CN102510566B - Method and device for searching neighbor-cell of LTE (long term evolution) system - Google Patents
Method and device for searching neighbor-cell of LTE (long term evolution) system Download PDFInfo
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Abstract
The invention discloses a method and a device for searching a neighbor-cell of an LTE (long term evolution) system. The method comprises the following steps of: when SSS (Secondary Synchronization Signal) detection is carried out on a digital signal, comparing the peak value corresponding to the relative power of the digital signal on the frequency domain with the preset threshold, confirming the real peak value corresponding to the relative power according to the compared result; calculating the Nid1 corresponding to the real peak value and the Nid1 corresponding to a fake peak value and carrying out the dropping treatment until the comparison is finished; calculating and obtaining the Nid1 corresponding to the real peak value and marks before and after 5 ms; finally, calculating the ID (identification) Nid2 and 5 ms timing determined through preset PSS(Primary Synchronization Signal) detection, the Nid1, the marks before and after 5ms to obtain the Cell ID of the neighbor cell and the frame timing. According to the invention, by means of carrying out the threshold judgment on the SSS relative power and carrying out the dropping treatment on the determined fake peak value, the probability of generating a fake cell in the process of searching the neighbor cell is reduced and the probability of exactly searching the neighbor cell is improved.
Description
Technical field
The present invention relates to communication technical field, in particular, relate to adjacent area searching method and the device of a kind of LTE (Long Term Evolution system, Long Term Evolution) system.
Background technology
Current, communication technical field by the 3G epoch in the transient process in 4G epoch, LTE (Long Term Evolution system, Long Term Evolution) system is thought accurate 4G wireless communication system widely.TD-LTE is the LTE system of TDD (Time Division Duplexing, time division duplex) version.
In the prior art, UE (User Equipment, subscriber equipment) (Primary Synchronization Signal, main synchronizing symbol and SSS (Secondary Synchronization Signal, auxiliary synchronizing symbol) carry out adjacent area search to utilize PSS.By PSS and SSS, determine the Nid1 that community adopts, the frame timing of Nid2 and community, and determine the unique ID in community (IDentity, community number) (ID=Nid1*3+Nid2) by Nid1 and Nid2.
For tdd mode, the time-domain position of PSS and SSS as shown in Figure 1, PSS is positioned at the 3rd OFDM (Orthogonal Frequency Division Multiplexing, the OFDM) symbol of Slot2 and Slot12, and SSS is positioned at last OFDM symbol of Slot1 and Slot11.On frequency domain, no matter system takies much bandwidth, and PSS and SSS are 6 RB in the middle of only taking.
Wherein, PSS symbols carry PSC code (Primary Synchronization Code, Primary Synchronisation Code), this PSC code is the Zadoff-Chu sequence being defined on frequency domain, based on this Zadoff-Chu sequence, by three different root sequences (25,29,34), can distinguish different Nid2.SSS symbols carry SSC code (Secondary Synchronization Code, secondary synchronization code), this SSC code is interweaved and is in series by the binary sequence of 2 31 length, co-exist in 336 kinds of possible sequential structures, utilizing this SSC code can distinguish two kinds of 5ms sign behind 5ms sign before 168 kinds of Nid1 and community or community may.
According to agreement 36.211, the definition of SSC sequence d (n) is as shown in formula (1) and formula (2):
Wherein, Nid1 and m
0, m
1corresponding relation as shown in figure 12.
Utilizing prior art to carry out in the process of adjacent area search, generally by PSS detection and SSS, detecting two steps and form.By PSS, detect Nid2 and the timing of 5ms frame that obtains adjacent area, the Nid1 and the front and back 5ms that by SSS, detect acquisition adjacent area identify.As shown in Figure 2, in TD-LTE system, all eNodeB (base station) are synchronous, if a UE is identical with the distance of two eNodeB, carries out so PSS and detect, and the 5ms frame that gets Zhe Liangge community is regularly identical.If the Nid2 of Zhe Liangge community is also identical, PSS detects and cannot distinguish Zhe Liangge community, and for only existing 3 different Nid2 to distribute, occur cannot distinguishing cell probability will be very high.Therefore,, for addressing the above problem, prior art reports a plurality of peak values conventionally when carrying out SSS detection, by threshold judgement, determines whether there are in this case a plurality of communities.
But while doing in the prior art SSS detection, except autocorrelation peak, the SSC corresponding to other Nid1 is relevant can go out to serve false correlation peak.From formula (1) and formula (2), by front 5ms sign, be SSS when relevant, use identical m with transmitting sequence
0nid1, its even sequence is identical, the false peaks of therefore can being correlated with out.Same, when being SSS and being correlated with by rear 5ms sign, use identical m with transmitting sequence
1nid1, its even sequence is also identical, the false peaks of also can being correlated with out.
Illustrate, when send Nid1=65 time, with front 5ms, identify and do relevantly, correlated results as shown in Figure 3, except the autocorrelation peak when the Nid1=65, has identical m with Nid1=65
0(m
0=6) the relevant out false peaks of other Nid1 (6,36,93,120,146) meeting; By rear 5ms sign, do relevantly, correlated results as shown in Figure 4, except the autocorrelation peak when the Nid1=65, has identical m with Nid1=65
1(m
1=9) other Nid1 (8,37,92,118,143,167) false peaks of also can being correlated with out.
Therefore, when the adjacent area of employing prior art is searched for, wherein easily occur false peaks carrying out when SSS detects, and the corresponding false community of the false peaks detecting not is the adjacent area that will detect or the adjacent area of existence, thereby causes quick and precisely realizing the search to all adjacent areas.
Summary of the invention
In view of this, the invention provides a kind of adjacent area searching method and device of LTE system, to overcome in prior art, carrying out when SSS detects easily detecting false community, thereby cause the problem that cannot quick and precisely search for all adjacent areas.
For achieving the above object, the invention provides following technical scheme:
An adjacent area searching method for Long Term Evolution LTE system, comprising:
Receive signal and process, obtaining corresponding digital signal;
Described digital signal is carried out to main synchronizing symbol PSS and detect, and the related power in time domain is determined the Nid2 of adjacent area and 5ms frame regularly according to the described digital signal of obtaining;
Described digital signal is carried out to auxiliary synchronizing symbol SSS to be detected, obtain the related power of described digital signal on frequency domain, peak value and default thresholding that described related power is corresponding compare, and determine corresponding real peak value according to comparative result, and the Nid1 that calculates the corresponding false peaks of Nid1 corresponding to real peak value, and related power corresponding to ghost peak carried out to range of decrease processing, until relatively finish, calculate and obtain Nid1 corresponding to definite real peak value and front and back 5ms sign;
According to described PSS, detect Nid2 and the 5ms timing of definite adjacent area, and described SSS detects adjacent area Nid1 corresponding to definite real peak value and 5ms sign in front and back is calculated, obtain cell ID Cell ID and the frame timing of adjacent area.
Preferably, described digital signal is carried out to auxiliary synchronizing symbol SSS and detect, the detailed process of calculating and obtain Nid1 corresponding to definite real peak value and front and back 5ms sign comprises:
The SSS symbol getting in digital signal is done to fast Fourier transform, obtain the frequency-region signal of described SSS symbol;
Extract the subcarrier of corresponding described SSS symbol in described frequency-region signal;
Utilize each local sequence of described SSS symbol respectively described subcarrier to be done relevant, obtain the corresponding correlated results of local sequence described in each;
Calculate related power corresponding to correlated results described in each, choose from large to small the peak value corresponding to related power of preset number;
Judge from large to small whether each peak value is greater than default thresholding, and according to judged result, determine the Nid1 of adjacent area.
Preferably, judge from large to small whether each peak value is greater than default thresholding, and determine that according to judged result the detailed process of adjacent area Nid1 is:
Choose current untreated peak-peak, when described untreated peak-peak is greater than default thresholding, described untreated peak-peak is designated as to real peak value, is designated as false peaks with the peak value that comprises identical binary sequence in the local sequence of described untreated peak-peak use when relevant;
Calculate and obtain Nid1 corresponding to described real peak value, and the Nid1 of corresponding described false peaks;
Reduce the amplitude of related power corresponding to described false peaks, the range value of described reduction be described real peak value related power amplitude 1/4;
Described in mark, real peak value is processed, returns to carry out and chooses current this step of untreated peak-peak, and choosing next peak value that is greater than described default thresholding is current peak-peak;
When described untreated peak value is all not more than default thresholding, finish comparison, calculate and obtain Nid1 and the front and back 5ms sign of the corresponding adjacent area of described real peak value.
Preferably, after obtaining the cell ID Cell ID and frame timing of adjacent area, also comprise:
In inquiry Neighboring Cell List, whether there is the described adjacent area Cell ID getting, if there is no, upgrade described Neighboring Cell List; If exist, do not upgrade.
Preferably, described in each local sequence by being designated as respectively m
0and m
1the binary sequence of two 31 length interweave in series;
Determine while being correlated with, use the m in local sequence
0the m comprising in the local sequence of using with described untreated peak-peak
0identical peak value is false peaks;
Or, use the m in local sequence
1the m comprising in the local sequence of using with described untreated peak-peak
1identical peak value is false peaks.
An adjacent area checkout gear for Long Term Evolution LTE system, comprising:
Front-end processing module, for receiving signal and processing, obtains corresponding digital signal;
Main synchronizing symbol PSS detection module, for described digital signal is carried out to PSS detection, and the related power in time domain is determined ID Nid2 and the timing of 5ms frame in the cell set of adjacent area according to the described digital signal of obtaining;
Auxiliary synchronizing symbol SSS detection module, for described digital signal is carried out to SSS detection, obtain the related power of described digital signal on frequency domain, peak value and default thresholding that described related power is corresponding compare, and determine corresponding real peak value according to comparative result, and the Nid1 that calculates the corresponding false peaks of Nid1 corresponding to real peak value, and related power corresponding to ghost peak carried out to range of decrease processing, until relatively finish, calculate and obtain Nid1 and the front and back 5ms sign of the corresponding adjacent area of described real peak value;
Adjacent area search module, for detecting definite adjacent area Nid2 and 5ms according to described PSS regularly, and described SSS detects adjacent area Nid1 corresponding to definite real peak value and 5ms sign in front and back is calculated, and obtains cell ID Cell ID and the frame timing of adjacent area.
Preferably, described auxiliary synchronizing symbol SSS detection module comprises:
Fast Fourier transform module, does fast Fourier transform to the SSS getting, and obtains the frequency-region signal of described SSS symbol;
Extract SSS sub-carrier block, for extracting the subcarrier of the corresponding described SSS symbol of described frequency-region signal;
SSS correlation module, relevant for utilizing each local sequence of described SSS symbol respectively described subcarrier to be done, obtain the corresponding correlated results of local sequence described in each;
Related power computing module, for calculating related power corresponding to correlated results described in each, chooses the peak value corresponding to related power of preset number from large to small;
SSS peak value processing module, for judging from large to small whether each peak value is greater than default thresholding, and determines the Nid1 of adjacent area according to judged result.
Preferably, described SSS peak value processing module comprises:
Threshold judgement module, be used for choosing current untreated peak-peak, when described untreated peak-peak is greater than default thresholding, determine that described untreated peak-peak is real peak value, determine that the peak value that comprises identical binary sequence in the local sequence of using with described untreated peak-peak while being correlated with is false peaks; When described untreated peak-peak is not more than default thresholding, finish, obtain Nid1 and the front and back 5ms sign of adjacent area;
Peak value computing module, for calculating and obtain Nid1 corresponding to described real peak value, and the Nid1 of corresponding described false peaks;
False peaks processing module, for reducing the amplitude of related power corresponding to described false peaks, the value of described reduction is 1/4 of described real peak value related power amplitude; And described in mark, real peak value is processed.
Preferably, also comprise:
Upgrade Neighboring Cell List module, for inquiring about Neighboring Cell List, whether have the described adjacent area CellID getting, if there is no, upgrade described Neighboring Cell List; If exist, do not upgrade.
Known via above-mentioned technical scheme, compared with prior art, the invention discloses a kind of adjacent area searching method and device of LTE system.The digital signal in carrying out adjacent area search, processing reception signal being obtained is carried out SSS detection, in detecting, this SSS obtains the related power of digital signal on frequency domain, successively corresponding peak value and the default thresholding of described related power compared, and determine according to comparative result the real peak value that related power is corresponding, and the Nid1 that calculates the corresponding false peaks of Nid1 corresponding to real peak value, and related power corresponding to ghost peak carried out to range of decrease processing, until relatively finish, calculate and obtain adjacent area Nid1 corresponding to definite real peak value and front and back 5ms sign; Finally by PSS, detect definite Nid2 and 5ms regularly and SSS detects definite Nid1 and 5ms sign in front and back is calculated, obtain Cell ID and the frame timing of adjacent area.By above-mentioned, SSS related power is carried out to threshold judgement, and definite false peaks is carried out to range of decrease processing, can be reduced in the probability that occurs false community in the process of searching for adjacent area, improve the probability of accurate searching neighboring area.
Accompanying drawing explanation
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, to the accompanying drawing of required use in embodiment or description of the Prior Art be briefly described below, apparently, accompanying drawing in the following describes is only embodiments of the invention, for those of ordinary skills, do not paying under the prerequisite of creative work, other accompanying drawing can also be provided according to the accompanying drawing providing.
Fig. 1 is the time-domain position schematic diagram of PSS and SSS under tdd mode in prior art;
Fig. 2 be in prior art two eNodeB to the identical schematic diagram of UE distance;
Fig. 3 is that before using during Nid1=65 in prior art, 5ms makees the related power schematic diagram of SSS when relevant;
Fig. 4 is that after using during Nid1=65 in prior art, 5ms makees the related power schematic diagram of SSS when relevant;
Fig. 5 is the method flow diagram of the adjacent area search of the disclosed a kind of LTE system of the embodiment of the present invention;
Fig. 6 is the disclosed SSS overhaul flow chart of the embodiment of the present invention;
Fig. 7 is the disclosed SSS related power of embodiment of the present invention schematic diagram;
Fig. 8 is that the embodiment of the present invention is disclosed through processing for the first time false peaks SSS related power schematic diagram afterwards;
Fig. 9 is that the embodiment of the present invention is disclosed through processing for the second time false peaks SSS related power schematic diagram afterwards;
Figure 10 is the device block diagram of the adjacent area search of the disclosed a kind of LTE system of the embodiment of the present invention;
Figure 11 is the block diagram of the disclosed SSS detection module of the embodiment of the present invention;
Figure 12 is disclosed Nid1 and m in the embodiment of the present invention
0, m
1corresponding relation.
Embodiment
For quote and know for the purpose of, the explanation of the technical term hereinafter using, write a Chinese character in simplified form or abridge and be summarized as follows:
LTE:Long Term Evolution system, long evolving system;
PSS:Primary Synchronization Signal, main synchronizing symbol;
SSS:Secondary Synchronization Signal, auxiliary synchronous signals;
ADC:Analog-to-Digital Converter, A/D converter;
LPF:Low Pass Filter, low pass filter;
FFT:Fast Fourier Transformation, fast Fourier transform;
Nid1: cell set ID;
Nid2: ID in cell set;
Ms: millisecond, chronomere;
Cell ID: cell ID or Cell Identity CI.
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, rather than whole embodiment.Embodiment based in the present invention, those of ordinary skills, not making the every other embodiment obtaining under creative work prerequisite, belong to the scope of protection of the invention.
From background technology, the false peaks of can being correlated with out in the process detecting at the SSS that carries out adjacent area search, and corresponding false peaks searches out Jia community and will affect the search of normal adjacent area when carrying out adjacent area search, causes inaccurate to adjacent area search.Therefore the embodiment of the invention discloses adjacent area searching method and the device in a kind of LTE system, by the false peaks occurring during SSS is detected, carry out range of decrease processing, avoid searching the corresponding Jia of false peaks community, thereby realize in the process that is reduced in adjacent area search, there is the probability of false community, and the object that improves the probability of accurate searching neighboring area.Particular content is elaborated by following examples.
Embodiment mono-
Refer to accompanying drawing 5, the method flow diagram for the present invention discloses a kind of adjacent area search of LTE system, mainly comprises the following steps:
Step S101, receives signal and processes, and obtains corresponding digital signal.
In the process of execution step S101, first to the received signal process, obtain required baseband signal, and then the baseband signal getting is carried out to sample quantization and analog-to-digital processing, finally obtain output, the corresponding digital signal that receives signal, and utilize this digital signal to carry out following PSS detection and SSS and detect.
Step S102, carries out PSS detection to described digital signal, and the related power in time domain is determined the Nid2 of adjacent area and 5ms regularly according to the described digital signal obtained.
In the process of execution step S102, in time domain, utilize 3 local sequences of local PSS symbols carry, be that PSC sequence is slided relevant to the digital signal receiving, the correlated results that utilization gets carries out the calculating of related power, and the related power getting according to calculating averages the calculating of relevant cumulative power, and determine the Nid2 of adjacent area and 5ms regularly according to related power.
Step S103, described digital signal is carried out to SSS detection, obtain the related power of described digital signal on frequency domain, and the corresponding peak value of described related power and default thresholding are compared, according to comparative result, determine the Nid1 of corresponding real peak value, and calculate the Nid1 of the corresponding false peaks of Nid1 corresponding to described real peak value, and related power corresponding to described false peaks carried out to range of decrease processing, until relatively finish, calculate and obtain Nid1 and the front and back 5ms sign of the corresponding adjacent area of real peak value.
In the process of execution step S103, in frequency domain, (this SSC code is interweaved and is in series by the binary sequence of 2 31 length to utilize 168 SSC codes of SSS symbols carry, co-exist in 336 kinds of possible sequential structures), carry out related calculation with the digital signal receiving, and utilize the correlated results getting to calculate related power.And utilize the related power getting to determine Nid1 and the front and back 5ms sign of adjacent area.
Known in background technology, in carrying out the process of correlation computations, except autocorrelation peak, the SSC corresponding to other Nid1 is relevant can go out to serve false correlation peak.Therefore, in the process of execution step S103, the peak value that the related power getting is corresponding compares with default thresholding the Nid1 that determines corresponding real peak value, and calculate the Nid1 of the corresponding false peaks of Nid1 corresponding to described real peak value, and related power corresponding to described false peaks carried out to range of decrease processing, so that reduce the impact that it detects other adjacent areas, finally determine the Nid1 of the adjacent area that real peak value is corresponding.
It should be noted that, the process comparing in this step is a cyclic process, obtain after the related power of described digital signal on frequency domain, choosing peak-peak and the default thresholding that related power is corresponding compares, be met the Nid1 corresponding to current peak-peak of threshold condition, obtain being greater than the Nid1 corresponding to peak-peak of default thresholding, this peak-peak is designated as to real peak value, and the Nid1 of the corresponding false peaks of Nid1 corresponding to this real peak value of calculative determination, and these false peaks of determining are done to the range of decrease and process, reduce the amplitude of its corresponding related power.Then enter circulation, again compare, choosing the untreated peak value that related power is corresponding compares with default thresholding again, be met the Nid1 corresponding to second largest peak value of threshold condition, this peak value is designated as to real peak value, calculate the Nid1 of the corresponding ghost peak of this Nid1, and these ghost peaks are done to the range of decrease and process.The like, until there is no to meet the peak value of default thresholding.Finally calculate and obtain adjacent area Nid1 corresponding to these definite real peak values and front and back 5ms sign.
In addition, this default thresholding can be set according to concrete scene, preferably in situation, may be selected to be 10, that is to say that default related power threshold value is 10, and as shown in Figures 3 and 4, the default thresholding 10 of this setting corresponds to the peak value of related power.
Step S104, detects definite adjacent area Nid2 and 5ms timing according to described PSS, and described SSS detects adjacent area Nid1 corresponding to definite real peak value and 5ms sign in front and back is calculated, and obtains cell ID Cell ID and the frame timing of adjacent area.
In the process of execution step S104, according to formula (3), utilize PSS to detect definite adjacent area Nid2, and SSS detect adjacent area Nid1 corresponding to definite real peak value, can determine the community Cell ID of current searched for adjacent area.While is detected definite 5ms regularly according to PSS and SSS detects the frame timing that definite front and back 5ms sign can be determined current searched for adjacent area.
ID＝Nid1*3+Nid2 (3)
Wherein, Nid1 detects and determines via SSS; Nid2 detects and determines via PSS; ID is the community Cell ID of current searched for adjacent area.
The false peaks occurring when relevant in the process that SSS detects is by the way carried out range of decrease operation, its corresponding related power is positioned under default thresholding, so that reduce the probability that searches the corresponding Jia of false peaks community, further be reduced in the probability that occurs false community in the process of searching for adjacent area, realize the object of the probability that improves accurate searching neighboring area.
Embodiment bis-
On the basis of the disclosed embodiment of the invention described above, this embodiment disclosed in this invention carries out SSS detection to above-mentioned, and the process of calculating and obtain adjacent area Nid1 corresponding to definite real peak value and front and back 5ms sign is elaborated.
As shown in Figure 6, mainly comprise the following steps:
Step S201, is FFT to the SSS symbol getting in digital signal, obtains the frequency-region signal of described SSS symbol.
Step S202, extracts the subcarrier of corresponding described SSS symbol in described frequency-region signal.
In the process of execution step S201 and step S202, on frequency domain, the SSS symbol in the digital signal receiving is done to FFT conversion, to obtain the frequency-region signal that this SSS symbol is corresponding, and then from the frequency-region signal getting, extract subcarrier SSS_Sc (the i) (i=0 that SSS symbol is corresponding, ..., 61).Wherein the value of i is relevant with the binary sequence length of the SSC code of SSS symbols carry.
Step S203, utilizes each local sequence of described SSS symbol respectively described subcarrier to be done relevant, obtains the corresponding correlated results of local sequence described in each.
In execution step S203, utilize local sequence Local_SSS (m, the i) (m=0 of 168 SSS symbols, ..., 167, i=0, ..., 61) carry out related calculation according to formula (4) with the SSS subcarrier of step S202 extraction respectively, obtain 168 correlated results.
Wherein, m=0 ..., the value of 167, m is relevant with the local sequence number of SSS symbol; I=0 ..., 61 is relevant with the binary sequence that forms local sequence.
Step S204, calculates related power corresponding to correlated results described in each, chooses from large to small the peak value corresponding to related power of preset number.
In the process of execution step S204, utilize formula (5) to carry out the calculating of related power to get in step S203 168 correlated results.
SSS_Corr_Power(m)＝||SSS_Corr_Result(m)||
2 (5)
Step S205, judges whether each peak value is greater than default thresholding from large to small, and determines adjacent area cell set ID Nid1 according to judged result.
In the process of execution step S205, as shown in Figure 6, mainly comprise the following steps:
Step S2051, chooses current untreated peak-peak, judges that whether described untreated peak-peak is greater than default thresholding, if so, performs step S2052; If not, perform step S2056.
Step S2052, determines that described untreated peak-peak is real peak value, determines that the peak value that comprises identical binary sequence in the local sequence of using with described untreated peak-peak while being correlated with is false peaks.
In the process of execution step S2052, referring to the Nid1 in accompanying drawing 12 and m
0, m
1mapping table, be specially determining when relevant, use the m in local sequence
0the m comprising in the local sequence of using with described untreated peak-peak
0identical peak value is false peaks.
Or, use the m in local sequence
1the m comprising in the local sequence of using with described untreated peak-peak
1identical peak value is false peaks.
Step S2053, calculates and obtains Nid1 corresponding to described real peak value, and Nid1 corresponding to corresponding described false peaks.
Step S2054, reduces the amplitude of related power corresponding to described false peaks, and the value of described reduction is 1/4 of described real peak value related power amplitude.
Step S2055, real peak value is processed described in mark, returns to execution step S2051.
Step S2056, calculates and obtains Nid1 and the front and back 5ms sign of adjacent area corresponding to described real peak value according to the Nid1 of the described real peak value of determining.
For the above-mentioned process of carrying out SSS detection of clearer description, with concrete data, be illustrated here.
If UE is You Liangge community around, Cell Id is respectively 121 (Nid1=40, Nid2=1) and 196 (Nid1=65, Nid2=1), and Zhe Liangge community is identical to the timing of UE, power difference 6dB.
As shown in Figure 7, be the relevant related power of front 5ms for SSS.As seen from Figure 7, the peak power that Nid1=40 is corresponding is maximum, the false peaks that the peak power that Nid1=65 is corresponding is introduced lower than Nid1=40.If while now adopting the mode of prior art to carry out the judgement of true and false peak value, will be difficult to detect this community of Nid1=65, or false community can be detected.
Therefore adopt the invention described above disclosed step S2051～step S2056 to search and false peaks is processed.
Execution step S2051, first judges in untreated peak value, whether peak-peak is greater than threshold condition.In this embodiment, getting default thresholding is 10, but is not limited in this.As shown in Figure 7, in untreated peak value, peak-peak is the peak value that Nid1=40 is corresponding, meets and is greater than default this Rule of judgment of thresholding.
Secondly, execution step S2052, by looking into the Nid1 shown in accompanying drawing 12 and m
0, m
1mapping table, the Nid1 of known this untreated peak-peak is 40, corresponding its Nid1 of false peaks is (10,69,97,124,150).
At execution step S2053, calculate Nid1 that this peak value is corresponding and the Nid1 of corresponding ghost peak.
After determining false peaks, each false peaks is processed according to formula (6),
SSS_Corr_Power(f)＝SSS_Corr_Power(f)-SSS_Corr_Power(r)/4 (6)
It should be noted that, if SSS_Corr_Power (f) is less than 0, SSS_Corr_Power (f) is set to 0.
Wherein, f is Nid1 corresponding to false peaks, and r is the Nid1 that this peak value is corresponding.
At execution step S2055, the corresponding peak value of Nid1=40 is labeled as processed.And then carry out the processing of next untreated peak-peak.
As shown in Figure 8, for above-mentioned false peaks, process SSS related power afterwards, as seen from the figure, the false peaks that Nid1=40 introduces is removed, and the peak value that Nid1=65 is corresponding has become second largest peak value.And then by iteration, carry out above-mentioned steps S2051～step S2055 again.
When carrying out for the second time iteration, in the untreated peak value finding, peak-peak is the peak value that Nid1=65 is corresponding, and it also meets default this condition of thresholding that is greater than, and through the Nid1 of known its corresponding false peaks of tabling look-up, is (6,36,93,120,146).And then utilize formula (6) to carry out the processing of false peaks, and it processes SSS related power afterwards as shown in Figure 9, from scheming, can find out, and the false peaks that Nid1=65 introduces is removed.Carrying out next iteration successively.
In disclosed embodiment of this invention, through after above-mentioned 2 iteration, in untreated peak value, do not had to meet the peak value that is greater than default this condition of thresholding, iteration finishes.Iterate to until find the Nid1 of all adjacent areas, and remove corresponding false peaks, finally perform step S2056, calculate and obtain adjacent area Nid1 corresponding to definite real peak value and front and back 5ms sign.
In conjunction with said process, determine Nid1 and the front and back 5ms sign of adjacent area, and in above-described embodiment one, openly carry out Nid2 and 5ms timing that PSS detects the adjacent area getting, according to formula (3), obtain cell ID Cell ID and the frame timing of adjacent area.
Disclosed embodiment of this invention, the false peaks occurring when relevant in the process that SSS detects is by the way carried out range of decrease operation, its corresponding related power is positioned under default thresholding, so that reduce the probability that searches the corresponding Jia of false peaks community, further be reduced in the probability that occurs false community in the process of searching for adjacent area, realize the object of the probability that improves accurate searching neighboring area.
Embodiment tri-
On the basis of the invention described above embodiment mono-and embodiment bis-disclosed methods, after getting the cell ID Cell ID and frame timing of adjacent area, also comprise:
In inquiry Neighboring Cell List, whether there is the described adjacent area Cell ID getting, if there is no, upgrade described Neighboring Cell List; If exist, do not upgrade.
In carrying out said process, carry out PSS detection identical with the process in above-described embodiment one and embodiment bis-with the process that SSS detects, therefore no longer repeat here, can cross-references.
In the disclosed embodiment of the invention described above, describe a kind of method of adjacent area detection of LTE system in detail, for method of the present invention, can adopt the device of various ways to realize, therefore the invention also discloses a kind of adjacent area checkout gear of LTE system, provide specific embodiment below and be elaborated.
As shown in figure 10, the device for the adjacent area of the disclosed a kind of LTE system of the embodiment of the present invention is detected, mainly comprises: front-end processing module 101, PSS detection module 102, SSS detection module 103, adjacent area search module 104 and renewal Neighboring Cell List module 105.
Front-end processing module 101, for receiving signal and processing, obtains corresponding digital signal.
PSS detection module 102, for described digital signal is carried out to PSS detection, and the related power in time domain is determined the Nid2 of adjacent area and 5ms regularly according to the described digital signal obtained.
SSS detection module 103, for described digital signal is carried out to SSS detection, obtain the related power of described digital signal on frequency domain, peak value and default thresholding that described related power is corresponding compare, and determine corresponding real peak value according to comparative result, and the Nid1 that calculates the corresponding false peaks of Nid1 corresponding to real peak value, and related power corresponding to ghost peak carried out to range of decrease processing, until relatively finish, calculate and obtain adjacent area Nid1 corresponding to definite real peak value and front and back 5ms sign.
Adjacent area search module 104, for detecting definite adjacent area Nid2 and 5ms according to described PSS regularly, and described SSS detects adjacent area Nid1 corresponding to definite real peak value and 5ms sign in front and back is calculated, and obtains cell ID Cell ID and the frame timing of adjacent area.
Upgrade Neighboring Cell List module 105, for inquiring about Neighboring Cell List, whether have the described adjacent area Cell ID getting, if there is no, upgrade described Neighboring Cell List; If exist, do not upgrade.
Because the implementation of above-mentioned modules is identical with process in the invention described above the disclosed embodiments, repeat no longer more here, can be corresponding carry out reference.
Above-mentioned disclosed SSS detection module 103, as shown in figure 11, it mainly comprises: FFT module 201, extraction SSS sub-carrier block 202, SSS correlation module 203, related power computing module 204 and SSS peak value processing module 205.
FFT module 201, does fast Fourier transform to the SSS getting, and obtains the frequency-region signal of described SSS symbol.
Extract SSS sub-carrier block 202, for extracting the subcarrier of the corresponding described SSS symbol of described frequency-region signal.
SSS correlation module 203, relevant for utilizing each local sequence of described SSS symbol respectively described subcarrier to be done, obtain the corresponding correlated results of local sequence described in each.
Related power computing module 204, for calculating related power corresponding to correlated results described in each, chooses the peak value corresponding to related power of preset number from large to small.
SSS peak value processing module 205, for judging from large to small whether each peak value is greater than default thresholding, and determines the Nid1 of adjacent area according to judged result.
In this SSS peak value processing module 205, mainly comprise: threshold judgement module 2051, peak value computing module 2052 and false peaks processing module 2053.
Threshold judgement module 2051, be used for choosing current untreated peak-peak, when described untreated peak-peak is greater than default thresholding, determine that described untreated peak-peak is real peak value, determine that the peak value that comprises identical binary sequence in the local sequence of using with described untreated peak-peak while being correlated with is false peaks; When described untreated peak-peak is not more than default thresholding, finish, obtain Nid1 and the front and back 5ms sign of adjacent area.
Peak value computing module 2052, for calculating and obtain Nid1 corresponding to described real peak value, and the Nid1 of corresponding described false peaks.
False peaks processing module 2053, for reducing the amplitude of related power corresponding to described false peaks, the value of described reduction is 1/4 of described real peak value related power amplitude; And described in mark, real peak value is processed.
Equally, the concrete implementation of above-mentioned modules, can, referring to the corresponding part in above-described embodiment two, therefore, no longer repeat here.
In sum:
By the invention described above the disclosed embodiments, in the process that SSS detects, occur that false peaks carries out range of decrease operation when relevant, its corresponding related power is positioned under default thresholding, so that reduce the probability that searches the corresponding Jia of false peaks community, further be reduced in the probability that occurs false community in the process of searching for adjacent area, realize the object of the probability that improves accurate searching neighboring area.
In this specification, each embodiment adopts the mode of going forward one by one to describe, and each embodiment stresses is the difference with other embodiment, between each embodiment identical similar part mutually referring to.For the disclosed device of embodiment, because it corresponds to the method disclosed in Example, so description is fairly simple, relevant part partly illustrates referring to method.
The software module that the method for describing in conjunction with embodiment disclosed herein or the step of algorithm can directly use hardware, processor to carry out, or the combination of the two is implemented.Software module can be placed in the storage medium of any other form known in random asccess memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable ROM, register, hard disk, moveable magnetic disc, CD-ROM or technical field.
Above-mentioned explanation to the disclosed embodiments, makes professional and technical personnel in the field can realize or use the present invention.To the multiple modification of these embodiment, will be apparent for those skilled in the art, General Principle as defined herein can, in the situation that not departing from the spirit or scope of the present invention, realize in other embodiments.Therefore, the present invention will can not be restricted to these embodiment shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.
Claims (9)
1. an adjacent area searching method for Long Term Evolution LTE system, is characterized in that, comprising:
Receive signal and process, obtaining corresponding digital signal;
Described digital signal is carried out to main synchronizing symbol PSS and detect, and the related power in time domain is determined the Nid2 of adjacent area and 5ms frame regularly according to the described digital signal of obtaining;
Described digital signal is carried out to auxiliary synchronizing symbol SSS to be detected, obtain the related power of described digital signal on frequency domain, peak value and default thresholding that described related power is corresponding compare, and determine corresponding real peak value according to comparative result, and the Nid1 that calculates the corresponding false peaks of Nid1 corresponding to real peak value, and related power corresponding to ghost peak carried out to range of decrease processing, until relatively finish, calculate and obtain Nid1 corresponding to definite real peak value and front and back 5ms sign;
According to described PSS, detect Nid2 and the 5ms timing of definite adjacent area, and described SSS detects adjacent area Nid1 corresponding to definite real peak value and 5ms sign in front and back is calculated, obtain cell ID Cell ID and the frame timing of adjacent area.
2. method according to claim 1, is characterized in that, described digital signal is carried out to auxiliary synchronizing symbol SSS and detect, and the detailed process of calculating and obtain Nid1 corresponding to definite real peak value and front and back 5ms sign comprises:
The SSS symbol getting in digital signal is done to fast Fourier transform, obtain the frequency-region signal of described SSS symbol;
Extract the subcarrier of corresponding described SSS symbol in described frequency-region signal;
Utilize each local sequence of described SSS symbol respectively described subcarrier to be done relevant, obtain the corresponding correlated results of local sequence described in each;
Calculate related power corresponding to correlated results described in each, choose from large to small the peak value corresponding to related power of preset number;
Judge from large to small whether each peak value is greater than default thresholding, and according to judged result, determine the Nid1 of adjacent area.
3. method according to claim 2, is characterized in that, judges from large to small whether each peak value is greater than default thresholding, and determines that according to judged result the detailed process of adjacent area Nid1 is:
Choose current untreated peak-peak, when described untreated peak-peak is greater than default thresholding, described untreated peak-peak is designated as to real peak value, is designated as false peaks with the peak value that comprises identical binary sequence in the local sequence of described untreated peak-peak use when relevant;
Calculate and obtain Nid1 corresponding to described real peak value, and the Nid1 of corresponding described false peaks;
Reduce the amplitude of related power corresponding to described false peaks, the range value of described reduction be described real peak value related power amplitude 1/4;
Described in mark, real peak value is processed, returns to carry out and chooses current this step of untreated peak-peak, and choosing next peak value that is greater than described default thresholding is current peak-peak;
When described untreated peak value is all not more than default thresholding, finish comparison, calculate and obtain Nid1 and the front and back 5ms sign of the corresponding adjacent area of described real peak value.
4. according to the method described in any one in claim 1～3, it is characterized in that, after obtaining the cell ID Cell ID and frame timing of adjacent area, also comprise:
In inquiry Neighboring Cell List, whether there is the described adjacent area Cell ID getting, if there is no, upgrade described Neighboring Cell List; If exist, do not upgrade.
5. according to the method described in claim 2 or 3, it is characterized in that, described in each, local sequence is by being designated as respectively m
0and m
1the binary sequence of two 31 length interweave in series;
Determine while being correlated with, use the m in local sequence
0the m comprising in the local sequence of using with described untreated peak-peak
0identical peak value is false peaks;
Or, use the m in local sequence
1the m comprising in the local sequence of using with described untreated peak-peak
1identical peak value is false peaks.
6. an adjacent area checkout gear for Long Term Evolution LTE system, is characterized in that, comprising:
Front-end processing module, for receiving signal and processing, obtains corresponding digital signal;
Main synchronizing symbol PSS detection module, for described digital signal is carried out to PSS detection, and the related power in time domain is determined ID Nid2 and the timing of 5ms frame in the cell set of adjacent area according to the described digital signal of obtaining;
Auxiliary synchronizing symbol SSS detection module, for described digital signal is carried out to SSS detection, obtain the related power of described digital signal on frequency domain, peak value and default thresholding that described related power is corresponding compare, and determine corresponding real peak value according to comparative result, and the Nid1 that calculates the corresponding false peaks of Nid1 corresponding to real peak value, and related power corresponding to ghost peak carried out to range of decrease processing, until relatively finish, calculate and obtain Nid1 and the front and back 5ms sign of the corresponding adjacent area of described real peak value;
Adjacent area search module, for detecting definite adjacent area Nid2 and 5ms according to described PSS regularly, and described SSS detects adjacent area Nid1 corresponding to definite real peak value and 5ms sign in front and back is calculated, and obtains cell ID Cell ID and the frame timing of adjacent area.
7. device according to claim 6, is characterized in that, described auxiliary synchronizing symbol SSS detection module comprises:
Fast Fourier transform module, does fast Fourier transform to the SSS getting, and obtains the frequency-region signal of described SSS symbol;
Extract SSS sub-carrier block, for extracting the subcarrier of the corresponding described SSS symbol of described frequency-region signal;
SSS correlation module, relevant for utilizing each local sequence of described SSS symbol respectively described subcarrier to be done, obtain the corresponding correlated results of local sequence described in each;
Related power computing module, for calculating related power corresponding to correlated results described in each, chooses the peak value corresponding to related power of preset number from large to small;
SSS peak value processing module, for judging from large to small whether each peak value is greater than default thresholding, and determines the Nid1 of adjacent area according to judged result.
8. device according to claim 7, is characterized in that, described SSS peak value processing module comprises:
Threshold judgement module, be used for choosing current untreated peak-peak, when described untreated peak-peak is greater than default thresholding, determine that described untreated peak-peak is real peak value, determine that the peak value that comprises identical binary sequence in the local sequence of using with described untreated peak-peak while being correlated with is false peaks; When described untreated peak-peak is not more than default thresholding, finish, obtain Nid1 and the front and back 5ms sign of adjacent area;
Peak value computing module, for calculating and obtain Nid1 corresponding to described real peak value, and the Nid1 of corresponding described false peaks;
False peaks processing module, for reducing the amplitude of related power corresponding to described false peaks, the value of described reduction is 1/4 of described real peak value related power amplitude; And described in mark, real peak value is processed.
9. according to the device described in any one in claim 6～8, it is characterized in that, also comprise:
Upgrade Neighboring Cell List module, for inquiring about Neighboring Cell List, whether have the described adjacent area Cell ID getting, if there is no, upgrade described Neighboring Cell List; If exist, do not upgrade.
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| US9351176B2 (en) | 2012-01-09 | 2016-05-24 | Qualcomm Incorporated | Phase and amplitude tracking in the presence of a walking pilot signal |
| WO2014000264A1 (en) * | 2012-06-29 | 2014-01-03 | Qualcomm Incorporated | Td-scdma rscp measurement correlation |
| CN103856956B (en) * | 2012-11-29 | 2017-09-08 | 重庆重邮信科通信技术有限公司 | A kind of LTE system cell detecting method |
| CN105357721B (en) * | 2014-07-30 | 2019-07-12 | 联芯科技有限公司 | Neighbor cell detecting method and device |
| CN104093168B (en) * | 2014-07-31 | 2017-10-24 | 武汉邮电科学研究院 | A kind of LTE homogeneous-frequency adjacent-domains detection method and device |
| CN104378764B (en) * | 2014-09-17 | 2018-04-27 | 北京北方烽火科技有限公司 | A kind of LTE system co-frequency cell detection method and device |
| CN107333280B (en) * | 2016-04-29 | 2020-09-15 | 北京紫光展锐通信技术有限公司 | User terminal and method for detecting adjacent cell thereof |
| CN106452621B (en) | 2016-07-19 | 2018-03-06 | 创达特（苏州）科技有限责任公司 | A kind of peak power, the determination method and device of peak to average power ratio |
| CN110166393B (en) * | 2018-02-13 | 2021-06-25 | 展讯通信（上海）有限公司 | Method and device for sending and receiving synchronization signal block |
| US10334516B1 (en) * | 2018-03-13 | 2019-06-25 | Hong Kong Applied Science And Technology Research Institute Co., Ltd. | Cell search in a wireless network |
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