CN103685120A - Resynchronization method and system for LTE system - Google Patents

Abstract

The invention discloses a resynchronization method and system used in an LTE system. The method includes the following steps: receiving a subframe containing at least a secondary synchronization signal; determining the position of the secondary synchronization signal according to the frame structure, and advancing it by N/M The sampling point intercepts SSS data with a length of K/M; uses the intercepted SSS data to perform down-sampling and filtering processing; judges whether there are co-frequency neighboring cells, and if there is a co-frequency neighboring cell, performs interference elimination according to the configured co-frequency neighboring cells; According to the secondary synchronization signal after co-channel interference is eliminated, the secondary synchronization channel estimation of the cell under test is performed to obtain the timing of the secondary synchronization signal; and according to the timing of the output secondary synchronization signal, the reference signal based on the cell is used for measurement again, and the output is measured. Timing is the final resynchronization timing output, and the present invention can greatly reduce the time required for the LTE resynchronization process, and greatly improve the timing accuracy and timing error range of the resynchronization output.

Description

A kind of resynchronization method and system used in LTE system

technical field

The present invention relates to a resynchronization method and system, in particular to a resynchronization method and system used in an LTE system.

Background technique

With the development and progress of society, people require mobile terminals not only to provide high-quality voice and text services, but also to provide high-speed, large-capacity and low-latency digital multimedia application services. In order to meet this growing demand of people, at the end of 2004, the 3rd Generation Partnership Project (3GPP, 3rdGeneration Partnership Project) started the Long Term Evolution (LTE, Long Term Evolution) project of the universal mobile communication system technology.

In the LTE system, the terminal often needs to perform timing synchronization with the base station before and after handover or when waking up from sleep. In the prior art, the specific steps of terminal resynchronization during handover and reselection are as follows:

(1) Receive 1ms including PSS (Primary Synchronization Signal, primary synchronization signal) and SSS (Secondary Synchronization Signal, secondary synchronization signal) data for down-sampling filtering;

(2) According to the frame timing and CP (Cyclic Prefix, cyclic prefix) type, determine the SSS position, and intercept the data with a length of 128 by 1 sampling point in advance;

(3) Judging whether there is an interfering cell, if there is an interfering cell, then perform step (4), otherwise perform step (5);

(4) Carry out secondary synchronization channel estimation according to interference cellid (cell number), utilize secondary synchronization channel estimation to reconstruct interference signal, and carry out interference elimination, continue step (5);

(5) The secondary synchronization channel is estimated according to the resynchronization cellid (cell number), and the peak position of the channel impulse response is obtained, and the peak position is the real SSS position.

However, the above-mentioned resynchronization method for switching reselection has the following disadvantages:

(1) The position where errors are prone to occur during the reselection process;

(2) The timing accuracy of the reselection output is not high;

(3) The range of the output OTD2 is between -992Ts and 32Ts. If the local timing is much ahead of the network timing, it is easy to have resynchronization timing output errors.

In the prior art, the resynchronization of the terminal when waking up from sleep is generally divided into the following two processes:

1. Synchronize the PSS processing process:

(1) The receiving length is 1ms, including PSS and SSS data, and downsampling filtering is performed;

(2) Perform primary synchronization channel estimation, and back up the corresponding channel impulse response power taps;

(3) Combine channel impulse responses;

(4) Determine whether it is the last time to receive data, if it is not the last time to receive data, exit directly, otherwise execute step (5).

(5) Perform primary synchronization channel estimation judgment, if the judgment is successful, it means that the PSS under synchronization is successful, otherwise, the PSS under synchronization fails.

2. SSS fine synchronization process:

(1) calling the SSS channel estimation function to complete the channel estimation function of secondary synchronization;

(2) Judging whether the current processing is the Kth SSS channel estimation, if not, then directly exit, otherwise step (3);

(3) call the SSS fine synchronization judgment function, if the judgment is successful, it means that the SSS fine synchronization is successful, otherwise the output fails, (4) change the frequency point or redo the PSS search process under the next NID2.

However, the above-mentioned resynchronization method when waking up from sleep also has the following deficiencies:

(1) The number of receiving data is too many, which affects the sleep time;

(2) There may be many PSS outputs under synchronization, and it is impossible to accurately determine the PSS position corresponding to the resynchronization cell, so it will affect the SSS fine synchronization in the second stage, resulting in wrong timing of resynchronization output;

(3) The timing precision of the output is not high.

Contents of the invention

In order to overcome the deficiencies in the above-mentioned prior art, the purpose of the present invention is to provide a resynchronization method and system used in the LTE system, which greatly reduces the time required for the resynchronization process in the LTE system and satisfies practical applications. ; At the same time, the timing accuracy and timing error range of the resynchronization output have been greatly improved.

In order to achieve the above and other purposes, the present invention provides a resynchronization method used in an LTE system, which is applied to a terminal in the LTE system, including the following steps:

Step 1, receiving a subframe including at least a secondary synchronization signal;

Step 2, determine the position of the secondary synchronization signal according to the frame structure, and intercept the SSS data with a length of K/M at N/M sampling points in advance, where N>=1, M is related to the receiving bandwidth, and K/M>=128, And K/M satisfies the 2 ⁿ relationship;

Step 3, using the intercepted SSS data to perform down-sampling and filtering processing;

Step 4, judging whether there is an adjacent cell with the same frequency, if there is an adjacent cell with the same frequency, go to step 5, otherwise go to step 6;

Step 5, performing interference cancellation according to the configured co-frequency adjacent cells;

Step 6: Estimating the secondary synchronization channel of the cell under test according to the secondary synchronization signal after co-channel interference is eliminated, and obtaining the timing of the secondary synchronization signal; and

Step 7: According to the timing of the output secondary synchronization signal, the reference signal based on the cell is used for measurement again, and the timing of the measurement output is output as the final resynchronization timing.

Further, step four also includes the following steps:

Perform channel estimation according to the locally generated secondary synchronization signal, and calculate and obtain the maximum power value in the first X taps and the average power of the noise power of the Y taps;

Calculate the peak-to-average ratio from the maximum power value in the first X taps and the average power of the noise power of the Y taps; and

Comparing the obtained peak-to-average ratio with a threshold value, if the peak-to-average ratio is smaller than the threshold value, it means that the cell is weak or does not exist; if the peak-to-average ratio is greater than the threshold value, it means that there is a strong cell. The same frequency interferes with neighboring cells.

Further, the threshold value is greater than or equal to 4.

Further, the calculation of the peak-to-average ratio is obtained by the following formula:

${\mathrm{<span\; class="notranslate">\; ratio</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; mean</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; pow</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{{\mathrm{<span\; class="notranslate">\; pow</span>}}_{\mathrm{<span\; class="notranslate">\; mean</span>}}}$

Among them, ratio _max/mean is the peak-to-average ratio, pow _max is the maximum power value in the first X taps, and pow _mean is the average power of the noise power of Y taps.

Further, X is 64, and Y is 128.

Further, step five also includes the following steps:

Calculate the channel impulse according to the local secondary synchronization signal generated by the configured co-frequency neighbor cell number, and select _N1 taps from it;

Calculating the denoising threshold;

Perform zero-clearing processing for channel impulses below the noise elimination threshold;

Perform secondary synchronization signal reconstruction based on channel impulse to eliminate co-channel interfering cells; and

The above process is repeated until all configured co-frequency adjacent cells are eliminated.

Further, the value of N ₁ is between 1 and 32.

Further, in step 1, the received subframe is subframe 0 or subframe 5, and the received data length is at least 0.5 ms plus the data length of 2 OFDM symbols.

Further, in step 3, the sampling rate of the downsampling filter used in the downsampling filtering process is not lower than 0.96 MHz.

In order to achieve the above and other objectives, the present invention also provides a resynchronization system used in the LTE system, which is applied to terminals in the LTE system, at least including:

a receiving module, configured to receive a subframe including at least a secondary synchronization signal;

The SSS position determination module determines the position of the secondary synchronization signal according to the frame structure, and intercepts the SSS data with a length of K/M at N/M sampling points in advance for down-sampling filtering, where N>=1, and M is related to the receiving bandwidth , K/M>=128, and K/M satisfies 2 ⁿ relationship;

The downsampling filter processing module uses the intercepted SSS data to perform downsampling filter processing;

The same-frequency interference elimination module is used to judge whether there is a same-frequency adjacent cell, so as to perform interference elimination when it is judged that there is a same-frequency adjacent cell;

The secondary synchronization channel estimation module performs secondary synchronization channel estimation of the measured cell according to the secondary synchronization signal after co-channel interference is eliminated, and obtains the timing of the secondary synchronization signal; and

The measurement module, according to the timing of the output secondary synchronization signal, uses the reference signal signal based on the cell to perform measurement again, and the timing of the measurement output is output as the final resynchronization timing.

Further, the co-channel interference elimination module also includes:

The channel estimation module performs channel estimation according to the secondary synchronization signal generated locally, and obtains the maximum power value in the first X taps and the average power of the noise power of the Y taps;

The peak-to-average ratio calculation module calculates the peak-to-average ratio according to the maximum power value obtained in the first X taps and the average power of the noise power of the Y taps;

The judging module compares the peak-to-average ratio with a threshold value to judge whether there is a strong co-channel interference neighboring cell; and

The interference elimination processing module performs interference elimination according to the configured co-frequency adjacent cells when the judging module judges that there is a strong co-frequency interfering neighboring cell.

Further, if the peak-to-average ratio is smaller than the threshold value, it indicates that the cell is weak or does not exist; if the peak-to-average ratio is greater than the threshold value, it indicates that there is a strong co-channel interference neighboring cell.

Further, the threshold value is greater than or equal to 4.

Further, the subframe received by the receiving module is subframe 0 or subframe 5, and the received data length is at least 0.5ms plus the data length of 2 OFDM symbols.

Compared with the prior art, the present invention is a resynchronization method and system for LTE system, by receiving the subframe containing the secondary synchronization signal, performing channel estimation and peak-to-average ratio calculation on the secondary synchronization signal, according to the peak-to-average ratio After judging the same-channel interference and eliminating the interference, the timing of the secondary synchronization signal is obtained through secondary synchronization channel estimation, which realizes the purpose of timing synchronization with the base station before and after switching or waking up from sleep in the LTE system. Compared with the prior art, the present invention enables The time required for the resynchronization process is greatly reduced to meet practical applications; the timing accuracy of the resynchronization output of the present invention is also greatly improved; the timing error range of the resynchronization of the present invention is also greatly improved.

Description of drawings

Fig. 1 is a kind of flowchart of the resynchronization method used in the LTE system of the present invention;

Fig. 2 is a schematic diagram of the position of the synchronization signal in a preferred embodiment of the present invention;

Fig. 3 is a flow chart of judging same-frequency adjacent cells in a preferred embodiment of the present invention;

FIG. 4 is a system architecture diagram of a resynchronization system used in an LTE system according to the present invention.

Detailed ways

The implementation of the present invention is described below through specific examples and in conjunction with the accompanying drawings, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific examples, and various modifications and changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

FIG. 1 is a flowchart of a resynchronization method used in an LTE system according to the present invention. As shown in Figure 1, a kind of resynchronization method used in LTE system of the present invention comprises the following steps:

Step 101, the terminal receives a subframe including SSS (Secondary Synchronization Signal), and the length of received data is at least including the Secondary Synchronization Signal as the lower limit.

Fig. 2 is a schematic diagram of the position of the synchronization signal in the preferred embodiment of the present invention. It can be seen that the secondary synchronization signal (SSS) is located in the last symbol of subframe 0 and subframe 5 of a radio frame, so in a preferred embodiment of the present invention, the terminal receives subframe 0 or subframe 5 data, and the length of the received data is at least The data length of 0.5ms plus 2 OFDM symbols can ensure that the received data contains the Secondary Synchronization Signal (SSS).

Step 102, determine the location of the SSS according to the frame structure, and intercept the SSS data with a length of K/M at N/M sampling points in advance for down-sampling filtering, where N>=1, M is related to the receiving bandwidth, and its value can refer to Table 1 below, K/M>=128, and K/M satisfies 2 ⁿ relationship.

In Table 1, for 15MHz bandwidth, in order to avoid 1536-point FFT processing, use the same sampling rate as 20MHz bandwidth, use 2048-point FFT

System bandwidth [MHz] 1.4 3 5 10 15 20 Baseband sampling rate [MHz] 1.92 3.84 7.68 15.36 30.72 30.72 Sampling points per subframe for one channel of data 1920 3840 7680 15360 30720 30720 Sampling rate normalization coefficient M 16 8 4 2 1 1 FFT points N 128 256 512 1024 2048 2048 The number of sampling points of Normal CP 9 18 36 72 144 144 Sampling points of Extended CP 32 64 128 256 512 512

Table 1

Step 103, use the intercepted SSS data to perform down-sampling filter processing. Here, the sampling rate of the down-sampling filter used in the down-sampling filter processing is not lower than 0.96MHz, and the output data length after down-sampling is K/2*M;

Step 104, judging whether there is an adjacent cell with the same frequency, if there is an adjacent cell with the same frequency, then enter step 105, otherwise enter step 106;

Fig. 3 is a flow chart of judging adjacent cells of the same frequency in a preferred embodiment of the present invention. As shown in Figure 3, the method for judging whether there is a co-frequency adjacent cell includes the following steps:

Step S1, firstly perform channel estimation according to the locally generated secondary synchronization signal, and calculate and obtain the maximum power value pow _max in the first X taps and the average power pow _mean of the noise power in Y taps. Assuming that the received signal is down-sampled, it can be expressed as:

${\stackrel{<span\; class="notranslate">\; =</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; [</span>{\stackrel{<span\; class="notranslate">\; =</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\stackrel{<span\; class="notranslate">\; =</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; ,</span>{\stackrel{<span\; class="notranslate">\; =</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}$

The local synchronization code can be expressed as:

${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; local</span>}}^{\mathrm{<span\; class="notranslate">\; Time</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; local</span>}}^{\mathrm{<span\; class="notranslate">\; Time</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; local</span>}}^{\mathrm{<span\; class="notranslate">\; Time</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; local</span>}}^{\mathrm{<span\; class="notranslate">\; Time</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 63</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}$

扩展后利用FFT(快速傅里叶变换)计算线性相关可以得到SSS信道估计结果如下the secondary sync sequence

After expansion, the SSS channel estimation result can be obtained by using FFT (Fast Fourier Transform) to calculate the linear correlation as follows

${\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; IFFT</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; FFT</span>}<span\; class="notranslate">\; (</span>{\stackrel{<span\; class="notranslate">\; =</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; conj</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; FFT</span>}<span\; class="notranslate">\; (</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}}_{\mathrm{<span\; class="notranslate">\; local</span>}}^{\mathrm{<span\; class="notranslate">\; Time</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>$

in ${\stackrel{\&OverBar;}{d}}_{\mathrm{local}}^{\mathrm{Time}}\left(j\right)=\left\{\begin{array}{cc}{d}_{\mathrm{local}}^{\mathrm{Time}}\left(j\right)& \mathrm{if}0\&le;j\&le;63\\ 0& \mathrm{if}64\&le;j\&le;(K/2*m-1)\end{array}\right..$

The channel impulse response of SSS channel estimation can be expressed as:

${\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; [</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; ,</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}$

The channel impulse response power tap can be expressed as:

P=[p(0),p(1),...,p(K/2*M)] ^T

in:

$\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; |</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}$

Take the previous 64 taps as an example, select the maximum power value pow _max and the corresponding position pos _max in the previous 64 taps

pow _max = max(p(i)), i=0, 1, ..., K/2*M-1

${\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arg</span>}\underset{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0,1</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}$

Select the noise power pow _noise from 128 taps, expressed as:

${\mathrm{<span\; class="notranslate">\; pow</span>}}_{\mathrm{<span\; class="notranslate">\; noise</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 16</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 16</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>& {\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; \&Greater\; Equal;</span>\mathrm{<span\; class="notranslate">\; 16</span>}\\ <span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 16</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; noise</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>& {\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; 16</span>}\end{array}\right.$

Calculate the average power pow _mean of the noise power

pow _mean = mean(pow _noise )

Save the maximum power value pow _max and the corresponding position for use in subsequent processes.

Step S2, according to the maximum power value pow _max in the first X taps and the average power pow _mean of the noise power of Y taps, calculate the peak-to-average ratio ratio _max/mean , expressed as:

${\mathrm{<span\; class="notranslate">\; ratio</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; mean</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; pow</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{{\mathrm{<span\; class="notranslate">\; pow</span>}}_{\mathrm{<span\; class="notranslate">\; mean</span>}}}$

Step S3, the peak-to-average ratio ratio _max/mean is compared with the threshold value. If it is less than the threshold value, it means that the cell is weak or does not exist. The threshold value range for judging that the cell is weak or does not exist is greater than or equal to 4, and the recommended value is set to It is set to 16. If it is greater than the threshold value, it indicates that there is a strong co-channel interference adjacent cell, and interference elimination processing needs to be performed on the strong co-channel interference adjacent cell.

Step 105, perform interference cancellation according to the configured same-frequency neighboring cells.

Generate the local SSS sequence according to the configured same-frequency neighbor cell ID (number) to calculate the channel impulse and express it as Among them, the power maximum value p _max and the corresponding position pos _max ′, from which N _{tap_num} taps are selected,

${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span>& {{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>\frac{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; \&le;</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>\\ {\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span>& \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; <</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; <</span>\frac{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; \&le;</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>\\ {\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span>& {{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ,</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; \&le;</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}<span\; class="notranslate">\; )</span>\\ & \end{array}\right.$

The value of N _{tap_num} ranges from 1 to 32, and the recommended value is 5.

Calculate the denoising threshold:

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; noise</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; the\; th</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; max</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 8</span>}}<span\; class="notranslate">\; ,</span>\frac{{\mathrm{<span\; class="notranslate">\; pow</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 8</span>}}<span\; class="notranslate">\; )</span>$

Clear to 0 for lower than P _{noise_th}

${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span>& \mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ></span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; noise</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; the\; <figure-callout\; id="0"\; label="th"\; filenames="HDA00002136105100021.png"\; state="\{\{state\}\}">th</figure-callout></span>}}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; others</span>}\end{array}\right.<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}$

Then, according to Perform SSS signal reconstruction to eliminate co-channel interference with neighboring cells. Step 105 is repeated until all configured same-frequency adjacent cells are eliminated.

In step 106, the secondary synchronization channel estimation of the cell under test is performed according to the SSS signal after co-channel interference is eliminated, and the timing of the SSS is obtained, which is similar to the processing in step 103.

Step 107, according to the timing of the output SSS, make a measurement again by using the CRS (cell-based reference signal) signal, and output the timing of the measurement as the final resynchronization timing.

FIG. 4 is a system architecture diagram of a resynchronization system used in an LTE system according to the present invention. As shown in Figure 4, a resynchronization system used in the LTE system of the present invention is applied to a terminal in the LTE system, and at least includes: a receiving module 40, an SSS position determining module 41, a downsampling filter processing module 42, A co-channel interference elimination module 43 , a secondary synchronization channel estimation module 44 and a measurement module 45 .

Wherein, the receiving module 40 is used to receive a subframe including at least the Secondary Synchronization Signal (SSS), and the received data length is limited to at least including the Secondary Synchronization Signal. In a preferred embodiment of the present invention, the receiving module 40 receives the subframe For the data of frame 0 or subframe 5, the received data length is at least 0.5ms plus the data length of 2 OFDM symbols; the SSS position determination module 41 determines the position of the SSS according to the frame structure, and intercepts the length of N/M sampling points in advance The SSS data of K/M is used for downsampling filtering, where N>=1, M is related to the receiving bandwidth, its value can refer to Table 1, K/M>=128, and K/M satisfies the 2 ⁿ relationship; The sampling filter processing module 42 uses the intercepted SSS data to perform down-sampling filter processing. Here, the sampling rate of the down-sampling filter used in the down-sampling filter processing is not lower than 0.96MHz, and the length of the output data after down-sampling is K/2 * M; same-frequency interference elimination module 43 is used to judge whether there is a same-frequency adjacent cell, so that when judging that there is a same-frequency adjacent cell, interference elimination is performed; the secondary synchronization channel estimation module 44 is based on the SSS signal after eliminating the same-frequency interference Carry out the secondary synchronous channel estimation of measured cell, obtain the timing of SSS; Measurement module 45 utilizes CRS (reference signal of measured cell) signal again according to the timing of outputted SSS to do a measurement, and the timing of measurement output is used as final repeating Synchronous timing output.

In a preferred embodiment of the present invention, the co-channel interference elimination module 43 further includes a channel estimation module 430 , a peak-to-average ratio calculation module 431 , a judgment module 432 and an interference elimination processing module 433 .

Wherein, the channel estimation module 430 performs channel estimation according to the locally generated secondary synchronization signal, and obtains the maximum power value in the first X taps and the average power of the noise power in the Y taps. Specifically, assuming that the received signal is down-sampled, it can be expressed as:

${\stackrel{<span\; class="notranslate">\; =</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; [</span>{\stackrel{<span\; class="notranslate">\; =</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\stackrel{<span\; class="notranslate">\; =</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; ,</span>{\stackrel{<span\; class="notranslate">\; =</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}$

The local synchronization code can be expressed as:

${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; local</span>}}^{\mathrm{<span\; class="notranslate">\; Time</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; local</span>}}^{\mathrm{<span\; class="notranslate">\; Time</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; local</span>}}^{\mathrm{<span\; class="notranslate">\; Time</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; local</span>}}^{\mathrm{<span\; class="notranslate">\; Time</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 63</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}$

扩展后利用FFT(快速傅里叶变换)计算线性相关可以得到SSS信道估计结果如下The Secondary Synchronization Sequence (Secondary Synchronization Signal SSS)

After expansion, the SSS channel estimation result can be obtained by using FFT (Fast Fourier Transform) to calculate the linear correlation as follows

${\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; IFFT</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; FFT</span>}<span\; class="notranslate">\; (</span>{\stackrel{<span\; class="notranslate">\; =</span>}{\mathrm{<span\; class="notranslate">\; e</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; conj</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; FFT</span>}<span\; class="notranslate">\; (</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}}_{\mathrm{<span\; class="notranslate">\; local</span>}}^{\mathrm{<span\; class="notranslate">\; Time</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>$

in ${\stackrel{\&OverBar;}{d}}_{\mathrm{local}}^{\mathrm{Time}}\left(j\right)=\left\{\begin{array}{cc}{d}_{\mathrm{local}}^{\mathrm{Time}}\left(j\right)& \mathrm{if}0\&le;j\&le;63\\ 0& \mathrm{if}64\&le;j\&le;(K/2*m-1)\end{array}\right..$

The channel impulse response of SSS channel estimation can be expressed as:

${\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; [</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&CenterDot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; ,</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}$

The channel impulse response power tap can be expressed as:

P=[p(0),p(1),...,p(K/2*M)] ^T

in:

$\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; |</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}$

Take the previous 64 taps as an example, select the maximum power value pow _max and the corresponding position pos _max in the first 64 taps

pow _max = max(p(i)), i=0, 1, ..., K/2*M-1

${\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arg</span>}\underset{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0,1</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}$

Select the noise power pow _noise from 128 taps, expressed as:

${\mathrm{<span\; class="notranslate">\; pow</span>}}_{\mathrm{<span\; class="notranslate">\; noise</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 16</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 16</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>& {\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; \&Greater\; Equal;</span>\mathrm{<span\; class="notranslate">\; 16</span>}\\ <span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 16</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; noise</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span>& {\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; 16</span>}\end{array}\right.$

Calculate the average power pow _mean of the noise power

pow _mean = mean(pow _noise )

Save the maximum power value pow _max and the corresponding position for use in subsequent processes.

The peak-to-average ratio calculation module 431 calculates the peak-to-average ratio ratio _max/mean according to the maximum power value pow _max in the obtained first X taps and the average power pow _mean of the noise power of Y taps, expressed as:

${\mathrm{<span\; class="notranslate">\; ratio</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; mean</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; pow</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{{\mathrm{<span\; class="notranslate">\; pow</span>}}_{\mathrm{<span\; class="notranslate">\; mean</span>}}}<span\; class="notranslate">\; .</span>$

Judging module 432 compares the peak-to-average ratio ratio _max/mean with a threshold value to determine whether there is a strong co-channel interference adjacent cell, if the peak-to-average ratio ratio _max/mean is less than the threshold value, it means that the cell is very weak Or does not exist, the threshold value range for judging that the cell is weak or non-existent is greater than or equal to 4, and the recommended value is set to 16. If the peak-to-average ratio ratio _max/mean is greater than the threshold value, it means that there is a strong co-channel interference neighboring cell, and you need to Interference elimination processing is performed on neighboring cells with strong co-channel interference.

其中功率最大值p_max和对应位置pos_max′，从其中选取N_{tap_num}个抽头，When the judgment module 432 judges that there is a strong same-frequency interference adjacent cell, the interference elimination processing module 433 performs interference elimination according to the configured same-frequency adjacent cell, specifically, first generates a local ID (number) according to the configured same-frequency adjacent cell The SSS sequence calculates the channel impulse, expressed as

Among them, the power maximum value p _max and the corresponding position pos _max ′, from which N _{tap_num} taps are selected,

${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span>& {{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>\frac{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; \&le;</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>\\ {\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span>& \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; <</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; <</span>\frac{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; \&le;</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>\\ {\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; r</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span>& {{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ,</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; \&le;</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; pos</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}<span\; class="notranslate">\; )</span>\\ & \end{array}\right.$

The value of N _{tap_num} ranges from 1 to 32, and the recommended value is 5.

Calculate the denoising threshold:

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; noise</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; the\; th</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; max</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 8</span>}}<span\; class="notranslate">\; ,</span>\frac{{\mathrm{<span\; class="notranslate">\; pow</span>}}_{\mathrm{<span\; class="notranslate">\; max</span>}}}{\mathrm{<span\; class="notranslate">\; 8</span>}}<span\; class="notranslate">\; )</span>$

Clear to 0 for lower than P _{noise_th}

${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}}_{\mathrm{<span\; class="notranslate">\; SCHE</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span>& \mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ></span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; noise</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; the\; <figure-callout\; id="0"\; label="th"\; filenames="HDA00002136105100021.png"\; state="\{\{state\}\}">th</figure-callout></span>}}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; others</span>}\end{array}\right.<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; <</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; tap</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; num</span>}}$

进行SSS信号重构，消除同频干扰邻区。重复进行此干扰消除处理直至将所有的配置同频邻区都消除干净。Then, according to

Perform SSS signal reconstruction to eliminate co-channel interference with neighboring cells. This interference elimination process is repeated until all configured same-frequency adjacent cells are completely eliminated.

It can be seen that the resynchronization method and system used in the LTE system of the present invention, by receiving the subframe containing the secondary synchronization signal, performs channel estimation and calculation of the peak-to-average ratio on the secondary synchronization signal, and judges the same-channel interference according to the peak-to-average ratio. After the interference is eliminated, the timing of the secondary synchronization signal is obtained through secondary synchronization channel estimation, which realizes the purpose of timing synchronization between the terminal in the LTE system before and after handover or sleep wake-up and the base station, and, compared with the prior art, the present invention makes the resynchronization process The required time is obviously reduced. Under the condition of not affecting the performance, the data received 5 times is reduced to 1 data, and the processing time is shortened from 27ms to 5ms, which meets the practical application; at the same time, the timing of the resynchronization output of the present invention Accuracy is more accurate, and the timing precision of the present invention can be accurate to 1 TS unit (wherein T _s =1/(15000×2048)), and before the present invention, resynchronization output timing unit is 32TS integral multiples; Timing error of the present invention The range has also been greatly improved. Before the present invention, the timing error range was less than 1km, and the timing error range of the present invention is at least 10km.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Any person skilled in the art can modify and change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be listed in the claims.

Claims (14)

1. for a resynchronization method for LTE system, be applied to the terminal in LTE system, comprise the steps:

Step 1, reception one at least comprises the subframe of auxiliary synchronous signals;

Step 2, determines the position at auxiliary synchronous signals place according to frame structure, and the SSS data that N/M sampled point intercepted length is K/M in advance, N >=1 wherein, and M is with to receive bandwidth relevant, K/M >=128, and K/M satisfied 2 ⁿrelation;

Step 3, utilizes the SSS data of intercepting to carry out down-sampled filtering processing;

Step 4, judges whether to exist homogeneous-frequency adjacent-domain, if there is homogeneous-frequency adjacent-domain, enters step 5, otherwise enters step 6;

Step 5, disturbs elimination according to the homogeneous-frequency adjacent-domain of configuration;

Step 6, carries out the auxiliary synchronization channel estimation of tested community, the timing of obtaining auxiliary synchronous signals according to the auxiliary synchronous signals of eliminating after co-channel interference; And

Step 7, the timing according to the auxiliary synchronous signals of output, utilizes the reference signal of tested community to measure again, measures the timing of output as final heavy synchronization timing output.

2. the resynchronization method for LTE system as claimed in claim 1, is characterized in that, step 4 also comprises the steps:

The auxiliary synchronous signals generating according to this locality carries out channel estimating, and the average power of the noise power of the maximum power value in front X the tap of calculating acquisition and Y tap;

According to the average power of the noise power of the maximum power value in a front X tap and Y tap, calculate peak-to-average force ratio; And

This peak-to-average force ratio and the threshold value that obtain are compared, if this peak-to-average force ratio is less than this threshold value, represents that community is very weak or do not exist, if this peak-to-average force ratio is greater than this threshold value, represent to exist strong co-channel interference adjacent area.

3. the resynchronization method for LTE system as claimed in claim 2, is characterized in that: this threshold value is more than or equal to 4.

4. the resynchronization method for LTE system as claimed in claim 2, is characterized in that, the calculating of this peak-to-average force ratio obtains by following formula:

${\mathrm{ratio}}_{\max /\mathrm{mean}}=\frac{{\mathrm{pow}}_{\max }}{{\mathrm{pow}}_{\mathrm{mean}}}$

Wherein, ratio _max/meanfor peak-to-average force ratio, pow _maxfor the maximum power value in a front X tap, pow _meanaverage power for the noise power of Y tap.

5. the resynchronization method for LTE system as claimed in claim 4, is characterized in that: X is that 64, Y is 128.

6. the resynchronization method for LTE system as claimed in claim 1, is characterized in that, step 5 also comprises the steps:

The local auxiliary synchronous signals generating according to the homogeneous-frequency adjacent-domain numbering of configuration calculates channel impulse, and therefrom chooses N ₁individual tap;

Calculate de-noising thresholding;

For the channel impulse lower than de-noising thresholding, carry out 0 processing clearly;

According to channel impulse, carry out auxiliary synchronous signals reconstruct, eliminate inter-frequency interference cell; And

Repeat said process, until all eliminate totally all configuration homogeneous-frequency adjacent-domains.

7. the resynchronization method for LTE system as claimed in claim 6, is characterized in that: N ₁value is between 1～32.

8. the resynchronization method for LTE system as claimed in claim 1, is characterized in that: in step 1, the subframe of reception is subframe 0 or subframe 5, and the data length of reception is at least the data length that 0.5ms adds 2 OFDM symbols.

9. the resynchronization method for LTE system as claimed in claim 1, is characterized in that: in step 3, down-sampled filtering is processed the desampling fir filter sample rate adopting and is not less than 0.96MHz.

10. for a heavy synchro system for LTE system, be applied to the terminal in LTE system, at least comprise:

Receive module, for receiving a subframe that at least comprises auxiliary synchronous signals;

SSS location positioning module, according to frame structure, determine the position at auxiliary synchronous signals place, and the SSS data that N/M sampled point intercepted length is K/M are in advance for down-sampled filtering, N >=1 wherein, M is relevant to reception bandwidth, K/M >=128, and K/M meets 2 ⁿrelation;

Module is processed in down-sampled filtering, utilizes the SSS data of intercepting, carries out down-sampled filtering processing;

Co-channel interference is eliminated module, for judging whether to exist homogeneous-frequency adjacent-domain, with when judgement exists homogeneous-frequency adjacent-domain, disturbs elimination;

Auxiliary synchronization channel is estimated module, according to the auxiliary synchronous signals of eliminating after co-channel interference, carries out the auxiliary synchronization channel estimation of tested community, the timing of obtaining auxiliary synchronous signals; And

Measure module, the timing according to the auxiliary synchronous signals of output, utilizes the reference signal signal based on community to measure again, measures the timing of output as final heavy synchronization timing output.

11. a kind of heavy synchro systems for LTE system as claimed in claim 10, is characterized in that, this co-channel interference is eliminated module and also comprised:

Channel estimating module, the auxiliary synchronous signals generating according to this locality carries out channel estimating, and the average power of the noise power of the maximum power value in front X the tap of acquisition and Y tap;

Peak-to-average force ratio calculates module, according to the average power of the noise power of the maximum power value in front X the tap obtaining and Y tap, calculates peak-to-average force ratio;

Judgement module, compares this peak-to-average force ratio and a threshold value, to judge whether to exist strong co-channel interference adjacent area; And

Interference elimination treatment module, when this judgement module judgement exists strong co-channel interference adjacent area, disturbs elimination according to the homogeneous-frequency adjacent-domain of configuration.

12. a kind of heavy synchro systems for LTE system as claimed in claim 11, is characterized in that: if peak-to-average force ratio is less than this threshold value, represents that this community is very weak or do not exist; If peak-to-average force ratio is greater than this threshold value, represent to exist strong co-channel interference adjacent area.

13. a kind of heavy synchro systems for LTE system as claimed in claim 11, is characterized in that: this threshold value is more than or equal to 4.

14. a kind of heavy synchro systems for LTE system as claimed in claim 11, is characterized in that: the subframe that this reception module receives is subframe 0 or subframe 5, and the data length of reception is at least the data length that 0.5ms adds 2 OFDM symbols.

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