CN103685120B - A kind of resynchronization method in LTE system and system - Google Patents

Abstract

The present invention discloses a kind of resynchronization method in LTE system and system, and the method comprises the steps: to receive a subframe including at least auxiliary synchronous signals；Determine the position at auxiliary synchronous signals place according to frame structure, and N/M sampled point intercepted length is the SSS data of K/M in advance；The SSS data intercepted are utilized to carry out down-sampled Filtering Processing；Judge whether homogeneous-frequency adjacent-domain, if there is homogeneous-frequency adjacent-domain, then carry out interference according to the homogeneous-frequency adjacent-domain of configuration and eliminate；The auxiliary synchronization channel carrying out tested community according to the auxiliary synchronous signals after eliminating co-channel interference is estimated, obtains the timing of auxiliary synchronous signals；And the timing of the auxiliary synchronous signals according to output, measure again with reference signal based on community, the timing measuring output re-synchronizes timing output as final, pass through the present invention, the time that the process that re-synchronizes of LTE can be made to need is greatly reduced, and makes to re-synchronize the timing accuracy of output and timing error range all improves a lot.

Description

A kind of resynchronization method in LTE system and system

Technical field

The present invention relates to a kind of resynchronization method and system, particularly relate to a kind of side of re-synchronizing in LTE system Method and system.

Background technology

Along with the development and progress of society, people require that mobile terminal can not only provide voice and the word clothes of high-quality Business, additionally it is possible to two-forty, Large Copacity and the digital multimedia application service of low latency are provided.In order to meet, people are this to be increased day by day Long demand, the end of the year 2004, third generation partner program (3GPP, 3rd Generation Partnership Project) Start Long Term Evolution (LTE, the Long Term Evolution) project of UMTS technology.

In LTE system, terminal in switching before and after or sleep wake up time, generally require be timed with base station synchronization.Existing Having in technology, terminal re-synchronizes in switching gravity treatment and specifically comprises the following steps that

(1) receive 1ms and comprise PSS (Primary Synchronization Signal, master sync signal) and SSS (Secondary Synchronization Signal, auxiliary synchronous signals) data carry out down-sampled filtering；

(2) according to frame timing and CP (Cyclic Prefix, Cyclic Prefix) type, determine SSS position, and in advance 1 adopt Sampling point intercepted length is the data of 128；

(3) judge whether interfered cell, if there is interfered cell, then perform step (4), otherwise perform step (5)；

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

(5) carry out auxiliary synchronization channel estimation according to re-synchronizing cellid (cell number), obtain channel impulse response peak value Position, peak is real SSS position.

But, the resynchronization method of above-mentioned switching gravity treatment has a disadvantage in that

(1) easily there is the position of mistake in reuse adoption process；

(2) timing accuracy of gravity treatment output is the highest；

(3) the OTD2 scope exported is between-992Ts～32Ts, if local timing shifts to an earlier date a lot of than network timing, It is easy to occur re-synchronizing timing output mistake.

In prior art, terminal is in the following two process that is generally divided into that re-synchronizes when waking up of sleeping:

One, lower PSS processing procedure is synchronized:

(1) receive a length of 1ms and comprise PSS and SSS data, and carry out down-sampled filtering；

(2) carry out primary synchronization channel estimation, and back up the channel impulse response power tap of correspondence；

(3) channel impulse response is merged process；

(4) decide whether it is to receive data for the last time, be not to receive data for the last time, directly exit, otherwise perform Step (5).

(5) carrying out primary synchronization channel and estimate judgement, adjudicate successfully, illustrate to synchronize lower PSS success, no person synchronizes lower PSS mistake Journey failure.

Two, SSS essence synchronizing process:

(1) call SSS channel estimation function and complete the channel estimation function of auxiliary synchronization；

(2) judge whether currently processed be that kth SSS channel is estimated, if it is not, the most directly exit, otherwise performs step Suddenly (3)；

(3) call SSS essence synchronization decisions function, if adjudicating successfully, illustrating that SSS essence synchronizes successfully, otherwise exporting failure, (4) frequency or the PSS search procedure under next NID2 of reforming are changed.

But, resynchronization method when above-mentioned sleep is waken up there is also following deficiency:

(1) receive data times many, affect the length of one's sleep；

(2) synchronizing lower PSS output may be more, it is impossible to the most accurately determines and re-synchronizes the PSS position that community is corresponding, therefore can Affect the SSS essence in the 2nd stage to synchronize, cause re-synchronizing output error timing；

(3) timing accuracy exported is the highest.

Summary of the invention

For the deficiency overcoming above-mentioned prior art to exist, the purpose of the present invention is to provide a kind of in LTE system Resynchronization method and system, its time that process that re-synchronizes in LTE system is needed is greatly reduced, meet actual should With；Make to re-synchronize the timing accuracy of output simultaneously and timing error range is all greatly improved.

For reaching above and other purpose, the present invention provides a kind of resynchronization method in LTE system, is applied to LTE Terminal in system, comprises the steps:

Step one, receives a subframe including at least auxiliary synchronous signals；

Step 2, determines the position at auxiliary synchronous signals place, and N/M sampled point intercepted length is K/ in advance according to frame structure The SSS data of M, wherein N ＞=1, M is relevant to reception bandwidth, K/M ＞=128, and K/M meets 2ⁿRelation；

Step 3, utilizes the SSS data intercepted to carry out down-sampled Filtering Processing；

Step 4, it may be judged whether there is homogeneous-frequency adjacent-domain, if there is homogeneous-frequency adjacent-domain, then enters step 5, otherwise enters step Six；

Step 5, carries out interference according to the homogeneous-frequency adjacent-domain of configuration and eliminates；

Step 6, the auxiliary synchronization channel carrying out tested community according to the auxiliary synchronous signals after eliminating co-channel interference is estimated, obtains Take the timing of auxiliary synchronous signals；And

Step 7, according to the timing of the auxiliary synchronous signals of output, measures again with reference signal based on community, surveys The timing of amount output re-synchronizes timing output as final.

Further, step 4 also comprises the steps:

The auxiliary synchronous signals generated according to this locality carries out channel estimation, and calculates the peak power obtained in front X tap The mean power of the noise power of value and Y tap；

Mean power according to the maximum power value in front X tap and the noise power of Y tap calculates peak-to-average force ratio；With And

This peak-to-average force ratio obtained and a threshold value are compared, if this peak-to-average force ratio is less than this threshold value, then it represents that community The most weak or do not exist, if this peak-to-average force ratio is more than this threshold value, then it represents that there is strong co-channel interference adjacent area.

Further, this threshold value is more than or equal to 4.

Further, the calculating of this peak-to-average force ratio is obtained by equation below:

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

Wherein, ratio_max/meanFor peak-to-average force ratio, pow_maxFor the maximum power value in front X tap, pow_meanTake out for Y The mean power of the noise power of head.

Further, X is 64, and Y is 128.

Further, step 5 also comprises the steps:

The local auxiliary synchronous signals that homogeneous-frequency adjacent-domain numbering according to configuration generates calculates channel impulse, and therefrom chooses N₁Individual Tap；

Calculate de-noising thresholding；

Process for carrying out clear 0 less than the channel impulse of de-noising thresholding；

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

Repeat said process, until all of configuration homogeneous-frequency adjacent-domain all eliminates totally.

Further, N₁Value is between 1～32.

Further, in step one, the subframe of reception is subframe 0 or subframe 5, and the data length of reception is at least 0.5ms adds the data length of 2 OFDM symbol.

Further, in step 3, the desampling fir filter sample rate that down-sampled Filtering Processing uses is not less than 0.96MHz。

For reaching above-mentioned and other purpose, the present invention also provides for a kind of re-synchronizing system in LTE system, is applied to Terminal in LTE system, at least includes:

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

SSS position determines module, determines the position at auxiliary synchronous signals place according to frame structure, and N/M sampled point cuts in advance Taking the SSS data of a length of K/M for down-sampled filtering, wherein N ＞=1, M is relevant to reception bandwidth, K/M ＞=128, and K/ M meets 2ⁿRelation；

Down-sampled Filtering Processing module, utilizes the SSS data intercepted, carries out down-sampled Filtering Processing；

Co-channel interference eliminates module, is used for judging whether homogeneous-frequency adjacent-domain, in time judging to there is homogeneous-frequency adjacent-domain, to carry out Interference eliminates；

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

Measure module, according to the timing of the auxiliary synchronous signals of output, do again with reference signal signal based on community Measuring, the timing measuring output re-synchronizes timing output as final.

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

Channel estimates module, and the auxiliary synchronous signals generated according to this locality carries out channel estimation, and obtains in front X tap The mean power of the noise power of maximum power value and Y tap；

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

Judge module, this peak-to-average force ratio and a threshold value are compared, to judge whether strong co-channel interference adjacent area；With And

Interference elimination treatment module, when this judgement module judges to there is strong co-channel interference adjacent area, according to the same frequency of configuration Adjacent area carries out interference and eliminates.

Further, if peak-to-average force ratio is less than this threshold value, then it represents that this community is the most weak or does not exists；If peak-to-average force ratio is more than This threshold value, then it represents that there is strong co-channel interference adjacent area.

Further, this threshold value is more than or equal to 4.

Further, the subframe that this reception module receives is subframe 0 or subframe 5, and the data length of reception is at least 0.5ms Add the data length of 2 OFDM symbol.

Compared with prior art, a kind of resynchronization method in LTE system of the present invention and system, comprised by reception The subframe of auxiliary synchronous signals, carries out channel estimation and calculates peak-to-average force ratio, judging co-channel interference according to peak-to-average force ratio auxiliary synchronous signals And estimate to obtain the timing of auxiliary synchronous signals by auxiliary synchronization channel again after eliminating interference, it is achieved that terminal switching in LTE system Front and back or sleep is waken up the purpose with base station Timing Synchronization, compared with prior art, the invention enables the process needs re-synchronized Time be greatly reduced, meet actual application；The timing accuracy re-synchronizing output of the present invention there has also been bigger raising；This The bright timing error range re-synchronized there has also been bigger raising.

Accompanying drawing explanation

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

Fig. 2 is the position view of synchronizing signal in present pre-ferred embodiments；

Fig. 3 is the flow chart in present pre-ferred embodiments judged homogeneous-frequency adjacent-domain；

Fig. 4 is the system architecture diagram of a kind of system that re-synchronizes in LTE system of the present invention.

Detailed description of the invention

Below by way of specific instantiation accompanying drawings embodiments of the present invention, those skilled in the art can Further advantage and effect of the present invention is understood easily by content disclosed in the present specification.The present invention also can be different by other Instantiation implemented or applied, the every details in this specification also can based on different viewpoints and application, without departing substantially from Various modification and change is carried out under the spirit of the present invention.

Fig. 1 is the flow chart of a kind of resynchronization method in LTE system of the present invention.As it is shown in figure 1, the present invention is a kind of Resynchronization method in LTE system, comprises the steps:

Step 101, terminal receives a subframe comprising SSS (auxiliary synchronous signals), and the data length of reception is to include at least Auxiliary synchronous signals is lower limit.

Fig. 2 is the position view of synchronizing signal in present pre-ferred embodiments.Visible, auxiliary synchronous signals (SSS) is positioned at The subframe 0 of one radio frames and last symbol of subframe 5, therefore in present pre-ferred embodiments, terminal receive subframe 0 or Subframe 5 data, the data length of reception at least 0.5ms adds the data length of 2 OFDM symbol, so can ensure that and receive Data in comprise auxiliary synchronous signals (SSS).

Step 102, determines the position at SSS place according to frame structure, and N/M sampled point intercepted length is the SSS number of K/M in advance According to for down-sampled filtering, wherein N ＞=1, M is relevant to reception bandwidth, and its value is referred to table 1 below, K/M ＞=128, And K/M meets 2ⁿRelation.

Wherein in table 1, for 15MHz bandwidth, in order to avoid 1536 FFT process, use adopt identical with 20MHz bandwidth Sample rate, uses 2048 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
One circuit-switched data every subframe sampling number	1920	3840	7680	15360	30720	30720
							Sample rate normalization coefficient M	16	8	4	2	1	1
FFT points N	128	256	512	1024	2048	2048
							The sampling number of Normal CP	9	18	36	72	144	144
The sampling number of Extended CP	32	64	128	256	512	512

Table 1

Step 103, utilizes the SSS data intercepted, carries out down-sampled Filtering Processing, here, down-sampled Filtering Processing uses Desampling fir filter sample rate be not less than 0.96MHz, down-sampled after the data length of output be K/2*M；

Step 104, it may be judged whether there is homogeneous-frequency adjacent-domain, if there is homogeneous-frequency adjacent-domain, then enters step 105, otherwise enters step Rapid 106；

Fig. 3 is the flow chart in present pre-ferred embodiments judged homogeneous-frequency adjacent-domain.As it is shown on figure 3, judge whether The method of homogeneous-frequency adjacent-domain comprises the steps:

Step S1, the auxiliary synchronous signals first generated according to this locality carries out channel estimation, and calculates in front X the tap of acquisition Maximum power value pow_maxAnd mean power pow of the noise power of Y tap_mean.Assume to receive signal through down-sampled After, can be expressed as:

${\stackrel{=}{e}}_{\mathrm{SCHE}}={[{\stackrel{=}{e}}_{\mathrm{SCHE}}\left(0\right),{\stackrel{=}{e}}_{\mathrm{SCHE}}\left(1\right),\·\·\·,{\stackrel{=}{e}}_{\mathrm{SCHE}}(K/2*M-1)]}^T$

Local synchronization code can be expressed as:

$d_{\mathrm{Local}}^{\mathrm{Time}}={[d_{\mathrm{Local}}^{\mathrm{Time}}\left(0\right),d_{\mathrm{Local}}^{\mathrm{Time}}\left(1\right),\·\·\·,d_{\mathrm{Local}}^{\mathrm{Time}}\left(63\right)]}^T$

By secondary synchronization sequencesUtilize FFT (fast Fourier transform) to calculate linear correlation after extension can obtain SSS channel estimation results is as follows

${\stackrel{\‾}{r}}_{\mathrm{SCHE}}=\mathrm{IFFT}(\mathrm{FFT}\left({\stackrel{=}{e}}_{\mathrm{SCHE}}\right)\×\mathrm{conj}\left(\mathrm{FFT}\left({\stackrel{\‾}{d}}_{\mathrm{Local}}^{\mathrm{Time}}\right)\right))$

Wherein ${\stackrel{\‾}{d}}_{\mathrm{Local}}^{\mathrm{Time}}\left(j\right)=\left\{\begin{array}{cc}{d}_{\mathrm{Local}}^{\mathrm{Time}}\left(j\right)& \mathrm{if}0\≤j\≤63\\ 0& \mathrm{if}64\≤j\≤(K/2*M-1)\end{array}\right..$

The channel impulse response that SSS channel is estimated can be expressed as:

${\stackrel{\‾}{r}}_{\mathrm{SCHE}}={[{\stackrel{\‾}{r}}_{\mathrm{SCHE}}\left(0\right),{\stackrel{\‾}{r}}_{\mathrm{SCHE}}\left(1\right),\·\·\·,{\stackrel{\‾}{r}}_{\mathrm{SCHE}}(K/2*M)]}^T$

Channel impulse response power tap can be expressed as:

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

Wherein:

$p\left(i\right)={\left|{\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}\left(i\right)\right|}^2,0<=i<K/2*M$

In the past as a example by 64 taps, choose maximum power value pow in above 64 taps_maxAnd the position pos of correspondence_max

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

${\mathrm{pos}}_{\max }=\arg \underset{i}{\max }\left(p\left(i\right)\right),i=\mathrm{0,1},\&CenterDot;\&CenterDot;\&CenterDot;,K/2*M-1$

Noise power pow is chosen from 128 taps_noise, it is formulated as:

${\mathrm{pow}}_{\mathrm{noise}}=\left\{\begin{array}{cc}[p\left(0\right),...,p({\mathrm{pos}}_{\max }-16),p({\mathrm{pos}}_{\max }+16),...,p(K/2*M)]& {\mathrm{pos}}_{\max }\&GreaterEqual;16\\ [p({\mathrm{pos}}_{\max }+16),...,p_{\mathrm{noise}}(K/2*M)]& {\mathrm{pos}}_{\max }<16\end{array}\right.$

Calculate mean power pow of noise power_mean

pow_mean=mean (pow_noise)

Preserve maximum power value pow_maxAnd the position of correspondence, use for subsequent process.

Step S2, according to the maximum power value pow in front X tap_maxAnd the mean power of the noise power of Y tap pow_mean, calculate peak-to-average force ratio ratio_max/mean, it is formulated as:

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

Step S3, peak-to-average force ratio ratio_max/meanCompare with threshold value, if less than thresholding, then it represents that this community is the most weak Or not existing, the most weak or non-existent thresholding span in judgement community is more than or equal to 4, it is proposed that value is set as 16, if More than threshold value, illustrate to exist strong co-channel interference adjacent area, need strong co-channel interference adjacent area is carried out interference elimination treatment.

Step 105, carries out interference according to the homogeneous-frequency adjacent-domain of configuration and eliminates.

Homogeneous-frequency adjacent-domain ID (numbering) according to configuration generates local SSS sequence calculating channel impulse and is expressed asWherein Power maximum p_maxWith correspondence position pos_max', choose N from which_{tap_num}Individual tap,

${\hat{h}}_{\mathrm{SCHE}}\left(i\right)=\left\{\begin{array}{cc}{\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}\left(i\right)& {{\mathrm{pos}}_{\max }}^{\&prime;}\&GreaterEqual;\frac{N_{\mathrm{tap}\_\mathrm{num}}}{2},({{\mathrm{pos}}_{\max }}^{\&prime;}-\frac{N_{\mathrm{tap}\_\mathrm{num}}}{2})\&le;i\&le;({{\mathrm{pos}}_{\max }}^{\&prime;}+\frac{N_{\mathrm{tap}\_\mathrm{num}}}{2})\\ {\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}\left(i\right)& 0<{{\mathrm{pos}}_{\max }}^{\&prime;}<\frac{N_{\mathrm{tap}\_\mathrm{num}}}{2},({{\mathrm{pos}}_{\max }}^{\&prime;}-1)\&le;i\&le;({{\mathrm{pos}}_{\max }}^{\&prime;}+(N_{\mathrm{tap}\_\mathrm{num}}-1))\\ {\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}\left(i\right)& {{\mathrm{pos}}_{\max }}^{\&prime;}=0,{{\mathrm{pos}}_{\max }}^{\&prime;}\&le;i\&le;({{\mathrm{pos}}_{\max }}^{\&prime;}+N_{\mathrm{tap}\_\mathrm{num}})\\ & \end{array}\right.$

N_{tap_num}Value is between 1～32, it is proposed that value is 5.

Calculating de-noising thresholding:

$P_{\mathrm{noise}\_\mathrm{th}}=\max (\frac{p_{\max }}{8},\frac{{\mathrm{pow}}_{\max }}{8})$

For less than P_{noise_th}Carry out clear 0 to process

${\hat{h}}_{\mathrm{SCHE}}\left(i\right)=\left\{\begin{array}{cc}{\hat{h}}_{\mathrm{SCHE}}\left(i\right)& p\left(i\right)>P_{\mathrm{noise}\_\mathrm{th}}\\ 0& \mathrm{others}\end{array}\right.,0<=i<N_{\mathrm{tap}\_\mathrm{num}}$

Then, further according toCarry out SSS signal reconstruction, eliminate co-channel interference adjacent area.Repeat step 105, until will All of configuration homogeneous-frequency adjacent-domain all eliminates totally.

Step 106, the auxiliary synchronization channel carrying out tested community according to the SSS signal after eliminating co-channel interference is estimated, obtains The timing of SSS, is similar to the process in step 103.

Step 107, according to the timing of the SSS of output, does once again with CRS (reference signal based on community) signal Measuring, the timing measuring output re-synchronizes timing output as final.

Fig. 4 is the system architecture diagram of a kind of system that re-synchronizes in LTE system of the present invention.As shown in Figure 4, the present invention A kind of in LTE system, re-synchronize system, be applied to the terminal of LTE system, at least include: receive module 40, SSS position Determine that module 41, down-sampled Filtering Processing module 42, co-channel interference eliminate module 43, auxiliary synchronization channel estimates module 44 and surveys Amount module 45.

Wherein, module 40 is received for receiving a subframe including at least auxiliary synchronous signals (SSS), the data length of reception To be limited including at least auxiliary synchronous signals, in present pre-ferred embodiments, receive module 40 and receive subframe 0 or the number of subframe 5 According to, the data length of reception at least 0.5ms adds the data length of 2 OFDM symbol；SSS position determines that module 41 is tied according to frame Structure determines the position at SSS place, and in advance N/M sampled point intercepted length be the SSS data of K/M for down-sampled filtering, wherein N ＞=1, M is relevant to reception bandwidth, and its value is referred to table 1, K/M ＞=128, and K/M and meets 2ⁿRelation；Down-sampled filtering Process module 42 and utilize the SSS data intercepted, carry out down-sampled Filtering Processing, here, the fall that down-sampled Filtering Processing uses is adopted Sample filter sample rate is not less than 0.96MHz, and the data length of down-sampled rear output is K/2*M；Co-channel interference eliminates module 43 For judging whether homogeneous-frequency adjacent-domain, with in time judging to there is homogeneous-frequency adjacent-domain, carry out interference and eliminate；Auxiliary synchronization channel estimates mould The auxiliary synchronization channel that group 44 carries out tested community according to the SSS signal after eliminating co-channel interference is estimated, obtains the timing of SSS；Survey Amount module 45, according to the timing of the SSS of output, does one-shot measurement again with CRS (reference signal of tested community) signal, surveys The timing of amount output re-synchronizes timing output as final.

In present pre-ferred embodiments, co-channel interference eliminates module 43 and also includes that channel estimates module 430, peak-to-average force ratio meter Calculate module 431, judge module 432 and interference elimination treatment module 433.

Wherein, channel estimates that the auxiliary synchronous signals that module 430 generates according to this locality carries out channel estimation, it is thus achieved that take out for front X Maximum power value in Tou and the mean power of the noise power of Y tap.Specifically, it is assumed that receive signal through down-sampled After, can be expressed as:

${\stackrel{=}{e}}_{\mathrm{SCHE}}={[{\stackrel{=}{e}}_{\mathrm{SCHE}}\left(0\right),{\stackrel{=}{e}}_{\mathrm{SCHE}}\left(1\right),\&CenterDot;\&CenterDot;\&CenterDot;,{\stackrel{=}{e}}_{\mathrm{SCHE}}(K/2*M-1)]}^T$

Local synchronization code can be expressed as:

$d_{\mathrm{Local}}^{\mathrm{Time}}={[d_{\mathrm{Local}}^{\mathrm{Time}}\left(0\right),d_{\mathrm{Local}}^{\mathrm{Time}}\left(1\right),\&CenterDot;\&CenterDot;\&CenterDot;,d_{\mathrm{Local}}^{\mathrm{Time}}\left(63\right)]}^T$

By secondary synchronization sequences (auxiliary synchronous signals SSS)FFT (fast Fourier transform) is utilized to calculate line after extension Property relevant can to obtain SSS channel estimation results as follows

${\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}=\mathrm{IFFT}(\mathrm{FFT}\left({\stackrel{=}{e}}_{\mathrm{SCHE}}\right)\&times;\mathrm{conj}\left(\mathrm{FFT}\left({\stackrel{\&OverBar;}{d}}_{\mathrm{Local}}^{\mathrm{Time}}\right)\right))$

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

The channel impulse response that SSS channel is estimated can be expressed as:

${\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}={[{\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}\left(0\right),{\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}\left(1\right),\&CenterDot;\&CenterDot;\&CenterDot;,{\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}(K/2*M)]}^T$

Channel impulse response power tap can be expressed as:

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

Wherein:

$p\left(i\right)={\left|{\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}\left(i\right)\right|}^2,0<=i<K/2*M$

In the past as a example by 64 taps, choose maximum power value pow in above 64 taps_maxAnd the position pos of correspondence_max

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

${\mathrm{pos}}_{\max }=\arg \underset{i}{\max }\left(p\left(i\right)\right),i=\mathrm{0,1},\&CenterDot;\&CenterDot;\&CenterDot;,K/2*M-1$

Noise power pow is chosen from 128 taps_noise, it is formulated as:

${\mathrm{pow}}_{\mathrm{noise}}=\left\{\begin{array}{cc}[p\left(0\right),...,p({\mathrm{pos}}_{\max }-16),p({\mathrm{pos}}_{\max }+16),...,p(K/2*M)]& {\mathrm{pos}}_{\max }\&GreaterEqual;16\\ [p({\mathrm{pos}}_{\max }+16),...,p_{\mathrm{noise}}(K/2*M)]& {\mathrm{pos}}_{\max }<16\end{array}\right.$

Calculate mean power pow of noise power_mean

pow_mean=mean (pow_noise)

Preserve maximum power value pow_maxAnd the position of correspondence, use for subsequent process.

Peak-to-average force ratio calculates module 431 according to the maximum power value pow in front X the tap obtained_maxAnd the making an uproar of Y tap Mean power pow of acoustical power_meanCalculate peak-to-average force ratio ratio_max/mean, it is formulated as:

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

Judge that module 432 is by this peak-to-average force ratio ratio_max/meanCompare with threshold value, strong with frequency to judge whether Interference adjacent area, if peak-to-average force ratio ratio_max/meanLess than threshold value, then it represents that this community is the most weak or does not exists, judgement community is very Weak or non-existent thresholding span is more than or equal to 4, it is proposed that value is set as 16, if peak-to-average force ratio ratio_max/meanMore than door Limit value, illustrates to exist strong co-channel interference adjacent area, needs strong co-channel interference adjacent area is carried out interference elimination treatment.

Interference elimination treatment module 433 is in time judging that module 432 judges to there is strong co-channel interference adjacent area, same according to configure Frequently adjacent area carries out interference elimination, specifically, first generates local SSS sequence according to the homogeneous-frequency adjacent-domain ID (numbering) of configuration and calculates Channel impulse, is expressed asWherein power maximum p_maxWith correspondence position pos_max', choose N from which_{tap_num}Individual tap,

${\hat{h}}_{\mathrm{SCHE}}\left(i\right)=\left\{\begin{array}{cc}{\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}\left(i\right)& {{\mathrm{pos}}_{\max }}^{\&prime;}\&GreaterEqual;\frac{N_{\mathrm{tap}\_\mathrm{num}}}{2},({{\mathrm{pos}}_{\max }}^{\&prime;}-\frac{N_{\mathrm{tap}\_\mathrm{num}}}{2})\&le;i\&le;({{\mathrm{pos}}_{\max }}^{\&prime;}+\frac{N_{\mathrm{tap}\_\mathrm{num}}}{2})\\ {\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}\left(i\right)& 0<{{\mathrm{pos}}_{\max }}^{\&prime;}<\frac{N_{\mathrm{tap}\_\mathrm{num}}}{2},({{\mathrm{pos}}_{\max }}^{\&prime;}-1)\&le;i\&le;({{\mathrm{pos}}_{\max }}^{\&prime;}+(N_{\mathrm{tap}\_\mathrm{num}}-1))\\ {\stackrel{\&OverBar;}{r}}_{\mathrm{SCHE}}\left(i\right)& {{\mathrm{pos}}_{\max }}^{\&prime;}=0,{{\mathrm{pos}}_{\max }}^{\&prime;}\&le;i\&le;({{\mathrm{pos}}_{\max }}^{\&prime;}+N_{\mathrm{tap}\_\mathrm{num}})\\ & \end{array}\right.$

N_{tap_num}Value is between 1～32, it is proposed that value is 5.

Calculating de-noising thresholding:

$P_{\mathrm{noise}\_\mathrm{th}}=\max (\frac{p_{\max }}{8},\frac{{\mathrm{pow}}_{\max }}{8})$

For less than P_{noise_th}Carry out clear 0 to process

${\hat{h}}_{\mathrm{SCHE}}\left(i\right)=\left\{\begin{array}{cc}{\hat{h}}_{\mathrm{SCHE}}\left(i\right)& p\left(i\right)>P_{\mathrm{noise}\_\mathrm{th}}\\ 0& \mathrm{others}\end{array}\right.,0<=i<N_{\mathrm{tap}\_\mathrm{num}}$

Then, further according toCarry out SSS signal reconstruction, eliminate co-channel interference adjacent area.Repeat this interference to eliminate Process until all of configuration homogeneous-frequency adjacent-domain is all eliminated totally.

Visible, a kind of resynchronization method in LTE system of the present invention and system, comprise auxiliary synchronous signals by reception Subframe, auxiliary synchronous signals is carried out channel estimation and calculate peak-to-average force ratio, judge co-channel interference according to peak-to-average force ratio and eliminate interference After again by auxiliary synchronization channel estimate obtain auxiliary synchronous signals timing, it is achieved that in LTE system terminal switching before and after or sleep Wake up the purpose with base station Timing Synchronization, and, compared with prior art, the invention enables that to re-synchronize process required time obvious Reducing, in the case of not affecting performance, be reduced to 1 secondary data by originally receiving 5 secondary data data, the time that processes was by originally 27ms shortens to 5ms, meets reality application；Meanwhile, the timing accuracy re-synchronizing output of the present invention is more accurate, and the present invention determines Shi Jingdu can be as accurate as 1 TS unit (wherein T_s=1/ (15000 × 2048)), and before the present invention, re-synchronize output timing Unit is 32TS integral multiple；The timing error range of the present invention there has also been bigger raising, and before the present invention, timing error range is less than 1km, the timing error range of the present invention is at least 10km.

The principle of above-described embodiment only illustrative present invention and effect thereof, not for limiting the present invention.Any Above-described embodiment all can be modified under the spirit and the scope of the present invention and change by skilled person.Therefore, The scope of the present invention, should be as listed by claims.

Claims (14)

1. the resynchronization method in LTE system, the terminal being applied in LTE system, comprise the steps:

Step one, receives a subframe including at least auxiliary synchronous signals；

Step 2, determines the position at auxiliary synchronous signals place, and N/M sampled point intercepted length is K/M's in advance according to frame structure SSS data, wherein N ＞=1, M is relevant to reception bandwidth, K/M ＞=128, and K/M meets 2ⁿRelation；

Step 3, utilizes the SSS data intercepted to carry out down-sampled Filtering Processing；

Step 4, it may be judged whether there is homogeneous-frequency adjacent-domain, if there is homogeneous-frequency adjacent-domain, then enters step 5, otherwise enters step 6；

Step 5, carries out interference according to the homogeneous-frequency adjacent-domain of configuration and eliminates；

Step 6, the auxiliary synchronization channel carrying out tested community according to the auxiliary synchronous signals after eliminating co-channel interference is estimated, obtains auxiliary The timing of synchronizing signal；And

Step 7, according to the timing of the auxiliary synchronous signals of output, the reference signal again with tested community is measured, and measures defeated The timing gone out re-synchronizes timing output as final.

2. the resynchronization method in LTE system as claimed in claim 1, it is characterised in that step 4 also includes as follows Step:

The auxiliary synchronous signals generated according to this locality carries out channel estimation, and calculates the maximum power value and Y obtained in front X tap The mean power of the noise power of individual tap；

Mean power according to the maximum power value in front X tap and the noise power of Y tap calculates peak-to-average force ratio；And

This peak-to-average force ratio obtained and a threshold value are compared, if this peak-to-average force ratio is less than this threshold value, then it represents that community is the most weak Or do not exist, if this peak-to-average force ratio is more than this threshold value, then it represents that there is strong co-channel interference adjacent area.

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

4. the resynchronization method in LTE system as claimed in claim 2, it is characterised in that the calculating of this peak-to-average force ratio is led to Cross equation below to obtain:

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

Wherein, ratio_max/meanFor peak-to-average force ratio, pow_maxFor the maximum power value in front X tap, pow_meanFor Y tap The mean power of noise power.

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

6. the resynchronization method in LTE system as claimed in claim 1, it is characterised in that step 5 also includes as follows Step:

The local auxiliary synchronous signals that homogeneous-frequency adjacent-domain numbering according to configuration generates calculates channel impulse, and therefrom chooses N₁Individual tap；

Calculate de-noising thresholding；

Process for carrying out clear 0 less than the channel impulse of de-noising thresholding；

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

Repeat said process, until all of configuration homogeneous-frequency adjacent-domain all eliminates totally.

7. the resynchronization method in LTE system as claimed in claim 6, it is characterised in that: N₁Value is between 1～32.

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

9. the resynchronization method in LTE system as claimed in claim 1, it is characterised in that: in step 3, down-sampled The desampling fir filter sample rate that Filtering Processing uses is not less than 0.96MHz.

10. be used in LTE system re-synchronizes a system, and the terminal being applied in LTE system at least includes:

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

SSS position determines module, determines the position at auxiliary synchronous signals place according to frame structure, and N/M sampled point intercepts long in advance The SSS data that degree is K/M are for down-sampled filtering, wherein N ＞=1, and M is relevant to reception bandwidth, K/M ＞=128, and K/M is full Foot 2ⁿRelation；

Down-sampled Filtering Processing module, utilizes the SSS data intercepted, carries out down-sampled Filtering Processing；

Co-channel interference eliminates module, is used for judging whether homogeneous-frequency adjacent-domain, in time judging to there is homogeneous-frequency adjacent-domain, to disturb Eliminate；

Auxiliary synchronization channel estimates module, carries out the auxiliary synchronization channel of tested community according to the auxiliary synchronous signals after eliminating co-channel interference Estimate, obtain the timing of auxiliary synchronous signals；And

Measure module, according to the timing of the auxiliary synchronous signals of output, measure again with reference signal based on community, measure The timing of output re-synchronizes timing output as final.

11. a kind of re-synchronize system in LTE system, it is characterised in that this co-channel interference Eliminate module also to include:

Channel estimates module, and the auxiliary synchronous signals generated according to this locality carries out channel estimation, and obtains the maximum in front X tap The mean power of the noise power of performance number and Y tap；

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

Judge module, this peak-to-average force ratio and a threshold value are compared, to judge whether strong co-channel interference adjacent area；And

Interference elimination treatment module, when this judgement module judges to there is strong co-channel interference adjacent area, according to the homogeneous-frequency adjacent-domain of configuration Carry out interference to eliminate.

12. a kind of re-synchronize system in LTE system, it is characterised in that: if peak-to-average force ratio is little In this threshold value, then it represents that this community is the most weak or does not exists；If peak-to-average force ratio is more than this threshold value, then it represents that exist strong dry with frequency Disturb adjacent area.

13. a kind of re-synchronize system in LTE system, it is characterised in that: this threshold value is big In equal to 4.

14. a kind of re-synchronize system in LTE system, it is characterised in that: this reception module The subframe received is subframe 0 or subframe 5, and the data length of reception at least 0.5ms adds the data length of 2 OFDM symbol.