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 PDF

Info

Publication number
CN105391473B
CN105391473B CN201510987898.0A CN201510987898A CN105391473B CN 105391473 B CN105391473 B CN 105391473B CN 201510987898 A CN201510987898 A CN 201510987898A CN 105391473 B CN105391473 B CN 105391473B
Authority
CN
China
Prior art keywords
downlink reference
data
module
lte
reference signal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201510987898.0A
Other languages
Chinese (zh)
Other versions
CN105391473A (en
Inventor
杜晓明
赵强
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Transcom Shanghai Technologies Co Ltd
Original Assignee
Shanghai TransCom Instruments Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai TransCom Instruments Co Ltd filed Critical Shanghai TransCom Instruments Co Ltd
Priority to CN201510987898.0A priority Critical patent/CN105391473B/en
Publication of CN105391473A publication Critical patent/CN105391473A/en
Application granted granted Critical
Publication of CN105391473B publication Critical patent/CN105391473B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details 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
    • H04B1/69Spread spectrum techniques
    • H04B1/707Spread spectrum techniques using direct sequence modulation
    • H04B1/7073Synchronisation aspects
    • H04B1/7083Cell search, e.g. using a three-step approach

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Synchronisation In Digital Transmission Systems (AREA)

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

Cell searching system based on TD-LTE downlink reference signals and method
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.
CN201510987898.0A 2015-12-24 2015-12-24 Cell searching system based on TD-LTE downlink reference signals and method Active CN105391473B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201510987898.0A CN105391473B (en) 2015-12-24 2015-12-24 Cell searching system based on TD-LTE downlink reference signals and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201510987898.0A CN105391473B (en) 2015-12-24 2015-12-24 Cell searching system based on TD-LTE downlink reference signals and method

Publications (2)

Publication Number Publication Date
CN105391473A CN105391473A (en) 2016-03-09
CN105391473B true CN105391473B (en) 2018-08-21

Family

ID=55423348

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201510987898.0A Active CN105391473B (en) 2015-12-24 2015-12-24 Cell searching system based on TD-LTE downlink reference signals and method

Country Status (1)

Country Link
CN (1) CN105391473B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106160916B (en) * 2016-08-25 2019-04-23 上海创远仪器技术股份有限公司 A kind of NB-IoT cell search apparatus and its searching method
CN114501606A (en) * 2022-01-21 2022-05-13 杰创智能科技股份有限公司 Physical cell identity detection method and device and electronic equipment

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
3GPP TS 36.211 V12.3.0;Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC);《Physical channels and modulation》;20140922;109-111页 *
Cell Search for 3GPP LTE System Using Interference;Youngkwon Ryu;《Ubiquitous and Future Networks》;20150810;全文 *

Also Published As

Publication number Publication date
CN105391473A (en) 2016-03-09

Similar Documents

Publication Publication Date Title
CN105409301B (en) LTE synchronous method and relevant device and system
CN104093168B (en) A kind of LTE homogeneous-frequency adjacent-domains detection method and device
CN104717174B (en) A kind of OFDM anti-interference synchronous methods under complexity multipath channel
CN106534031B (en) A kind of LTE downlink frame synchronization method of low complex degree
CN107820273A (en) The method and device of sidelink synchronizing signal in a kind of detection D2D
CN102340796B (en) Secondary synchronization channel detection method and device
CN104754623B (en) The small region search method and system eliminated based on LTE system interference
WO2017211212A1 (en) Method and device for positioning interference source cell, and base station
CN104735750A (en) Cell searching method and terminal
CN108282434A (en) A kind of detection method of LTE downlinks primary synchronization signal
CN108880661B (en) Incoherent threshold decision frame synchronization method, device and readable storage medium thereof
CN103889069B (en) A kind of accidental access signal method of sending and receiving applied to large coverage
CN105391473B (en) Cell searching system based on TD-LTE downlink reference signals and method
CN107872418A (en) A kind of time-frequency synchronization method for OFDM passages
CN105634542B (en) A kind of TD-SCDMA multi-cell searchs method
CN102143574A (en) Timing synchronization method suitable for IEEE (Institute of Electrical and Electronic Engineers) 802.16m preamble structure
CN103369665B (en) TD-LTE relay system and synchronizing signal extraction method and device thereof
CN105871530B (en) A kind of timing tracking method of anti-high dynamic frequency deviation variation
CN102271384A (en) Primary cell searching method for long term evolution (LTE) system
CN105072075A (en) Multi-threshold decision OFDM synchronization method
CN104980184B (en) Small region search method and equipment for TD-SCDMA system
CN106160969A (en) A kind of LTE down-going synchronous data launch configuration and method of reseptance
CN103108337B (en) Detection method, device and base station for random access signal
CN105792249A (en) Web search ranking method and system
CN105049170B (en) A kind of coarse timing synchronization method of FlashLinQ system

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
CP03 Change of name, title or address

Address after: Block C, No. 7, Lane 205, Gaoji Road, Songjiang District, Shanghai, 201601

Patentee after: Chuangyuan Xinke (Shanghai) Technology Co.,Ltd.

Address before: 4th Floor, Building 28, No. 69, Guiqing Road, Xuhui District, Shanghai, 200233

Patentee before: TRANSCOM INSTRUMENTS Co.,Ltd.

CP03 Change of name, title or address