CN105391473B - Cell searching system based on TD-LTE downlink reference signals and method - Google Patents
Cell searching system based on TD-LTE downlink reference signals and method Download PDFInfo
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- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
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Abstract
The present invention relates to a kind of cell searching system and method based on TD LTE downlink reference signals, including preliminary synchronisation module, to carry out the initial synchronisation of main plot and obtain the frame header positions of TD LTE radio frames；Data memory module, to store the data of a radio frames；It is blind to search module, carry out cell searching to be based on TD LTE downlink reference signals；Logic control module coordinates preliminary synchronisation module, data memory module and the blind job order searched between module to control.Using the cell searching system and method based on TD LTE downlink reference signals of this kind of structure, the dynamic range of the cell searching of TD LTE wireless terminals test can be improved, in the case where not increasing complexity, improve the analytic ability of wireless test terminal co-frequency cell, the search capability of TD LTE wireless test terminal-pair power weaker cells is improved, there is wider application range.
Description
Technical field
The present invention relates to wireless communication technology fields more particularly to cell searching technical field, in particular to one kind to be based on
The cell searching system and method for TD-LTE downlink reference signals.
Background technology
Cell searching is one of the important technology of network optimization testing field.Only is completing cell searching and can correctly look for
To after wireless frame header position, data of correctly eating dishes without rice or wine can be acquired, other desired measurement items is completed and calculates.Wherein small and weak area
Search is also always one paid special attention in network optimization test.The correct of base station system parameter is matched in the accurate measurement in small and weak area
Set play the role of it is vital.Currently, TD-LTE uses identical networking mode, and traditional wireless test terminal housing estate is searched
Rope mainly uses the method that PSS synchronizes two steps synchronous with SSS.Wherein PSS be used for determine half frame position andSSS determines nothing
Line frame header position andAnd according toWithValue determines cell ID.After the parameter of main plot is determined, it is desirable to parse
Other co-frequency cells, it is necessary to which the data of wireless test terminal-pair main plot are rebuild, and are balanced out in original receives data
The reconstruction signal of main plot reduces the interference of strong cell, to ensure correctly to parse small and weak area.
However above-mentioned cell method for reconstructing has the following problems：
Due to the power control mechanism of LTE system complexity and the channel combination of complexity, it is desirable to cell is accurately rebuild,
Complexity is high, and operand is big.
Since data can inevitably introduce calculating error after repeatedly rebuilding, and with the increase for rebuilding cell number, essence
Degree can be lower and lower, and most of small and weak area is caused not parse correctly.
Although TD-LTE uses synchronous network, since different community reaches wireless test terminal, there are time delays and multipath etc.
Problem makes reconstruction cell complexity further increase, and precision further decreases.
Invention content
The purpose of the present invention is overcoming the above-mentioned prior art, providing one kind can realize that TD-LTE is wirelessly surveyed
Examination terminal parsing co-frequency cell, in the case where not increasing complexity, improve the parsing energy of wireless test terminal co-frequency cell
The cell searching system and method based on TD-LTE downlink reference signals of power.
To achieve the goals above, the cell searching system and method tool of the invention based on TD-LTE downlink reference signals
There is following composition：
The cell searching system based on TD-LTE downlink reference signals, is mainly characterized by, and the system includes：
Preliminary synchronisation module, to carry out the initial synchronisation of main plot and obtain the frame header positions of TD-LTE radio frames；
Data memory module, to store the data of a radio frames；
It is blind to search module, carry out cell searching to be based on TD-LTE downlink reference signals；
Logic control module, to control coordinate the preliminary synchronisation module, data memory module and it is blind search module it
Between job order.
Preferably, the blind module of searching includes：
Data buffer storage unit, to read wireless frame data；
Downlink reference signal generation unit, to generate local reference signal；
Reference signal correlation unit is from a locally generated after being extracted to corresponding downlink reference signal in will be data cached
Downlink reference signal carry out relevant operation；
Noise reduction unit, to carry out noise reduction process to sliding correlated results；
Threshold judgement unit, to carry out threshold judgement and recognize cell by extracting correlation peak.
The invention further relates to a kind of small region search method of the system described in basis based on TD-LTE downlink reference signals,
It is characterized in that, the method includes the following steps：
(1) initial synchronization module described in carries out the initial synchronisation of main plot and obtains the frame head position of TD-LTE radio frames
It sets；
(2) data memory module described in stores the data of a radio frames；
(3) the blind module of searching described in is based on TD-LTE downlink reference signals progress cell searching.
Preferably, the initial synchronization module carries out the initial synchronisation of main plot and obtains the frame head of TD-LTE radio frames
Position includes the following steps：
(1-1) main signal synchronizes：The 5ms timings of radio frames are determined using time domain sliding correlation method；
(1-2) auxiliary signal synchronizes：Frequency domain descrambling is carried out according to radio frames 5ms timing positions and according to the generating mode of SSS
Method synchronizes the i.e. wireless frame header position of 10ms timings of determining radio frames.
Preferably, between the step (1) and (2), it is further comprising the steps of：
Logic control module described in (1-3) judges whether the initial synchronization module synchronizes success, if it is, after
Continuous step (2), otherwise continues step (1-4)；
All modules of Logic control module control system described in (1-4) reset, restart initial synchronization module then
Continue step (1).
Preferably, the data memory module stores the data of a radio frames, specially：
The data memory module shifts to an earlier date the data that 500 chip store a radio frames.
Preferably, the blind module of searching includes data buffer storage unit, downlink reference signal generation unit, reference signal phase
Unit, noise reduction unit and threshold judgement unit are closed, the blind module of searching is searched based on TD-LTE downlink reference signals progress cell
Rope includes the following steps：
Data buffer storage unit described in (3-1) carries out data buffer storage；
It is all possible small that downlink reference signal generation unit described in (3-2) generates TD-LTE under single antenna port case
Downlink reference signal in each Symbol in area；
After corresponding downlink reference signal extracts during reference signal correlation unit described in (3-3) will be data cached and originally
The downlink reference signal that ground generates carries out relevant operation；
Noise reduction unit described in (3-4) carries out cumulative noise reduction to the relevant correlations of multiple Symbol；
Threshold judgement unit described in (3-5) carries out mean deviation to the correlation after noise reduction and calculates decision threshold and root
Judge that cell whether there is according to the downlink reference signal corresponding to all correlation peaks beyond thresholding.
More preferably, the data buffer storage unit carries out data buffer storage, includes the following steps：
Data buffer storage unit described in (3-1-1) reads the data of a Symbol from the data memory module；
Data are transformed to frequency-region signal by (3-1-2) from time-domain signal；
(3-1-3) extracts downlink reference signal from the frequency-region signal after transformation.
More preferably, the downlink reference signal corresponding to all correlation peaks beyond thresholding judges that cell is
No presence, includes the following steps：
(3-5-1) judges whether the downlink reference signal of cell exceeds threshold value, if it is, continue step (3-5-2),
Otherwise continue step (3-5-3)；
(3-5-2) judges the cell to exist；
(3-5-3) judge the cell for there is no.
The cell searching system and method based on TD-LTE downlink reference signals in the invention are used, according to TD-LTE
It synchronizes the preferable feature of the specified downlink reference signal autocorrelation of the principle built a station and cell and carries out cell searching, Ke Yiti
The dynamic range of the cell searching of high TD-LTE wireless terminals test, in the case where not increasing complexity, improves wireless survey
The analytic ability of terminal co-frequency cell is tried, the search capability of TD-LTE wireless test terminal-pair power weaker cells is improved, has
Wider application range.
Description of the drawings
Fig. 1 is the structural schematic diagram of the cell searching system based on TD-LTE downlink reference signals.
Fig. 2 is the blind structural schematic diagram for searching module of the cell searching system based on TD-LTE downlink reference signals.
Fig. 3 is the flow chart of the small region search method based on TD-LTE downlink reference signals.
Reference numeral：
1 initial synchronization module
2 Logic control modules
3 data memory modules
4 blind search module
41 data buffer storage units
42 local downlink reference signal generation units
43 reference signal correlation units
44 threshold judgement units
45 noise reduction units
Specific implementation mode
In order to more clearly describe the technology contents of the present invention, carried out with reference to specific embodiment further
Description.
The purpose of the present invention is achieved through the following technical solutions：According to PSS in TD-LTE and SSS in radio frames
The feature that middle relative position is fixed, is properly positioned the initial position of TD-LTE radio frames, i.e., wireless frame head, and it is complete to obtain a frame
Wireless frame data.Then the characteristics of utilizing TD-LTE synchronous networks, carries out based on downlink reference signal this frame data
The operation of cell searching obtains complete cell information.
The present invention search system include：
(1) initial synchronization module：It is same using PSS (Primary Synchronization Signal, primary synchronization signal)
Step and SSS (Secondary Synchronization Signal, secondary synchronization signal) method of synchronization, carry out main plot synchronization.
Wherein PSS is synchronized, and the 5ms timings of radio frames are determined using time domain sliding correlation method.SSS is synchronized according to radio frames 5ms timings
Position carries out sliding related operation, and to phase respectively according to three kinds of different values using three kinds of PSS of space acquisition data pair
It closes result to be compared, judges that correlation is maximum and exceeds the sequence of thresholding.And then calculate most strong TD-LTE cells
Half frame positions of 5ms, and frequency domain de-scrambling method is carried out according to the generating mode of SSS and is synchronized, it is carried according to above-mentioned PSS synchronization modules
The wireless frame positions of 5ms of confession judge current SSS location informations, and according to the generation feature of SSS signals, are transported using descrambling
It calculates, obtains the wireless frame positions of 10ms.Value range due to SSS signals in subframe 0 with 5 position of subframe is different, only needs
The frame header position of TD-LTE can correctly be judged by carrying out a descrambling operation, determine the 10ms timings of radio frames, i.e. radio frames
Head position.
(2) Logic control module：It is synchronized successfully according to PSS, SSS in initial synchronization module or failure flags is
System control.If receiving synchronous Success Flag, Logic control module control system log-on data store and start it is blind search module,
And wireless frame head location information is passed into data access module.If receiving synchronization failure mark, control system is whole
Module is zeroed out, and initial synchronization module is restarted, until synchronizing success.
(3) data access module：When the data access opening flag and frame header position information for receiving Logic control module
Afterwards, data access module will store 10ms data, i.e. a radio frames.
(4) blind to search module：The blind module of searching of Logic control module control carries out cell searching, is to be based on TD-LTE downlinks
The preferable feature of reference signal autocorrelation carries out.The local reference signal and number that local reference signal generation module is generated
It is sent into correlation module according to the data of the TD-LTE radio frames of memory module storage and carries out sliding relevant operation, to all possible
504 TD-LTE cells are traversed, and the cell signal to be sent out to all base stations near TD-LTE wireless terminals carries out small
Area searching.The step is repeated in multiple Symbol of the downlink reference signal transmitted in TD-LTE radio frames, to each
Downlink reference signal in Symbol carries out blind search.Then the sliding correlated results of multiple Symbol is subjected to cumulative noise reduction, it is right
White Gaussian noise is offset, and to keep the relevant peaks of downlink reference signal more obvious, then is carried out by threshold judgement module
Cell is adjudicated, and then further increases the accuracy and dynamic range of wireless terminal cell searching.
Blind module of searching includes：
Local reference signal generation unit：It is all possible 504 small for generating TD-LTE under single antenna port case
Downlink reference signal in each Symbol in area.And by Logic control module be sent into it is blind search mould correlation unit in the block, and with number
It is related that sliding is carried out according to the data of eating dishes without rice or wine in memory module.
Correlation unit, receive from data access module eat dishes without rice or wine data and come from TD-LTE downlink reference signals
After the reference signal corresponding with Symbol that generation module generates, FFT processing is carried out to data of eating dishes without rice or wine first, then by frequency domain number
The downlink reference signal that corresponding downlink reference signal is from a locally generated after extracting in carries out relevant operation.According to agreement,
The corresponding different downlink reference signals of 504 Cell ID will carry out relevant operation respectively, then deposit correlated results
The related operation of a data is completed in storage.It slides front and back each 500 chip that relevant sliding window length is wireless frame head, i.e.,
Window grows 1000 chip.Corresponding each chip will carry out correlation storage after completing related operation, finally be sent into noise reduction list
Member.
Noise reduction unit receives the correlation of correlation unit feeding, adds up to the relevant correlations of multiple Symbol,
Additive white Gaussian noise is balanced out, to make the correlation peak there are cell be easier to extract.
Threshold judgement unit calculates decision threshold to the related progress mean deviation that correlation unit passes out, all to exceed door
Downlink reference signal corresponding to the correlation peak of limit both may determine that the presence of a cell.
The present invention searching method be：
Initial synchronization module carries out the first of main plot and synchronizes to obtain the frame header position of radio frames, and by Logic control module
It controls data access module and carries out data storage.After data access module, end mark is returned to Logic control module,
There is Logic control module to control blind module of searching again and carry out the cell searching based on TD-LTE downlink reference signals, and by a frame not
Downlink reference signal with time slot passes sequentially through and blind searches module.Every time it is blind search after will result be sent into noise reduction module in tire out
Add noise reduction to come out, finally makes decisions the data feeding threshold judgement module after noise reduction, and then extract TD-LTE cells to be
No presence.
Specifically include following steps：
(1) initial synchronisation：The simultaneously operating of main plot is carried out by initial synchronization module.Initial synchronisation is synchronized by PSS and SSS
Synchronous two steps are completed.According to agreement, PSS and SSS are all located on 72 subcarriers at center, i.e. on 6 RB at center, do not include
DC.It is to carry out the sliding relevant operation of time domain with local PSS sequences using the data of space acquisition to complete together that wherein PSS, which is synchronized,
Walk operation.If synchronizing success, Success Flag is sent to Logic control module and opens SSS synchronizations, while being provided wireless
Half frame position of frame.If synchronization failure, failure flags are sent to Logic control module.What SSS synchronizations were then taken is frequency domain
De-scrambling method.In TD-LTE, SSS is transmitted in the last symbol of subframe 0 and subframe 5, and wherein subframe 0 is corresponding is
SSS1, and it is SSS that subframe 5 is corresponding2.Wherein SSS1It is that the m-sequence for being 31 by 2 length is interwoven, each
31 different values, corresponding different m can be taken0And m1.In the same cell, SSS2With SSS1Use identical 2 m-
sequence.Unlike, in SSS2In, the two sequence have exchanged position on frequency domain, to ensure that SSS2
And SSS1Belong to different set.Half frame position provided according to PSS, it is easy to determine the positions SSS in current data, as long as
Descrambling operation is carried out according to the requirement of agreement to current data, just can determine that current data is subframe 0 or subframe 5, into
One step determines the frame header position of TD-LTE system radio frames.Since TD-LTE uses identical networking, as long as master is determined
The data of the frame header position of cell, other small and weak areas also just determine therewith.In view of space channel, delay, multipath, distance etc.
The influence of factor, therefore a sliding window is set, to ensure that other small and weak areas can correctly search.
(2) logic control：What logic control was mainly completed is system allotment and control action.According to initial synchronization module,
Data access module and the blind flag bit searched module and reported, judge the state of current system, to which control system completion is next
The operation of step.According to the synchronous mark of PSS and SSS in initial synchronization module, the current synchronous regime of system is judged.It is synchronous at
Work(, then system continue data storage and blind search operation.Synchronization failure, system will then carry out reset operation, re-start
The simultaneously operating of main plot, until synchronizing success.Module end mark is searched according to blind, then can judge whether current system is completed
Whole operations, and then determine whether system resets and start the operation of a new round and still to continue waiting for.
(3) signal stores：TD-LTE uses identical networking, and ideally, whole cells should keep synchronous, i.e. frame head position
It is consistent to set.But actual spacing wave receives channel, delay, the influence of multipath and distance reaches wireless test terminal
Data complete frame header position can not be kept consistent.Therefore the signal of eating dishes without rice or wine of storage needs at the frame header position of main plot
The front and back surplus for respectively reserving 500 chip, just can guarantee can collect the relatively complete radio frames of other weaker cells in this way
Data, and using relevant mode is slided, related operation is carried out one by one to 1000 whole chip.
(4) blind to search：Blind search algorithm is the good characteristic of the autocorrelation for the downlink reference signal specified using cell, to carry out
Cell searching.Downlink reference signal and timeslot number, No. Symbol and antenna end slogan it is related, position in a frequency domain is again
It is related with PCI.Therefore, for even for a specific PCI, different time-gap, different Symbol, different antennae port case
Under corresponding downlink reference signal be also different.LTE system defines 504 PCI values altogether.Want to complete cell searching, just
Relevant operation is carried out respectively to this corresponding downlink reference signal of 504 PCI.Simultaneously it is corresponding to same PCI it is different under
Row reference signal correlation out related to data of eating dishes without rice or wine carries out accumulation operations, believes LTE in this way, white Gaussian noise can be reduced
Number interference reduce judgement difficulty, and then increase small and weak area searching to keep the correlation peak of downlink reference signal more obvious
Ability and precision.The threshold judgement of cell is by the way of dynamic threshold.So-called dynamic threshold, exactly calculates current data
Basic threshold value of the average power content as judgement, all correlation peaks are in the numerical value of basic threshold value 2 times or more, all judgement
There are cells.The multiple proportion of the thresholding will also carry out multiple adjustment according to actual conditions.
The present invention is based on the small region search method of TD-LTE downlink reference signals and systems, include the following steps：
1, the initial synchronization operation of wireless test terminal is completed.Mainly synchronized using PSS synchronizations and SSS.It eats dishes without rice or wine
Data are sent into after ADC is sampled in FPGA, carry out low-pass filtering operation, and filtered data are sent into initial synchronisation mould
Block.Since PSS and SSS only occupy the bandwidth of the 1.08MHz among 20MHz system bandwidths, it is sent into initial synchronisation mould
The data of block will also carry out a low-pass filtering, to meet the requirement of related data.Data after secondary filtering are completed first
PSS is synchronized.It is synchronized if it succeeds, starting SSS, and half frame position is provided, to extract the SSS in a corresponding subframe
Data.If it fails, then reset system, starts new search.After SSS synchronous averagings in second step, can will extract one
Time domain data in a subframe passes through on DFT transform to frequency domain, and calculates m using descrambling mode according to agreement0And m1Value,
And by the way of tabling look-up, cell PCI is determined, and then determine the frame header position of cell.If SSS synchronization failures can also be reset
System restarts to search for.
2, after initial synchronization module successful synchronization is to main plot, data storage is carried out.The data of storage are currently to use
In next wireless frame data of related operation radio frames.And required according to sliding window, 500 chip carry out data storage in advance.
3, the data that a Symbol is read from the data of storage are searched to blind in module, remove cyclic prefix, carry out DFT
Time-domain signal is transformed to frequency domain, and goes out downlink reference signal from the extracting data after transformation by operation.Due to whole to be traversed
504 PCI, therefore the signal extracted will also traverse whole PCI values on the basis of the Symbol data, and with
The corresponding downlink reference signal locally generated carries out related operation.Correlated results is stored, and carries out the operation of next Symbol,
The related operation of six Symbol is carried out altogether.After the related operation for completing six Symbol, by the corresponding six groups of correlations of each PCI
Value carries out cumulative noise reduction operation, then finds out the maximum value of the corresponding each correlations of each PCI, and record.In completion
After stating operation, that is, complete the operation of a chip.According to the length of sliding window, to carry out 1000 times in total as operation, because
This each PCI will record 1000 correlation peaks.After the completion of the operation all of 1000 chip, according to each PCI's of record
Maximum value in 1000 correlations makes decisions, and is finally then judged as that current area exists more than thresholding.
In the following, in conjunction with specific testing process, the embodiment of the present invention is further elaborated.In the embodiment of the present invention
In, if system default single antenna port certainly exists, carry out that space TD-LTE cells are blind searches explanation.
(1) spatial data is passed to after AD is sampled in FPGA, and carries out low-pass filtering operation to get to the base band of LTE
Data, data bandwidth 20MHz.Since PSS and SSS only occupy the subcarrier of centre 72 of system bandwidth, to passing through
The data of low-pass filter also want a low-pass filtering.PSS synchronization modules are first fed by the data of secondary filtering to carry out together
Step, using the sliding correlation technique in time domain.After PSS is synchronized successfully, followed by SSS simultaneously operatings.When PSS synchronize at
To get to half frame position after work(, according to half frame position, data of the extraction SSS in a subframe, and to the time domain data into
In row DFT transform to frequency domain.According to the description in agreement, SSS is synchronized descrambles what mode was completed using frequency domain data.According to current
The interleaving mode of data in subframe, calculates m0And m1Value.And according to the m in agreement0And m1The table of value is tabled look-up.When
It tables look-up success, then system will carry out data storage, and carry out blind searching operation.
(2) Logic control module receives the successful failure flags that initial synchronization module is sent, and according to the mark to system
Carry out whole control.In initial synchronization module, any one of PSS is synchronous and SSS is synchronized transmission synchronization failure mark,
Logic control module will reset system, re-start initial synchronization operation.What is received when system is initial synchronisation
Success Flag, then Logic control module will control data access module progress GML data storage operation.Data storage duration is set
It is set to 10ms, thus can completely stores the data of a frame.After data store end operation, Logic control module will be opened
Blind module of searching carries out cell searching.
(3) frame header position provided according to initial synchronization module, blind module of searching can cache the data of a Symbol, and will
The data carry out DFT and are transformed into frequency domain.Utilize the downlink reference signal for 504 PCI of correspondence that frequency domain data is from a locally generated
Frequency domain correlation is carried out respectively, and correlation is stored.Then according to frame header position, next descending reference is calculated
The position of signal, and the data of a Symbol are extracted, it carries out DFT and is transformed into frequency domain, and be from a locally generated using frequency domain data
The downlink reference signal of 504 PCI of correspondence carry out frequency domain correlation respectively, and by correlated results and the preceding phase once stored
Pass value carries out cumulative noise reduction, then will it is cumulative after correlation store.And so on, amount to and calculate six reference signals, adds up
Six times, obtain 504 groups of correlations.Extract every group of maximum value and record in this 504 groups of correlations.Theoretically, TD-LTE systems
System is synchronous network, i.e., the frame header position of whole cells should be always.But in actual conditions, the difference of channel situation,
Situations such as difference of minizone distance and building etc. are to the reflection of signal so that wireless signal reaches wireless test terminal
Time has differences, i.e., frame header position can not be completely the same.When it is above-mentioned it is blind search operation after the completion of, can move chip's
After data, then carry out primary blind searching operation.If window a length of 1000, and before setting the blind initial position for searching operation as main plot frame head
500 chip.
Performance measurement：Cell searching is carried out by blind search method, current wireless test terminal is synchronized to weak cell ability and carries
One times or more is risen；Traditional main plot cancellation algorithms, 5,6 cells that can only be resolved near wireless test terminal；Using
After blind search algorithm carries out cell searching, the cell number that is resolved at 12,13 or so, misinformation probability control 1% or so,
It searches for the dynamic range of cell in 15dB or so
The cell searching system and method based on TD-LTE downlink reference signals in the invention are used, according to TD-LTE
It synchronizes the preferable feature of the specified downlink reference signal autocorrelation of the principle built a station and cell and carries out cell searching, Ke Yiti
The dynamic range of the cell searching of high TD-LTE wireless terminals test, in the case where not increasing complexity, improves wireless survey
The analytic ability of terminal co-frequency cell is tried, the search capability of TD-LTE wireless test terminal-pair power weaker cells is improved, has
Wider application range.
In this description, the present invention is described with reference to its specific embodiment.But it is clear that can still make
Various modifications and alterations are without departing from the spirit and scope of the invention.Therefore, the description and the appended drawings should be considered as illustrative
And not restrictive.
Claims (7)
1. a kind of cell searching system based on TD-LTE downlink reference signals, which is characterized in that the system includes：
Preliminary synchronisation module, to carry out the initial synchronisation of main plot and obtain the frame header positions of TD-LTE radio frames；
Data memory module, to store the data of a radio frames；
It is blind to search module, including：
Data buffer storage unit, to read wireless frame data；
TD-LTE downlink reference signal generation units, to generate local reference signal；
Reference signal correlation unit is from a locally generated down after being extracted to corresponding downlink reference signal in will be data cached
Row reference signal carries out relevant operation；
Noise reduction unit, to carry out noise reduction process to sliding correlated results；
Threshold judgement unit, to carry out threshold judgement and recognize cell by extracting correlation peak；
Logic control module is coordinated the preliminary synchronisation module, data memory module and blind is searched between module to control
Job order.
2. a kind of small region search method of system according to claim 1 based on TD-LTE downlink reference signals, feature
It is, the method includes the following steps：
(1) initial synchronization module described in carries out the initial synchronisation of main plot and obtains the frame header position of TD-LTE radio frames；
(2) data memory module described in stores the data of a radio frames；
Data buffer storage unit described in (3-1) carries out data buffer storage；
It is all possible that TD-LTE downlink reference signal generation units described in (3-2) generate TD-LTE under single antenna port case
Downlink reference signal in each Symbol of cell；
It is after corresponding downlink reference signal extracts during reference signal correlation unit described in (3-3) will be data cached and local raw
At downlink reference signal carry out relevant operation；
Noise reduction unit described in (3-4) carries out cumulative noise reduction to the relevant correlations of multiple Symbol；
Threshold judgement unit described in (3-5) carries out mean deviation to the correlation after noise reduction and calculates decision threshold and according to institute
There is the downlink reference signal corresponding to the correlation peak beyond thresholding to judge that cell whether there is.
3. the small region search method according to claim 2 based on TD-LTE downlink reference signals, which is characterized in that described
Initial synchronization module carry out the initial synchronisation of main plot and obtain the frame header positions of TD-LTE radio frames, include the following steps：
(1-1) main signal synchronizes：The 5ms timings of radio frames are determined using time domain sliding correlation method；
(1-2) auxiliary signal synchronizes：Frequency domain de-scrambling method is carried out according to radio frames 5ms timing positions and according to the generating mode of SSS
Synchronize the i.e. wireless frame header position of 10ms timings of determining radio frames.
4. the small region search method according to claim 2 based on TD-LTE downlink reference signals, which is characterized in that described
The step of (1) and (2) between, it is further comprising the steps of：
Logic control module described in (1-3) judges whether the initial synchronization module synchronizes success, if it is, continuing to walk
Suddenly (2) otherwise continue step (1-4)；
All modules of Logic control module control system described in (1-4) are reset, restarting initial synchronization module then proceedes to
Step (1).
5. the small region search method according to claim 2 based on TD-LTE downlink reference signals, which is characterized in that described
Data memory module store a radio frames data, specially：
The data memory module shifts to an earlier date the data that 500 chip store a radio frames.
6. the small region search method according to claim 2 based on TD-LTE downlink reference signals, which is characterized in that described
Data buffer storage unit carry out data buffer storage, include the following steps：
Data buffer storage unit described in (3-1-1) reads the data of a Symbol from the data memory module；
Data are transformed to frequency-region signal by (3-1-2) from time-domain signal；
(3-1-3) extracts downlink reference signal from the frequency-region signal after transformation.
7. the small region search method according to claim 2 based on TD-LTE downlink reference signals, which is characterized in that described
The downlink reference signal corresponding to all correlation peaks beyond thresholding judge that cell whether there is, including following step
Suddenly：
(3-5-1) judges whether the downlink reference signal of cell exceeds threshold value, if it is, continuing step (3-5-2), otherwise
Continue step (3-5-3)；
(3-5-2) judges the cell to exist；
(3-5-3) judge the cell for there is no.
Priority Applications (1)
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| WO2010147445A3 (en) * | 2009-06-19 | 2011-03-31 | 엘지전자 주식회사 | Cell searching method and apparatus in multi-carrier system |
| CN104427520A (en) * | 2013-08-26 | 2015-03-18 | 普天信息技术研究院有限公司 | Adjacent region detection method under co-channel interference |
| CN104581787A (en) * | 2015-01-22 | 2015-04-29 | 天津大学 | LTE system multi-cell search method based on interference cancellation |
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| WO2010147445A3 (en) * | 2009-06-19 | 2011-03-31 | 엘지전자 주식회사 | Cell searching method and apparatus in multi-carrier system |
| CN104427520A (en) * | 2013-08-26 | 2015-03-18 | 普天信息技术研究院有限公司 | Adjacent region detection method under co-channel interference |
| CN104581787A (en) * | 2015-01-22 | 2015-04-29 | 天津大学 | LTE system multi-cell search method based on interference cancellation |
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