CN1753346A - Method of time sharing segment multipath searching - Google Patents
Method of time sharing segment multipath searching Download PDFInfo
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- CN1753346A CN1753346A CNA2004100830348A CN200410083034A CN1753346A CN 1753346 A CN1753346 A CN 1753346A CN A2004100830348 A CNA2004100830348 A CN A2004100830348A CN 200410083034 A CN200410083034 A CN 200410083034A CN 1753346 A CN1753346 A CN 1753346A
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Abstract
This invention discloses a time-sharing, segmented and multi-path search method for overcoming the loss of some paths resulted in the multi-path shift when the searching ability is not enough, the search sphere is greater than the search windows and the time-sharing and segmentation search is necessary. In searching, compensated search is done to solve the problem that some adjacent searching windows are laminated and the search sphere becomes narrow. The coherent search windows are laminated partly in the compensated search.
Description
Technical field
The present invention relates to the communications field, particularly the Multipath searching technology in the code division multiple access system.
Background technology
Along with the fast development of mobile communication business, the application of mobile data and multimedia communication will be more and more widely, in the near future, even will become the main business that mobile communication is carried above traditional speech.And traditional second generation global system for mobile communications (Global System for mobileCommunication, abbreviation " GSM ") mobile communications network can't adapt to this new development trend, for this reason, GSM will progressively carry out the transition to 3-G (Generation Three mobile communication system).Wherein, third generation partner program (3rd Generation Partnership Project, abbreviation " 3GPP ") Wideband Code Division Multiple Access (WCDMA) (the Wideband Code Division Multiple Access of institute's standard, be called for short " WCDMA ")/universal mobile telecommunications system (Universal Mobile Telecommunications System, be called for short " UMTS ") constantly improve and the mature technique standard with it, and flexible net framework, level and smooth evolution pattern, many advantages such as effective investment, and develop into the major technique of 3G (Third Generation) Moblie gradually, and accepted by increasing mobile communication carrier and equipment supplier.
The WCDMA/UMTS system comprises Radio Access Network (Radio Access Network is called for short " RAN ") and core network (Core Network is called for short " CN ") two large divisions.Mainly comprise two category nodes among the RAN: base station (Node B) and radio network controller (Radio NetworkController is called for short " RNC ").Node B is responsible for the transmitting-receiving and the bottom layer treatment of wireless signal, for example modulation, coding and decoding etc.RNC connects RAN and CN by the Iu interface, and the management of responsible on-air radio resource, for example, sends Cell Broadcast CB, distributes RAB between wireless channel, allocating cell parameter, managing mobile phone and the system or the like.
And CN mainly comprises (the Mobile Switching Center of mobile switching centre, be called for short " MSC "), Visited Location Registor (Visitor Location Register, be called for short " VLR "), attaching position register (Home Location Register, be called for short " HLR "), (the Gateway MSC of mobile gateway office, be called for short " GMSC "), GPRS serving GPRS support node (Serving GPRS SupportNode, be called for short " SGSN ") and gateway GPRS supporting node (GGSN) (GPRS GatewaySupport Node is called for short " GGSN ") etc.
In the WCDMA system, can extend the coverage of Node B by the repeater.Require little zone to adopt the repeater to cover for telephone traffic, can reduce network construction cost, accelerate the engineering construction progress, and help the reasonable utilization of Internet resources.The repeater is as a signal repeater, and on down direction, the repeater receives the signal of alms giver Node B, amplifies the back and is launched by user antenna; On up direction, the signal of user antenna receiving mobile is beamed back alms giver Node B again after the amplification, thereby finishes the reception and the amplification of uplink and downlink link radiofrequency signal.
Bring a variation behind the drawing-in system of repeater: the multipath variation increase that the travelling carriage wireless signal arrives Node B increases multipath signal, and multipath signal bring the gain of 3dB at least can for Node B.If this multipath signal with sufficient intensity is not discerned by Node B, will cause strong interference to system, reduce the Eb/IO value of signal, cause speech quality to descend, even call drop.Therefore must carry out the search of multipath signal, be called Multipath searching.
In the WCDMA system, Multipath searching is based on that the known pilot pattern of pilot bit searches for.Owing to run into difficulties such as device operational capability deficiency, processor can not carry out Multipath searching on the whole time period at present, i.e. search can not disposablely be finished, and can only carry out Multipath searching on limited scope, and this hunting zone is called search window.In some cases, if the hunting zone that need carry out exceeds the size of search window, need utilize the search window time sharing segment to search for.Method below in conjunction with accompanying drawing 1 explanation time sharing segment search multipath signal.
In the method for existing time sharing segment multipath searching, be N little equal portions at first with the whole scope division that needs to search for, each little equal portions is single search window length, what deserves to be explained is, and the hunting zone of a discontented search window is also as 1 little equal portions at last.Successively N five equilibrium scope carried out Multipath searching then, promptly finish and then carry out the i+1 time after the i time search and search for, until finishing the N time search.At last, the result that will search for is merged into once again, as the result of this extensive search, carries out subsequent processes.It more than is the current method of in a big way, carrying out time sharing segment multipath searching.
In actual applications, there is following problem in such scheme: to the capturing ability deficiency of multipath, may lose some multipath in the multipath when search.
Cause the main cause of this situation to be, existing technical scheme is carried out the time sharing segment search with the search window that the hunting zone is divided into a plurality of non-overlapping copies, because multipath can drift about, finish in the process that enters next search window a search window, some multipath may occur and in the search window scope that will enter, float in the firm search window scope of searching for, thereby cause losing of these multipaths.
Summary of the invention
In view of this, main purpose of the present invention is to provide a kind of method of time sharing segment multipath searching, makes that in the search capability deficiency hunting zone great-than search window and need time sharing segment when search can overcome losing of some multipath that the multipath drift causes.
For achieving the above object, the invention provides a kind of method of time sharing segment multipath searching, comprise following steps:
A is divided into a plurality of adjacent search window by the time sharing segment mode with the Multipath searching scope, and has the part scope overlapping between the described adjacent search window;
B searches for successively to described search window, seeks multipath signal;
C merges the Search Results of each described search window, draws total multi-path searching results.
Wherein, overlapping range size is determined according to the time delay of processor and the speed of multipath drift between the adjacent described search window.
When the time delay of described processor is 800ms, and the speed of the described multipath drift that drift constantly causes because subscriber equipment transmits is when being not more than 1 chip/800ms, and overlapping scope is 1 chip between the adjacent described search window.
Overlapping scope has amount of redundancy between the adjacent described search window.
Adjacent described search window is meant the search window of the i time search and the search window of the i+1 time search, and wherein, the afterbody of the search window of the i time search and the head of the i+1 time search window are overlapping.
For the first time the search window afterbody of the search window head of search and last search other described search window of getting along well is overlapping.
By relatively finding, technical scheme difference with the prior art of the present invention is, there is not lap between the search window of prior art scheme, the present invention program is when carrying out the time sharing segment search, the adjacency search window has the part scope overlapping, and, for since original search window between the overlapping hunting zone that causes narrow down, solve by compensating search, and corresponding search window also has the part scope overlapping in the compensation search.
Difference on this technical scheme, brought comparatively significantly beneficial effect, specifically, because in the method for the improved time sharing segment multipath searching of the present invention, adjacent search window has lap, like this when the multipath drift takes place, if the overlapping scope of search window is provided with appropriately, some multipath just can not occur and float to situation in the firm search window scope of searching in the search window scope that will enter, thereby some multipath loses when having avoided Multipath searching, improved the capturing ability of system, improved the performance of receiver in the code division multiple access system of knowing clearly greatly multipath signal.
Description of drawings
Fig. 1 is the schematic diagram according to existing time sharing segment search multipath signal method;
Fig. 2 is the method flow diagram of time sharing segment multipath searching according to an embodiment of the invention;
Fig. 3 is the schematic diagram of the improved time sharing segment search of use according to an embodiment of the invention multipath signal method.
Embodiment
For making the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in further detail below in conjunction with accompanying drawing.
Generally speaking, principle of the present invention is, in the process of the hunting zone being carried out the time sharing segment search, increases total searching times, promptly increases the number of search window, makes the search window of adjacent time sharing segment have the part scope to overlap.Wherein, the length of the part that overlaps is determined according to actual conditions, can be when guaranteeing that search window is switched owing to the multipath drift not cause some multipath to float in the firm search window scope of searching in the search window scope that will enter, thus losing of some multipath of causing by the multipath drift avoided.
The method of the improved time sharing segment multipath searching that the present invention propose is described below in conjunction with accompanying drawing 2.
At first, in step 101, whole Multipath searching scope is carried out segmentation, every segment length is a search window size, and the hunting zone of a discontented search window has the part scope overlapping also as a segmentation between the adjacent sectional at last, and the size of lap is τ.That is to say that the head of the search window that the afterbody of search window and the i+1 time of the i time search are searched for overlaps, its overlapping scope is τ.
The size that it is pointed out that overlapping scope τ is mainly by the processing delay T of processor and the speed decision of multipath drift.The processing delay T of processor is meant each segmentation limit is carried out the spent time of Multipath searching.The multipath drift velocity is meant the displacement of multipath signal in the unit interval.The multipath drift velocity can be by obtaining on the present 3GPP agreement, and it mainly comprises to the drift velocity of the x time of the transmitter of subscriber equipment (User Equipment is called for short " UE ") with to the speed of Node B.Yet, in actual applications, also need consider factors such as equipment variation itself or accident, therefore, what deserves to be explained is that the multipath drift velocity is an empirical value, need to add enough redundancies, application to routine can be benchmark with the drift velocity of UE transmitter generally, and its peak is 1chip/800ms.As a preferred embodiment of the present invention, the speed of supposing the multipath drift is no more than 1chip/800ms, and the processing delay of each search window is 800ms, then in the ideal case, only need twice search, 1 chip (chip) that overlaps mutually promptly can satisfy the needs of catching multipath, yet in actual applications, owing to be subjected to the influences such as phase change that Doppler frequency shift causes, can be corresponding as required adding redundant, for example τ can be made as 2 chip.
After the size according to the selected overlapping scope τ of mentioned above principle, even the multipath drift takes place, multipath signal can not be free on outside the overlapping scope certainly yet, so as long as the overlapping scope is carried out repeat search one time, just multipath can not occur and lose, thereby overcome the deficiencies in the prior art.
Yet, because search window overlaps mutually, causing the narrow range of the scope of N search than N search in the prior art, this need be by carrying out M compensation search again after N search.The searching times of compensation is by the size that overlaps and total searching times N decision, and the scope of overlapping is big more, and total searching times is many more, then needs the scope that compensates then long more; Otherwise then the scope of Jiao Dieing is more little, and total searching times is few more, then needs the scope that compensates also more little.M search of compensation also needs to do the mutual overlap operation of corresponding search window.As a preferred embodiment of the present invention, suppose that whole hunting zone is 500chip, a search window size is 20chip, the size of overlapping scope τ is 2chip.According to existing time sharing segment multipath searching method, need carry out 25 search successively.According to improved time sharing segment multipath searching method of the present invention, then need carry out 28 search, 3 times of wherein being added search needs to compensate search too.What deserves to be explained is that the head of the 1st search does not carry out overlap operation, the afterbody of searching for the last search after the compensation does not carry out overlap operation.
Certainly, some the time need not carry out M compensation search again, this is applicable to that usually whole hunting zone is less and needs the less situation of searching times.For example, suppose that whole hunting zone is 72chip, a search window size is 20chip, and the size of overlapping scope τ is 2chip.According to existing time sharing segment multipath searching method, need carry out 4 search successively; According to improved time sharing segment multipath searching method of the present invention, also only need carry out 4 search.Cause the reason of this situation to be, the hunting zone of a discontented search window also need once be searched at last, if the difference of a hunting zone that this is last and a search window is Δ,, then need not compensate search as long as the distance that N hunting zone of the present invention narrowed down is not more than Δ.
Then, enter step 102, all described search window are searched for the searching multipath signal successively.Specifically, be meant and after finishing the i time search, the i+1 time search carried out in next segmentation that wherein two segmentation overlay range size are τ, until the search of finishing whole hunting zone.
Enter step 103 at last, the Search Results of each search window is merged, draw total multi-path searching results.
Below in conjunction with accompanying drawing 3, the embodiment of utilization improved time sharing segment multipath searching method of the present invention is described.
As shown in the figure, suppose that whole hunting zone is 74chip, a search window size is 20chip, and the size that overlapping scope τ is set according to above-mentioned principle is 2chip.The 1st time the hunting zone is 1chip to the 20chip, and consuming time is T; Carry out the 2nd search then, the hunting zone is 19chip to the 38chip, and consuming time is T; Carry out the 3rd search then, the hunting zone is 37chip to the 56chip, and consuming time is T; Carry out the 4th search then, the hunting zone is 55chip to the 74chip, and consuming time is T.So far, finish search to gamut.Then mentioned above searching results is merged, draw total multi-path searching results.
Though by reference some preferred embodiment of the present invention, the present invention is illustrated and describes, but those of ordinary skill in the art should be understood that, can do various changes to it in the form and details, and the spirit and scope of the present invention that do not depart from appended claims and limited.
Claims (6)
1. the method for a time sharing segment multipath searching is characterized in that, comprises following steps:
A is divided into a plurality of adjacent search window by the time sharing segment mode with the Multipath searching scope, and has the part scope overlapping between the described adjacent search window;
B searches for successively to described search window, seeks multipath signal;
C merges the Search Results of each described search window, draws total multi-path searching results.
2. the method for time sharing segment multipath searching according to claim 1 is characterized in that, range size overlapping between the adjacent described search window is determined according to the time delay of processor and the speed of multipath drift.
3. the method for time sharing segment multipath searching according to claim 2, it is characterized in that, when the time delay of described processor is 800ms, and described because subscriber equipment transmits the speed of the multipath drift that drift constantly causes when being not more than 1 chip/800ms, and overlapping scope is 1 chip between the adjacent described search window.
4. the method for time sharing segment multipath searching according to claim 2 is characterized in that, overlapping scope has amount of redundancy between the adjacent described search window.
5. the method for time sharing segment multipath searching according to claim 1, it is characterized in that, adjacent described search window is meant the search window of the i time search and the search window of the i+1 time search, and wherein, the afterbody of the search window of the i time search and the head of the i+1 time search window are overlapping.
6. the method for time sharing segment multipath searching according to claim 1 is characterized in that, for the first time the search window afterbody of the search window head of search and last search other described search window of getting along well is overlapping.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200410083034A CN1753346B (en) | 2004-09-23 | 2004-09-23 | Method of time sharing segment multipath searching |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200410083034A CN1753346B (en) | 2004-09-23 | 2004-09-23 | Method of time sharing segment multipath searching |
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| CN1753346A true CN1753346A (en) | 2006-03-29 |
| CN1753346B CN1753346B (en) | 2010-05-12 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN200410083034A Expired - Fee Related CN1753346B (en) | 2004-09-23 | 2004-09-23 | Method of time sharing segment multipath searching |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011038605A1 (en) * | 2009-09-30 | 2011-04-07 | 中兴通讯股份有限公司 | Multi-path searching method and corresponding multi-path searcher in code division multiple access system |
| CN102655420A (en) * | 2011-03-02 | 2012-09-05 | 中兴通讯股份有限公司 | Subsection frequency domain method and device for realizing multi-diameter search |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3407711B2 (en) * | 2000-04-27 | 2003-05-19 | 日本電気株式会社 | Path search circuit in DS-CDMA receiver |
| GB2368238B (en) * | 2000-10-17 | 2004-04-14 | Ubinetics Ltd | A method of searching a code space |
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2004
- 2004-09-23 CN CN200410083034A patent/CN1753346B/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011038605A1 (en) * | 2009-09-30 | 2011-04-07 | 中兴通讯股份有限公司 | Multi-path searching method and corresponding multi-path searcher in code division multiple access system |
| CN102655420A (en) * | 2011-03-02 | 2012-09-05 | 中兴通讯股份有限公司 | Subsection frequency domain method and device for realizing multi-diameter search |
| WO2012116527A1 (en) * | 2011-03-02 | 2012-09-07 | 中兴通讯股份有限公司 | Segmented frequency domain method and device for realizing multi-path search |
| CN102655420B (en) * | 2011-03-02 | 2014-11-05 | 中兴通讯股份有限公司 | Subsection frequency domain method and device for realizing multi-diameter search |
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| Publication number | Publication date |
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| CN1753346B (en) | 2010-05-12 |
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Granted publication date: 20100512 Termination date: 20200923 |