CN103973333A - Cell coarse search method and device, and terminal - Google Patents

Abstract

The embodiment of the invention provides a cell coarse search method and device, and a terminal. The cell coarse search method comprises the steps of receiving first length data, carrying out characteristic window detection based on the characteristic window power ratio on the first length data, and obtaining at least first candidate characteristic windows and second candidate characteristic windows; carrying out correlation calculation on all the first candidate characteristic windows and the second candidate characteristic windows, and obtaining a related peak corresponding to each candidate characteristic window; determining DwPTS positions corresponding to the positions of the first candidate characteristic windows, wherein the related peaks corresponding to the first candidate characteristic windows are the maximum in the related peaks corresponding to the first candidate characteristic windows and the second candidate characteristic windows, and the first candidate characteristic windows are the same as DwPTSs in initial position. According to the cell coarse search method and device, and the terminal, it is avoided that due to influence from signal fading, real DwPTS positions are missed or false DwPTS positions are found, and therefore influence on the cell coarse search performance from signal fading is reduced.

Description

A kind of thick small region search method, device and terminal

Technical field

The embodiment of the present invention relates to field of telecommunications, relates in particular to a kind of thick small region search method, device and terminal.

Background technology

TD-SCDMA frame length is 10ms, comprises that length is 5ms and 2 identical subframes of frame structure.In the frame structure of subframe; comprise 7 business time-slots; wherein; the 1st business time-slot is down link (Downlink; DL) business time-slot; the 2nd business time-slot is up link (Uplink, UL) business time-slot, between these two business time-slots, is exchange point; comprise three parts; from left to right down link pilot timeslot (DL Pilot Time Slot, DwPTS, 96 chips), protection interval (Guard Period successively; GP; 96 chips) and uplink pilot time slot (UL Pilot Time Slot, UpPTS, 160 chips).DwPTS is divided into two parts, is from left to right the DL synchronous code (Synchronization Code-DL, SYNC-DL) of GP and 64 chips of 32 chips successively.The not scrambling of SYNC-DL code.

DwPTS is for TD-SCDMA synchronizing process designs, the weak signal that there is no signal in the both sides of SYNC-DL or produce due to convolution afterbody.For this reason, the first step that TD-SCDMA is synchronous, be just to locate DwPTS position, and this is just called thick Cell searching.

Current terminal has a kind of Window (Characteristic Window, CW) algorithm in realizing, and only finds DwPTS position by power information.As shown in Figure 1, with reference to Fig. 1, the 128 chip data that Window is Time Continuous, comprise two parts to Window structure, are from left to right the GP of DwPTS and 32 chips successively.At transmitting terminal, the power of GP is 0, and SYNC-DL sends with total power, and, in whole reception signal, with respect to the GP power (not signaling) on SYNC-DL both sides, SYNC-DL performance number is very large, is approximately peak value.Suppose that 128 chips of every group of Time Continuous in subframe are done to following Window power ratio to be calculated: by the power of 64 chips of both sides and divided by the power of remaining 64 chips and, obtain Window power ratio.Ideally, Window characteristic of correspondence window power ratio minimum in the power ratio obtaining at all these.According to this principle, terminal is calculated all Window power ratios that the length receiving is the data of subframe lengths and Window length sum, and the wherein power ratio of minimum of search, corresponding 128 chip data are the Window detecting, again because CW aligns with the left side of DwPTS, thereby also DwPTS position just detected.

But, due to the impact of signal fadeout, adopt this algorithm may miss real DwPTS position or find false DwPTS position, thereby have influence on thick Cell searching performance.

Summary of the invention

In view of this, the object of the embodiment of the present invention is to provide a kind of thick small region search method, device and terminal, to avoid because the impact of signal fadeout is missed real DwPTS position or found false DwPTS position, thereby reduce the impact of signal fadeout for thick Cell searching performance.

For solving the problems of the technologies described above, the embodiment of the present invention provides scheme as follows:

The embodiment of the present invention provides a kind of thick small region search method, for a TD-SCDMA system terminal, comprising:

Receive one first length data; The length of described the first length data is subframe lengths and Window length sum;

Described the first length data is carried out detecting based on the Window of Window power ratio, obtain at least the first candidate feature window and the second candidate feature window;

Each candidate feature window in described at least the first candidate feature window and the second candidate feature window is carried out to correlation calculations, obtain the each self-corresponding correlation peak of described each candidate feature window;

Determine the DwPTS position corresponding with described the first candidate feature window position; Wherein, the correlation peak maximum of described the first candidate feature window correspondence in described at least the first candidate feature window and the second candidate feature window; Described the first candidate feature window is identical with the original position of described DwPTS.

Preferably, described in carry out the basic SYNC-DL of correlation calculations based on M chip lengths, described described the first length data is carried out detecting based on the Window of Window power ratio, obtain at least the first candidate feature window and the second candidate feature window specifically comprises:

In described the first length data according to the fixed step size Window length window of sliding, and using each the Window length data that meets candidate feature window primary election condition in all Window length data of described Window length window process as detection window; Wherein, a described fixed step size is P chip, and the span of P is [1, Window length];

All described detection window are divided into at least two group detection window, in arbitrary group of detection window described in making at least two group detection window, only comprise that the detection window of the continuous process of described Window length window and the detection window number that described arbitrary group of detection window comprises are not more than M;

A candidate feature window described in the detection window of Window power ratio minimum in every group of detection window in described at least two group detection window is defined as at least the first candidate feature window and the second candidate feature window.

Preferably, described candidate feature window primary election condition comprises:

The Window power ratio of described detection window is less than a Window power ratio thresholding; Or,

The Window power ratio of described detection window is less than a Window power ratio thresholding, the second power ratio is less than the second thresholding and the 3rd power ratio is less than the 3rd thresholding;

Wherein, described the second power ratio be left side chip power and with middle chip power and ratio; Described left side chip power and be the chip power sum of the left side GP length data of described detection window; Chip power and be the chip power sum of the remaining data except left side GP length data and right side GP length data in described detection window in the middle of described;

Described the 3rd power ratio be right side chip power and with described in the middle of chip power and ratio; Described right side chip power and be the chip power sum of the right side GP length data of described detection window.

Preferably, described described at least the first candidate feature window and the second candidate feature window are carried out to correlation calculations, obtain in the step of the each self-corresponding correlation peak of each candidate feature window, the correlation peak that any candidate feature window is corresponding calculates according to following mode:

According to the each frequency deviation pre-compensation value in Q frequency deviation pre-compensation value, described any candidate feature window is carried out to frequency deviation pre-compensation, and by described any the candidate feature window after the frequency deviation pre-compensation obtaining carry out with the basic SYNC-DL of R in the correlation peak of each basic SYNC-DL calculate, obtain the each self-corresponding correlation peak of described each basic SYNC-DL;

Using the maximum in described R basic SYNC-DL and described Q the R*Q that frequency deviation pre-compensation value is a corresponding correlation peak as correlation peak corresponding to described any candidate feature window;

Wherein, Q is more than or equal to 1, R and is more than or equal to 1.

Preferably, the number of chips of basic SYNC-DL is M, to a basic SYNC-DL in described R basic SYNC-DL, the span of a is [1, R], any candidate feature window after described frequency deviation pre-compensation is carried out calculating with the correlation peak of described a basic SYNC-DL, obtain described a basic correlation peak corresponding to SYNC-DL and specifically comprise the steps:

By in chip received power sequence r (m+n) substitution formula one, formula two, formula three or the formula four of any the candidate feature window after described a basic SYNC-DL sequence s (m) and described frequency deviation pre-compensation, obtain sequence P (n); Wherein, m=0 ~ M-1; N=0 ~ N, number of chips-M that N is Window;

Basic correlation peak corresponding to SYNC-DL using the maximum in P (n) as described a;

Wherein, formula one is: $P\left(n\right)=\frac{1}{64}\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{s}^{*}\left(m\right)r(m+n);$

Formula two is: $P\left(n\right)=\frac{1}{64}\left|\underset{m=0}{\overset{U}{\mathrm{\Σ}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\Σ}}}{s}^{*}\left(m\right)r(m+n)\right|;$

Formula three is: $P\left(n\right)=\frac{\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{s}^{*}\left(m\right)r(m+n)}{\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{r}^{*}(m+n)r(m+n)};$

Formula four is: $P\left(n\right)=\frac{\left|\underset{m=0}{\overset{U}{\mathrm{\Σ}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\Σ}}}{s}^{*}\left(m\right)r(m+n)\right|}{\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{r}^{*}(m+n)r(m+n)};$

S ^*(m) be the conjugate sequence of s (m), 0<U<M-1.

The embodiment of the present invention also provides a kind of thick cell search apparatus, for a TD-SCDMA system terminal, comprising:

Receiver module, for receiving one first length data; The length of described the first length data is subframe lengths and Window length sum;

Detection module, detects based on the Window of Window power ratio for described the first length data is carried out, and obtains at least the first candidate feature window and the second candidate feature window;

Computing module, for each candidate feature window of described at least the first candidate feature window and the second candidate feature window is carried out to correlation calculations, obtains the each self-corresponding correlation peak of described each candidate feature window;

Determination module, for determining the DwPTS position corresponding with described the first candidate feature window position; Wherein, the correlation peak maximum of described the first candidate feature window correspondence in described at least the first candidate feature window and the second candidate feature window; Described the first candidate feature window is identical with the original position of described DwPTS.

Preferably, described in carry out the basic SYNC-DL of correlation calculations based on M chip lengths, described detection module specifically comprises:

Sliding unit, for in described the first length data according to the fixed step size Window length window of sliding, and using each the Window length data that meets candidate feature window primary election condition in all Window length data of described Window length window process as detection window; Wherein, a described fixed step size is P chip, and the span of P is [1, Window length];

Division unit, for all described detection window are divided into at least two group detection window, in arbitrary group of detection window described in making at least two group detection window, only comprise that the detection window of the continuous process of described Window length window and the detection window number that described arbitrary group of detection window comprises are not more than M;

Determining unit, for a candidate feature window at least the first candidate feature window described in the detection window of Window power ratio minimum in every group of detection window sequence of described at least two group detection window sequences is defined as and the second candidate feature window.

Preferably, described candidate feature window primary election condition comprises:

The Window power ratio of described detection window is less than a Window power ratio thresholding; Or,

The Window power ratio of described detection window is less than a Window power ratio thresholding, the second power ratio is less than the second thresholding and the 3rd power ratio is less than the 3rd thresholding;

Wherein, described the second power ratio be left side chip power and with middle chip power and ratio; Described left side chip power and be the chip power sum of the left side GP length data of described detection window; Chip power and be the chip power sum of the remaining data except left side GP length data and right side GP length data in described detection window in the middle of described;

Described the 3rd power ratio be right side chip power and with described in the middle of chip power and ratio; Described right side chip power and be the chip power sum of the right side GP length data of described detection window.

Preferably, in described computing module, the correlation peak that any candidate feature window is corresponding calculates according to following mode:

According to the each frequency deviation pre-compensation value in Q frequency deviation pre-compensation value, described any candidate feature window is carried out to frequency deviation pre-compensation, and by described any the candidate feature window after the frequency deviation pre-compensation obtaining carry out with the basic SYNC-DL of R in the correlation peak of each basic SYNC-DL calculate, obtain the each self-corresponding correlation peak of described each basic SYNC-DL; Using the maximum in described R basic SYNC-DL and described Q the R*Q that frequency deviation pre-compensation value is a corresponding correlation peak as correlation peak corresponding to described any candidate feature window;

Wherein, Q is more than or equal to 1, R and is more than or equal to 1.

Preferably, the number of chips of basic SYNC-DL is M, and to a basic SYNC-DL in described R basic SYNC-DL, the span of a is [1, R], and described computing unit comprises:

Computation subunit, for by chip received power sequence r (m+n) substitution formula one, formula two, formula three or the formula four of any the candidate feature window after described a basic SYNC-DL sequence s (m) and described frequency deviation pre-compensation, obtain sequence P (n); Wherein, m=0 ~ M-1; N=0 ~ N, number of chips-M that N is Window; Basic correlation peak corresponding to SYNC-DL using the maximum in P (n) as described a;

Wherein, formula one is: $P\left(n\right)=\frac{1}{64}\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n);$

Formula two is: $P\left(n\right)=\frac{1}{64}\left|\underset{m=0}{\overset{U}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|;$

Formula three is: $P\left(n\right)=\frac{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)}{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{r}^{*}(m+n)r(m+n)};$

Formula four is: $P\left(n\right)=\frac{\left|\underset{m=0}{\overset{U}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|}{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{r}^{*}(m+n)r(m+n)};$

S ^*(m) be the conjugate sequence of s (m), 0<U<M-1.

The embodiment of the present invention also provides a kind of terminal that comprises above-described thick cell search apparatus.

Can find out from the above, the embodiment of the present invention at least has following beneficial effect:

By the each candidate feature window at least the first candidate feature window and the second candidate feature window is carried out to correlation calculations, obtain the each self-corresponding correlation peak of described each candidate feature window, determine the DwPTS position corresponding with the candidate feature window position of correlation peak maximum corresponding at least the first candidate feature window and the second candidate feature window, just avoid because the impact of signal fadeout is missed real DwPTS position or found false DwPTS position, thereby reduced the impact of signal fadeout for thick Cell searching performance.

Brief description of the drawings

Fig. 1 is Window result schematic diagram;

The flow chart of steps of a kind of thick small region search method that Fig. 2 provides for the embodiment of the present invention;

Fig. 3 is the interior thick synchronous flow chart of a subframe of preferred implementation;

Fig. 4 is the structural representation that 5 hypothesis path-dependencies of preferred implementation detect.

Embodiment

For making object, technical scheme and the advantage of the embodiment of the present invention clearer, below in conjunction with the accompanying drawings and the specific embodiments the embodiment of the present invention is described in detail.

The flow chart of steps of a kind of thick small region search method that Fig. 2 provides for the embodiment of the present invention, with reference to Fig. 2, the embodiment of the present invention provides a kind of thick small region search method, for a TD-SCDMA system terminal, comprises the steps:

Step 201, receives one first length data; The length of described the first length data is subframe lengths and Window length sum;

Step 202, carries out detecting based on the Window of Window power ratio to described the first length data, obtains at least the first candidate feature window and the second candidate feature window;

Step 203, carries out correlation calculations to the each candidate feature window in described at least the first candidate feature window and the second candidate feature window, obtains the each self-corresponding correlation peak of described each candidate feature window;

Step 204, determines the DwPTS position corresponding with described the first candidate feature window position; Wherein, the correlation peak maximum of described the first candidate feature window correspondence in described at least the first candidate feature window and the second candidate feature window; Described the first candidate feature window is identical with the original position of described DwPTS.

Visible, by the each candidate feature window at least the first candidate feature window and the second candidate feature window is carried out to correlation calculations, obtain the each self-corresponding correlation peak of described each candidate feature window, determine the DwPTS position corresponding with the candidate feature window position of correlation peak maximum corresponding at least the first candidate feature window and the second candidate feature window, just avoid because the impact of signal fadeout is missed real DwPTS position or found false DwPTS position, thereby reduced the impact of signal fadeout for thick Cell searching performance.

Wherein, described subframe lengths is 6400 chip lengths, and described Window length is 128 chip lengths.

Described at least the first candidate feature window is different with the second candidate feature window original position each other.

Described described the first length data is carried out detecting based on the Window of Window power ratio, obtain at least the first candidate feature window and the second candidate feature window can have following various ways.

< mode one >

Mode one, finds front Num_P Window length data of Window power ratio minimum as described at least the first candidate feature window and the second candidate feature window in the whole Window length data in described the first length data.

< mode two >

Consider in described the first length data that position may also comparatively approach compared with the Window power ratio of approaching Window length data and because the impacts such as decline become very low, thereby pass-through mode may miss the real Window compared with distant positions place once front Num_P the Window length data finding, and can have mode two:

In whole Window length data in described the first length data, find all Window length data that are less than a Window power ratio thresholding as described at least the first candidate feature window and the second candidate feature window.

This Window power ratio thresholding can arrange comparatively loosely, for example can be in [0.4,1] interior value, thus obtain more candidate feature window, reduce the possibility of missing real Window.

< mode three >

Consider that TD-SCDMA system adopts the basic SYNC-DL of M chip lengths, M is typically 64, and for 64 chip sequences, the impact of a sampled data is very little, in the situation that the setting of Window power ratio thresholding is looser, if the Window power ratio of a Window length data meets specific Window power ratio thresholding, the follow-up individual continuous Window length data of initial chip of maximum M-1 that just have.Based on this principle, can select a candidate feature window by the each position range in some discrete position ranges, thereby reduce the possibility of missing real Window.So can there be mode three:

The described basic SYNC-DL of correlation calculations based on M chip lengths that carry out, describedly carries out detecting based on the Window of Window power ratio to described the first length data, obtains at least the first candidate feature window and the second candidate feature window specifically comprises:

In described the first length data according to the fixed step size Window length window of sliding, and using each the Window length data that meets candidate feature window primary election condition in all Window length data of described Window length window process as detection window; Wherein, a described fixed step size is P chip, and the span of P is [1, Window length];

All described detection window are divided into at least two group detection window, in arbitrary group of detection window described in making at least two group detection window, only comprise that the detection window of the continuous process of described Window length window and the detection window number that described arbitrary group of detection window comprises are not more than M;

A candidate feature window described in the detection window of Window power ratio minimum in every group of detection window in described at least two group detection window is defined as at least the first candidate feature window and the second candidate feature window.

Wherein, described candidate feature window primary election condition can comprise:

The Window power ratio of described detection window is less than a Window power ratio thresholding.

Wherein, described Window power ratio thresholding can be less than or equal to 1.

Preferably, desirable 1,2,3 or 4 of P, described Window power ratio thresholding desirable 0.5.

In mode three, mention, described candidate feature window primary election condition can comprise that the Window power ratio of described detection window is less than a Window power ratio thresholding.Consider that the received power of Window both sides GP length data is all less than the received power of intermediate data, in order to improve the detection efficiency of candidate feature window, alternately, described candidate feature window primary election condition can comprise:

The Window power ratio of described detection window is less than a Window power ratio thresholding, the second power ratio is less than the second thresholding and the 3rd power ratio is less than the 3rd thresholding;

Wherein, described the second power ratio be left side chip power and with middle chip power and ratio; Described left side chip power and be the chip power sum of the left side GP length data of described detection window; Chip power and be the chip power sum of the remaining data except left side GP length data and right side GP length data in described detection window in the middle of described;

Described the 3rd power ratio be right side chip power and with described in the middle of chip power and ratio; Described right side chip power and be the chip power sum of the right side GP length data of described detection window.

Wherein, described the second thresholding can be less than or equal to 0.5; Described the 3rd thresholding can be less than or equal to 0.5.

Mention in embodiments of the present invention: the each candidate feature window in described at least the first candidate feature window and the second candidate feature window is carried out to correlation calculations, obtain the each self-corresponding correlation peak of described each candidate feature window.Here, correlation calculations need to be considered the impact of the frequency shift (FS) FO of search of initial zone, can use some hypothesis path, each hypothesis path correspondence FO pre-compensation value separately, carry out FO compensation with this to receiving data, the each self-corresponding correlation peak of described each candidate feature window that obtained thus just more approaches actual conditions, thereby can overcome the impact of FO.In view of this, described described at least the first candidate feature window and the second candidate feature window are carried out to correlation calculations, obtain in the step of the each self-corresponding correlation peak of each candidate feature window, the correlation peak that any candidate feature window is corresponding calculates according to following mode:

According to the each frequency deviation pre-compensation value in Q frequency deviation pre-compensation value, described any candidate feature window is carried out to frequency deviation pre-compensation, and by described any the candidate feature window after the frequency deviation pre-compensation obtaining carry out with the basic SYNC-DL of R in the correlation peak of each basic SYNC-DL calculate, obtain the each self-corresponding correlation peak of described each basic SYNC-DL;

Using the maximum in described R basic SYNC-DL and described Q the R*Q that frequency deviation pre-compensation value is a corresponding correlation peak as correlation peak corresponding to described any candidate feature window;

Wherein, Q is more than or equal to 1, R and is more than or equal to 1.

Here, described by described any the candidate feature window after the frequency deviation pre-compensation obtaining carry out with the basic SYNC-DL of R in the correlation peak of each basic SYNC-DL calculate and can adopt various code related algorithms, for example:

To a basic SYNC-DL in described R basic SYNC-DL, the span of a is [1, R], any candidate feature window after described frequency deviation pre-compensation is carried out calculating with the correlation peak of described a basic SYNC-DL, obtain described a basic correlation peak corresponding to SYNC-DL and specifically comprise the steps:

By in chip received power sequence r (m+n) substitution formula one, formula two, formula three or the formula four of any the candidate feature window after described a basic SYNC-DL sequence s (m) and described frequency deviation pre-compensation, obtain sequence P (n); Wherein, m=0 ~ M-1; N=0 ~ N, number of chips-M that N is Window;

Basic correlation peak corresponding to SYNC-DL using the maximum in P (n) as described a;

Wherein, formula one is: $P\left(n\right)=\frac{1}{64}\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n);$

Formula two is: $P\left(n\right)=\frac{1}{64}\left|\underset{m=0}{\overset{U}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|;$

Formula three is: $P\left(n\right)=\frac{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)}{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{r}^{*}(m+n)r(m+n)};$

Formula four is: $P\left(n\right)=\frac{\left|\underset{m=0}{\overset{U}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|}{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{r}^{*}(m+n)r(m+n)};$

S ^*(m) be the conjugate sequence of s (m), 0<U<M-1.

Wherein, M is 64 o'clock, and U preferably gets 31.

Compared with adopting formula one, adopting formula two is that basic SYNC-DL is treated as shorter sequence, alleviates the large coherent loss that may cause when large frequency demodulation error exists with this.

Compared with adopting formula one, two, adopt formula the three, the 4th, consider the UL strong jamming of TDD system, thereby by correlativity calculation result normalization, improve thus the fairness that correlation peak corresponding to different candidate feature windows compared, improve the accuracy of determined DwPTS position.

For the embodiment of the present invention is described clearlyer, provide the preferred implementation of the embodiment of the present invention below:

Fig. 3 is the interior thick synchronous flow chart of a subframe of preferred implementation, and with reference to Fig. 3, the thick cell synchronous flow process of this preferred implementation comprises the steps:

Step 300, starts, signal input;

The length of described the first length data is 6400+128=6528 chip lengths, is made as l _frame, described the first length data is 6528 chips.

Step 301, slip CW length window is also carried out the Preliminary screening of candidate feature window based on Window power ratio;

Window based on Window power ratio detects and adopts aforesaid way three, and P gets 2, and in this step, the described Window length window of sliding can obtain L=l _frame/ P Window length data, this preferred implementation is taken from the from left to right described Window length window of sliding, and the call number of the Window length data obtaining is thus followed successively by 1,2, ..., L, call number that can use characteristic window length data is come the position of identification characteristics window length data.

The power ratio calculating of carrying out here comprises calculated characteristics window power ratio, the second power ratio and the 3rd power ratio.The Window power ratio R of Window length data _ican be obtained by following formula:

R _i＝(P _{left_i}+P _{right_i})/P _{middle_i};i＝1,2,..,L

Wherein, P _{left_i}for the power sum of 32 chips in left side of Window length data, Pr _{ight_i}for the power sum of 32 chips in right side of Window length data, P _{middle_i}for the power sum of 64 chips in centre except 32, left side chip and 32, right side chip of Window length data.

The second power ratio R _{left_i}can be obtained by following formula:

R _{left_i}＝P _{left_i}/P _{middle_i};i＝1,2,..,L

The 3rd power ratio R _{right_i}can be obtained by following formula:

R _{right_i}＝P _{right_i}/P _{middle_i};i＝1,2,..,L

Also just obtained thus CW power ratio sequence { R corresponding to Window length data position _i; I=1,2 .., L}, the second power ratio sequence { R _{left_i}; I=1,2 .., L} and the 3rd power ratio sequence { R _{right_i}; I=1,2 .., L}.

Carry out the Preliminary screening of candidate feature window, using the Window length data that meets following power ratio threshold condition in corresponding CW power ratio, the second power ratio and the 3rd power ratio as detection window.

Wherein, for example, R _tget 0.5, R _{t_left}get 0.5, R _{t_right}get 0.5.

Thus, detection window position sequence (the detection window position in sequence represents with the call number of detection window) and corresponding CW power ratio sequence have just been obtained.

Step 302, the set of locations based on CW power ratio is divided;

Detection window position sequence is carried out to the division of set of locations, each set of locations only comprises that the detection window position number that detection window position that call number is continuous and each set of locations comprise is all not more than M.

For example, if detection window position sequence be 3 ~ 4,10 ~ 80,1000 ~ 1030}, gets 64 by M, can be divided into 4 groups, wherein,

The 1st group be 3 ~ 4}, and the 2nd group be 10 ~ 73}, and the 3rd group be 74 ~ 80}, the 4th group is { 1000 ~ 1030}; Or,

The 1st group is that { 3 ~ 4}, the 2nd group is that { 10 ~ 35}, the 3rd group is that { 36 ~ 80}, the 4th group is { 1000 ~ 1030}.

That is to say, continuous while being greater than M position when comprising in detection window position sequence, can every continuous N position be divided into respectively to a set of locations according to order from left to right, if there be remaining continuous position and number deficiency M, remaining continuous position is divided separately to a set of locations; Or,

Can adopt other dividing mode, be not more than M as long as the each set of locations after dividing all only comprises the position of detection window of the continuous process of described Window length window and the position number of each set of locations.

If set of locations obtains G set of locations after dividing, to each set of locations wherein, record the detection window positional information (i.e. the call number of this detection window) of CW power ratio minimum corresponding in this set of locations, using the CW power ratio of this detection window as CW power ratio corresponding to this set of locations, thus, signal corresponding to this set of locations is exactly 128 chips of this detection window.

Step 303, the set of locations sequence based on CW power ratio;

By CW power ratio corresponding this G set of locations is arranged according to ascending order, obtain CW power ratio sequence and corresponding detection window position sequence after sequence.

Step 304, finds some candidate feature windows;

Consider the complexity of correlation calculations, can determine according to terminal capability the maximum number of the candidate feature window that carries out correlation calculations, be made as T_num, for example 1 ~ 5.Here, T_num is less than or equal to G, front T_num detection window position in the corresponding detection window position sequence obtaining in desirable step 303, and front T_num detection window of its correspondence is T_num candidate feature window.

Thus, this T_num the signal that candidate feature window is corresponding 128*T_num chip altogether.

Step 305, each candidate feature window is carried out to correlation calculations, obtain the each self-corresponding correlation peak of each candidate feature window, and record position (being call number) and correlation peak corresponding to this candidate feature window that corresponding correlation peak is greater than the candidate feature window of correlation peak thresholding T_corr;

Step 306, finds maximal correlation peak value position;

Maximizing in the correlation peak that the candidate feature window of record is corresponding in step 305, the corresponding candidate feature window position of this maximum is Window position, also just obtained thus the DwPTS position of this 6528 chip signal (i.e. this first length data), thus the thick Cell searching success to this first length data; And if correlation peak corresponding to all candidate feature windows is all not more than T_corr, the thick Cell searching failure to this first length data.

In step 305, any candidate feature window is carried out to correlation calculations, obtain the correlation peak that this any candidate feature window is corresponding specific as follows:

Consider the FO tolerance of SYNC-DL sequence in TD-SCDMA, we obtain with 5 or 7 hypothesis paths the correlation peak that this any candidate feature window is corresponding.Be illustrated as an example of 5 hypothesis paths example below with reference to Fig. 4.5 FO pre-compensation value corresponding to hypothesis path are respectively 32KHz, 16KHz, 0KHz ,-16KHz ,-32KHz.5 FO precompensation modules of 128 chips input of this any candidate feature window are carried out to the FO precompensation of analog value, from each FO precompensation module out, enter correlation peak computing module and carry out correlation calculations.Wherein, in each correlation peak computing module inside, can to 128 chips after FO precompensation carry out with 32 basic SYNC-DL in each basic SYNC-DL correlation peak calculate, obtain correlation peak corresponding to each basic SYNC-DL, and correlation peak corresponding to this each basic SYNC-DL exported to maximal correlation peak value and select module.Maximal correlation peak value selects module in 5*32=160 correlation peak of its output, to select maximum wherein at 5 correlation peak computing modules, and this maximum is the correlation peak that this any candidate feature window is corresponding.

Wherein, to 128 chips after FO precompensation carry out with 32 basic SYNC-DL in the correlation peak of the basic SYNC-DL of a calculate and can adopt traditional relevance formula, obtain sequence P (n) by s (m) and r (m+n) substitution formula one, basic correlation peak corresponding to SYNC-DL using the maximum in P (n) as described a;

Consider when large frequency demodulation error exists, use traditional relevance formula may cause large coherent loss.In order to alleviate this problem, can further SYNC code be treated as shorter sequence, replace with formula two by above-mentioned formula one, in this preferred implementation, getting U is 31; Or,

Consider the UL strong jamming of TDD system, above-mentioned formula one can be replaced with to formula three, thereby by correlativity calculation result normalization; Or,

In the time that the UL strong jamming of large frequency demodulation error and TDD system is all considered, above-mentioned formula one can be replaced with to formula four.

In this preferred implementation, owing to having limited the scope of correlation calculations, thereby can not bring too large computation complexity, can be accepted by terminal realizes.

In this preferred implementation, further, can introduce original position and verify with the DwPTS position to obtaining with multiple first length data at subframe lengths interval.For example, each the first length data in 6 the first length data is obtained to DwPTS position according to step 301 ~ 306, be more than or equal to 2 if exceed n(n in 5 results that obtained by posterior 5 the first length data of original position) between individual result and the DwPTS position that obtained in the first the most front length data by original position for example, within the scope of certain error (16 chips), think that the DwPTS position being obtained in the first the most front length data by original position is successful.

The embodiment of the present invention also provides a kind of thick cell search apparatus, for a TD-SCDMA system terminal, comprising:

Receiver module, for receiving one first length data; The length of described the first length data is subframe lengths and Window length sum;

Detection module, detects based on the Window of Window power ratio for described the first length data is carried out, and obtains at least the first candidate feature window and the second candidate feature window;

Computing module, for each candidate feature window of described at least the first candidate feature window and the second candidate feature window is carried out to correlation calculations, obtains the each self-corresponding correlation peak of described each candidate feature window;

Determination module, for determining the DwPTS position corresponding with described the first candidate feature window position; Wherein, the correlation peak maximum of described the first candidate feature window correspondence in described at least the first candidate feature window and the second candidate feature window; Described the first candidate feature window is identical with the original position of described DwPTS.

Visible, by the each candidate feature window at least the first candidate feature window and the second candidate feature window is carried out to correlation calculations, obtain the each self-corresponding correlation peak of described each candidate feature window, determine the DwPTS position corresponding with the candidate feature window position of correlation peak maximum corresponding at least the first candidate feature window and the second candidate feature window, just avoid because the impact of signal fadeout is missed real DwPTS position or found false DwPTS position, thereby reduced the impact of signal fadeout for thick Cell searching performance.

Wherein, described in carry out the basic SYNC-DL of correlation calculations based on M chip lengths, described detection module specifically can comprise:

Sliding unit, for in described the first length data according to the fixed step size Window length window of sliding, and using each the Window length data that meets candidate feature window primary election condition in all Window length data of described Window length window process as detection window; Wherein, a described fixed step size is P chip, and the span of P is [1, Window length];

Division unit, for all described detection window are divided into at least two group detection window, in arbitrary group of detection window described in making at least two group detection window, only comprise that the detection window of the continuous process of described Window length window and the detection window number that described arbitrary group of detection window comprises are not more than M;

Determining unit, for a candidate feature window at least the first candidate feature window described in the detection window of Window power ratio minimum in every group of detection window sequence of described at least two group detection window sequences is defined as and the second candidate feature window.

Further, Ke Yiyou:

Described candidate feature window primary election condition comprises:

The Window power ratio of described detection window is less than a Window power ratio thresholding; Or,

The Window power ratio of described detection window is less than a Window power ratio thresholding, the second power ratio is less than the second thresholding and the 3rd power ratio is less than the 3rd thresholding;

Wherein, described the second power ratio be left side chip power and with middle chip power and ratio; Described left side chip power and be the chip power sum of the left side GP length data of described detection window; Chip power and be the chip power sum of the remaining data except left side GP length data and right side GP length data in described detection window in the middle of described;

Described the 3rd power ratio be right side chip power and with described in the middle of chip power and ratio; Described right side chip power and be the chip power sum of the right side GP length data of described detection window.

In addition,, in described computing module, the correlation peak that any candidate feature window is corresponding calculates according to following mode:

According to the each frequency deviation pre-compensation value in Q frequency deviation pre-compensation value, described any candidate feature window is carried out to frequency deviation pre-compensation, and by described any the candidate feature window after the frequency deviation pre-compensation obtaining carry out with the basic SYNC-DL of R in the correlation peak of each basic SYNC-DL calculate, obtain the each self-corresponding correlation peak of described each basic SYNC-DL; Using the maximum in described R basic SYNC-DL and described Q the R*Q that frequency deviation pre-compensation value is a corresponding correlation peak as correlation peak corresponding to described any candidate feature window;

Wherein, Q is more than or equal to 1, R and is more than or equal to 1.

The number of chips of basic SYNC-DL is M, and to a basic SYNC-DL in described R basic SYNC-DL, the span of a is [1, R], and described computing unit can comprise:

Computation subunit, for by chip received power sequence r (m+n) substitution formula one, formula two, formula three or the formula four of any the candidate feature window after described a basic SYNC-DL sequence s (m) and described frequency deviation pre-compensation, obtain sequence P (n); Wherein, m=0 ~ M-1; N=0 ~ N, number of chips-M that N is Window; Basic correlation peak corresponding to SYNC-DL using the maximum in P (n) as described a;

Wherein, formula one is: $P\left(n\right)=\frac{1}{64}\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n);$

Formula two is: $P\left(n\right)=\frac{1}{64}\left|\underset{m=0}{\overset{U}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|;$

Formula three is: $P\left(n\right)=\frac{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)}{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{r}^{*}(m+n)r(m+n)};$

Formula four is: $P\left(n\right)=\frac{\left|\underset{m=0}{\overset{U}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|}{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{r}^{*}(m+n)r(m+n)};$

S ^*(m) be the conjugate sequence of s (m), 0<U<M-1.

The embodiment of the present invention also provides a kind of terminal, and described terminal comprises above-described thick cell search apparatus.

The above is only the execution mode of the embodiment of the present invention; should be understood that; for those skilled in the art; do not departing under the prerequisite of embodiment of the present invention principle; can also make some improvements and modifications, these improvements and modifications also should be considered as the protection range of the embodiment of the present invention.

Claims (11)

1. a thick small region search method, for a TD-SCDMA system terminal, is characterized in that, comprising:

Receive one first length data; The length of described the first length data is subframe lengths and Window length sum;

Described the first length data is carried out detecting based on the Window of Window power ratio, obtain at least the first candidate feature window and the second candidate feature window;

Described at least the first candidate feature window and the second candidate feature window are carried out to correlation calculations, obtain the each self-corresponding correlation peak of each candidate feature window;

Determine the DwPTS position corresponding with described the first candidate feature window position; Wherein, the correlation peak maximum of described the first candidate feature window correspondence in described at least the first candidate feature window and the second candidate feature window; Described the first candidate feature window is identical with the original position of described DwPTS.

2. method according to claim 1, it is characterized in that, the described basic SYNC-DL of correlation calculations based on M chip lengths that carry out, described described the first length data is carried out detecting based on the Window of Window power ratio, obtains at least the first candidate feature window and the second candidate feature window specifically comprises:

In described the first length data according to the fixed step size Window length window of sliding, and using each the Window length data that meets candidate feature window primary election condition in all Window length data of described Window length window process as detection window; Wherein, a described fixed step size is P chip, and the span of P is [1, Window length];

All described detection window are divided into at least two group detection window, in arbitrary group of detection window described in making at least two group detection window, only comprise that the detection window of the continuous process of described Window length window and the detection window number that described arbitrary group of detection window comprises are not more than M;

A candidate feature window described in the detection window of Window power ratio minimum in every group of detection window in described at least two group detection window is defined as at least the first candidate feature window and the second candidate feature window.

3. method according to claim 2, is characterized in that, described candidate feature window primary election condition comprises:

The Window power ratio of described detection window is less than a Window power ratio thresholding; Or,

The Window power ratio of described detection window is less than a Window power ratio thresholding, the second power ratio is less than the second thresholding and the 3rd power ratio is less than the 3rd thresholding;

Wherein, described the second power ratio be left side chip power and with middle chip power and ratio; Described left side chip power and be the chip power sum of the left side GP length data of described detection window; Chip power and be the chip power sum of the remaining data except left side GP length data and right side GP length data in described detection window in the middle of described;

Described the 3rd power ratio be right side chip power and with described in the middle of chip power and ratio; Described right side chip power and be the chip power sum of the right side GP length data of described detection window.

4. method according to claim 1, it is characterized in that, described described at least the first candidate feature window and the second candidate feature window are carried out to correlation calculations, obtain in the step of the each self-corresponding correlation peak of each candidate feature window, the correlation peak that any candidate feature window is corresponding calculates according to following mode:

According to the each frequency deviation pre-compensation value in Q frequency deviation pre-compensation value, described any candidate feature window is carried out to frequency deviation pre-compensation, and by described any the candidate feature window after the frequency deviation pre-compensation obtaining carry out with the basic SYNC-DL of R in the correlation peak of each basic SYNC-DL calculate, obtain the each self-corresponding correlation peak of described each basic SYNC-DL;

Using the maximum in described R basic SYNC-DL and described Q the R*Q that frequency deviation pre-compensation value is a corresponding correlation peak as correlation peak corresponding to described any candidate feature window;

Wherein, Q is more than or equal to 1, R and is more than or equal to 1.

5. method according to claim 4, it is characterized in that, the number of chips of basic SYNC-DL is M, to a basic SYNC-DL in described R basic SYNC-DL, the span of a is [1, R], any the candidate feature window after described frequency deviation pre-compensation is carried out calculating with the correlation peak of described a basic SYNC-DL, obtain described a basic correlation peak corresponding to SYNC-DL and specifically comprise the steps:

By in chip received power sequence r (m+n) substitution formula one, formula two, formula three or the formula four of any the candidate feature window after described a basic SYNC-DL sequence s (m) and described frequency deviation pre-compensation, obtain sequence P (n); Wherein, m=0 ~ M-1; N=0 ~ N, number of chips-M that N is Window;

Basic correlation peak corresponding to SYNC-DL using the maximum in P (n) as described a;

Wherein, formula one is: $P\left(n\right)=\frac{1}{64}\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n);$

Formula two is: $P\left(n\right)=\frac{1}{64}\left|\underset{m=0}{\overset{U}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|;$

Formula three is: $P\left(n\right)=\frac{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)}{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{r}^{*}(m+n)r(m+n)};$

Formula four is: $P\left(n\right)=\frac{\left|\underset{m=0}{\overset{U}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|}{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{r}^{*}(m+n)r(m+n)};$

S ^*(m) be the conjugate sequence of s (m), 0<U<M-1.

6. a thick cell search apparatus, for a TD-SCDMA system terminal, is characterized in that, comprising:

Receiver module, for receiving one first length data; The length of described the first length data is subframe lengths and Window length sum;

Detection module, detects based on the Window of Window power ratio for described the first length data is carried out, and obtains at least the first candidate feature window and the second candidate feature window;

Computing module, for each candidate feature window of described at least the first candidate feature window and the second candidate feature window is carried out to correlation calculations, obtains the each self-corresponding correlation peak of described each candidate feature window;

Determination module, for determining the DwPTS position corresponding with described the first candidate feature window position; Wherein, the correlation peak maximum of described the first candidate feature window correspondence in described at least the first candidate feature window and the second candidate feature window; Described the first candidate feature window is identical with the original position of described DwPTS.

7. device according to claim 6, is characterized in that, described in carry out the basic SYNC-DL of correlation calculations based on M chip lengths, described detection module specifically comprises:

Sliding unit, for in described the first length data according to the fixed step size Window length window of sliding, and using each the Window length data that meets candidate feature window primary election condition in all Window length data of described Window length window process as detection window; Wherein, a described fixed step size is P chip, and the span of P is [1, Window length];

Division unit, for all described detection window are divided into at least two group detection window, in arbitrary group of detection window described in making at least two group detection window, only comprise that the detection window of the continuous process of described Window length window and the detection window number that described arbitrary group of detection window comprises are not more than M;

Determining unit, for a candidate feature window at least the first candidate feature window described in the detection window of Window power ratio minimum in every group of detection window sequence of described at least two group detection window sequences is defined as and the second candidate feature window.

8. device according to claim 7, is characterized in that, described candidate feature window primary election condition comprises:

The Window power ratio of described detection window is less than a Window power ratio thresholding; Or,

The Window power ratio of described detection window is less than a Window power ratio thresholding, the second power ratio is less than the second thresholding and the 3rd power ratio is less than the 3rd thresholding;

Wherein, described the second power ratio be left side chip power and with middle chip power and ratio; Described left side chip power and be the chip power sum of the left side GP length data of described detection window; Chip power and be the chip power sum of the remaining data except left side GP length data and right side GP length data in described detection window in the middle of described;

Described the 3rd power ratio be right side chip power and with described in the middle of chip power and ratio; Described right side chip power and be the chip power sum of the right side GP length data of described detection window.

9. device according to claim 6, is characterized in that, in described computing module, the correlation peak that any candidate feature window is corresponding calculates according to following mode:

According to the each frequency deviation pre-compensation value in Q frequency deviation pre-compensation value, described any candidate feature window is carried out to frequency deviation pre-compensation, and by described any the candidate feature window after the frequency deviation pre-compensation obtaining carry out with the basic SYNC-DL of R in the correlation peak of each basic SYNC-DL calculate, obtain the each self-corresponding correlation peak of described each basic SYNC-DL; Using the maximum in described R basic SYNC-DL and described Q the R*Q that frequency deviation pre-compensation value is a corresponding correlation peak as correlation peak corresponding to described any candidate feature window;

Wherein, Q is more than or equal to 1, R and is more than or equal to 1.

10. device according to claim 9, is characterized in that, the number of chips of basic SYNC-DL is M, and to a basic SYNC-DL in described R basic SYNC-DL, the span of a is [1, R], and described computing unit comprises:

Computation subunit, for by chip received power sequence r (m+n) substitution formula one, formula two, formula three or the formula four of any the candidate feature window after described a basic SYNC-DL sequence s (m) and described frequency deviation pre-compensation, obtain sequence P (n); Wherein, m=0 ~ M-1; N=0 ~ N, number of chips-M that N is Window; Basic correlation peak corresponding to SYNC-DL using the maximum in P (n) as described a;

Wherein, formula one is: $P\left(n\right)=\frac{1}{64}\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n);$

Formula two is: $P\left(n\right)=\frac{1}{64}\left|\underset{m=0}{\overset{U}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|;$

Formula three is: $P\left(n\right)=\frac{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)}{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{r}^{*}(m+n)r(m+n)};$

Formula four is: $P\left(n\right)=\frac{\left|\underset{m=0}{\overset{U}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|+\left|\underset{m=U+1}{\overset{M-1}{\mathrm{\&Sigma;}}}{s}^{*}\left(m\right)r(m+n)\right|}{\underset{m=0}{\overset{M-1}{\mathrm{\&Sigma;}}}{r}^{*}(m+n)r(m+n)};$

S ^*(m) be the conjugate sequence of s (m), 0<U<M-1.

11. 1 kinds of terminals, is characterized in that, comprise the thick cell search apparatus as described in any one in claim 6 to 10.