CN101719890B - District searching method and d device applied to long-period evolution system - Google Patents
District searching method and d device applied to long-period evolution system Download PDFInfo
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- CN101719890B CN101719890B CN2009102418266A CN200910241826A CN101719890B CN 101719890 B CN101719890 B CN 101719890B CN 2009102418266 A CN2009102418266 A CN 2009102418266A CN 200910241826 A CN200910241826 A CN 200910241826A CN 101719890 B CN101719890 B CN 101719890B
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Abstract
The invention provides district searching method and device applied to a long-period evolution system. The district searching method comprises the following steps of: A, acquiring symbol timing information and CP mode information according to the iterative characteristic of CP data; B, carrying out the fast Fourier transform of NFFT data points in an OFDM symbol according to symbol timing information to obtain frequency domain data of the OFDM symbol; C, extracting a first candidate detection signal from the frequency domain data of the OFDM symbol according to a corresponding subcarrier position of main and secondary synchronous signals in a frequency domain; D, detecting the ID and the position of the main synchronous signal according to the first candidate detection signal and the known main synchronous signal sequence; E, acquiring a second candidate detection signal of the secondary synchronous signal according to the position and the CP mode information of the main synchronous signal, and detecting the ID of the secondary synchronous signal according to the second candidate detection signal and the known secondary synchronous signal sequence, thereby obtaining frame synchronization information. According to the invention, the complicated design of a narrowband low-pass filter can be avoided, and the operand is reduced.
Description
Technical field
The invention belongs to wireless communication technology field, particularly a kind of method and apparatus that is applied to the Cell searching of 3GPP LTE (Long Term Evolution of third generation gpp) system.
Background technology
The LTE system is the evolution of 3G; It improves and has strengthened the aerial access technology of 3G; Adopt OFDM (OFDM) and multiple-input and multiple-output (MIMO) sole criterion, the peak rate of descending 100Mbit/s and up 50Mbit/s can be provided under the 20MHz spectral bandwidth, improved the performance of Cell Edge User as its wireless network evolution; Improve cell capacity, reduced system delay.
The LTE system is based on a kind of wireless communication system of OFDM technology, so the OFDM symbol is the base unit in its frame structure.Specifically, its frame structure constitutes according to following mode step by step: a radio frames is made up of 10 sub-frame that (subframe 0#～9#), each subframe is made up of 2 time slots, and each time slot is made up of 6 or 7 OFDM symbols.
The same with existing wireless network, the LTE system also is a kind of cellular system of sub-district system.The id information of each sub-district is by N in the LTE system
ID (1)And N
ID (2)Two parts are formed, promptly
Wherein, N
ID (2)Information by master sync signal entrained (PSS, Primary Synchronization Signal),
Each N
ID (2)Corresponding specific known array; N
ID (1)(SSS, SecondarySynchronization Signal) is entrained by auxiliary synchronous signals,
Each N
ID (1)Corresponding a pair of specific known array.
Primary/secondary synchronizing signal is positioned on centre 62 number of sub-carrier of specific OFDM symbol, is specifically to be distributed on each 31 number of sub-carrier of direct current both sides, and is as shown in Figure 1.Direct current subcarrier among Fig. 1 and 5 idle sub-carrier are not sent any signal, and the effect of idle sub-carrier is for a protection being provided at interval between primary/secondary synchronizing signal and the data-signal.
Divide according to transmission means, there are FDD (FDD) and two kinds of patterns of TDD (time division duplex) in the LTE system.With reference to Fig. 2, for fdd mode, master sync signal is positioned at last OFDM symbol of first time slot of 0# and 5# subframe; Auxiliary synchronous signals is positioned at the penult OFDM symbol of first time slot of 0# and 5# subframe.For tdd mode, master sync signal is positioned at the 3rd OFDM symbol of first time slot of 1# and 6# subframe; Auxiliary synchronous signals is positioned at last OFDM symbol of second time slot of 0# and 5# subframe.This shows that for any pattern, every frame all comprises two primary/secondary synchronizing signals.It should be noted that for master sync signal the signal of twice appearance is from same sequence, promptly master sync signal is to send in the cycle with the field, finds the master sync signal position also can only confirm the original position of each field afterwards like this; For auxiliary synchronous signals; The signal of twice appearance is from two different sequences that satisfy certain relation; That is to say ID for same auxiliary synchronous signals; It is to send in the cycle with the frame that two sequences of S1 and S2 are arranged, and confirms that like this information of frame synchronization has also just obtained after the pairing particular sequence of auxiliary synchronous signals.
The LTE system is through introducing the intersymbol interference that Cyclic Prefix (CP) avoids multipath to bring, and promptly (length is N a symbol
FFT, N
FFTLength for fast Fourier transform (FFT) in the system) (length is N to the data of afterbody
CP) to constitute a new length to the head of symbol be N to copy
FFT+ N
CPSymbol.The introducing of Cyclic Prefix makes the OFDM symbol have such characteristic, and promptly a part of data (CP) are according to certain intervals (N
FFT) carry out repetition.In the LTE system, there are two kinds of patterns in CP: normal mode and mode of extension.For normal mode, CP length is shorter relatively, can hold 7 OFDM symbols in the time slot (length is 0.5ms), and the CP length N of first symbol
CPN1CP length N with other symbols
CPN2Compare longer a little, shown in (a) among Fig. 3.For mode of extension, the CP length N
CPELonger relatively, be approximately about 3.6 times of CP length under the normal mode.Just because of this, under expansion CP pattern, the symbolic number that time slot can hold will be lacked than the normal mode formula, can only hold 6.The CP identical length of all symbols is same under the expansion CP pattern, shown in (b) among Fig. 3.In the LTE system, CP length and N under the different bandwidth configuration
FFTAs shown in the table.
Conventional LTE small region search method is: at first, utilize narrowband low-pass filter to leach receiving the narrower frequency band that comprises the PSS/SSS signal in the data; Secondly, on time domain, be directed against three position and ID thereof that possible PSS signal slides respectively and is correlated with and discerns the PSS signal whole reception data; Once more, detect the CP pattern of current system; At last,, determine the position of SSS signal, and accomplish detection it according to the position and the CP pattern of PSS signal.This implementation method often needs complicated narrowband low-pass filter design and more operand.And, exist under the situation of big frequency deviation, need the operand of several times of further increases to solve the frequency deviation problem, otherwise its detection performance can worsen rapidly.
Summary of the invention
Technical problem to be solved by this invention provides a kind of small region search method and device that is applied to long evolving system, to avoid complicated narrowband low-pass filter design, reduces operand.
For solving the problems of the technologies described above, the present invention provides technical scheme following:
A kind of small region search method that is applied to long evolving system comprises the steps:
A, obtain symbol regularly and the CP pattern information according to the repeat property of CP data;
B, according to symbol timing information, to the N in the OFDM symbol
FFTData points is done FFT, obtains the frequency domain data of OFDM symbol, wherein, and N
FFTLength for FFT;
C, according to primary and secondary synchronization signals pairing sub-carrier positions in frequency domain, from the frequency domain data of OFDM symbol, extract the first couple candidate detection signal;
D, according to the first couple candidate detection signal and known master sync signal sequence, detect the ID and the position thereof of the employed master sync signal of current area;
E, according to the position and the CP pattern information of master sync signal; Obtain the second couple candidate detection signal at auxiliary synchronous signals place; According to the ID of the second couple candidate detection signal and the known employed auxiliary synchronous signals of auxiliary synchronous signals Sequence Detection current area, and obtain frame synchronization information according to the ID of auxiliary synchronous signals.
Above-mentioned small region search method, wherein, steps A comprises:
To receive data and himself delay N
FFTData carry out related operation based on two kinds of CP length of normal mode and mode of extension respectively, obtain two groups of correlated serieses;
The peak value of two groups of correlated serieses relatively, peak value position that will be bigger be as the original position of symbol, and the pairing CP pattern of peak value that will be bigger is as CP pattern that current area adopted.
Above-mentioned small region search method, wherein, step D comprises:
The computing that master sync signal that each is known and the first all couple candidate detection signals are done conjugate multiplication and added up obtains three sequences;
Find out three maximal peak point in the sequence, with the ID of the pairing master sync signal of maximal peak point ID, with the position of the pairing character position of maximal peak point as master sync signal as the employed master sync signal of current area.
Above-mentioned small region search method, wherein, step e comprises:
The computing that the auxiliary synchronous signals that each is known and the second couple candidate detection signal are done conjugate multiplication and added up obtains the sequence that is made up of 336 points;
Find out the peak point in the sequence that constitutes by 336 points, with the ID of the pairing auxiliary synchronous signals of this peak point ID as the employed auxiliary synchronous signals of current area;
The sequence corresponding according to this peak point is first auxiliary synchronous signals or second auxiliary synchronous signals in the frame, confirms frame synchronization information.
Above-mentioned small region search method wherein, also comprises after the steps A:
Carry out frequency offset estimating and timing estimation;
Carry out frequency deviation adjustment and regularly adjustment according to frequency offset estimation result and timing estimation results.
A kind of cell search apparatus that is applied to long evolving system comprises:
Symbol timing and CP mode detector are used for obtaining symbol timing and CP pattern information according to the repeat property of CP data;
The FFT converter is used for according to symbol timing information, to the N in the OFDM symbol
FFTData points is done FFT, obtains the frequency domain data of OFDM symbol, wherein, and N
FFTLength for FFT;
The subcarrier withdrawal device is used for according to primary and secondary synchronization signals in the pairing sub-carrier positions of frequency domain, from the frequency domain data of OFDM symbol, extracts the first couple candidate detection signal;
Master sync signal position and ID detector thereof are used for according to the first couple candidate detection signal and known master sync signal sequence, detect the ID and the position thereof of the employed master sync signal of current area;
Auxiliary synchronous signals ID and frame sync detector; Be used for position and CP pattern information according to master sync signal; Obtain the second couple candidate detection signal at auxiliary synchronous signals place; According to the ID of the second couple candidate detection signal and the known employed auxiliary synchronous signals of auxiliary synchronous signals Sequence Detection current area, and obtain frame synchronization information according to the ID of auxiliary synchronous signals.
Above-mentioned cell search apparatus, wherein, said symbol regularly is further used for the CP mode detector:
To receive data and himself delay N
FFTData carry out related operation based on two kinds of CP length of normal mode and mode of extension respectively, obtain two groups of correlated serieses;
The peak value of two groups of correlated serieses relatively, peak value position that will be bigger be as the original position of symbol, and the pairing CP pattern of peak value that will be bigger is as CP pattern that current area adopted.
Above-mentioned cell search apparatus, wherein, said master sync signal position and ID detector thereof are further used for:
The computing that master sync signal that each is known and the first all couple candidate detection signals are done conjugate multiplication and added up obtains three sequences;
Find out three maximal peak point in the sequence, with the ID of the pairing master sync signal of maximal peak point ID, with the position of the pairing character position of maximal peak point as master sync signal as the employed master sync signal of current area.
Above-mentioned cell search apparatus, wherein, said auxiliary synchronous signals ID and frame sync detector are further used for:
The computing that the auxiliary synchronous signals that each is known and the second couple candidate detection signal are done conjugate multiplication and added up obtains the sequence that is made up of 336 points;
Find out the peak point in the sequence that constitutes by 336 points, with the ID of the pairing auxiliary synchronous signals of this peak point ID as the employed auxiliary synchronous signals of current area;
The sequence corresponding according to this peak point is first auxiliary synchronous signals or second auxiliary synchronous signals in the frame, confirms frame synchronization information.
Above-mentioned cell search apparatus wherein, also comprises:
Synchronization and estimation and adjustment unit are used to carry out frequency offset estimating and timing estimation, and carry out frequency deviation adjustment and regularly adjustment according to frequency offset estimation result and timing estimation results.
The present invention at first confirms the original position and the CP pattern of symbol according to the repeat property of CP data; Then; Signal is transferred to frequency domain from time domain, and in frequency domain, detect the ID and the frame synchronization information of primary and secondary synchronization signals, like this; Just avoid complicated narrowband low-pass filter design, reduced operand.
Description of drawings
Fig. 1 is the frequency domain distribution sketch map of PSS signal in specific OFDM symbol;
Fig. 2 is the position view of primary/secondary synchronizing signal in particular time-slot in the fdd mode;
Fig. 3 is the formation sketch map of OFDM symbol cyclic prefix;
Fig. 4 is the structural representation of the cell search apparatus that is applied to long evolving system of the embodiment of the invention;
Fig. 5 is the flow chart of the small region search method that is applied to long evolving system of the embodiment of the invention.
Embodiment
For making the object of the invention, technical scheme and advantage clearer, will combine accompanying drawing and specific embodiment to describe the present invention below.
The present invention is at first according to the repeat property completion symbol timing of CP data and the detection of CP pattern; Regularly each symbol is carried out the FFT conversion according to symbol then, take out master sync signal and carry out the master sync signal detection, confirm its position and ID in the data of the corresponding sub-carrier positions of frequency domain institute; According to the data of master sync signal position and CP pattern taking-up auxiliary synchronous signals position, accomplish detection at last to auxiliary synchronous signals ID.Meanwhile, can launch synchronization and estimation certain (several) the individual particular moment in cell search process and adjust, improve its follow-up detection performance to guarantee frequency and time synchronized preferably.The launching in cell search process, to launch once of said synchronization and estimation and adjustment also can be launched repeatedly, perhaps in case to launch be continuous operation.Said certain specific moment can be accomplish symbol regularly with the detection of CP pattern after any time.
With reference to Fig. 4, the cell search apparatus that is applied to long evolving system of the embodiment of the invention mainly comprises: symbol timing and CP mode detector 10, FFT converter 20, subcarrier withdrawal device 30, master sync signal position and ID detector 40 thereof, auxiliary synchronous signals ID and frame sync detector 50, synchronization and estimation and adjustment unit 60.Below the function of above-mentioned each module is described in detail.
Symbol timing and CP mode detector 10
Symbol is original position and CP pattern informations of confirming symbol according to the repeat property of CP data with CP mode detector 10 regularly.As the also exportable failure flags of a kind of preferred version, if detect failure, finish Cell searching, avoid erroneous detection.
As embodiment, symbol regularly will receive data with CP mode detector 10 and himself postpones N
FFTData carry out related operation based on two kinds of CP length of normal mode and mode of extension respectively; Can obtain two groups of correlated serieses; The peak value that compares two groups of correlated serieses; Bigger peak value position is the original position of symbol, and the big pairing CP pattern of peak value is the CP pattern that current area adopts.Confirm the original position and the CP pattern (the CP pattern can be confirmed symbol lengths) of a certain symbol, just can confirm the original position of all symbols, promptly obtained symbol timing information.If in the power of big peak value and its place sequence, compare with its average power with other points of certain intervals, less than certain threshold value, detect failure so, otherwise success.
Master sync signal position and ID detector 40 thereof
Master sync signal position and ID detector 40 thereof are according to three known master sync signal sequences; In a plurality of first couple candidate detection signals that possibly comprise master sync signal, discern and detect, find out the ID of the employed master sync signal of current area and the position at place thereof.As the also exportable failure flags of a kind of preferred version.If detect failure, finish Cell searching, avoid erroneous detection.
As embodiment; The computing that master sync signal that master sync signal position and ID detector 40 thereof can be known with each and the first all couple candidate detection signals are done conjugate multiplication and added up; Can obtain three sequences like this; Find out three maximal peak point in the sequence, the ID of the pairing master sync signal of this maximal peak point is the master sync signal ID of current area so; The pairing character position of this maximal peak point is the position of master sync signal.If the power of big peak value is compared with the average power that its belongs to other points in sequence, less than certain threshold value, detect failure so, otherwise success.
Auxiliary synchronous signals ID and frame sync detector 50
Auxiliary synchronous signals ID and frame sync detector 50 are according to known master sync signal position and CP pattern information (can confirm certain location relation between the primary and secondary synchronization signals through the CP pattern), find out the second couple candidate detection signal at auxiliary synchronous signals place.Utilize 168 pairs of known auxiliary synchronous signals to accomplish the detection of auxiliary synchronous signals ID, and then find frame synchronization information, be i.e. the original position of each radio frames with this couple candidate detection signal.As the also exportable failure flags of a kind of preferred version.If detect failure, finish Cell searching, avoid erroneous detection.
As embodiment; The computing that auxiliary synchronous signals ID and frame sync detector 50 can be done 168 pairs of known auxiliary synchronous signals and the second couple candidate detection signal conjugate multiplication and add up; Can obtain the sequence that constitutes by 336 points like this; Find out the peak point in the sequence, the ID of the pairing auxiliary synchronous signals of this peak point is the employed auxiliary synchronous signals ID of current area so.The sequence corresponding according to this peak value is first auxiliary synchronous signals or second auxiliary synchronous signals in the frame, can confirm frame synchronization information.Power like peak value in the infructescence is compared with the average power of other points, less than certain threshold value, detects failure so, otherwise success.
Synchronization and estimation and adjustment unit 60
Synchronization and estimation and adjustment unit 60 comprise estimation and adjustment (frequency offset estimator, frequency deviation adjuster) and the estimation regularly and the adjustment (timing estimator, timing adjuster) of frequency deviation, and it can utilize CP data or detected primary and secondary synchronization signals to accomplish.Frequency deviation can independently respectively be accomplished with estimation regularly and also can accomplish together through uniting estimation.Obtain to adjust when receiving signal according to estimated result after the estimation of frequency deviation and timing next time, reduce the influence of frequency deviation and timing offset subsequent detection.
Synchronization and estimation can be launched with adjustment certain (several) the individual particular moment in cell search process, to guarantee frequency and time synchronized preferably, improves its follow-up detection performance.The launching in cell search process, to launch once of said synchronization and estimation and adjustment also can be launched repeatedly, perhaps in case to launch be continuous operation.Said certain specific moment can be accomplish symbol regularly with the detection of CP pattern after any time.
About the existing more prior art of the synchronization and estimation of ofdm system and adjustment, for example, based on maximum likelihood timing and diviation combined estimation method, at this its practical implementation is not done and to be given unnecessary details.
Accordingly, the present invention also provides a kind of small region search method that is applied to long evolving system.
With reference to Fig. 5, the small region search method that is applied to long evolving system of the embodiment of the invention mainly comprises the steps:
Step 501: obtain symbol timing and CP pattern information according to the repeat property of CP data;
As the also exportable failure flags of a kind of preferred version,, avoid erroneous detection if the failure of this step finishes Cell searching.
As embodiment, can be with receiving data and himself delay N
FFTData carry out related operation based on two kinds of CP length of normal mode and mode of extension respectively; Can obtain two groups of correlated serieses; The peak value that compares two groups of correlated serieses; Bigger peak value position is the original position of symbol, and the big pairing CP pattern of peak value is the CP pattern that current area adopts.Confirm the original position and the CP pattern (the CP pattern can be confirmed symbol lengths) of a certain symbol, just can confirm the original position of all symbols, promptly obtained symbol timing information.If in the power of big peak value and its place sequence, compare with its average power with other points of certain intervals, less than certain threshold value, this step failure so, otherwise success.
Step 502: according to symbol timing information, to the N in the OFDM symbol
FFTData points is done FFT, obtains the frequency domain data of OFDM symbol, wherein, and N
FFTLength for FFT;
Step 503:, from the frequency domain data of OFDM symbol, extract the first couple candidate detection signal according to primary and secondary synchronization signals pairing sub-carrier positions in frequency domain;
A part of data pick-up in the frequency domain data of each OFDM symbol is come out; The position of institute's extracted data is PSS/SSS signal pairing sub-carrier positions in OFDM symbol frequency domain; Obviously this part should be more than or equal to 62, even can guarantee to exist PSS signals all under the situation of big frequency deviation to be extracted fully like this.For back literary composition statement is convenient this partial data is called the first couple candidate detection signal.
Step 504:, detect the ID and the position thereof of the employed master sync signal of current area according to the first couple candidate detection signal and known master sync signal sequence;
As the also exportable failure flags of a kind of preferred version.If the failure of this step finishes Cell searching, avoid erroneous detection.
As embodiment; The computing that master sync signal that can each is known and the first all couple candidate detection signals are done conjugate multiplication and added up; Can obtain three sequences like this; Find out three maximal peak point in the sequence, the ID of the pairing master sync signal of this maximal peak point is the master sync signal ID of current area so; The pairing character position of this maximal peak point is the position of master sync signal.If the power of big peak value is compared with the average power that its belongs to other points in sequence, less than certain threshold value, this step failure so, otherwise success.
Step 505: according to the position and the CP pattern information of master sync signal; Obtain the second couple candidate detection signal at auxiliary synchronous signals place; According to the ID of the second couple candidate detection signal and the known employed auxiliary synchronous signals of auxiliary synchronous signals Sequence Detection current area, and obtain frame synchronization information according to the ID of auxiliary synchronous signals.
As the also exportable failure flags of a kind of preferred version.If the failure of this step finishes Cell searching, avoid erroneous detection.
As embodiment; The computing that can 168 pairs of known auxiliary synchronous signals and the second couple candidate detection signal done conjugate multiplication and add up; Can obtain the sequence that constitutes by 336 points like this; Find out the peak point in the sequence, the ID of the pairing auxiliary synchronous signals of this peak point is the employed auxiliary synchronous signals ID of current area so.The sequence corresponding according to this peak value is first auxiliary synchronous signals or second auxiliary synchronous signals in the frame, can confirm frame synchronization information.Power like peak value in the infructescence is compared with the average power of other points, less than certain threshold value, and this step failure so, otherwise success.
Wherein, also can comprise after the step 501:
Carry out frequency offset estimating and timing estimation, carry out frequency deviation adjustment and regularly adjustment according to frequency offset estimation result and timing estimation results.
Can utilize CP data or detected primary and secondary synchronization signals to accomplish.Frequency deviation can independently respectively be accomplished with estimation regularly and also can accomplish together through uniting estimation.Obtain to adjust when receiving signal according to estimated result after the estimation of frequency deviation and timing next time, reduce the influence of frequency deviation and timing offset subsequent detection.
Synchronization and estimation can be launched with adjustment certain (several) the individual particular moment in cell search process, to guarantee frequency and time synchronized preferably, improves its follow-up detection performance.The launching in cell search process, to launch once of said synchronization and estimation and adjustment also can be launched repeatedly, perhaps in case to launch be continuous operation.Said certain specific moment can be accomplish symbol regularly with the detection of CP pattern after any time.
About the existing more prior art of the synchronization and estimation of ofdm system and adjustment, for example, based on maximum likelihood timing and diviation combined estimation method, at this its practical implementation is not done and to be given unnecessary details.
Should be noted that at last; Above embodiment is only unrestricted in order to technical scheme of the present invention to be described; Those of ordinary skill in the art is to be understood that; Can make amendment or be equal to replacement technical scheme of the present invention, and not break away from the spirit of technical scheme of the present invention, it all should be encompassed in the middle of the claim scope of the present invention.
Claims (8)
1. a small region search method that is applied to long evolving system is characterized in that, comprises the steps:
A, obtain symbol regularly and the CP pattern information according to the repeat property of cyclic prefix CP data;
B, according to symbol timing information, the N in the pair of orthogonal frequency division multiplex OFDM symbol
FFTData points is done FFT, obtains the frequency domain data of OFDM symbol, wherein, and N
FFTLength for FFT;
C, according to primary and secondary synchronization signals pairing sub-carrier positions in frequency domain, from the frequency domain data of OFDM symbol, extract the first couple candidate detection signal;
D, according to the first couple candidate detection signal and known master sync signal sequence, detect the ID and the position thereof of the employed master sync signal of current area;
E, according to the position and the CP pattern information of master sync signal; Obtain the second couple candidate detection signal at auxiliary synchronous signals place; According to the ID of the second couple candidate detection signal and the known employed auxiliary synchronous signals of auxiliary synchronous signals Sequence Detection current area, and obtain frame synchronization information according to the ID of auxiliary synchronous signals;
Wherein, steps A comprises:
To receive data and himself delay N
FFTData carry out related operation based on two kinds of CP length of normal mode and mode of extension respectively, obtain two groups of correlated serieses;
The peak value of two groups of correlated serieses relatively, peak value position that will be bigger be as the original position of symbol, and the pairing CP pattern of peak value that will be bigger is as CP pattern that current area adopted.
2. small region search method as claimed in claim 1 is characterized in that step D comprises:
The computing that master sync signal that each is known and the first all couple candidate detection signals are done conjugate multiplication and added up obtains three sequences;
Find out three maximal peak point in the sequence, with the ID of the pairing master sync signal of maximal peak point ID, with the position of the pairing character position of maximal peak point as master sync signal as the employed master sync signal of current area.
3. small region search method as claimed in claim 1 is characterized in that step e comprises:
The computing that the auxiliary synchronous signals that each is known and the second couple candidate detection signal are done conjugate multiplication and added up obtains the sequence that is made up of 336 points;
Find out the peak point in the sequence that constitutes by 336 points, with the ID of the pairing auxiliary synchronous signals of this peak point ID as the employed auxiliary synchronous signals of current area;
The sequence corresponding according to this peak point is first auxiliary synchronous signals or second auxiliary synchronous signals in the frame, confirms frame synchronization information.
4. small region search method as claimed in claim 1 is characterized in that, also comprises after the steps A:
Carry out frequency offset estimating and timing estimation;
Carry out frequency deviation adjustment and regularly adjustment according to frequency offset estimation result and timing estimation results.
5. a cell search apparatus that is applied to long evolving system is characterized in that, comprising:
Symbol timing and CP mode detector are used for obtaining symbol timing and CP pattern information according to the repeat property of CP data;
The FFT converter is used for according to symbol timing information, to the N in the OFDM symbol
FFTData points is done FFT, obtains the frequency domain data of OFDM symbol, wherein, and N
FFTLength for FFT;
The subcarrier withdrawal device is used for according to primary and secondary synchronization signals in the pairing sub-carrier positions of frequency domain, from the frequency domain data of OFDM symbol, extracts the first couple candidate detection signal;
Master sync signal position and ID detector thereof are used for according to the first couple candidate detection signal and known master sync signal sequence, detect the ID and the position thereof of the employed master sync signal of current area;
Auxiliary synchronous signals ID and frame sync detector; Be used for position and CP pattern information according to master sync signal; Obtain the second couple candidate detection signal at auxiliary synchronous signals place; According to the ID of the second couple candidate detection signal and the known employed auxiliary synchronous signals of auxiliary synchronous signals Sequence Detection current area, and obtain frame synchronization information according to the ID of auxiliary synchronous signals;
Wherein, said symbol regularly is further used for the CP mode detector:
To receive data and himself delay N
FFTData carry out related operation based on two kinds of CP length of normal mode and mode of extension respectively, obtain two groups of correlated serieses;
The peak value of two groups of correlated serieses relatively, peak value position that will be bigger be as the original position of symbol, and the pairing CP pattern of peak value that will be bigger is as CP pattern that current area adopted.
6. cell search apparatus as claimed in claim 5 is characterized in that, said master sync signal position and ID detector thereof are further used for:
The computing that master sync signal that each is known and the first all couple candidate detection signals are done conjugate multiplication and added up obtains three sequences;
Find out three maximal peak point in the sequence, with the ID of the pairing master sync signal of maximal peak point ID, with the position of the pairing character position of maximal peak point as master sync signal as the employed master sync signal of current area.
7. cell search apparatus as claimed in claim 5 is characterized in that, said auxiliary synchronous signals ID and frame sync detector are further used for:
The computing that the auxiliary synchronous signals that each is known and the second couple candidate detection signal are done conjugate multiplication and added up obtains the sequence that is made up of 336 points;
Find out the peak point in the sequence that constitutes by 336 points, with the ID of the pairing auxiliary synchronous signals of this peak point ID as the employed auxiliary synchronous signals of current area;
The sequence corresponding according to this peak point is first auxiliary synchronous signals or second auxiliary synchronous signals in the frame, confirms frame synchronization information.
8. cell search apparatus as claimed in claim 5 is characterized in that, also comprises:
Synchronization and estimation and adjustment unit are used to carry out frequency offset estimating and timing estimation, and carry out frequency deviation adjustment and regularly adjustment according to frequency offset estimation result and timing estimation results.
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| CN102300286B (en) * | 2010-06-23 | 2014-10-01 | 富士通株式会社 | Method and device for obtaining auxiliary synchronization information and method and device for searching adjacent cells |
| CN101895982B (en) * | 2010-07-12 | 2012-12-19 | 合肥东芯通信股份有限公司 | Downlink synchronous method, equipment and system applied to long-term evolution |
| CN102387582B (en) * | 2010-08-31 | 2014-11-26 | 联芯科技有限公司 | Detection method and device for cell group numbers of secondary synchronization sequences of LTE (long term evolution) system |
| CN102223696B (en) * | 2011-06-17 | 2013-09-25 | 电子科技大学 | Cell searching method in LTE (long term evolution) system |
| CN102421114B (en) * | 2011-11-30 | 2014-04-23 | 合肥东芯通信股份有限公司 | Device and method for searching same-frequency neighbor cells of long term evolution (LTE) system |
| CN103379077A (en) * | 2012-04-27 | 2013-10-30 | 株式会社Ntt都科摩 | Frame synchronization and symbol synchronization method and device in wireless communication system |
| KR101626457B1 (en) * | 2013-12-20 | 2016-06-01 | 주식회사 쏠리드 | Apparatus and method for detecting frame synchronization of long term evolution signal, and repeater thereof |
| US10206189B2 (en) | 2015-07-27 | 2019-02-12 | Telefonaktiebolaget Lm Ericsson (Publ) | Narrowband LTE cell search |
| CN106658697B (en) | 2015-11-04 | 2020-11-17 | 中兴通讯股份有限公司 | Synchronization signal sending and detecting method, base station and terminal |
| TW201931813A (en) * | 2018-01-09 | 2019-08-01 | 財團法人資訊工業策進會 | Wireless communication device and time and frequency synchronization method and non-transitory computer readable medium of the same |
| CN110830408B (en) * | 2019-11-13 | 2022-02-22 | 天津德力仪器设备有限公司 | Method for rapidly capturing CAS in EMBMS system |
| CN110971549B (en) * | 2019-12-09 | 2022-02-01 | 湖北大学 | MIMO-ADO-OFDM visible light communication system and receiving method |
| CN112637946B (en) * | 2020-12-17 | 2022-04-05 | 重庆邮电大学 | PSS timing synchronization method suitable for large frequency deviation |
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2009
- 2009-12-09 CN CN2009102418266A patent/CN101719890B/en not_active Expired - Fee Related
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