipath k is adjudicated, if the power of current multipath k, then enters described step of known local training sequence being added frequency deviation again greater than presetting thresholding.

3. the method for estimation of carrier wave frequency deviation according to claim 2 is characterized in that, before the step of calculating described carrier wave frequency deviation, also comprises following steps:

If the power that many multipaths are arranged is greater than the described thresholding that presets,, obtain detected amplitude or detection power after each multipath relevant respectively then according to the synchronizing information of each multipath;

If what obtain is detected amplitude, detected amplitude on each multipath that then will obtain merges, obtain the detected amplitude after multipath merges, detected amplitude after again multipath being merged is carried out the merging of the detected amplitude of a plurality of training sequence cycle and many code channels again, the detected amplitude after obtaining multipath, multicycle, many code channels and merging;

If what obtain is detection power, detection power on each multipath that then will obtain merges, obtain the detection power after multipath merges, detection power after again multipath being merged is carried out the merging of the detection power of a plurality of training sequence cycle and many code channels again, the detection power after obtaining multipath, multicycle, many code channels and merging;

In the step of described calculating carrier wave frequency deviation, calculate carrier wave frequency deviation according to detected amplitude or detection power after described multipath, multicycle, the merging of many code channels.

4. the method for estimation of carrier wave frequency deviation according to claim 3 is characterized in that, detected amplitude or detection power on each multipath that will obtain by following formula merge:

$\mathrm{MutiPathAbsCorr}\left(m\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\mathrm{\α}\left(k\right)*\mathrm{AbsCo}{\mathrm{rr}}_k\left(m\right)$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, M are the parameter that the frequency deviation region of detection as required is provided with, AbsCorr _k(m) be detected amplitude or detection power after k bar multipath relevant, MutiPathAbsCorr (m) is detected amplitude or the detection power of multipath after merging, and K is for participating in the many through quantity of merging;

The merging of detected amplitude or detection power that detected amplitude after by following formula the multipath that obtains being merged or detection power are carried out a plurality of training sequence cycle and many code channels:

$\mathrm{CombAbsCorr}\left(m\right)=\underset{s=1}{\overset{S}{\mathrm{\Σ}}}\mathrm{\β}\left(s\right)*\mathrm{MutiPathAbsCor}{r}_s\left(m\right)$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, CombAbsCorr (m) they are detected amplitude or the detection power after multipath, multicycle, the merging of many code channels; S is the periodicity of the training sequence of participation merging and the summation of code channel number.

5. according to the method for estimation of each described carrier wave frequency deviation in the claim 1 to 4, it is characterized in that, known local training sequence added frequency deviation by step-length by following formula:

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M; N=1,2 ... N, ± Δ f*M are the frequency deviation detection range, Biased for immobile phase, Δ t is the time interval between two chips in the training sequence, and N is the length of training sequence, and x (n) is a training sequence, y _m(n) for having added the training sequence of frequency deviation.

6. according to the method for estimation of each described carrier wave frequency deviation in the claim 1 to 4, it is characterized in that, the training sequence that receives be correlated with the described local training sequence that has added frequency deviation, obtain described detected amplitude after relevant by following formula:

${\mathrm{AbsCorr}}_k\left(m\right)=|\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{RecPilot}\left(n\right)*y_m\left(n\right)|$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, AbsCorr _k(m) be the detected amplitude after relevant, Rec Pilot (n), n=1,2 ... the training sequence of N on the synchronous points of described multipath k, receiving;

Perhaps, the training sequence that receives is correlated with the described local training sequence that has added frequency deviation, obtains described detection power after relevant by following formula:

${\mathrm{AbsCorr}}_k\left(m\right)={[\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{RecPilot}\left(n\right)*y_m\left(n\right)]}^2$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, AbsCorr _k(m) be the detection power after relevant, RecPilot (n), n=1,2 ... the training sequence of N on the synchronous points of described multipath k, receiving.

7. according to the method for estimation of each described carrier wave frequency deviation in the claim 1 to 4, it is characterized in that, calculate in the step of carrier wave frequency deviation, comprise following substep in described detected amplitude or detection power according to described acquisition:

According to the detected amplitude of described acquisition or the maximum value calculation carrier wave frequency deviation in the detection power; Perhaps,

Calculate the detected amplitude of described acquisition or the difference of detection power, according to the described Difference Calculation carrier wave frequency deviation that calculates.

8. the estimation unit of a carrier wave frequency deviation is characterized in that, comprising:

Frequency deviation is added module, is used for known local training sequence is added frequency deviation by step-length, has obtained adding the local training sequence of frequency deviation;

Correlation module is used for the synchronizing information according to current multipath k, and the training sequence that receives is correlated with the described local training sequence that has added frequency deviation, obtains described detected amplitude or detection power after relevant;

The frequency offset calculation module is used for calculating carrier wave frequency deviation according to the detected amplitude or the detection power of described acquisition.

9. the estimation unit of carrier wave frequency deviation according to claim 8 is characterized in that, the estimation unit of described carrier wave frequency deviation also comprises:

Judging module is used for the power of current multipath k is adjudicated, if the power of current multipath k greater than presetting thresholding, then indicates described frequency deviation to add module known local training sequence is added frequency deviation by step-length.

10. the estimation unit of carrier wave frequency deviation according to claim 9 is characterized in that, the estimation unit of carrier wave frequency deviation also comprises:

Merge module, be used for the detected amplitude on each multipath is merged, obtain the detected amplitude after multipath merges, detected amplitude after again multipath being merged is carried out the merging of the detected amplitude of a plurality of training sequence cycle and many code channels again, obtain multipath, multicycle, detected amplitude after many code channels merge, perhaps, detection power on each multipath is merged, obtain the detection power after multipath merges, detection power after again multipath being merged is carried out the merging of the detection power of a plurality of training sequence cycle and many code channels again, obtains multipath, multicycle, detection power after many code channels merge;

Described merging module indicates detected amplitude or the detection power after described frequency offset calculation module merges according to described multipath, multicycle, many code channels to calculate carrier wave frequency deviation.

11. the estimation unit of carrier wave frequency deviation according to claim 10 is characterized in that, detected amplitude or detection power on each multipath that described merging module will obtain by following formula merge:

$\mathrm{MutiPathAbsCorr}\left(m\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\mathrm{\α}\left(k\right)*\mathrm{AbsCor}{r}_k\left(m\right)$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, M are the parameter that the frequency deviation region of detection as required is provided with, AbsCorr _k(m) be detected amplitude or detection power after k bar multipath relevant, MutiPathAbsCorr (m) is detected amplitude or the detection power of multipath after merging, and K is for participating in the many through quantity of merging;

The merging of detected amplitude or detection power that detected amplitude after described merging module merges the multipath that obtains by following formula or detection power are carried out a plurality of training sequence cycle and many code channels:

$\mathrm{CombAbsCorr}\left(m\right)=\underset{s=1}{\overset{S}{\mathrm{\Σ}}}\mathrm{\β}\left(s\right)*\mathrm{MutiPathAbsCor}{r}_s\left(m\right)$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, CombAbsCorr (m) they are detected amplitude or the detection power after multipath, multicycle, the merging of many code channels; S is the periodicity of the training sequence of participation merging and the summation of code channel number.

12. the estimation unit of each described carrier wave frequency deviation in 11 is characterized in that according to Claim 8, described frequency deviation add module by following formula to known local training sequence by step-length interpolation frequency deviation:

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M; N=1,2 ... N, ± Δ f*M are the frequency deviation detection range,

Biased for immobile phase, Δ t is the time interval between two chips in the training sequence, and N is the length of training sequence, and x (n) is a training sequence, y _m(n) for having added the training sequence of frequency deviation.

13. the estimation unit of each described carrier wave frequency deviation in 11 according to Claim 8, it is characterized in that, described correlation module is correlated with the described local training sequence that has added frequency deviation to the training sequence that receives by following formula, obtains described detected amplitude after relevant:

${\mathrm{AbsCorr}}_k\left(m\right)=|\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{RecPilot}\left(n\right)*y_m\left(n\right)|$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, AbsCorr _k(m) be the detected amplitude after relevant, RecPilot (n), n=1,2 ... the training sequence of N on the synchronous points of described multipath k, receiving;

Perhaps, the training sequence that receives is correlated with the described local training sequence that has added frequency deviation, obtains described detection power after relevant by following formula:

${\mathrm{AbsCorr}}_k\left(m\right)={[\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{RecPilot}\left(n\right)*y_m\left(n\right)]}^2$

Wherein, m=-M ,-M+1 ,-M+2 ...-1,0,1,2...M, AbsCorr _k(m) be the detection power after relevant, Rec Pilot (n), n=1,2 ... the training sequence of N on the synchronous points of described multipath k, receiving.

14. the estimation unit of each described carrier wave frequency deviation in 11 is characterized in that described frequency offset calculation module is according to the detected amplitude of described acquisition or the maximum value calculation carrier wave frequency deviation in the detection power according to Claim 8; Perhaps,

Described frequency offset calculation module is calculated the detected amplitude of described acquisition or the difference of detection power, according to the described Difference Calculation carrier wave frequency deviation that calculates.

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