CN102281097B - The transmission method of TS0 time slot signal in a kind of TD-SCDMA system - Google Patents

Abstract

The invention discloses a kind of transmission method of TS0 time slot signal, comprise: the RRU in high-speed rail cell, TS0 time slot sends the default pilot signal of common channel signal and lasting whole TS0 time slot, and wherein, common channel signal and pilot signal are on mutually orthogonal code channel; Be positioned at the high ferro repeater on High Speed Railway Trains, for arbitrary carrier wave, receive described pilot signal at TS0 time slot, and according to the pilot signal that self preserves, estimate the channel characteristics of each chip on TS0 time slot; According to the channel characteristics of each chip on the TS0 time slot estimating to obtain, MMSE demodulation is carried out to common channel signal on TS0 time slot, obtains the chip level signal of common channel signal; Again the chip level signal obtained is carried on described arbitrary carrier wave, sends to the UE on High Speed Railway Trains.Application the present invention, can overcome Doppler's diffusion, and in raising high-speed rail cell, UE is to the signal receiving performance of TS0 time slot.

Description

The transmission method of TS0 time slot signal in a kind of TD-SCDMA system

Technical field

The present invention relates to the Doppler frequency shift technology of communication system in high-speed motion situation, particularly the transmission method of TS0 time slot signal in a kind of TD-SCDMA system.

Background technology

In a wireless communication system, when subscriber equipment (UE) high-speed mobile, there will be Doppler frequency shift.Doppler frequency shift is that high-speed railway covers the biggest problem faced, and the solution at present for Doppler frequency shift is as follows:

(1) automatic frequency control (AFC): the UE of UE carries out automatic frequency control, in real time in order to lock the frequency of base station;

(2) the auxiliary AFC of base station: base station by the up frequency deviation estimating UE, can compensate descending, to reduce the requirement to UE AFC function.

Meanwhile, switching also is the problem covered at a high speed, and in order to reduce switching, ordinary circumstance all can adopt the mode of distributing cell to cover, and Ji Yige community comprises multiple RRU, sends identical signal to UE simultaneously.

Under the coverage condition of distributing cell, the correcting frequency deviation problem of TS0 can be there is.Concrete distributing cell environment as shown in Figure 1, when train moves between two RRU, can there is different frequency deviations in the signal from two RRU that UE receives, when two signals intensity relatively time, Doppler's diffusion can be produced after superposition, time domain is shown as formation Selective intensity.The baseband signal that repeater receives can be expressed as:

$r\left(t\right)=\underset{l=1}{\overset{W}{\mathrm{\Σ}}}\underset{i=1}{\overset{848}{\mathrm{\Σ}}}{h}_{\mathrm{li}}{d}_{i}p(t-l{T}_c-i{T}_c)+n\left(t\right)$

Wherein h _libe l article of footpath, channel impulse response that i-th symbol is corresponding.Above-mentioned Doppler is spread, if do not add solution, UE can be caused cannot correctly to receive TS0 signal.And because TS0 time slot is for carrying broadcast singal, there is no corresponding up channel, therefore, the auxiliary AFC in base station cannot be applied and solve Doppler's diffusion problem.Meanwhile, the AFC due to UE is locked-center frequency, can only overcome Doppler frequency shift, and cannot overcome Doppler's diffusion.

Summary of the invention

In view of this, the invention provides a kind of transmission method of TS0 time slot signal, Doppler's diffusion can be overcome, improve UE to the receptivity of TS0 time slot signal.

For achieving the above object, the present invention adopts following technical scheme:

A transmission method for TS0 time slot signal, comprising:

RRU in high-speed rail cell, TS0 time slot sends the default pilot signal of common channel signal and lasting whole TS0 time slot, and wherein, common channel signal and pilot signal are on mutually orthogonal code channel;

Be positioned at the high ferro repeater on High Speed Railway Trains, for arbitrary carrier wave, receive described pilot signal at TS0 time slot, and according to the pilot signal that self preserves, estimate the channel characteristics of each chip on TS0 time slot;

According to the channel characteristics of each chip on the TS0 time slot estimating to obtain, MMSE demodulation is carried out to common channel signal on TS0 time slot, obtains the chip level signal of common channel signal; Again the chip level signal obtained is carried on described arbitrary carrier wave, sends to the UE on High Speed Railway Trains.

Preferably, describedly MMSE carried out to common channel signal on TS0 time slot be demodulated into:

$\hat{d}={(H^{H}H+{\mathrm{\σ}}^2)}^{-1}{H}^{H}r$

Wherein, the dimension of H is (848+W-1) × 848, for the chip level signal of common channel signal, σ ²for noise power, r is the common channel signal of TS0 time slot on described arbitrary carrier wave of receiving of high ferro repeater.

Preferably, describedly MMSE carried out to common channel signal on TS0 time slot be demodulated into:

The common channel signal segmentation of TS0 time slot on described arbitrary carrier wave that high ferro repeater is received, every section comprises N+W-1 sample point, and adjacent two sections have W repeated sample point; Described W is the multidiameter delay value of channel; Described N is the segmentation parameter of systemic presupposition;

Putting in order according to sample point, the sample point of each section of demodulation successively; Wherein, to the N+W-1 of an every section sample point, according to the channel characteristics of N+W-1 chip of correspondence, MMSE demodulation is carried out to N+W-1 the sample point of this section, and export the N number of chip level signal of demodulation result as correspondence of wherein top n sample point; To each in this section of remaining W sample point, from the Received signal strength of this sample point, other sample points in this section are eliminated the interference of this sample point, and W sample point after interference being eliminated is used for the demodulation of next a section of N+W-1 sample point.

Preferably, according to the computing capability of high ferro repeater and the accuracy requirement of demodulation result, described N is determined.

Preferably, carry out disturbing the mode eliminated be to each residue in W sample point in every section:

$r_i^{\′}=r_i-\underset{j=1}{\overset{W}{\mathrm{\Σ}}}{\hat{d}}_{i-W+j}\·h_{W-j+1,i-W+j}$

Wherein, r _ifor the Received signal strength of arbitrary sample point i in residue W sample point, r _i' be the result after sample point i elimination interference.

Preferably, the method comprises further: the pilot signal sending downlink synchronous sequence and lasting whole DwPTS time slot on DwPTS time slot, wherein, continue the pilot signal of whole DwPTS time slot with the pilot signal that TS0 time slot sends on identical code channel, or the code channel that employing is mutually orthogonal with the downlink synchronous sequence of DwPTS time slot;

Be positioned at the high ferro repeater on High Speed Railway Trains, for described arbitrary carrier wave, be received in the pilot signal that this time slot sends at DwPTS time slot, estimate the channel characteristics of each chip on DwPTS time slot;

According to the channel characteristics of each chip on the DwPTS time slot estimating to obtain, MMSE demodulation is carried out to the downlink synchronous sequence on DwPTS time slot, obtains the chip level signal of downlink synchronous sequence; Again the chip level signal obtained is carried on described arbitrary carrier wave, sends to the UE on High Speed Railway Trains.

Preferably, describedly MMSE carried out to the downlink synchronous sequence on DwPTS time slot be demodulated into:

${\hat{d}}^{\′}={(H^{\′H}{H}^{\′}+{\mathrm{\σ}}^{\′2})}^{-1}{H}^{\′H}{r}^{\′}$

Wherein, the dimension of H ＇ is (64+W-1) × 64, for the chip level signal of downlink synchronous sequence, σ ^{' 2}for noise power, r' is the downlink synchronous sequence of DwPTS time slot on described arbitrary carrier wave of receiving of high ferro repeater.

Preferably, describedly MMSE carried out to the downlink synchronous sequence on DwPTS time slot be demodulated into:

The downlink synchronous sequence segmentation of DwPTS time slot on described arbitrary carrier wave that high ferro repeater is received, every section comprises N ＇+W-1 sample point, and adjacent two sections have W repeated sample point; Described W is the multidiameter delay value of channel; Described N ＇ is the segmentation parameter of systemic presupposition;

To the N ＇+W-1 of every section sample point, according to the channel characteristics of N ＇+W-1 chip of correspondence, MMSE demodulation is carried out to N ＇+W-1 the sample point of this section, and export N ＇ the chip level signal of demodulation result as correspondence of a N ＇ sample point wherein; To each in this section of remaining W sample point, from the Received signal strength of this sample point, other sample points in this section are eliminated the interference of this sample point, and W sample point after interference being eliminated is used for the demodulation of next section of N ＇+W-1 sample point.

Preferably, according to the computing capability of high ferro repeater and the accuracy requirement of demodulation result, determine described N ＇.

Preferably, carry out disturbing the mode eliminated be to each residue in W sample point in after the downlink synchronous sequence segmentation of DwPTS time slot every section:

${r_i^{\′}}^{\′}={r_i}^{\′}-\underset{j=1}{\overset{W}{\mathrm{\Σ}}}{{\hat{d}}^{\′}}_{i-W+j}\·{h^{\′}}_{W-j+1,i-W+j}$

Wherein, r _i' for remaining the Received signal strength of arbitrary sample point i in W sample point in after the downlink synchronous sequence segmentation of DwPTS time slot every section, r _i' ' eliminate the result after interference for sample point i in after the downlink synchronous sequence segmentation of DwPTS time slot every section.

As seen from the above technical solution, in the present invention, the RRU in high-speed rail cell TS0 time slot send signal time, except transmission common channel signal except, further transmission continues the default pilot signal of whole TS0 time slot, and the code channel of the code channel of this pilot signal and common channel signal is mutually orthogonal.High ferro repeater on High Speed Railway Trains, for each carrier wave, receives the signal of TS0 time slot, comprising common channel signal and pilot signal.Pilot signal due to TS0 time slot continues whole TS0 time slot, therefore the pilot signal utilizing high ferro repeater to receive and the pilot signal of himself preserving, the channel characteristics obtaining each chip on TS0 time slot can be estimated, thus obtain the accurate channel characteristic of TS0 time slot; Recycle this characteristic of channel and MMSE demodulation is carried out to the common channel signal that TS0 time slot receives, obtain chip level signal accurately, eliminate Doppler's diffusion; Finally this chip level signal is carried in corresponding carriers and sends to UE.Like this, processed by high ferro repeater and the common channel signal of the TS0 time slot sent, be the signal having eliminated Doppler's diffusion, can directly carry out the process of demodulation code at UE place, greatly improve UE to the receptivity of TS0 time slot signal.

Accompanying drawing explanation

Fig. 1 is that the Doppler of TS0 time slot in distributing cell spreads schematic diagram.

Fig. 2 is the particular flow sheet of TS0 slot transmission method in the present invention.

Fig. 3 is the schematic diagram that in the embodiment of the present invention, RRU sends TS0 time slot signal.

Stepwise schematic views when Fig. 4 is MMSE segment processing in the embodiment of the present invention.

Embodiment

For making object of the present invention, technological means and advantage clearly understand, below in conjunction with accompanying drawing, the present invention is described in further details.

In the technical scheme that background technology provides, TS0 time slot comprises 848 chips altogether, for carrying out channel estimating, network side carries midamble sequence in middle 128+16 chip of TS0 time slot, like this, UE, according to the midamble sequence of self preserving and the midamble signal being received from network side, carries out channel estimating, and using the characteristic of channel of channel estimation results as whole TS0 time slot, for the solution mediation decoding of common channel signal.In above-mentioned channel estimation process, because midamble sequence utilizes 144, the centre chip of TS0 time slot to carry, therefore, the channel estimation results obtained according to this midamble sequencal estimation in fact reflects the characteristic of channel of 144 chips in the middle of TS0 time slot accurately, due to generally, can not be there is too large change in the characteristic of channel of whole TS0 time slot, therefore, the channel estimation results utilizing midamble sequence to obtain can as the characteristic of channel of whole TS0 time slot.But, in high-speed rail cell, because UE movement velocity is very high, therefore, there will be Doppler shift, two different Doppler shift signals intensity relatively time, there is Selective intensity, characteristic of channel generation great variety in TS0 time slot, in this case, the channel estimation results obtained by midamble sequence cannot characterize the characteristic of channel of whole TS0 time slot, therefore, UE cannot correct demodulation common channel signal, thus causes receptivity greatly to reduce.

Based on the analysis of the above-mentioned UE receptivity decline problem to being caused by Doppler shift in high-speed rail cell, basic thought of the present invention is: introduce the pilot signal continuing whole time slot at TS0 time slot, thus estimate the characteristic of channel obtaining each chip of TS0 time slot, recycle the demodulation that this characteristic of channel carries out common channel signal.

Below by specific embodiment, specific implementation of the present invention is described.

Fig. 2 is the transmission method flow chart of TS0 time slot signal in the embodiment of the present invention.As shown in Figure 2, the method comprises:

Step 201, the High Speed Railway Trains being arranged in high-speed rail cell arranges high ferro repeater.

Existing high ferro repeater is placed on High Speed Railway Trains, for receiving the signal of launching tower, after amplifying, is transmitted to UE again.Also need in the present invention to arrange high ferro repeater on High Speed Railway Trains, this high ferro repeater increases Base-Band Processing function, can carry out demodulation, frequency deviation is estimated and compensate of frequency deviation to the signal received.The realization of corresponding function is existing mode, is just integrated on high ferro repeater.

Step 202, the RRU in high-speed rail cell, sends common channel signal at TS0 time slot and continues the default pilot signal of whole TS0 time slot.

In the present invention, the pilot signal continuing whole time slot is sent at TS0 time slot, this pilot signal is that the present invention is newly-installed, the concrete Sequence composition of this pilot signal can be arranged as required, but must can continue whole TS0 time slot in time, and select the idle code channel of TS0 time slot to carry this pilot signal.The Sequence composition of concrete pilot signal is preserved in high ferro repeater in advance with the code channel information taken.

Wherein, Fig. 3 is the schematic diagram that in the present invention, TS0 time slot sends signal.As shown in Figure 3, assuming that common channel signal has PICH, S-CCPCH and P-CCPCH, each common channel signal takies 2 code channels, forms data-signal d=[d ₁d ₂d ₈₄₈], utilize other idle code channels except 6 code channels shared by above-mentioned three common channel signals in TS0 time slot, the continuous pilot signal that transmission the present invention is arranged, and this pilot signal is sent together with the data-signal of common signal channel.

Further, specify in existing 3GPP standard, the signal of TS0 time slot and the signal demand of DwPTS time slot ensure fixing phase relation, in the present invention, after TS0 time slot introduces the pilot signal continuing whole time slot, for meeting this phase relation, preferably, also need to introduce pilot signal at DwPTS time slot, continue whole DwPTS time slot, the code channel that on this time slot, pilot signal takies is identical with the code channel that newly-installed pilot signal on TS0 time slot takies, or adopts the code channel mutually orthogonal with the synchronizing sequence of DwPTS time slot.On this DwPTS time slot concrete, the concrete Sequence composition of pilot signal is preserved in high ferro repeater in advance with the code channel information taken.

Step 203, for arbitrary carrier wave, high ferro repeater receives newly-installed pilot signal at TS0 time slot, and utilizes this pilot signal to estimate the channel characteristics of each chip on TS0 time slot.

High ferro repeater, when carrying out signal transacting, can process multiple carrier signal, and wherein, the process for each carrier wave is all identical, is described below for one of them carrier wave.

The code channel information newly arranging pilot signal that high ferro repeater utilizes self to preserve, receives the newly-installed pilot signal of TS0 time slot, and utilizes the concrete Sequence composition of self preservation pilot signal, estimates the channel characteristics of each chip on TS0 time slot.The method of concrete channel estimating can adopt any existing mode to realize, and just repeats no more here.

Because newly-installed pilot signal continues whole TS0 time slot, therefore the channel estimation results obtained according to this pilot signal comprises the channel characteristics of each chip, namely obtained the channel estimation results of each chip corresponding by actual channel estimating, and be not using the channel characteristics of the channel characteristics of middle 144 chips as whole time slot 848 chips as existing mode.

Step 204, estimates the channel characteristics of each chip on the TS0 time slot that obtains, carries out MMSE demodulation, obtain the chip level signal of common channel signal to common channel signal on TS0 time slot according to step 203.

For high ferro repeater, the common channel signal received at TS0 time slot can be write as matrix form:

Wherein, $\left[\begin{array}{c}{d}_1\\ d_2\\ \·\\ \·\\ \·\\ d_{848}\end{array}\right]$ For the common channel signal sent in abovementioned steps 202, channel matrix for estimating the sytem matrix that the channel characteristics of whole each chip of TS0 time slot obtained is formed in step 203, the dimension of H is (848+W-1) × 848, can MMSE be adopted to solve transmission symbol d by through type (3) thus:

$\hat{d}={(H^{H}H+{\mathrm{\σ}}^2)}^{-1}{H}^{H}r---\left(3\right)$

Demodulation result for chip (chip) the level signal of common channel signal.Because in sytem matrix H, the channel characteristics of each chip is that actual estimated obtains, therefore, provided the actual channel situation comprising Selective intensity in this sytem matrix H, the demodulation result utilizing this actual channel situation to draw namely rectify a deviation after chip level signal.

But, if directly utilize above-mentioned formula (3) demodulation common channel signal, then due to R=H ^hh+ σ ²dimension be 848*848, computation complexity will be caused higher.

For reducing the computation complexity of MMSE process, in the present invention, provide a kind of MMSE demodulation mode of segmented.

Particularly, first, the common channel signal of the TS0 time slot received high ferro repeater carries out segmentation, and every section comprises N+W-1 sample point, and adjacent two sections have W-1 repeated sample point, and Fig. 4 is stepwise schematic views; Wherein, adjacent two sections of W-1 repeated sample points arranged, usually 16 are set to, N is the segmentation parameter of systemic presupposition, N is larger, and the accuracy of segment processing result is higher, and N is less, computation complexity is lower, can rationally arrange N value according to the disposal ability of high ferro repeater with to the required precision of result.

Next, when MMSE demodulation, putting in order according to sample point, the sample point of each section of demodulation successively; Wherein, to the N+W-1 of an every section sample point, according to the channel characteristics of N+W-1 chip of correspondence, MMSE demodulation is carried out to N+W-1 the sample point of this section, and export the N number of chip level signal of demodulation result as correspondence of wherein top n sample point; To each in this section of remaining W-1 sample point, from the Received signal strength of this sample point, other sample points in this section are eliminated the interference of this sample point, and W-1 sample point after interference being eliminated is used for the demodulation of next a section of N+W-1 sample point.

For first paragraph in Fig. 4, the signal phasor of this section of sample point formation can be expressed as:

Wherein, $\left[\begin{array}{c}{r}_1\\ r_2\\ \·\\ \·\\ \·\\ r_N\\ r_{N+1}\\ \·\\ \·\\ \·\\ r_{N+W-1}\end{array}\right]$ Represent N+W-1 sample point signal in the common channel signal first paragraph that high ferro repeater receives, for the channel matrix that the channel characteristics of N+W-1 chip of a corresponding first paragraph N+W-1 sample point is formed, $\left[\begin{array}{c}{d}_1\\ d_2\\ \·\\ \·\\ \·\\ d_N\\ d_{N+1}\\ \·\\ \·\\ \·\\ d_{N+W-1}\end{array}\right]$ For N+W-1 sample point of first paragraph in the chip level signal of the common channel signal of RRU transmission.

Use MMSE algorithm, can obtain:

$\left[\begin{array}{c}{\hat{d}}_1\\ {\hat{d}}_2\\ \·\\ \·\\ \·\\ {\hat{d}}_N\\ {\hat{d}}_{N+1}\\ \·\\ \·\\ \·\\ {\hat{d}}_{N+W-1}\end{array}\right]={[{\left(H^{\left(1\right)}\right)}^H{H}^{\left(1\right)}+{\mathrm{\σ}}^2]}^{-1}{\left(H^{\left(1\right)}\right)}^H{r}^{\left(1\right)}$

After obtaining above-mentioned estimation, export top n estimated value, as the estimated value of this sample point;

Recycling following formula pair $\left[\begin{array}{c}{r}_{N+1}\\ r_{N+2}\\ \·\\ \·\\ \·\\ r_{N+W-1}\end{array}\right]$ Carry out interference to eliminate:

$r_i^{\′}=r_i-\underset{j=1}{\overset{W}{\mathrm{\Σ}}}{\hat{d}}_{i-W+j}\·h_{W-j+1,i-W+j}i=N+1,...,N+W-1$

R _ifor the Received signal strength of sample point i, r _i' be the result after sample point i elimination interference.Afterwards, the r after interference being eliminated _i' substitute corresponding r _i, for carrying out second segment MMSE detection, by that analogy.

In above-mentioned segmentation MMSE process, in common channel signal after segmentation, adjacent two sections arrange W-1 repeated sample point, are the multi-path delay spread considered in mobile channel.Particularly, when system maximum delay expands to W chip, the value of sample point on arbitrary chip, the interference effect of sample point value on each W chip before and after it can be subject to, therefore, after carrying out common channel signal segmentation, for every segment signal, W, its foremost sample point and backmost W sample point, the interference of sample point value in other section can be subject to, based on this, when carrying out segmentation, by adjacent two sections, W sample point is set, and after every section of sample point carries out MMSE demodulation, only export top n sample point, and after the interference of sample point in this section to W sample point rear in this section is eliminated, a rear W sample point is used for the demodulation of next section of sample point.Like this, in every section of demodulating process, utilize the signal after eliminating interference the last period to carry out demodulation, and utilize demodulation result to eliminate the interference of this section to a rear segment signal, thus realize different points of intersegmental mutual interference step by step, demodulate chip level signal accurately.

Step 205, the chip level signal that step 204 demodulates by high ferro repeater, is carried on the UE corresponding carrier wave sent on High Speed Railway Trains.

High ferro repeater chip level signal is carried on corresponding carriers sends to UE time, specifically to send the process of signal identical process and base station for it, such as carry out Digital Up Convert, and other carrier waves on signal merges, digital-to-analogue conversion, to be modulated to corresponding carriers first-class.

After above-mentioned process, chip level signal after correction is sent to UE by high ferro repeater, and between high ferro repeater and UE, there is not the Selective intensity that extra Doppler frequency shift causes, therefore, UE can receive the chip level signal after correction according to existing mode, and carries out further data decision.

In addition, in abovementioned steps 202, if DwPTS time slot also sends the pilot signal of lasting whole time slot, then can according to the signal of mode process DwPTS time slot same as described above, namely high ferro repeater is according to the pilot signal of self preserving and the pilot signal being received from RRU, estimates the channel characteristics of whole each chip of DwPTS time slot, recycles this channel characteristics and carry out demodulation to downlink synchronous sequence, obtain chip level signal, finally this chip level signal is carried in corresponding carriers and sends to UE.Wherein, concrete channel estimating is identical with above-mentioned TS0 time slot with the process of MMSE demodulation, just because the number of chips of DwPTS time slot is different from TS0 time slot, and makes the dimension difference to some extent of corresponding system matrix H.

So far, method flow of the present invention terminates.According to the method for the invention described above, in high ferro repeater, accurately estimate the channel characteristics of whole each chip of TS0 time slot, and utilize it to carry out common channel signal demodulation, thus obtain the signal after correction, again signal after this correction is sent to UE, thus improve the receptivity of UE.

These are only preferred embodiment of the present invention, be not intended to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (8)

1. the transmission method of TS0 time slot signal in TD-SCDMA system, it is characterized in that, the method comprises:

RRU in high-speed rail cell, TS0 time slot sends the default pilot signal of common channel signal and lasting whole TS0 time slot, and wherein, common channel signal and pilot signal are on mutually orthogonal code channel;

Be positioned at the high ferro repeater on High Speed Railway Trains, for arbitrary carrier wave, receive described pilot signal at TS0 time slot, and according to the pilot signal that self preserves, estimate the channel characteristics of each chip on TS0 time slot;

According to the channel characteristics of each chip on the TS0 time slot estimating to obtain, MMSE demodulation is carried out to common channel signal on TS0 time slot, obtains the chip level signal of common channel signal; Again the chip level signal obtained is carried on described arbitrary carrier wave, sends to the UE on High Speed Railway Trains.

2. method according to claim 1, is characterized in that, describedly carries out MMSE to common channel signal on TS0 time slot and is demodulated into:

The common channel signal segmentation of TS0 time slot on described arbitrary carrier wave that high ferro repeater is received, every section comprises N+W-1 sample point, and adjacent two sections have W-1 repeated sample point; Described W is the multidiameter delay value of channel; Described N is the segmentation parameter of systemic presupposition;

Putting in order according to sample point, the sample point of each section of demodulation successively; Wherein, to the N+W-1 of an every section sample point, according to the channel characteristics of N+W-1 chip of correspondence, MMSE demodulation is carried out to N+W-1 the sample point of this section, and export the N number of chip level signal of demodulation result as correspondence of wherein top n sample point; To each in this section of remaining W-1 sample point, from the Received signal strength of this sample point, other sample points in this section are eliminated the interference of this sample point, and W-1 sample point after interference being eliminated is used for the demodulation of next a section of N+W-1 sample point.

3. method according to claim 2, is characterized in that, according to the computing capability of high ferro repeater and the accuracy requirement of demodulation result, determines described N.

4. method according to claim 2, is characterized in that, carries out disturbing the mode eliminated be to each residue in W-1 sample point in every section:

$r_i^{\′}=r_i-\underset{j=1}{\overset{W}{\mathrm{\Σ}}}{\hat{d}}_{i-W+j}\·h_{W-j+1,i-W+j}$

Wherein, r _ifor the Received signal strength of arbitrary sample point i in residue W-1 sample point, r _i' be the result after sample point i elimination interference, $\hat{d}=\left[\begin{array}{c}{\hat{d}}_1\\ {\hat{d}}_2\\ .\\ .\\ .\\ {\hat{d}}_{848}\end{array}\right]$ For the chip level signal of common channel signal, h _{w-j+1, i-W+j}for the channel impulse response in the i-th-W+j on TS0 time slot symbol, W-j+1 article footpath.

5. according to described method arbitrary in claim 1 to 4, it is characterized in that, the method comprises further: the pilot signal sending downlink synchronous sequence and lasting whole DwPTS time slot on DwPTS time slot, wherein, continue the pilot signal of whole DwPTS time slot with the pilot signal that TS0 time slot sends on identical code channel, or the code channel that employing is mutually orthogonal with the downlink synchronous sequence of DwPTS time slot;

Be positioned at the high ferro repeater on High Speed Railway Trains, for described arbitrary carrier wave, be received in the pilot signal that this time slot sends at DwPTS time slot, estimate the channel characteristics of each chip on DwPTS time slot;

According to the channel characteristics of each chip on the DwPTS time slot estimating to obtain, MMSE demodulation is carried out to the downlink synchronous sequence on DwPTS time slot, obtains the chip level signal of downlink synchronous sequence; Again the chip level signal obtained is carried on described arbitrary carrier wave, sends to the UE on High Speed Railway Trains.

6. method according to claim 5, is characterized in that, describedly carries out MMSE to the downlink synchronous sequence on DwPTS time slot and is demodulated into:

The downlink synchronous sequence segmentation of DwPTS time slot on described arbitrary carrier wave that high ferro repeater is received, every section comprises N ＇+W-1 sample point, and adjacent two sections have W-1 repeated sample point; Described W is the multidiameter delay value of channel; Described N ＇ is the segmentation parameter of systemic presupposition;

To the N ＇+W-1 of every section sample point, according to the channel characteristics of N ＇+W-1 chip of correspondence, MMSE demodulation is carried out to N ＇+W-1 the sample point of this section, and export N ＇ the chip level signal of demodulation result as correspondence of a N ＇ sample point wherein; To each in this section of remaining W-1 sample point, from the Received signal strength of this sample point, other sample points in this section are eliminated the interference of this sample point, and W-1 sample point after interference being eliminated is used for the demodulation of next section of N ＇+W-1 sample point.

7. method according to claim 6, is characterized in that, according to the computing capability of high ferro repeater and the accuracy requirement of demodulation result, determines described N ＇.

8. method according to claim 6, is characterized in that, carries out disturbing the mode eliminated be to each residue in W-1 sample point in after the downlink synchronous sequence segmentation of DwPTS time slot every section:

$r_i^{\′\′}={r_i}^{\′\′\′}-\underset{j=1}{\overset{W}{\mathrm{\Σ}}}{{\hat{d}}^{\′}}_{i-W+j}\·{h^{\′}}_{W-j+1,i-W+j}$

Wherein, r _i" ' for remaining the Received signal strength of arbitrary sample point i in W-1 sample point in after the downlink synchronous sequence segmentation of DwPTS time slot every section, r _i" eliminate the result after interference for sample point i in after the downlink synchronous sequence segmentation of DwPTS time slot every section, ${\hat{d}}^{\′}=\left[\begin{array}{c}{{\hat{d}}^{\′}}_1\\ {{\hat{d}}^{\′}}_2\\ .\\ .\\ .\\ {{\hat{d}}^{\′}}_{64}\end{array}\right]$ For the chip level signal of downlink synchronous sequence, h' _{w-j+1, i-W+j}for the channel impulse response in the i-th-W+j on DwPTS time slot symbol, W-j+1 article footpath.