CN106603189B  Cell searching interference elimination method in a kind of LTE system  Google Patents
Cell searching interference elimination method in a kind of LTE system Download PDFInfo
 Publication number
 CN106603189B CN106603189B CN201611078252.1A CN201611078252A CN106603189B CN 106603189 B CN106603189 B CN 106603189B CN 201611078252 A CN201611078252 A CN 201611078252A CN 106603189 B CN106603189 B CN 106603189B
 Authority
 CN
 China
 Prior art keywords
 pss
 sss
 signal
 correlation
 correlation peak
 Prior art date
Links
 238000003379 elimination reactions Methods 0.000 title claims abstract description 21
 230000000875 corresponding Effects 0.000 claims abstract description 20
 230000001427 coherent Effects 0.000 claims abstract description 13
 229920001467 poly(styrenesulfonates) Polymers 0.000 claims abstract 55
 201000009594 systemic scleroderma Diseases 0.000 claims abstract 55
 238000000034 methods Methods 0.000 claims description 13
 125000004122 cyclic group Chemical group 0.000 claims description 6
 238000001914 filtration Methods 0.000 claims description 4
 239000000562 conjugates Substances 0.000 claims description 3
 230000001360 synchronised Effects 0.000 abstract description 9
 239000010410 layers Substances 0.000 description 6
 230000001131 transforming Effects 0.000 description 4
 230000001413 cellular Effects 0.000 description 2
 239000002965 ropes Substances 0.000 description 2
 230000000694 effects Effects 0.000 description 1
 230000002708 enhancing Effects 0.000 description 1
 230000002452 interceptive Effects 0.000 description 1
 230000004048 modification Effects 0.000 description 1
 238000006011 modification reactions Methods 0.000 description 1
 238000005070 sampling Methods 0.000 description 1
 238000006467 substitution reactions Methods 0.000 description 1
Classifications

 H—ELECTRICITY
 H04—ELECTRIC COMMUNICATION TECHNIQUE
 H04J—MULTIPLEX COMMUNICATION
 H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
 H04J11/0069—Cell search, i.e. determining cell identity [cellID]

 H—ELECTRICITY
 H04—ELECTRIC COMMUNICATION TECHNIQUE
 H04J—MULTIPLEX COMMUNICATION
 H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
 H04J11/0069—Cell search, i.e. determining cell identity [cellID]
 H04J11/0073—Acquisition of primary synchronisation channel, e.g. detection of cellID within cellID group

 H—ELECTRICITY
 H04—ELECTRIC COMMUNICATION TECHNIQUE
 H04W—WIRELESS COMMUNICATION NETWORKS
 H04W56/00—Synchronisation arrangements
Abstract
Description
Technical field
The present invention relates to LTE (Long Term Evolution, long term evolution project) systems technology fields, in particular to Cell searching interference elimination method in a kind of LTE system.
Background technique
LTE is known as 3.9G by popular, and the data download capabilities with 100Mbps are considered the master from 3G to 4G evolution Flow Technique.It improves and enhances the aerial access technology of 3G, using OFDM and MIMO as the unique of its wireless network evolution Standard.If UE (equipment) in LTE system will be communicated by LTE cellular network, need to carry out cell searching to detect To the physicallayer cell identifier of cell.Due to each cell and a pair of of primary synchronization signal (PSS) and auxiliary synchronous signal (SSS) phase It is mutually corresponding, therefore during cell searching, UE can be detected the physicallayer cell identifier of cell (i.e. by detecting PSS and SSS Cell ID).Detection physicallayer cell identifier is related to obtaining cell ID group mark from by the SSS sequence of base station broadcastAnd cell ID group mark has been obtained from by the PSS sequence of base station broadcastCell ID group Interior markFrom PSS Sequence Detection to cell ID group in markLater from SSS sequence Detect cell ID group markDetecting cell ID group markWith mark in cell ID groupLater, can make WithRelationship determine physicallayer cell identifier, wherein N_{ID}It is physicallayer cell identifier, That is cell ID, because there are 168 unique Cell ID groups to identify in each groupWith mark in three unique Cell ID groupsSo there is 504 unique physical layer identifications in total in LTE cellular network.
In complete cell search process, it usually needs successively determine multiple candidate cells, be first detected Cell is usually the strongest cell of signal, if the signal in this group of mean people area is not eliminated, will generate shadow to the detection of subsequent cell It rings, for this purpose, in actual application, often taking measures to carry out interference elimination after determining a cell every time, then again Carry out the detection of next cell.
The PSS that Reconstruction Method eliminates the cell being searched is generallyd use in the prior art, to realize cell searching mistake Interference in journey is eliminated；Since there are identical networkings for LTE network, there can be the cochannel interference between neighboring community.Due to Only there are three PSS for whole network, therefore adjacent two cell may use the same PSS, then use the two of the same PSS When the downlink synchronous signal of cell reaches UE simultaneously substantially, the PSS for using Reconstruction Method carrying out that elimination is interfered to will lead to two cells is same When be eliminated, so as to cause that can only search relatively stronger cell, and relatively weak cell cannot be searched, therefore PSS detectionphase carries out interfering the cell for eliminating and will lead to and searching under certain scenes incomplete using Reconstruction Method.For relatively Weak cell carries out PSS interference using Reconstruction Method and eliminates and can cause PSS cannot be by greatest extent because channel estimation value is inaccurate Elimination, while can also introduce biggish interference, cause weaker cell that cannot be detected.
Since SSS has 504, neighboring community can not use same cell ID (mark), therefore neighboring community is used SSS be different, along with the scrambling code that adjacent two cell using the same PSS is used when generating SSS is identical, therefore phase Interference between adjacent two cells can become by force, eliminate to be not enough to eliminate to greatest extent using the progress SSS interference of zero setting method merely and work as Interference under preceding scene between two cells.
Summary of the invention
The purpose of the present invention is to overcome the shortcomings of the existing technology with it is insufficient, it is dry to provide cell searching in a kind of LTE system The method for disturbing elimination, this method is directed to be reached simultaneously using the downlink synchronous signal of the homogeneous frequency adjacent area of the same PSS signal The case where UE, both may search for the relatively stronger cell of signal, and also may search for the relatively weak cell of signal, overcome small The infull technical problem of area searching, can be improved the performance of UE downgoing synchronous and the performance of handover, to improve user's body It tests.
The purpose of the invention is achieved by the following technical solution: cell searching interference elimination method in a kind of LTE system, Steps are as follows:
S1, reception signal is obtained；
S2, three groups of local PSS sequences are gone into time domain from frequency domain respectively, are then carried out respectively with reception signal in step S1 Three groups of PSS correlations are obtained after related operation；
S3, be directed to each group of PSS correlation, by the first thresholding by PSS correlation by relationship ranking from big to small It searches out to come in former PSS correlation peaks, be arrived until searching for less than the PSS correlation peak or current search for crossing the first thresholding PSS correlation peak reaches certain number X, then terminates to search for, and saves each PSS relevant peaks searched above by the first thresholding It is worth mark in position and cell ID group；
S4, for each PSS correlation peak location got in each group of PSS correlation in step S3, from maximum PSS correlation peak location starts, with the sequence of PSS correlation peak from big to small, for each PSS correlation peak location, into The following operation of row:
S41, first according to current PSS correlation peak location, carry out SSS coherent detection to signal is received, obtain SSS correlation Value, then searched for the SSS correlation peak of the second thresholding, and therefrom get a maximum SSS phase by the second thresholding Close peak value；Enter step S42；
S42, SSS interference are eliminated: the corresponding SSS signal reconstruction of maximum SSS correlation peak being come out, then will be reconstructed The SSS signal come is cut from the reception signal of corresponding position, obtains the signal after interference is eliminated；Subsequently into step S43；
S43, according to current PSS correlation peak location, the reception signal after eliminating for step S42 interference carries out SSS again Coherent detection obtains SSS correlation, and the SSS correlation peak of the second thresholding was then searched for by the second thresholding, is judged whether there is Cross the SSS correlation peak of the second thresholding；
If so, selecting a maximum SSS correlation peak from the SSS correlation peak for crossing the second thresholding；Then sentence Whether the number for the maximum SSS correlation peak that open close the second thresholding of mistake has been chosen in total reaches certain number Y, if it is not, S42 is then entered step, if so, entering step S44；
If it is not, then entering step S44；
Under S44, current PSS correlation peak location, SSS interference, which is eliminated, to be completed, for next PSS correlation peak location, Back to step S41.
Preferably, three groups of local PSS sequences from frequency domain go to time domain respectively specific step is as follows in the step S2:
S21, the interior mark of cell ID group according to PSS sequenceValue 0,1 and 2, get three groups of local frequency domains PSS sequence, wherein the length of local frequency domain PSS sequence is 62；
S22, every group of local frequency domain PSS sequence is both mapped on each 31 subcarriers in direct current subcarrier front and back；
S23, for the every group of signal got in step S22,33 are supplemented before local frequency domain PSS sequence subcarrier Zero, 32 zero are supplemented later, are removed 128 point, inverse fast Fourier transforms of progress after frequency processing, are finally obtained three groups of local time domains PSS sequence.
Preferably, each group PSS correlation is got by following steps in the step S2:
S24, starting point P0 is got in receiving signal, 256 sampled points is then taken since starting point P0, then to it The FFT transform for doing at 256 points obtains the first frequencyregion signal；Wherein receiving the first starting point P0 got in signal is reception First sampled point of signal.
S25,128 sampled points are taken from one group of local time domain PSS sequence, zero padding to 256 sampled points is simultaneously 256 points of FFT Transformation, obtains the second frequencyregion signal；
S26, the first frequencyregion signal and the second frequencyregion signal conjugate multiplication are obtained into third signal, then by third signal into The IFFT that 256 points of row obtains timedomain signal；
Preceding 128 sampled point of S27, the timedomain signal for taking step S26 to get, as one group of local time domain PSS sequence with It receives signal and slides the correlation after 128 related operations；
S28, judge whether carry out related calculation to obtain correlation at reception signal ending, if so, this group of related operation knot Beam；If it is not, returning to step S24 after starting point P0 is then added 128 sampled points.
Preferably, each group of PSS correlation is directed in step S3, by the first thresholding by PSS correlation according to from big It is come out to small relationship ranking in former PSS correlation peaks with sequential search from big to small, detailed process is as follows:
S31, it is directed to each group of PSS correlation, sets the first thresholding first；
S32, the PSS correlation peak that the first thresholding was searched for by the first thresholding, judged whether there is the PSS of the first thresholding Correlation peak；
If so, selecting a maximum PSS correlation peak from the PSS correlation peak for crossing the first thresholding, then sentence Whether the number of the disconnected current maximum PSS correlation peak chosen in total by the first thresholding reaches certain number X, if It is then to enter step S34；If it is not, then entering step S33；
If it is not, then entering step S34；
S33, by each several positions of the maximum PSS correlation peak location got in step S32 and its adjacent front and back The correlation zero setting set；It is then return to step S32；
S34, the search by the first thresholding for PSS correlation peak terminate.
Further, it is 5 that the threshold value of first thresholding, which is 9000, X value,.
Preferably, the process of SSS coherent detection is carried out such as according to current PSS correlation peak location in step S41 and S43 Under:
S411, using current PSS correlation peak location as PSS timing position, in conjunction with the various relative positions of PSS and SSS Relationship determines each timing position of SSS；
S412,128 point SSS timedomain signals are taken respectively in each timing position of SSS, then by 128 point SSS timedomain signals 128 FFT transform are carried out, 128 sampled point frequencyregion signals are obtained；
The corresponding data of label 65 in S413,128 sampled point frequency domain sequences are direct current subcarrier, before direct current subcarrier 31 frequency domain sequences are respectively extracted afterwards, and the frequency domain sequence of 62 points of composition is SSS frequencyregion signal；
S414, the generating mode according to SSS are gradually descrambled and are carried out related calculation using the correlation of msequence, obtain SSS Correlation peak, and therefrom get SSS maximum correlation peaks；
S415, according to SSS maximum correlation peaks, carry out duplex mode, CP type, cell ID group and identify and front and back field Judgement, is so far obtained with cell ID and frame timing.
Further, the relative positional relationship of PSS and SSS includes four kinds, wherein TDD (time division duplex) and Normal Under CP (general cyclic prefix) relative positional relationship, the relative position PSS and SSS is 412 sampled points；TDD and Extended CP Under (extended cyclic prefix) relative positional relationship, the relative position PSS and SSS is 480 sampled points；FDD (frequency division duplex) and Under Normal CP relative positional relationship, the relative position PSS and SSS is 137 sampled points；FDD and Extended CP is with respect to position It sets under relationship, is 160 under PSS and SSS relative positional relationship.
Further, the corresponding SSS signal reconstruction of SSS maximum correlation peaks is come out in the step S42 specific Process is as follows:
S421, according in step S415 determine cell ID and frame timing, generate SSS frequencyregion signal；
S422, the corresponding SSS signal of SSS maximum correlation peaks is extracted from reception signal；
S423, minimum is carried out for the SSS signal obtained in the SSS frequencyregion signal and step S422 generated in step S421 Two multiply channel estimation, and carry out time domain noise reduction processing to channel estimation value sequence；
S444, the time domain noise reduction for getting step S423 treated channel estimation value sequence are multiplied by step S421 SSS frequencyregion signal, obtained sequence are the SSS frequencyregion signal for reconstructing and；
S445, the step S444 SSS frequencyregion signal reconstructed is gone in time domain, and adds prefix, that is, reconstructed Whole SSS timedomain signal.
Preferably, the threshold value of the second thresholding is 200 in the step S4；Y is 2.
Preferably, the reception signal obtained in the step S1 be filtering and it is downsampled treated receive signal.
The present invention has the following advantages and effects with respect to the prior art:
(1) the method for the present invention uses three groups of local PSS sequences to carry out related operation with reception signal respectively first, to obtain Get three groups of PSS correlations, for each group of PSS correlation, and by the first thresholding search for PSS correlation in by from greatly to Small relationship ranking saves mark in these PSS correlation peak locations and cell ID group in former PSS correlation peaks；It connects Get off for these PSS correlation peak locations saved, since the position of maximum PSS correlation peak, for each PSS Correlation peak location carries out SSS coherent detection to signal is received in position corresponding with PSS correlation peak location, passes through the The search of two thresholdings successively detected SSS correlation peak according to sequence from big to small, and every time after SSS coherent detection, SSS signal reconstruction at SSS correlation peak is come out, reception signal of the next SSS signal from corresponding position then will be reconstructed In cut, realize SSS interference eliminate.It can be seen that for small using the homogeneous frequency adjacent of the same PSS signal in LTE system The case where downlink synchronous signal in area reaches UE simultaneously, by the method for the invention in cell searching, both may search for same frequency The strong cell of signal in neighboring community also may search for the cell that signal is weak into homogeneous frequency adjacent area, therefore the method for the present invention Ensure the complete of cell searching, effectively preventing eliminating using Reconstruction Method progress PSS interference in the prior art causes to search Rope to the relatively stronger cell of signal, and the relatively weak cell of signal cannot be searched to the phenomenon that.It greatly improves under UE The performance of row synchronous performance and handover, to improve user experience.And use Reconstruction Method by SSS in the method for the present invention It is eliminated, can be eliminated to greatest extent under current scene using the interference between adjacent two cell of the same PSS.
(2) the method for the present invention by the first thresholding by PSS correlation by relationship ranking from big to small in former PSS When correlation peak searches out next, wherein these PSS correlation peaks are successively searched with sequence from big to small, are being searched for every time When, a maximum PSS correlation peak in the PSS correlation peak of thresholding was chosen, and get the PSS correlation peak position It sets, the correlation of each several positions of the PSS correlation peak location and its adjacent front and back is then subjected to zero setting；Due to searching for every time When, current maximum PSS correlation peak is set to zero, therefore when searching for next time, the PSS correlation peak searched will be second to this Maximum PSS correlation peak, therefore the present invention effectively eliminates PSS strong correlation peak to the weak relevant peaks of PSS by way of zero setting Interference, achieve the purpose that interference is eliminated, the interference of PSS can be eliminated to greatest extent, determine potential effective relevant peaks It is worth mark in position and cell ID group, effectively reduces the complexity that PSS interference is eliminated, improves the efficiency that PSS interference is eliminated. And the present invention is in zeroing process, before and after current maximum PSS correlation peak the correlation of adjacent each several positions also by It is set to zero, therefore the method for the present invention can avoid current maximum PSS correlation peak frontrear position correlation to next time simultaneously The interference that PSS correlation peak generates when searching for, eliminates interference of the PSS strong correlation peak to the weak relevant peaks of PSS to greatest extent.This Inventive method effectively prevents in the prior art for relatively weak cell, and carrying out that PSS interference eliminates using Reconstruction Method can be because It is inaccurate for channel estimation value, cause PSS that cannot be eliminated to greatest extent, while can also introduce biggish interference, causes weaker Cell the technical issues of cannot being detected.
(3) signal is received in the method for the present invention to be first filtered and drop before carrying out related operation with local PSS sequence Sampling processing, wherein the performance of cell searching is improved, by downsampled by filtering out the signal other than PSS and SSS bandwidth The calculation amount of related operation is reduced, cell searching efficiency is improved.
Detailed description of the invention
Fig. 1 is the method for the present invention flow chart.
Specific embodiment
Present invention will now be described in further detail with reference to the embodiments and the accompanying drawings, but embodiments of the present invention are unlimited In this.
Embodiment
Present embodiment discloses cell searching interference elimination methods in a kind of LTE system, as shown in Figure 1, steps are as follows:
S1, reception signal is obtained；The reception signal obtained in the present embodiment be filtering and it is downsampled treated receive letter Number, wherein being 30.72MHz, pass band width 472.5KHz, resistance to the sample rate for receiving the filter that signal is filtered Band initial frequency is 547.5KHz, attenuation outside a channel 20dB, passband fluctuation 0.1dB；It is used when downsampled processing in step S1 Be 16 times.
S2, three groups of local PSS sequences are gone into time domain from frequency domain respectively, are then carried out respectively with reception signal in step S1 Three groups of PSS correlations are obtained after related operation.
Three groups of local PSS sequences from frequency domain go to time domain respectively specific step is as follows in this step S2:
S21, the interior mark of cell ID group according to PSS sequenceValue 0,1 and 2, get three groups of local frequency domains PSS sequence, wherein the length of local frequency domain PSS sequence is 62；
S22, every group of local frequency domain PSS sequence is both mapped on each 31 subcarriers in direct current subcarrier front and back；
S23, for the every group of signal got in step S22,33 are supplemented before local frequency domain PSS sequence subcarrier Zero, 32 zero are supplemented later, are removed progress 128 point IFFT transformation (fast Fourier inverse transformation) after frequency processing, are finally obtained three The local time domain PSS sequence of group.
Each group PSS correlation is got by following steps in this step:
S24, starting point P0 is got in receiving signal, 256 sampled points is then taken since starting point P0, then to it The FFT transform (Fast Fourier Transform) for doing at 256 points, obtains the first frequencyregion signal S1；Wherein receive the got in signal One starting point P0 is the first sampled point for receiving signal.
S25,128 sampled points are taken from one group of local time domain PSS sequence, zero padding to 256 sampled points is simultaneously 256 points of FFT Transformation, obtains the second frequencyregion signal S2；
S26, the first frequencyregion signal S1 and the second frequencyregion signal S2 conjugate multiplication are obtained into third signal S3, then by third The IFFT that signal S3 carries out at 256 points obtains timedomain signal S4；
S27, preceding 128 sampled point for taking timedomain signal S4, as one group of local time domain PSS sequence and reception signal sliding Correlation after 128 related operations；
S28, judge whether carry out related calculation to obtain correlation at reception signal ending, if so, this group of related operation knot Beam；If it is not, returning to step S24 after starting point P0 is then added 128 sampled points.
S3, be directed to each group of PSS correlation, by the first thresholding by PSS correlation by relationship ranking from big to small It searches out to come in former PSS correlation peaks, be arrived until searching for less than the PSS correlation peak or current search for crossing the first thresholding PSS correlation peak reaches certain number X, then terminates to search for, and saves each PSS relevant peaks searched above by the first thresholding It is worth mark in position and cell ID group；It is 5 that the threshold value of the first thresholding, which is 9000, X value, in the present embodiment.
In step S3 be directed to each group of PSS correlation, by the first thresholding by PSS correlation according to pass from big to small It is that ranking is come out in former PSS correlation peaks with sequential search from big to small, detailed process is as follows:
S31, it is directed to each group of PSS correlation, sets the first thresholding first；
S32, the PSS correlation peak that the first thresholding was searched for by the first thresholding, judged whether there is the PSS of the first thresholding Correlation peak；
If so, selecting a maximum PSS correlation peak from the PSS correlation peak for crossing the first thresholding, then sentence Whether the number of the disconnected current maximum PSS correlation peak chosen in total by the first thresholding reaches certain number X, if It is then to enter step S34；If it is not, then entering step S33；
If it is not, then entering step S34；
S33, by each several positions of the maximum PSS correlation peak location got in step S32 and its adjacent front and back The correlation zero setting set；It is then return to step S32；It will wherein be got most in step S32 in this step in the present embodiment The correlation zero setting of each position of a big PSS correlation peak location and its adjacent front and back；
S34, the search by the first thresholding for PSS correlation peak terminate.
Through the above steps can by PSS correlation according to relationship ranking from big to small in former PSS relevant peaks Value is come out with sequential search from big to small, to get corresponding PSS correlation peak location.
S4, for each PSS correlation peak location got in each group of PSS correlation in step S3, from maximum PSS correlation peak location starts, and for each PSS correlation peak location, proceeds as follows:
S41, first according to current PSS correlation peak location, carry out SSS coherent detection to signal is received, obtain SSS correlation Value, then searched for the SSS correlation peak of the second thresholding, and therefrom get a maximum SSS phase by the second thresholding Close peak value；Enter step S42；The threshold value of the second thresholding is 200 in the present embodiment.
S42, SSS interference are eliminated: the corresponding SSS signal reconstruction of maximum SSS correlation peak being come out, then will be reconstructed The SSS signal come is cut from the reception signal of corresponding position, obtains the signal after interference is eliminated；Subsequently into step S43；
S43, according to current PSS correlation peak location, the reception signal after eliminating for step S42 interference carries out SSS again Coherent detection obtains SSS correlation, and the SSS correlation peak of the second thresholding was then searched for by the second thresholding, is judged whether there is Cross the SSS correlation peak of the second thresholding；
If so, selecting a maximum SSS correlation peak from the SSS correlation peak for crossing the second thresholding；Then sentence Whether the number for the maximum SSS correlation peak that open close the second thresholding of mistake has been chosen in total reaches certain number Y, if it is not, S42 is then entered step, if so, entering step S44；
If it is not, then entering step S44；
Under S44, current PSS correlation peak location, SSS interference, which is eliminated, to be completed, for next PSS correlation peak location, Back to step S41.
In the present embodiment, according to current PSS correlation peak location in step S41 and S43, the mistake of SSS coherent detection is carried out Journey is as follows:
S411, using current PSS correlation peak location as PSS timing position, in conjunction with the various relative positions of PSS and SSS Relationship determines each timing position of SSS；Wherein the relative positional relationship of PSS and SSS includes four kinds, wherein TDD (the timedivision Duplex) and Normal CP (general cyclic prefix) relative positional relationship under, the relative position PSS and SSS be 412 sampled points； Under TDD and Extended CP (extended cyclic prefix) relative positional relationship, the relative position PSS and SSS is 480 sampled points； Under FDD (frequency division duplex) and Normal CP relative positional relationship, the relative position PSS and SSS is 137 sampled points；FDD and It is 160 under PSS and SSS relative positional relationship under Extended CP relative positional relationship.
S412,128 point SSS timedomain signals are taken respectively in each timing position of SSS, then by 128 point SSS timedomain signals 128 FFT transform are carried out, 128 frequencyregion signals are obtained；
The corresponding data of label 65 in S413,128 sampled point frequency domain sequences are direct current subcarrier, before direct current subcarrier 31 frequency domain sequences are respectively extracted afterwards, and the frequency domain sequence of 62 points of composition is SSS frequencyregion signal；
S414, the generating mode according to SSS are gradually descrambled and are carried out related calculation using the correlation of msequence, obtain SSS Correlation peak, and therefrom get SSS maximum correlation peaks；
S415, according to SSS maximum correlation peaks, carry out duplex mode, CP type, cell ID group and identify and front and back field Judgement, is so far obtained with cell ID and frame timing.
The detailed process for coming out the corresponding SSS signal reconstruction of SSS maximum correlation peaks in the present embodiment step S42 is such as Under:
S421, according in step S415 determine cell ID and frame timing, generate SSS frequencyregion signal；
S422, the corresponding SSS signal of SSS maximum correlation peaks is extracted from reception signal；
S423, minimum is carried out for the SSS signal obtained in the SSS frequencyregion signal and step S422 generated in step S421 Two multiply channel estimation, and carry out time domain noise reduction processing to channel estimation value sequence；
S444, the time domain noise reduction for getting step S423 treated channel estimation value sequence are multiplied by step S421 SSS frequencyregion signal, obtained sequence are the SSS frequencyregion signal for reconstructing and；
S445, the step S444 SSS frequencyregion signal reconstructed is gone in time domain, and adds prefix, that is, reconstructed Whole SSS timedomain signal.
The present embodiment above method carries out related operation with reception signal respectively by three groups of local PSS sequences, to obtain Three groups of PSS correlations are got, for each group of PSS correlation, are obtained in PSS correlation by relationship ranking from big to small preceding Several PSS correlation peaks gets maximum several PSS correlation peaks in PSS correlation peak；Then from maximum PSS phase The position for closing peak value starts, and for each PSS correlation peak location, carries out one or many SSS coherent detections, so as to It, can be relatively strong by signal when downlink synchronous signal in the homogeneous frequency adjacent area using the same PSS signal reaches UE simultaneously Cell and the relatively weak cell of signal search, effectively prevent in the prior art using Reconstruction Method carry out PSS interference disappear Except leading to can only to search the relatively stronger cell of signal, and the relatively weak cell of signal cannot be searched to the phenomenon that.Greatly The performance of big raising UE downgoing synchronous and the performance of handover, to improve user experience.And it is adopted in the method for the present invention SSS is eliminated with reconstruct side, can be eliminated to greatest extent under current scene using between adjacent two cell of the same PSS Interference.
In the present embodiment by repeat after abovementioned steps S32 and S33 can by PSS correlation according to from big to small Relationship ranking come out in former PSS correlation peaks with sequence from big to small is searched.In each search, selection is moved into one's husband's household upon marriage A maximum PSS correlation peak in the PSS correlation peak of limit, and the PSS correlation peak location is got, then should The correlation of each several positions of PSS correlation peak location and its adjacent front and back carries out zero setting；It is current maximum when due to searching for every time PSS correlation peak be set to zero, therefore when searching for next time, the PSS correlation peak searched will be second to this maximum PSS phase Close peak value.
Therefore the present invention effectively eliminates interference of the PSS strong correlation peak to the weak relevant peaks of PSS by way of zero setting, reaches The purpose eliminated is interfered, the interference of PSS can be eliminated to greatest extent, determines potential effectively correlation peak location and cell Mark in ID group effectively reduces the complexity that PSS interference is eliminated, and improves the efficiency that PSS interference is eliminated.And the present invention exists In zeroing process, the correlation of adjacent each several positions is also set to zero, therefore this before and after current maximum PSS correlation peak Inventive method can avoid current maximum PSS correlation peak frontrear position correlation from searching PSS correlation peak next time simultaneously The interference generated when rope eliminates interference of the PSS strong correlation peak to the weak relevant peaks of PSS to greatest extent.The method of the present invention is effective It avoids in the prior art for relatively weak cell, carries out the PSS interference meeting of elimination because of channel estimation value using Reconstruction Method It is inaccurate, cause PSS that cannot be eliminated to greatest extent, while can also introduce biggish interference, causes weaker cell cannot be by The technical issues of detecting.
The above embodiment is a preferred embodiment of the present invention, but embodiments of the present invention are not by abovedescribed embodiment Limitation, other any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present invention, It should be equivalent substitute mode, be included within the scope of the present invention.
Claims (10)
Priority Applications (1)
Application Number  Priority Date  Filing Date  Title 

CN201611078252.1A CN106603189B (en)  20161129  20161129  Cell searching interference elimination method in a kind of LTE system 
Applications Claiming Priority (1)
Application Number  Priority Date  Filing Date  Title 

CN201611078252.1A CN106603189B (en)  20161129  20161129  Cell searching interference elimination method in a kind of LTE system 
Publications (2)
Publication Number  Publication Date 

CN106603189A CN106603189A (en)  20170426 
CN106603189B true CN106603189B (en)  20190507 
Family
ID=58594097
Family Applications (1)
Application Number  Title  Priority Date  Filing Date 

CN201611078252.1A CN106603189B (en)  20161129  20161129  Cell searching interference elimination method in a kind of LTE system 
Country Status (1)
Country  Link 

CN (1)  CN106603189B (en) 
Families Citing this family (2)
Publication number  Priority date  Publication date  Assignee  Title 

CN107359953B (en) *  20170630  20181106  京信通信系统（中国）有限公司  A kind of TDLTE synchronous method and synchronizer 
US10334516B1 (en) *  20180313  20190625  Hong Kong Applied Science And Technology Research Institute Co., Ltd.  Cell search in a wireless network 
Citations (1)
Publication number  Priority date  Publication date  Assignee  Title 

CN102685849A (en) *  20110315  20120919  富士通株式会社  Information acquisition device, cell searching device and receiver 
Family Cites Families (5)
Publication number  Priority date  Publication date  Assignee  Title 

CN102572970A (en) *  20111221  20120711  华为技术有限公司  Method and device for searching cell in homogeneousfrequency neighboring cells 
CN103686889A (en) *  20120830  20140326  富士通株式会社  Cell searching method, cell searching device and user equipment 
US9479218B2 (en) *  20130422  20161025  Mediatek Singapore Pte Ltd.  Methods for LTE cell search with large frequency offset 
CN104579415B (en) *  20131021  20170412  富士通株式会社  Cell searching device and method as well as user equipment 
US20150372772A1 (en) *  20140618  20151224  Lg Electronics Inc.  Method and apparatus for receiving signal in wireless communication system 

2016
 20161129 CN CN201611078252.1A patent/CN106603189B/en active IP Right Grant
Patent Citations (1)
Publication number  Priority date  Publication date  Assignee  Title 

CN102685849A (en) *  20110315  20120919  富士通株式会社  Information acquisition device, cell searching device and receiver 
Also Published As
Publication number  Publication date 

CN106603189A (en)  20170426 
Similar Documents
Publication  Publication Date  Title 

JP5698811B2 (en)  Synchronization in multicarrier CDMA systems  
US8976773B2 (en)  Cell identifier encoding and decoding methods and apparatus  
US10218459B2 (en)  Apparatus and methods for symbol timing error detection, tracking and correction  
US9397799B2 (en)  Method and apparatus for interleaving sequence elements of an OFDMA synchronization channel  
US8873488B2 (en)  Method and apparatus for transmitting synchronization signals in an OFDM based cellular communications system  
JP5171950B2 (en)  Downlink frame generation method and cell search method  
ES2684122T3 (en)  Method and apparatus for quick cell search  
JP2013232940A (en)  Synchronization transmissions in wireless communication system  
EP2518961B1 (en)  Method and device for detecting primary synchronization signal and generating sequence in long term evolution (lte) system  
CN1934812B (en)  Method and apparatus for pilot signal transmission  
US9137075B2 (en)  Subcarrier spacing identification  
US8781467B2 (en)  Technique for cell signature determination  
Manolakis et al.  A closed concept for synchronization and cell search in 3GPP LTE systems  
JP4591973B2 (en)  Transmission and reception of reference preamble signal in OFDMA or OFDM communication system  
RU2475981C2 (en)  Assessment of channel with efficient suppression of inchannel interference  
CN103701733B (en)  A kind of method of TD LTE relay system offset estimation  
US8411552B2 (en)  Cell search method in OFDM cellular system, frame transmission method thereof, and forward link frame structure thereof  
US7561628B2 (en)  Apparatus and method for cell acquisition and downlink synchronization acquisition in a wireless communication system  
US8767708B2 (en)  Methods for cell search in synchronous interference limited channels  
US9337994B2 (en)  Method, receiver and system for signal synchronization  
ES2428388T3 (en)  Method and system for synchronization in a communication system  
CN102281250B (en)  Method and apparatus for a synchronization channel in an OFDMA system  
US7751308B2 (en)  Cell search method for orthogonal frequency division multiplexing based cellular communication system  
Tsai et al.  Cell search in 3GPP long term evolution systems  
US20150333859A1 (en)  Secondary synchronization sequences for cell group detection in a cellular communications system 
Legal Events
Date  Code  Title  Description 

PB01  Publication  
PB01  Publication  
SE01  Entry into force of request for substantive examination  
SE01  Entry into force of request for substantive examination  
GR01  Patent grant  
GR01  Patent grant 