CN101360077B - Data receiving method for TD-SCDMA system - Google Patents

Abstract

The invention discloses a data receive method used for a time division-synchronous code division multiple access (TD-SCDMA) system, comprising the following steps: S302, reconstructing a frame structure of the time division-synchronous code division multiple access (TD-SCDMA) system into a frame structure including two training sequences, and utilizing the two training sequences for channel estimation to a data division in the frame structure of the time division-synchronous code division multiple access (TD-SCDMA) system, wherein, the two training sequences are respectively positioned at the head part and the middle part of the frame structure of the time division-synchronous code division multiple access (TD-SCDMA) system; and S304, detecting the data division for receiving a data division according to channel estimation results of the data division. The invention can accurately detect the received data under the condition of rather high terminal movement velocity, particularly under high speed moving.

Description

The data receive method that is used for TDS-CDMA system

Technical field

The present invention relates to the communications field, relate more specifically to a kind of data receive method that is used for TDS-CDMA system.

Background technology

Existing TD SDMA (Time Division Synchronization CodeDivision Multiple Access; Be called for short TD-SCDMA) the basic frame structure of system is as shown in Figure 1, mainly by the long middle trained sequence (Mid-amble) of the long data division of each one 352 chip of two ends, middle 144 chips partly and the long protection of afterbody 16 chips at interval (GP) constitute.Wherein, data division also possibly comprise transport block format combination indication (TFCI), power control command word (TPC) and synchronous control command word (SS), and its position distribution is as shown in Figure 2.

Under existing TD-SCDMA system frame structure; Receiver utilizes Mid-amble partly to carry out channel estimating; And think that the channel fading characteristic of data division of both sides partly is consistent with Mid-amble; Therefore will bring in the equalizer of data division detection based on the channel estimation results of Mid-amble part, equalizer can adopt matched filtering or joint-detection mode to carry out Data Detection.

The random process that becomes when the wireless channel in the mobile communication is one, a typical characteristic is exactly the time selective fading characteristic.And the movement velocity at the correlation time of decline and terminal is relevant, and the big more decline of movement velocity is short more correlation time.Emulation and test result show; When movement velocity is no more than 120km/h at the terminal; Under the existing TD-SCDMA system frame structure; The correlation of the channel fading at Mid-amble part center and the decline of remote data local channel surpasses 90%, and therefore the channel estimating based on the Mid-amble part detects the data division that can be used for both sides fully.But after the terminal movement velocity further strengthened, the decline of Mid-amble local channel descended rapidly with the correlation of remote data local channel decline, and for example correlation has dropped to about 70% during the 250km/h movement velocity.At this moment, the channel estimating of Mid-amble part fully equivalence be the channel impulse response characteristic of both sides data division, the deterioration that directly utilizes its participation data division detection will bring receiver performance.

Summary of the invention

One or more problems in view of the above the invention provides a kind of data receive method that is used for TDS-CDMA system.

According to the data receive method that is used for TDS-CDMA system of the present invention; May further comprise the steps: S302; Transform the frame structure of TDS-CDMA system as comprise two training sequences frame structure; And utilize two training sequences that the data division in the frame structure of TDS-CDMA system is carried out channel estimating, wherein, two training sequences lay respectively at the stem and the middle part of the frame structure of TDS-CDMA system; And S304, according to the channel estimation results of data division, data portion detects, to receive data division.

Wherein, step S302 may further comprise the steps: S3022 transform the frame structure of TDS-CDMA system as comprise two training sequences frame structure; S3024 carries out channel estimating to two training sequences respectively, to draw the channel impulse response of two training sequences; And S3026, utilize the channel impulse response of two training sequences, draw the channel impulse response of data division.

Wherein, the length of two training sequences is identical, and is made up of the basic training sequences of 64 chip lengths and the Cyclic Prefix of 8 chip lengths respectively.Code word in two training sequences can be the same or different.

Wherein, in step S3024, through respectively two training sequences being carried out the signal impulse response that combined channel estimates to draw two training sequences.In step S3026, utilize the channel impulse response of two training sequences, draw the channel impulse response of a plurality of data sementations in the data division through linear interpolation and/or linear extrapolation method.In step S304, the mode data portion through joint-detection and/or matched filtering detects.

Wherein, Comprise at data division under the situation of transport block format combination indication and power control command word, after transport block format combination indication and the training sequence of power control command word immediately following the middle part of the frame structure that is positioned at TDS-CDMA system in two training sequences.

Wherein, carry out joint-detection through the following steps data portion: the corresponding sytem matrix A of a plurality of data sementations in the construction data part; Through associated detecting method, detect the symbolic information of a plurality of data sementations based on the linear block balance least mean-square error $d={(A^H{R}_n^{-1}A+R_d)}^{-1}\·A^H{R}_n^{-1}e,$ Wherein, e is that intermediate data partly receives signal, R _nBe noise correlation matrix, R _dBe signal correlation matrix, A ^HAssociate matrix for A.

Wherein, right through the Cholesky decomposition method $d={(A^H{R}_n^{-1}A+R_d)}^{-1}\·A^H{R}_n^{-1}e$ Simplify, wherein, the Cholesky decomposition method may further comprise the steps: calculate $T=A^H{R}_n^{-1}A+R_d,$ Obtain:

Wherein, the T matrix is a block diagonal matrix, and the first half of T matrix and Lower Half are also inconsistent; Respectively frame of broken lines fritter in the following formula being carried out Cholesky decomposes; Get two little block lengths, Lower Halves with the center of T diagonal of a matrix to the first half and obtain a little block length; Extract 3 * 3 totally 9 matrixes that fritter constitutes out, and it carried out Cholesky decompose and obtain lower triangular matrix: $\left[\begin{array}{ccc}{T}_{A1}& T_{B1}^H& 0\\ T_{B1}& T_{A1}& T_{B12}^H\\ 0& T_{B12}& T_{A2}\end{array}\right]=\left[\begin{array}{ccc}{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="H071D5844720070808E000042.png"\; state="\{\{state\}\}">L</figure-callout>}}_1& 0& 0\\ L_2& L_3& 0\\ 0& L_4& L_5\end{array}\right]\&CenterDot;{\left[\begin{array}{ccc}{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="H071D5844720070808E000042.png"\; state="\{\{state\}\}">L</figure-callout>}}_1& 0& 0\\ L_2& L_3& 0\\ 0& L_4& L_5\end{array}\right]}^H,$ And get two little block lengths downwards with the center of T diagonal of a matrix, extract 2 * 2 totally 4 matrixes that fritter constitutes out, and it carried out Cholesky decompose and obtain lower triangular matrix: $\left[\begin{array}{cc}{T}_{A2}& T_{B2}^H\\ T_{B2}& {\mathrm{<figure-callout\; id="2"\; label="T\; A"\; filenames="H071D5844720070808E000042.png"\; state="\{\{state\}\}">T</figure-callout>}}_A\end{array}\right]=\left[\begin{array}{cc}{L}_6& 0\\ L_7& L_8\end{array}\right]\&CenterDot;{\left[\begin{array}{cc}{L}_6& 0\\ L_7& L_8\end{array}\right]}^H;$ Utilization is filled with the fritter that upper triangular matrix obtains, and obtain the matrix L after T matrix reduction Cholesky decomposes: carries out data demodulates through front and back to the mode of equilibrium.

Through the present invention, can under the bigger situation of terminal movement velocity, accurately detect the data that received.

Description of drawings

Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes the application's a part, and illustrative examples of the present invention and explanation thereof are used to explain the present invention, do not constitute improper qualification of the present invention.In the accompanying drawings:

Fig. 1 is the basic frame structure sketch map of existing TD-SCDMA system;

Fig. 2 is the position view of TFCI, TPC and SS under the basic frame structure of existing TD-SCDMA system;

Fig. 3 is the schematic flow sheet according to the data receive method that is used for the TD-SCDMA system of the embodiment of the invention;

Fig. 4 is the basic frame structure sketch map according to the TD-SCDMA system of two training sequences of the embodiment of the invention;

Fig. 5 is the position view according to the TFCI under the basic frame structure of the TD-SCDMA system of two training sequences of the embodiment of the invention, TPC, SS;

Fig. 6 is the channel estimating interpolation sketch map under 2 the situation according to the data block 1 of the embodiment of the invention and 2 segments; And

Fig. 7 is the organigram according to the data division sytem matrix of the embodiment of the invention.

Embodiment

With reference to accompanying drawing, specify embodiment of the present invention below.

With reference to figure 3, the data receive method that is used for the TD-SCDMA system according to the embodiment of the invention is described.As shown in Figure 3; This data receive method may further comprise the steps: S302; Transform the frame structure of TDS-CDMA system as comprise two training sequences frame structure; And utilize two training sequences that the data division in the frame structure of TDS-CDMA system is carried out channel estimating, wherein, two training sequences lay respectively at the stem and the middle part of the frame structure of TDS-CDMA system; And S304, according to the channel estimation results of data division, data portion detects, to receive data division.

Wherein, step S302 may further comprise the steps: S3022 transform the frame structure of TDS-CDMA system as comprise two training sequences frame structure; S3024 carries out channel estimating to two training sequences respectively, to draw the channel impulse response of two training sequences; And S3026, utilize the channel impulse response of two training sequences, draw the channel impulse response of data division.

Wherein, in step S3024, through respectively two training sequences being carried out the signal impulse response that combined channel estimates to draw two training sequences.In step S3026, utilize the channel impulse response of two training sequences, draw the channel impulse response of a plurality of data sementations in the data division through linear interpolation and/or linear extrapolation method.In step S304, the mode data portion through joint-detection and/or matched filtering detects.

For example; As shown in Figure 4, the Frame of the TD-SCDMA system in the data receive method shown in Figure 3 is made up of training sequence Pre-amble and Mid-amble, the data division of two sections each 352 chips and the protection interval (GP) of afterbody 16 chips of two sections each 72 chips respectively.Wherein, protection remains unchanged at interval.

Wherein, Pre-amble can take identical training sequence with Mid-amble, also can adopt independently training sequence separately.Wherein, the training sequence of arbitrary 72 chips all is made up of the basic training sequences of 64 chip lengths and the Cyclic Prefix of 8 chip lengths.Similar with the Mid-amble sign indicating number skew allocative decision of existing TD-SCDMA system, the different user of the same time slot in same sub-district will distribute different Pre-amble and Mid-amble to squint.

Accordingly, if contain physical layer control signaling symbols in the bands such as TFCI, TPC and SS in the data division, its position also should change accordingly.In the present embodiment, the position of TFCI, TPC and SS is as shown in Figure 5.Wherein, TPC and SS follow Mid-amble closely.

In sum, in the present embodiment, utilize two training sequences channel estimation results interpolation separately to obtain the accurate channel impulse response of each segmentation of data division, utilize the method for joint-detection and/or matched filtering that data division is all detected then.

Adopt identical training sequence with Pre-amble and Mid-amble below, and data block 1 and 2 segments are 2 and are example, specific embodiments of the invention is elaborated.In this case, receive data through following steps:

At first, partly carry out the multi-user association channel estimating to Pre-amble and Mid-amble respectively, obtain two groups of channel impulse response h of corresponding Pre-amble and Mid-amble respectively ₁And h ₂Wherein, combined channel estimates to adopt following zero mode of compeling:

h ₁＝M ^-1.e _m1

h ₂＝M ^-1.e _m2 (1)

Wherein, M is the right Theory of Circular Matrix of the basic training sequences formation of 64 chip lengths; e _M1And e _M2Be respectively the receiving sequence of Pre-amble part and Mid-amble part.

Then, according to known channel impulse response h ₁And h ₂Carry out linear interpolation and extrapolation, obtain the channel estimation results h of two data blocks _D11, h _D12And h _D21, h _D22(wherein, Fig. 6 shows the channel estimating interpolation under the situation of data block 1 and 2 segmentations).Wherein:

$h_{d11}=\frac{304}{424}{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="H071D5844720070808E000042.png"\; state="\{\{state\}\}">h</figure-callout>}}_1+\frac{120}{424}{\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="H071D5844720070808E000042.png"\; state="\{\{state\}\}">h</figure-callout>}}_2$

$h_{d12}=\frac{128}{424}{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="H071D5844720070808E000042.png"\; state="\{\{state\}\}">h</figure-callout>}}_1+\frac{296}{424}{\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="H071D5844720070808E000042.png"\; state="\{\{state\}\}">h</figure-callout>}}_2$

$h_{d21}=\frac{544}{424}{h}_2-\frac{120}{424}{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="H071D5844720070808E000042.png"\; state="\{\{state\}\}">h</figure-callout>}}_1$

$h_{d22}=\frac{720}{424}{h}_2-\frac{296}{424}{h}_1---\left(2\right)$

Then, with above-mentioned h _D11, h _D12And h _D21, h _D22Carry out the thresholding reprocessing respectively, the tap that is higher than preset thresholding keeps, and is lower than the zero clearing of thresholding, obtains the channel impulse response through each user of reprocessing.Wherein, corresponding one group of impulse response of each data sementation of each user.

At last, two data segmentations according to following mode data portion detect.As shown in Figure 7, the corresponding sytem matrix A of construction data piece part.Wherein, fritter V ₁The vectorial horizontally-arranged that is obtained by the channel impulse response convolution compound code word of channel code scrambler separately of the corresponding data block segmentation 1 of each user constitutes; Fritter V ₂The vectorial horizontally-arranged that is obtained by the channel impulse response convolution compound code word of channel code scrambler separately of the corresponding data block segmentation 2 of each user constitutes.

Use associated detecting method, detect each user's symbolic information d based on linear block balance least mean-square error (MMSE-BLE).

$d={(A^H{R}_n^{-1}A+R_d)}^{-1}\&CenterDot;A^H{R}_n^{-1}e---\left(3\right)$

Wherein, e is that intermediate data partly receives signal, R _nBe noise correlation matrix, R _dBe signal correlation matrix, A ^HAssociate matrix for A.

The definition matrix $T=A^H{R}_n^{-1}A+R_d,$ Then equality (3) can use Cholesky (cholesky) decomposition method of following simplification to carry out, and the process that T matrix reduction Cholesky decomposes is following:

I. calculate $T=A^H{R}_n^{-1}A+R_d$ Obtain following form:

Wherein, the T matrix is a block diagonal matrix, and because the corresponding channel impulse response of the first half Lower Half of A matrix inconsistent, the first half of T matrix and Lower Half are also inconsistent;

Ii. respectively frame of broken lines fritter in the equality (4) being carried out Cholesky decomposes; Get two little block lengths, Lower Halves with the center of T diagonal of a matrix to the first half and obtain a little block length; Extract 3 * 3 totally 9 matrixes that fritter constitutes out, and it carried out Cholesky decompose and obtain lower triangular matrix:

$\left[\begin{array}{ccc}{T}_{A1}& T_{B1}^H& 0\\ T_{B1}& T_{A1}& T_{B12}^H\\ 0& T_{B12}& T_{A2}\end{array}\right]=\left[\begin{array}{ccc}{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="H071D5844720070808E000042.png"\; state="\{\{state\}\}">L</figure-callout>}}_1& 0& 0\\ L_2& L_3& 0\\ 0& L_4& L_5\end{array}\right]\&CenterDot;{\left[\begin{array}{ccc}{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="H071D5844720070808E000042.png"\; state="\{\{state\}\}">L</figure-callout>}}_1& 0& 0\\ L_2& L_3& 0\\ 0& L_4& L_5\end{array}\right]}^H---\left(5\right)$

Get two little block lengths downwards with the center of T diagonal of a matrix, extract 2 * 2 totally 4 matrixes that fritter constitutes out, and it is carried out Cholesky decompose and obtain lower triangular matrix:

$\left[\begin{array}{cc}{T}_{A2}& T_{B2}^H\\ T_{B2}& T_{A2}\end{array}\right]=\left[\begin{array}{cc}{L}_6& 0\\ L_7& L_8\end{array}\right]\&CenterDot;{\left[\begin{array}{cc}{L}_6& 0\\ L_7& L_8\end{array}\right]}^H---\left(6\right)$

Iii. the T matrix is simplified Cholesky and decompose, the fritter that promptly utilizes (5) and (6) to obtain is filled, and obtains the matrix L after the T matrix reduction Cholesky decomposition with the mode of following filling:

1) fritter L1 fills out the upper left corner in matrix L;

2) fritter L2, L3 horizontally-arranged are filled out below the L1 of matrix L, and L3 is positioned on the leading diagonal, and according to the leading diagonal center of zigzag continuation to matrix L;

3) fritter L4, L5 horizontally-arranged are filled out below the leading diagonal center of matrix L, and wherein L5 is positioned on the leading diagonal;

4) fritter L7, L8 horizontally-arranged, and, fill up cornerwise all the vacant positions of leading diagonal and interior lateral mass according to the zigzag continuation, wherein, L8 is positioned on the leading diagonal all the time.

Iv. carry out data demodulates to the mode of equilibrium before and after utilizing.Wherein, symbol after the matched filtering $d_{\mathrm{MF}}=A^H{R}_n^{-1}e,$ Separate forward direction equilibrium equation Ld _FW=d _MF, obtain intermediate variable d _FW, separate the back to equilibrium equation L ^HD=d _FW, obtain final demodulation symbol d.

Through the present invention, can under the bigger situation of terminal movement velocity, accurately detect the data that received.

The above is merely embodiments of the invention, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.All within spirit of the present invention and principle, any modification of being done, be equal to replacement, improvement etc., all should be included within the claim scope of the present invention.

Claims (9)

1. a data receive method that is used for TDS-CDMA system is characterized in that, may further comprise the steps:

S302; Transform the frame structure of TDS-CDMA system as comprise two training sequences frame structure; And utilize said two training sequences that the data division in the said frame structure is carried out channel estimating; Wherein, Said frame structure is made up of training sequence Pre-amble and Mid-amble, the data division of two sections each 352 chips and the protection interval (GP) of afterbody 16 chips of two sections each 72 chips respectively, and said two training sequences lay respectively at the stem and the middle part of the frame structure of said TDS-CDMA system

And said step S302 may further comprise the steps:

S3022 transform the frame structure of said TDS-CDMA system as comprise two training sequences frame structure;

S3024 carries out channel estimating to said two training sequences respectively, to draw the channel impulse response of said two training sequences; And

S3026; Utilize the channel impulse response of said two training sequences; Draw the channel impulse response of said data division, wherein, in said step S3026; Utilize the channel impulse response of said two training sequences, draw the channel impulse response of a plurality of data sementations in the said data division through linear interpolation and/or linear extrapolation method; And

S304 according to the channel estimation results of said data division, detects said data division, to receive said data division.

2. data receive method according to claim 1 is characterized in that the length of said two training sequences is identical.

3. data receive method according to claim 2 is characterized in that, said two training sequences are made up of the basic training sequences of 64 chip lengths and the Cyclic Prefix of 8 chip lengths respectively.

4. data receive method according to claim 3 is characterized in that, the code word in said two training sequences is identical or different.

5. data receive method according to claim 4 is characterized in that, in said step S3024, through respectively said two training sequences being carried out the signal impulse response that combined channel estimates to draw said two training sequences.

6. data receive method according to claim 5 is characterized in that, in said step S304, the mode through joint-detection and/or matched filtering detects said data division.

7. each described data receive method in requiring according to aforesaid right; It is characterized in that; Comprise at said data division under the situation of transport block format combination indication and power control command word, after said transport block format combination indication and the training sequence of said power control command word immediately following the middle part of the frame structure that is positioned at said TDS-CDMA system in said two training sequences.

8. data receive method according to claim 7 is characterized in that, through following steps said data division is carried out joint-detection:

Construct the corresponding sytem matrix A of a plurality of data sementations in the said data division;

Through associated detecting method, detect the symbolic information of said a plurality of data sementations based on the linear block balance least mean-square error

Wherein, e is that intermediate data partly receives signal, R _nBe noise correlation matrix, R _dBe signal correlation matrix, A ^HAssociate matrix for A.

9. data receive method according to claim 8; It is characterized in that; Through the Cholesky decomposition method

simplified; Wherein, said Cholesky decomposition method may further comprise the steps:

Calculate $T=A^H{R}_n^{-1}A+R_d,$ Obtain:

wherein; The T matrix is a block diagonal matrix, and the first half of T matrix and Lower Half are also inconsistent;

Respectively frame of broken lines fritter in the following formula being carried out Cholesky decomposes; Get two little block lengths, Lower Halves with the center of T diagonal of a matrix to the first half and obtain a little block length; Extract 3 * 3 totally 9 matrixes that fritter constitutes out, and it carried out Cholesky decompose and obtain lower triangular matrix: $\left[\begin{array}{ccc}{T}_{A1}& T_{B1}^H& 0\\ T_{B1}& T_{A1}& T_{B12}^H\\ 0& T_{B12}& T_{A2}\end{array}\right]=\left[\begin{array}{ccc}{L}_1& 0& 0\\ L_2& L_3& 0\\ 0& L_4& L_5\end{array}\right]\&CenterDot;{\left[\begin{array}{ccc}{L}_1& 0& 0\\ L_2& L_3& 0\\ 0& L_4& L_5\end{array}\right]}^H,$ And get two little block lengths downwards with the center of T diagonal of a matrix, extract 2 * 2 totally 4 matrixes that fritter constitutes out, and it carried out Cholesky decompose and obtain lower triangular matrix:

$\left[\begin{array}{cc}{T}_{A2}& T_{B2}^H\\ T_{B2}& T_{A2}\end{array}\right]=\left[\begin{array}{cc}{L}_6& 0\\ L_7& L_8\end{array}\right]\&CenterDot;{\left[\begin{array}{cc}{L}_6& 0\\ L_7& L_8\end{array}\right]}^H;$

Utilization is filled with the fritter that upper triangular matrix obtains, and obtains the matrix L after T matrix reduction Cholesky decomposes:

Carry out data demodulates through front and back to the mode of equilibrium.

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