CN1275403C - Frequency control method and device for WCDMA system - Google Patents

Abstract

The present invention discloses a frequency control device of a wideband code division multiple access system in the field of mobile communication. The frequency control device comprises a DPCCH frequency deviation compensator (201), a DPCCH coherent demodulator (202), a frequency deviation estimator (205), a frequency deviation controller (206), an autocorrelator (203) and a Doppler frequency deviation estimator (204). The present invention overcomes the defects that large system calculation amount, serious resource waste and low running efficiency existing in the prior art and caused by that the frequency deviation and the maximum Doppler frequency shift in a base station of the WCDMA system can not be simultaneously estimated; the present invention is a frequency control device and a frequency control method of a wideband code division multiple access system, which have the advantages of calculation amount and storage amount increase avoidance, quick estimation, wide range and reliability.

Description

Broadband CDMA system control method for frequency and device

Technical field:

The present invention relates to the wireless mobile communications field, relate in particular to the control method for frequency in the Frequency Division Duplexing (FDD) formula communication system of 3G (Third Generation) Moblie Wideband Code Division Multiple Access (WCDMA).

Background technology:

Expansion day by day along with mobile communcations system range of application in social every field, people are also more and more higher for the requirement of mobile communcations system, from early stage analog communication technology, develop into the digital communication technology of present voice-over signal, then towards the third generation mobile system development of data service.In any communication system, because physical device frequency drift long-term or short-term itself makes the crystal oscillator frequency of receiver and the crystal oscillator frequency of transmitter have certain deviation, be incorporated into if this frequency departure does not take measures to be eliminated and bring influence to communication quality in the communication system, so one of top priority of receiver is exactly to eliminate this frequency departure automatically in the communication system, the frequency of receiver and transmitter is complementary, also be usually said automatic frequency control (Automatic Frequency Control, AFC), equally also need to carry out automatic frequency control in WCDMA (Wideband Code Division Multiple Access) communication system.Propose in the Chinese patent 1264228 " automatic frequency control apparatus and method in the broadband CDMA system " after Cell searching obtains slot synchronization, frame synchronization and main scrambler number CPICH (Common Pilot Channel, Common Pilot Channel) channel descrambling and de-spreading, CPICH symbol after the demodulation is done fast fourier transform to frequency domain, extract frequency departure information according to energy spectrometer then.Its invention is at the portable terminal in the WCDMA system, but the base station receives and handles a plurality of users' signal simultaneously in the WCDMA system, if use same FFT (Fast Fourier Transform, fast fourier transform) technology, obviously amount of calculation is bigger, the hardware resource that consumes is more, is unlikely to realize.In Chinese patent 1318932 " portable mobile wireless electric system; wherein employed portable radio device and frequency error predicting method ", utilize in addition and postpone to grip altogether complex multiplication, calculate the phase information that arc tangent is obtained two plural numbers by the rotation of coordinate digital calculating method then, finally can the calculated rate deviation information.

In mobile radio communications system,, generally be referred to as Doppler frequency-shift f because the athletic meeting of travelling carriage itself causes another frequency shift (FS) _D( $f_D=\frac{v}{\mathrm{\λ}}\cos \mathrm{\α}{=f}_m\·\cos \mathrm{\α},$ f _mBe maximum Doppler frequency-shift, angle between the alpha wave arrival direction and the travelling carriage direction of motion), it has reflected the time-varying characteristics of wireless channel, the main and carrier wavelength of Doppler frequency-shift size, and the speed of travelling carriage and the travelling carriage direction of motion are relevant with the angle of electric wave arrival direction.Because wireless channel environment constantly changes in time, also will make corresponding change to the estimation of characteristics of radio channels, specifically, will do dynamic adjustment to the channel estimating filter length according to the Doppler frequency-shift size exactly.In radio communication, there is multipath transmisstion in addition,, seek the time delay and the phase information that arrive receiver multipath, and the coherent integration length of Multipath searching is with the Doppler frequency-shift dynamic change so will carry out Multipath searching at receiver end.So, must estimate the filter length of Doppler frequency-shift with the coherence length and the channel estimating of dynamic adjustment Multipath searching in order to improve the receptivity of WCDMA system base station receiver.Because maximum Doppler frequency-shift is only relevant with translational speed under certain carrier frequency, the equivalence so estimation of maximum Doppler frequency-shift and moving speed estimation are said so in some sense.Because in the WCDMA system, often need effectively estimate for translational speed, though pair method of WCDMA system base-station medium frequency estimation of deviation has been arranged, method of estimation for maximum doppler frequency is also arranged, but one can not carried out effective estimation approach to frequency departure and maximum doppler frequency simultaneously, thereby make in existing system, can only adopt two kinds of diverse ways that two kinds of parameters are estimated, amount of calculation is very huge, the storage demand of corresponding system is also very big, serious waste of resources owing to adopt two kinds of diverse ways, makes running efficiency of system low simultaneously.

Summary of the invention:

The objective of the invention is to overcome can't estimating WCDMA system base-station medium frequency deviation and maximum doppler frequency simultaneously of prior art existence, thereby cause that the system-computed amount is big, serious waste of resources, shortcoming that operational efficiency is low, a kind ofly can solve the estimation of WCDMA system base-station medium frequency deviation and the estimation of maximum Doppler frequency-shift simultaneously in the hope of proposing, avoid increasing amount of calculation and memory space, estimate rapidly, scope is wide, broadband CDMA system frequency control apparatus and method reliably.

For achieving the above object, the present invention has constructed a kind of broadband CDMA system frequency control apparatus, comprise DPCCH (Dedicated Physical Control Channel, Dedicated Physical Control Channel) compensate of frequency deviation device, DPCCH coherent demodulator, frequency departure estimator, frequency displacement controller comprise that also autocorrelator and Doppler frequency-shift estimate device;

Described DPCCH compensate of frequency deviation device receives the DPCCH symbol data behind the descrambling and de-spreading, the frequency offset information compensation DPCCH that utilization feeds back, carry out behind the frequency offset compensation it being sent into described DPCCH coherent demodulator, DPCCH compensate of frequency deviation device (201) receives the frequency departure information that is fed back by described frequency departure estimator (205), finish the compensate of frequency deviation of symbol, described DPCCH coherent demodulator removes the phase place deflection that transmitting terminal DPCCH symbol brings, signal is delivered to described autocorrelator, auto-correlation function to DPCCH is estimated, auto-correlation function result after estimating is delivered to described Doppler frequency-shift estimator and described frequency departure estimator respectively, estimate maximum Doppler frequency-shift value and frequency departure information respectively by described Doppler frequency-shift estimator and described frequency departure estimator; At last the Doppler frequency-shift value is input to described frequency displacement controller, calculates current Multipath searching coherent integration length and channel estimating filter length by described frequency displacement controller.

Described autocorrelator (203) further comprises delayer (501,502), grips multiplier (503), summer (504) altogether; I, the Q two-way part of DPCCH symbol behind described delayer (501,502) reception coherent demodulation and the compensate of frequency deviation, postpone the individual symbol of k (k=0,1,2,3 ° of ° of ° k are integer), enter the described multiplier (503) of gripping altogether with former I, Q data again, by described summer (504) value of taking advantage of of gripping altogether again of continuous a plurality of symbols is sued for peace, obtain the approximate correlation function value R (k) under some k values;

Estimation procedure is as follows as a result according to the auto-correlation function of importing for described Doppler frequency-shift estimator: the variable to auto-correlation function R (k) judges that from small to large the first step judges that whether R (k) is less than 0; Otherwise whether judge R (k) again, otherwise with regard to the Doppler frequency-shift value of direct given minimum less than certain given constant;

Described frequency departure estimator (205) further comprises arc tangent device (701), phase frequency deviation transducer (702) and filter (703), described arc tangent device (701) utilizes arctan function to ask the multiple angle of R (1), described phase frequency deviation transducer (702) is converted into the original frequency deviation with phase deviation, at last by described filter (703) to the filtering of original frequency deviation, to the end frequency deviation f.

The invention allows for a kind of broadband CDMA system control method for frequency, may further comprise the steps:

The first step: DPCCH symbol behind the frequency of utilization estimation of deviation value compensation descrambling and de-spreading;

Second step: the DPCCH symbol is carried out coherent demodulation;

The 3rd step: ask auto-correlation function R[k], k=0,1,2 ... k is an integer,

f _DBe maximum Doppler frequency-shift, _pBe that azimuth, p that p directly arrives the base station are that multipath numbering, l are symbol numeration, r[p, l] amplitude of l the symbol in expression p bar footpath; Ts is the DPCCH mark space;

The 4th the step: output auto-correlation function R[1], ask R[1] main argument, to the correspondent frequency deviate of converting, and this exemplary frequency deviation values done filtering, promptly obtain the exemplary frequency deviation values of system;

The 5th step: utilize the coherent integration length of the Doppler frequency-shift control Multipath searching of estimating and the filter length of channel estimating.

Correlation demodulation in described second step further may further comprise the steps:

(1) the DPCCH symbolic solution behind the frequency offset compensation is multiplexed with frequency pilot sign and non-frequency pilot sign;

(2) frequency pilot sign and the local pilot tone that produces are multiplied each other, non-frequency pilot sign determining device obtains the information of the non-frequency pilot sign of transmitting terminal;

(3) will obtain the information of the non-frequency pilot sign of transmitting terminal and the non-frequency pilot sign of reception multiplies each other;

(4) multiplexing treated frequency pilot sign and non-frequency pilot sign.

The interval of the value number of k and k itself can be chosen according to amount of calculation and the precision that requires Doppler frequency-shift to estimate in described the 3rd step, the 3rd step further may further comprise the steps: k is calculated since 0 according to formula, in case Re (R[k]) occurring occurs just being equivalent to find J smaller or equal to 0 ₀(2 π f _DKTs) first zero point; Otherwise calculate maximum k always,, illustrate that at this moment mobile station speed is smaller if first zero point also do not occur, adopt c*R[0] (0＜c＜1) replace 0, step above repeating, if also do not find the value of corresponding k, then direct given receptible minimum Doppler frequency-shift value.

Adopt method and apparatus of the present invention, can solve the estimation of WCDMA system base-station medium frequency deviation and the estimation of maximum Doppler frequency-shift simultaneously, avoid increasing amount of calculation and memory space, estimate rapidly, scope is wide, reliable.

Description of drawings:

Fig. 1 is a general base station RAKE receiver schematic diagram.

Fig. 2 is a broadband CDMA system frequency control apparatus structure chart of the present invention.

Fig. 3 is a DPCCH frequency compensation schematic diagram.

Fig. 4 is a DPCCH coherent demodulation schematic diagram.

Fig. 5 is that the DPCCH auto-correlation function is estimated schematic diagram.

Fig. 6 is the multispectral estimation schematic diagram of reining in.

Fig. 7 is that frequency departure is estimated schematic diagram.

Embodiment:

Be described in further detail below in conjunction with the enforcement of accompanying drawing technical scheme.According to these structure charts, the technical staff in same field can be easy to realize the present invention.

The algorithm principle of broadband CDMA system medium frequency control of the present invention is as follows:

If the p bar single drive signal that the base station receives through being down-converted to base band and the postscript of sampling is: $r_p\left(m\right)={\mathrm{\α}}_p{e}^{j{\mathrm{\θ}}_p}\left[I\left(m\right)+\mathrm{jQ}\left(m\right)\right],$ α _pThe expression channel fading, θ _pThe skew of expression channel phase, for easy, the initial phase of supposing to transmit is 0, and does not consider the phase shift that propagation delay causes, then θ _p=2 π (f _DCos _p+ Δ f) mTc, wherein m is the chip numeration, Tc is the chip time interval, f _DBe maximum Doppler frequency-shift, _pBe the azimuth that p directly arrives the base station, it should be the function of when and where, the carrier frequency offset of Δ f receiver (base station) and transmitter (travelling carriage).I (m) and Q (m) are respectively the DPDCH and the original chip data of DPCCCH of travelling carriage emission.

If be designated as through the base station receiver descrambling and de-spreading and to the DPCCH symbol after the DPCCH coherent demodulation: S[p, l], it is a plural number, and wherein p is the multipath numbering, and l is the symbol numeration, then $S[p,l]=r[p,l]{\mathrm{je}}^{j{\mathrm{\θ}}_p^{\′}},$ R[p wherein, l] and θ _p' represent the amplitude and the phase deviation of l the symbol in p bar footpath, then θ respectively _p'=2 π (f _DCos _p+ Δ f) lTs, Ts are the DPCCH mark space.

At first narrate maximum Doppler frequency-shift f _DEstimation principle.

Suppose through behind the desirable frequency offset compensation, then

If auto-correlation function is expressed as R _p[k], k are positive integer.

For a certain definite _p, when n＜0, make g=-n, then have

So

Order $R\left[k\right]=\underset{p}{\mathrm{\Σ}}{R}_p\left[k\right],$ Expression is sued for peace to the values of taking advantage of of gripping altogether again in all footpaths of arriving the base station from all directions, and then Re (R[k]) is J ₀(2 π f _DKTs) function.Because Re (R[k]) also comprised amplitude information, for fear of the error of bringing thus, choose J ₀(2 π f _DKTs)=0, asking for R[k] in observe Re (R[k]) size, in case Re (R[k]) occurs can stopping R[k smaller or equal to 0 o'clock] calculate, try to achieve f _D, our said instantaneity that Here it is.In order to reduce amount of calculation, auto-correlation function has only limited R[k], if Doppler frequency-shift is less, also be mobile station speed hour, at limited R[k] in can't satisfy J ₀(2 π f _DKTs), so at this moment we will estimate to be for further processing Here it is our said segmenting to little Doppler frequency-shift again.

Narrate frequency deviation f estimation principle below again.

Hypothesis (is got T=1 or 2Ts) usually in certain section time interval T now, supposes Doppler frequency-shift (f _DCos _p) and symbol amplitude (, being designated as r) in order to simplify constant substantially, R then _P[T]=r ²e ^{J2 π Δ fT}, obviously according to R _P[T] is easy to try to achieve 2 π Δ fT=atan (R _P[T])=, and then obtain frequency departure information $\mathrm{\Δf}=\frac{a\tan \left(R_P\right[T\left]\right)}{2\mathrm{\πT}},$ At this moment R _P[T] is exactly the R[k when k=1 or 2], so correlation method can while estimating frequency offset information and maximum Doppler frequency-shift.

The operating procedure following (corresponding) of broadband CDMA system medium frequency control of the present invention with accompanying drawing 2:

The first step: DPCCH symbol (201) behind the frequency of utilization skew estimated value compensation descrambling and de-spreading.

Second step: the DPCCH symbolic solution behind the frequency offset compensation is multiplexed with frequency pilot sign and non-frequency pilot sign, frequency pilot sign multiplies each other with the local pilot tone that produces, non-frequency pilot sign determining device obtains the information of the non-frequency pilot sign of transmitting terminal, multiply each other with the non-frequency pilot sign that receives again, just be equivalent to the demodulation of non-frequency pilot sign in fact, multiplexing treated frequency pilot sign and non-frequency pilot sign then, this coherent demodulation of DPCCH symbol just (202).

The 3rd step: ask auto-correlation function R[k], k=0,1,2 ... k is an integer, and the value number of k and the interval of k itself can be chosen according to amount of calculation and the precision that requires Doppler frequency-shift to estimate, in case Re (R[k]) occurring occurs just being equivalent to find J smaller or equal to 0 ₀(2 π f _DKTs) first zero point; Otherwise calculate maximum k always, if first zero point also do not occur, illustrate that at this moment mobile station speed is smaller, so just adopt c*R[0] (0＜c＜1) replace 0, step above repeating, if also do not find the value of corresponding k, then direct given receptible minimum doppler frequency (203).

The 4th the step: output auto-correlation function R[1] (plural number), ask R[1] main argument (being phase deviation), convert the correspondent frequency deviation then to, and this frequency departure done filtering, promptly obtain the frequency departure (204,205) of system.

The 5th step: utilize the coherent integration length of the Doppler frequency-shift control Multipath searching of estimating and the filter length (206) of channel estimating.

Fig. 1 is a general base station RAKE receiver schematic diagram.By entering into the base band RAKE receiver behind antenna 101.1 and 101.2 data down-conversions that receive, one the tunnel through multipath 102 and multipath distributor 103, find the time delay and the phase place of every multipath, give tracking descrambling and de-spreading device 104 with time delay and phase information then, the data utilization that the tracking descrambling and de-spreading gets off to antenna obtains phase information and carries out descrambling and de-spreading.DPCCH data behind the descrambling and de-spreading are delivered to frequency displacement controller 105, to be fixed frequency shift (FS) and Doppler frequency-shift, skew need be done compensation to fixed frequency, the filter length of Doppler frequency-shift information Control back channel estimating and feed back to the coherent integration length of Multipath searching with the control Multipath searching is to improve the reliability and the accuracy of Multipath searching.DPDCH behind the descrambling and de-spreading (Dedicated Physical Data Channel, Dedicated Physical Data Channel) and the DPCCH data enter channel estimating compensator 106 simultaneously, estimate channel phase shift and amplitude by DPCCH, then corresponding D PDCH data are done compensation; Enter multipath combiner 107 at last, the DPDCH data in each bar footpath are carried out high specific merge, so far just finished base band RAKE and received.DPDCH data after the merging enter the decoder of back.

Fig. 2 is the FREQUENCY CONTROL schematic diagram.The broadband CDMA system frequency control apparatus is made up of following components: A, DPCCH (Dedicated Physical Control Channel, Dedicated Physical Control Channel) compensate of frequency deviation device 201; B, DPCCH coherent demodulator 202; C, autocorrelator 203; D, Doppler frequency-shift are estimated device 204; E, frequency departure estimator 205; F, frequency displacement controller 206.

Particularly, various piece mainly contains following effect:

Described DPCCH (Dedicated Physical Control Channel, Dedicated Physical Control Channel) compensate of frequency deviation device 201 carries out frequency offset compensation according to the DPCCH symbol of the frequency departure of estimating after to descrambling and de-spreading, another scheme is exactly that the data that directly receive after doing down-sampled and A/D conversion at antenna are done frequency offset compensation, and the present invention only describes the device of first kind of scheme.

Described DPCCH coherent demodulator 202, remove exactly behind the compensate of frequency deviation the sign of DPCCH symbol (comprise up DPCCH and insert frequency pilot sign and non-frequency pilot sign) itself, eliminate because the phase place deflection that DPCCH symbol itself is brought.Frequency pilot sign among the DPCCH directly multiplies each other with the local frequency pilot sign that produces, non-frequency pilot sign then will utilize the frequency pilot sign after the coherent demodulation to realize through certain algorithm, the coherent demodulation of non-frequency pilot sign is a part of content of channel estimating in fact, it or not content of the present invention, so do not elaborate, directly utilize the partial results of channel estimating to get final product here.

DPCCH symbol after 203 pairs of frequency offset compensations of described autocorrelator and the coherent demodulation carries out auto-correlation processing, estimates the auto-correlation function of DPCCH.

Described Doppler frequency-shift estimator 204 utilizes auto-correlation function to estimate maximum Doppler frequency-shift.

Described frequency departure estimator 205 is taken from the wherein some values of correlation function by asking for arc tangent and being converted to frequency departure, further frequency departure filtering has just been obtained frequency departure accurately then.

Described frequency displacement controller 206 is determined the coherent integration length of Multipath searching and the filter length of channel estimating according to the Doppler frequency-shift size of estimating.

Fig. 3 is the described DPCCH compensate of frequency deviation of Fig. 2 device 201 structural representations.It receives the frequency departure that is fed back by frequency departure estimator 205, at first enters frequency plot offset assembly 301, converts frequency shift (FS) to each symbol respective phase skew (plural e ^{J θ}Form), then with the descrambling and de-spreading of direct input after the DPCCH data enter simultaneously and grip multiplier 302 altogether and grip again altogether and take advantage of, just be equivalent to finish the compensate of frequency deviation of symbol in fact.

Fig. 4 is described DPCCH coherent demodulator 202 structural representations of Fig. 2.It receives the DPCCH symbol data behind the compensate of frequency deviation, at first respectively to I, the data of Q two-way are by demodulation multiplexer 402 and 403, pilot portion and non-pilot portion are separated, local pilot tone generator 401 produces the frequency pilot sign identical with transmitting terminal, then with the I of the frequency pilot sign that receives, the Q two-way multiplies each other respectively, remove the phase place deflection that frequency pilot sign brings, promptly finish the coherent demodulation of frequency pilot sign, obtain the information of the non-frequency pilot sign of transmitting terminal in addition through non-frequency pilot sign determining device 404, the I of same and the non-frequency pilot sign that receives, the Q two-way multiplies each other through non-pilot demodulator 406 in I road and the non-pilot demodulator 408 in Q road respectively, remove the phase place deflection that non-frequency pilot sign brings, promptly finish the coherent demodulation (saying it is semi-coherent demodulation exactly) of non-frequency pilot sign, at last more respectively with I, the frequency pilot sign of Q two-way and non-frequency pilot sign are by multiplexer 409,410 is multiplexing, can obtain the I of DPCCH symbol behind coherent demodulation and the compensate of frequency deviation, the Q two-way.

Fig. 5 is described autocorrelator 203 structural representations of Fig. 2.Its input is I, the Q two-way of DPCCH symbol behind coherent demodulation and the compensate of frequency deviation, enter delayer 501 and 502 at first respectively, all postpone k (k=0,1,2 ... k is an integer) individual symbol, enter with former I, Q data then and grip multiplier 503 altogether, sue for peace in the value of taking advantage of of gripping altogether again of 504 pairs of continuous a plurality of symbols of summer again, promptly obtain the approximate correlation function value R (k) under some k values, get the auto-correlation function that a plurality of different k values have just obtained the DPCCH symbol.

Fig. 6 is the described Doppler frequency-shift estimation procedure of a Fig. 2 schematic diagram.Its input is the auto-correlation function of DPCCH symbol.Its process mainly is that the variable of auto-correlation function R (k) is judged from small to large, and the first step judges that whether R (k) is less than 0; Otherwise whether judge R (k) again, otherwise with regard to multispectral value of reining in of direct given minimum less than certain given constant.Fig. 5 and Fig. 6 should be in continuous processes, just just for the convenient mapping respectively of drawing in fact.

Fig. 7 is that frequency departure is estimated schematic diagram, and its input also is the auto-correlation function of DPCCH symbol.But only get wherein some functional values (generally being R (1)), at first arc tangent device 701 utilizes arctan function to ask the multiple angle of R (1), it is exactly a process of tabling look-up in fact, and phase frequency deviation transducer 702 is converted into initial frequency drift according to the principle of narrating previously with phase deviation then.Last 703 pairs of initial frequency drift filtering of filter (filtering is more flexible, both can do linear filtering, also can do nonlinear filtering etc.) have promptly obtained last frequency shift (FS) Δ f.

Claims (6)

1, a kind of broadband CDMA system frequency control apparatus, comprise DPCCH compensate of frequency deviation device (201), DPCCH coherent demodulator (202), frequency departure estimator (205), frequency displacement controller (206), it is characterized in that, also comprise autocorrelator (203) and Doppler frequency-shift estimator (204);

Described DPCCH compensate of frequency deviation device (201) receives the DPCCH symbol data behind the descrambling and de-spreading, the frequency offset information compensation DPCCH that utilization feeds back, carry out behind the frequency offset compensation it being sent into described DPCCH coherent demodulator (202), DPCCH compensate of frequency deviation device (201) receives the frequency departure information that is fed back by described frequency departure estimator (205), finish the compensate of frequency deviation of symbol, described DPCCH coherent demodulator (202) removes the phase place deflection that transmitting terminal DPCCH symbol brings, signal is delivered to described autocorrelator (203), described autocorrelator (203) is estimated the auto-correlation function of DPCCH, auto-correlation function result after estimating is delivered to described Doppler frequency-shift estimator (204) and described frequency departure estimator (205) respectively, estimate maximum Doppler frequency-shift value and frequency departure information respectively by described Doppler frequency-shift estimator (204) and described frequency departure estimator (205); At last the Doppler frequency-shift value is input to described frequency displacement controller (206), calculates current Multipath searching coherent integration length and channel estimating filter length by described frequency displacement controller (206);

Described autocorrelator (203) further comprises delayer (501,502), grips multiplier (503), summer (504) altogether; I, the Q two-way part of DPCCH symbol behind described delayer (501,502) reception coherent demodulation and the compensate of frequency deviation, postpone the individual symbol of k (k=0,1,2,3 ° of ° of ° k are integer), enter the described multiplier (503) of gripping altogether with former I, Q data again, by described summer (504) value of taking advantage of of gripping altogether again of continuous a plurality of symbols is sued for peace, obtain the approximate correlation function value R (k) under some k values;

Estimation procedure is as follows as a result according to the auto-correlation function of importing for described Doppler frequency-shift estimator: the variable to auto-correlation function R (k) judges that from small to large the first step judges that whether R (k) is less than 0; Otherwise whether judge R (k) again, otherwise with regard to the Doppler frequency-shift value of direct given minimum less than certain given constant;

Described frequency departure estimator (205) further comprises arc tangent device (701), phase frequency deviation transducer (702) and filter (703), described arc tangent device (701) utilizes arctan function to ask the multiple angle of R (1), described phase frequency deviation transducer (702) is converted into the original frequency deviation with phase deviation, at last by described filter (703) to the filtering of original frequency deviation, to the end frequency deviation f.

2, broadband CDMA system frequency control apparatus according to claim 1, it is characterized in that, described DPCCH compensate of frequency deviation device (201) further comprises frequency plot offset assembly (301) and grips multiplier (302) altogether, described frequency plot offset assembly (301) receives the frequency departure that is fed back by described frequency departure estimator (205), convert frequency departure to each symbol respective phase skew, then with the descrambling and de-spreading of direct input after the DPCCH data enter the described multiplier (302) of gripping altogether simultaneously and grip again altogether and take advantage of, finish the frequency departure compensation of symbol.

3, broadband CDMA system frequency control apparatus according to claim 1, it is characterized in that, described DPCCH coherent demodulator (202) further comprises local pilot tone generator (401), demodulation multiplexer (402,403), non-frequency pilot sign determining device (404), the I road pilot tone device (405) that is concerned with, relevant device (407) of Q road pilot tone and multiplexer (409,410), described demodulation multiplexer (402,403) respectively to I, the data of Q two-way are separated pilot portion and non-pilot portion, described local pilot tone generator (401) produces the frequency pilot sign identical with transmitting terminal, then with described demodulation multiplexer (402,403) I of Shu Chu frequency pilot sign, the Q two-way multiplies each other through relevant device (405) of I road pilot tone and the relevant device (407) of Q road pilot tone respectively, remove the phase place deflection that frequency pilot sign brings, finish the coherent demodulation of frequency pilot sign; Pass through described non-frequency pilot sign determining device (404) simultaneously and obtain the information of the non-frequency pilot sign of transmitting terminal, passing through the non-pilot demodulator of non-pilot demodulator in described I road (406) and Q road (408) respectively with I, the Q two-way of the non-frequency pilot sign that receives multiplies each other, remove the phase place deflection that non-frequency pilot sign brings, finish the coherent demodulation of non-frequency pilot sign; The frequency pilot sign of I, Q two-way and non-frequency pilot sign is multiplexing by described multiplexer (409,410), obtain I, the Q two paths of signals of DPCCH symbol behind coherent demodulation and the compensate of frequency deviation.

4, a kind of broadband CDMA system control method for frequency is characterized in that, may further comprise the steps:

The first step: DPCCH symbol behind the frequency of utilization estimation of deviation value compensation descrambling and de-spreading;

Second step: the DPCCH symbol is carried out coherent demodulation;

The 3rd step: ask auto-correlation function R[k], k=0,1,2 ... k is an integer,

f _DBe maximum Doppler frequency-shift, _pBe that azimuth, p that p directly arrives the base station are that multipath numbering, l are symbol numeration, r[p, l] amplitude of l the symbol in expression p bar footpath; Ts is the DPCCH mark space;

This step further may further comprise the steps: k is calculated since 0 according to formula, occur just being equivalent to find J smaller or equal to 0 in case Re (R[k]) occurs ₀(2 π f _DKTs) first zero point; Otherwise calculate maximum k always,, illustrate that at this moment mobile station speed is smaller, adopt c if first zero point also do not occur ^*R[0] replace 0, wherein top step is repeated in 0＜c＜1, if also do not find the value of corresponding k, then direct given receptible minimum Doppler frequency-shift value;

The 4th the step: output auto-correlation function R[1], ask R[1] main argument, to the correspondent frequency deviate of converting, and this value done filtering, promptly obtain the exemplary frequency deviation values of system;

The 5th step: utilize the coherent integration length of the Doppler frequency-shift value control Multipath searching of estimating and the filter length of channel estimating.

5, broadband CDMA system control method for frequency according to claim 4 is characterized in that, the correlation demodulation in described second step further may further comprise the steps:

(1) the DPCCH symbolic solution behind the frequency offset compensation is multiplexed with frequency pilot sign and non-frequency pilot sign;

(2) frequency pilot sign and the local pilot tone that produces are multiplied each other, non-frequency pilot sign determining device obtains the information of the non-frequency pilot sign of transmitting terminal;

(3) the non-frequency pilot sign of the information of the non-frequency pilot sign that will obtain and reception multiplies each other;

(4) multiplexing treated frequency pilot sign and non-frequency pilot sign.

6, broadband CDMA system control method for frequency according to claim 4 is characterized in that, the interval of the value number of k and k itself can be chosen according to amount of calculation and the precision that requires Doppler frequency-shift to estimate in described the 3rd step.

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