CN104243064B - A kind of spread spectrum TOA distance-finding method under non line of sight multi-path dense scene - Google Patents
A kind of spread spectrum TOA distance-finding method under non line of sight multi-path dense scene Download PDFInfo
- Publication number
- CN104243064B CN104243064B CN201410437925.2A CN201410437925A CN104243064B CN 104243064 B CN104243064 B CN 104243064B CN 201410437925 A CN201410437925 A CN 201410437925A CN 104243064 B CN104243064 B CN 104243064B
- Authority
- CN
- China
- Prior art keywords
- correlation function
- slip
- slip correlation
- peak
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Abstract
The present invention proposes the distance-finding method under a kind of indoor non line of sight multi-path dense scene based on the time of advent (Time of Arrival, TOA).Receiving terminal spread-spectrum signal is carried out slip relevant to former transmitting terminal spread-spectrum signal, obtain slip correlation function, slip correlation function carries out first path search and determines first footpath time delay, and then obtained testing distance by TOA range finding.In order to improve range accuracy, the decision threshold in first path search is optimized, have found the decision threshold of optimum, make average range error minimum.Measurement result shows, under typical indoor non line of sight scene, the first path search mean error of this method is less than 24.67ns, and average range error is less than 7.4m.
Description
Technical field
The invention belongs to signal detection and estimation technical field, particularly to the distance-finding method that a kind of time of advent is estimated.
Background technology
Indoor positioning technologies can realize the rapid location to personnel and article under the complex environments such as residential building, office building, library, underground garage, kinds of goods warehouse.Indoor positioning serves very important effect in the life and work and scientific research of people.The distance-finding method realizing being effective against under non line of sight (NonLineofSight, NLOS) indoor scene multipath effect is the primary condition realizing indoor positioning technologies.For sighting distance (LineofSight, LOS) path, receiving terminal can ask for first footpath signal by searching maximum diameter power signal, and then asks for time of arrival (toa) (TimeofArrival, TOA), obtains target range.But indoor NLOS environment exists multi-path dense, the peak power relevant peaks that a large amount of multipath signal superpositions obtain is not necessarily the relevant peaks at first signal place, footpath.This phenomenon causes that first footpath signal is difficult to extract, and TOA resultant error is bigger.Based on this background, the present invention proposes a kind of non line of sight multi-path dense scene spread spectrum TOA distance-finding method.First, it is relevant that receiving terminal spread-spectrum signal is carried out slip by application slip correlation technique to transmitting terminal spread-spectrum signal, obtains slip correlation function.Secondly, the first path search algorithm of design, slip correlation function is carried out first path search and obtains the TOA of first place, footpath relevant peaks.Finally, TOA is adopted to estimate testing distance.On this basis, in order to improve range accuracy, the decision threshold measured using in first path search by reality is optimized.
Spread spectrum range finding based on TOA is to utilize the correlation properties of frequency expansion sequence to calculate the spreading code propagation delay time in space, and then obtains the distance of objective body.Spread spectrum range finding has the advantages such as range accuracy height, good in anti-interference performance, strong adaptability.Spread spectrum distance-finding method based on TOA is currently mainly applied in navigator fix, satellite TT&C system.In range-measurement system, the mensuration adjusted the distance is exactly to the estimation and the tracking that arrive frequency expansion sequence and local frequency expansion sequence time difference.The specific works principle of spread spectrum range-measurement system: at transmitting terminal, information source, through spread spectrum and modulation, is launched by transmitter.Receiving terminal, signal processes through relevant grade, TOA algorithm for estimating obtain launching signal and receiving the delay inequality of signal, and then try to achieve the TOA time of advent, thus the distance calculated between target to be measured and transmitting terminal, complete range finding task.
TOA technology obtains the application of wide model owing to its algorithm is relatively easy and precision is higher.The TOA range-measurement systems such as GPS (GlobalPositionSystem) are mainly used in LOS scene, high-power los path is there is under this kind of scene, of substantially equal with first footpath time delay based on the time delay of maximum correlation peak in the correlation function that slip correlation technique obtains, range-measurement system has degree of precision.And under indoor NLOS scene, owing to there is multi-path dense, in relevant process of sliding, a lot of multi-path denses are a large amount of superpositions in same relevant peaks, causing that the maximum correlation peak time delay obtained by slip correlative measurement is not necessarily first footpath time delay, even maximum correlation peak is not necessarily the relevant peaks at first place, footpath.Existing document all adopts crest energy measuring that as the relevant peaks at first signal place, footpath, crest maximum for energy is obtained TOA.It has the drawback that, owing to there is intensive multipath under indoor NLOS, and a lot of multipaths a large amount of superpositions in same crest when being correlated with so that peak-peak is not necessarily first footpath signal, and range finding exists bigger error.In indoor NLOS range finding field, up to now, still there is no to be effective against the TOA distance-finding method of multi-path dense impact.
Summary of the invention
In order to overcome defect of the prior art, the present invention proposes the spread spectrum TOA distance-finding method under a kind of non line of sight NLOS multi-path dense scene, and the method can be effective against multi-path dense to the TOA impact estimated.
The present invention is achieved through the following technical solutions:
The spread spectrum distance-finding method time of advent under a kind of non line of sight multi-path dense scene, comprises the following steps:
A. spread spectrum range-measurement system launches spread-spectrum code signals, and after wireless channel propagation, receiver obtains and receives signal, to transmitting signal, receiving end signal is carried out slip relevant, obtains n slip correlation function；Here n slip correlation function be by n dual-mode antenna between the signal that receives launch signal to it and carry out slip and relevant obtain；
B., when channel measurement, measure the air line distance d between dual-mode antenna simultaneouslyi, 1≤i≤n, and then obtain precise delayWherein c is the light velocity；
C. decision threshold p is chosen；
D. for i-th slip correlation function, being found by all peak values of described slip correlation function waveform, note peak-peak is am；
E. first path search: obtained region of search D=(pa by decision threshold pm,am), namely by upper and lower two border a in described slip correlation functionm、pamThe one piece of bar-shaped zone determined；Finding all crests in D, the minimum peak value of time delay is designated as ap, apNamely the peak value of the relevant peaks at the signal place, first footpath that first path search obtains under decision threshold p, remembers apTime delay be τi；.
F. first path search error ei=τi-ξi, corresponding to different decision threshold p, mean error is
G. judgeWhether it is minima, ifIt not minima, then return to step c, again choose decision threshold p；IfBe minima, then now corresponding p is optimum decision thresholding, τiHeaded by footpath time delay；
H. according to τiObtain range measurement.
Accompanying drawing explanation
Fig. 1 is the slip correlated process schematic diagram of the spread spectrum TOA distance-finding method of the present invention；
Fig. 2 is typical case slip correlation function figure, and wherein first footpath is maximum peak；
Fig. 3 is typical case slip correlation function figure, and wherein first footpath is not maximum peak；
Fig. 4 is the first path search flow chart of the spread spectrum TOA distance-finding method of the present invention；
Fig. 5 is the first path search schematic diagram of the present invention, and wherein first footpath is at maximum peak；
Fig. 6 is the first path search schematic diagram of the present invention, and wherein first footpath is not at maximum peak；
Fig. 7 is the mean error figure of first path search under the different decision thresholds adopting the first path search method of the present invention to obtain.
Detailed description of the invention
Illustrate below in conjunction with accompanying drawing and detailed description of the invention the present invention is further described.
Owing to there is multi-path dense, in order to obtain TOA, it is necessary to ask for the time delay of first footpath signal.In spread spectrum range-measurement system, the spread-spectrum signal of transmitting terminal is usually the carrier wave modulated by spreading code, and spreading code (such as m-sequence) has good autocorrelation, and it is after wireless channel propagation, it is possible to determine propagation delay time according to its waveform correlation.Based on this principle, it is relevant that receiving end signal in spread spectrum range-measurement system is carried out slip by the present invention to former transmitting signal, extracts first footpath by slip correlation function.Relevant principle of sliding is, by the time different for the signal lag that receives, carries out matched filtering with former transmitting signal respectively, obtains the matching result of different delayed time, the slip correlation function namely obtained.Concrete slip correlated process is as shown in Figure 1.
The typical case obtained by above procedure slides correlation function waveform such as shown in accompanying drawing 2,3.By accompanying drawing 2,3 it can be seen that typical slip correlation function is to be made up of several relevant peaks.Owing to there is multipath effect, the crest of slip correlation function is actually being formed by stacking by multiple arrival footpath signal.Owing to, under indoor NLOS scene, there is multi-path dense in channel, the power of multipath and time delay are all random.Thus, the relevant peaks of peak power is not necessarily the relevant peaks at first place, footpath.Rational method must be adopted accurately to extract the relevant peaks at first signal place, footpath from slip correlation function.
The present invention adopt left and right difference point-score find slip relevant peaks, particularly as follows:
Certain point for slip correlation function curve, remember that its coordinate is (k, f (k)), the slip correlation function value that after moving to left a unit, this point is corresponding is f (k-1), the slip correlation function value that after moving to right a unit, this moment is corresponding is f (k+1), if having
Set up, then this point is slip correlation peak；If this formula is false, then this point is not slip correlation peak.
Traditional method thinks that maximum correlation peak is exactly the relevant peaks (such as accompanying drawing 2) at first place, footpath, multi-path dense component is there is yet with channel, multipath component is overlapped mutually the power causing that the power of first signal place, footpath relevant peaks is likely to be less than other multipath place relevant peaks, now first footpath is not in the maximum correlation peak of slip correlation function, utilizes the time delay of maximum correlation peak to carry out TOA and estimates to introduce very big error (such as accompanying drawing 3).Considering case above, the present invention proposes a kind of first path search method of NLOS multi-path dense scene spread spectrum TOA distance-finding method, and its flow chart as shown in Figure 4, comprises the steps:
1) being found by all peak values of slip correlation function waveform, note peak-peak is am, the maximum crest in accompanying drawing 2 is first crest, and now am=10-5.075。
2) determine decision threshold p (dB), p obtain region of search D=(pam,am), the one piece of bar-shaped zone namely determined by upper and lower two borders in slip correlation function.
3) finding all crests in D, the minimum peak value of time delay is designated as ap, apNamely the peak value of the relevant peaks at the signal place, first footpath that first path search obtains under decision threshold p, remembers apTime delay be τi。
4)τiNamely footpath time delay headed by.
The method is actually determines a region of search in slip correlation function waveform.I.e. region between two dotted lines in accompanying drawing 5,6.For not in the relevant peaks of region of search, noise jamming is serious, and signal power is sufficiently small, gives up these relevant peaks during judgement.For the relevant peaks in region of search, find the relevant peaks that wherein time delay is minimum, the relevant peaks at place, footpath headed by namely.
In accompanying drawing 5, as decision threshold p=-36.65dB, region of search ranges for (10-6.909,10-5.075).Figure has A1, B1, C1, D1, E1, F1, G1Totally 7 relevant peaks, and in region of search, only have A1, B1, G1Three relevant peaks, the minimum peak of time delay is A1, time delay is 100ns, and then the first footpath signal time delay that first path search obtains is 100ns.The slip correlation function head footpath signal time delay of accompanying drawing 5 is exactly the time delay of the maximum relevant peaks of peak value.
In accompanying drawing 6, as decision threshold p=-25.3dB, region of search scope (10-6.843,10-5.579).Figure has A2, B2, C2, D2, E2, F2Totally 6 relevant peaks, being positioned at region of search has A2, B2, C2, D2, F2Totally 5 relevant peaks, the minimum peak of time delay is A2Peak, time delay is 40ns, then the first footpath signal time delay that first path search obtains is 40ns.The slip correlation function head footpath signal time delay of accompanying drawing 6 is not the time delay of the maximum relevant peaks of peak value, otherwise varied with accompanying drawing 5.
After using first path search method to obtain TOA, by signal velocity, and then obtain testing distance.The precision of TOA directly determines range accuracy.
The first footpath that said method is found has higher precision.In order to improve first path search precision, it is necessary to decision threshold p is optimized, finds optimum decision threshold, make average search error be minimized, range accuracy is greatly improved.
The first path search method that the present invention adopts, has applied to decision threshold p, and for different p values, the effect of first path search is different.In order to improve the precision of first path search, it is necessary to all judging thresholds, use above-mentioned first path search method respectively, so that it is determined that an optimum decision threshold.
In order to obtain accurate first footpath time delay, when channel measurement, measure the air line distance d between dual-mode antenna simultaneouslyi(1≤i≤n), and then obtain precise delayWherein c is the light velocity.When this channel measurement, n takes 1440.
First path search error eiThe first footpath τ being in Fig. 2 slip correlation function and obtainingiWith precise delay ξiBetween difference ei=τi-ξi, corresponding to different decision threshold p, ask for the mean error of correspondence
Take and make formula (2)Reaching minimum decision threshold p, thresholding p now is the optimum decision thresholding that the present invention obtains.
In order to determine optimum decision thresholding, it is necessary to obtain sufficient amount of slip correlation function.For this, carry out typical indoor NLOS channel measurement, obtain 1440 channel sounding data, corresponding different channel datas, respectively transmitting terminal spread-spectrum signal is passed through channel, simulate reception signal, it is relevant to launching signal do slip to receive signal, after obtaining 1440 slip correlation functions, and the first path search method of the application present invention, obtain the mean error of first path search under different decision threshold, as shown in Figure 7.
As shown in Figure 7, there is a decision threshold so that first path search mean error reaches minimum, and this threshold value is-18.7dB, and first path search mean error now isRange finding mean error is 7.4m, it is achieved that the optimization of decision threshold.
The present invention proposes the spread spectrum TOA distance-finding method under a kind of non line of sight multi-path dense scene.Receiving terminal spread-spectrum signal is carried out slip relevant to former transmitting terminal spread-spectrum signal, obtain slip correlation function, slip correlation function carries out first path search and determines first footpath time delay, and then obtained testing distance by TOA range finding.In order to improve range accuracy, the decision threshold in first path search is optimized, have found the decision threshold of optimum, make average range error minimum.
Above content is in conjunction with concrete preferred implementation further description made for the present invention, it is impossible to assert that specific embodiment of the invention is confined to these explanations.For general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, it is also possible to make some simple deduction or replace, protection scope of the present invention all should be considered as belonging to.
Claims (3)
1. the spread spectrum distance-finding method time of advent under a non line of sight multi-path dense scene, it is characterised in that: said method comprising the steps of:
A. receiving end signal is carried out slip to transmitting signal relevant, obtain n slip correlation function；
B., when channel measurement, measure the air line distance d between dual-mode antenna simultaneouslyi, 1≤i≤n, and then obtain precise delayWherein c is the light velocity；
C. decision threshold p is chosen；
D. for i-th slip correlation function, being found by all peak values of described slip correlation function waveform, note peak-peak is am；
E. first path search: obtained region of search D=(pa by decision threshold pm,am), namely by upper and lower two border a in described slip correlation functionm、pamThe one piece of bar-shaped zone determined；Finding all crests in D, the minimum peak value of time delay is designated as ap, apNamely the peak value of the relevant peaks at the signal place, first footpath that first path search obtains under decision threshold p, remembers apTime delay be τi；
F. first path search error ei=τi-ξi, corresponding to different decision threshold p, mean error is
G. judgeWhether it is minima, ifIt not minima, then return to step c, again choose decision threshold p；IfBe minima, then now corresponding p is optimum decision thresholding, τiHeaded by footpath time delay；
H. according to τiObtain range measurement.
2. method according to claim 1, it is characterized in that: described step a is particularly as follows: spread spectrum range-measurement system launches spread-spectrum code signals, after wireless channel propagation, receiver obtains and receives signal, by the time different for the signal lag received, matched filtering is carried out respectively with former transmitting signal, obtain the matching result of different delayed time, be acquired slip correlation function.
3. method according to claim 1, it is characterised in that: described step d adopt left and right difference point-score find slip relevant peaks, particularly as follows:
Certain point for described slip correlation function curve, remember that its coordinate is (k, f (k)), the slip correlation function value that after moving to left a unit, this point is corresponding is f (k-1), the slip correlation function value that after moving to right a unit, this point is corresponding is f (k+1), if having
Set up, then this point is slip correlation peak；If this formula is false, then this point is not slip correlation peak.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410437925.2A CN104243064B (en) | 2014-08-29 | 2014-08-29 | A kind of spread spectrum TOA distance-finding method under non line of sight multi-path dense scene |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410437925.2A CN104243064B (en) | 2014-08-29 | 2014-08-29 | A kind of spread spectrum TOA distance-finding method under non line of sight multi-path dense scene |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104243064A CN104243064A (en) | 2014-12-24 |
| CN104243064B true CN104243064B (en) | 2016-07-06 |
Family
ID=52230499
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410437925.2A Active CN104243064B (en) | 2014-08-29 | 2014-08-29 | A kind of spread spectrum TOA distance-finding method under non line of sight multi-path dense scene |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104243064B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3255851B1 (en) | 2016-06-08 | 2019-08-07 | Nxp B.V. | Processing module for a communication device and method therefor |
| CN107959513B (en) * | 2016-10-13 | 2019-11-22 | 大唐移动通信设备有限公司 | A kind of method and apparatus that ranging is carried out using delay parameter |
| CN111381225B (en) * | 2020-04-09 | 2022-03-22 | 中国电子科技集团公司第二十八研究所 | High-precision civil aviation approach landing distance measurement system and method based on VDB system |
| CN114826331A (en) * | 2022-04-22 | 2022-07-29 | 青岛鼎信通讯股份有限公司 | Low-voltage line carrier communication signal multipath time delay characteristic test method |
| CN116299166B (en) * | 2023-05-24 | 2023-08-04 | 四川思凌科微电子有限公司 | Low-complexity fusion ranging method for chirp signals |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001281330A (en) * | 2000-03-30 | 2001-10-10 | Clarion Co Ltd | Spread spectrum communication distance measurement device |
| WO2007056662A2 (en) * | 2005-11-02 | 2007-05-18 | Sirf Technology, Inc. | System and method for detecting multipath effects in a gps receiver |
| CN101394233A (en) * | 2007-09-21 | 2009-03-25 | 哈尔滨工业大学深圳研究生院 | Pulse wideband multipath signal modeling method and system under indoor view distance environment |
| CN103118429A (en) * | 2013-03-12 | 2013-05-22 | 南京烽火星空通信发展有限公司 | WIFI (Wireless Fidelity) positioning method |
| CN103220781A (en) * | 2013-04-24 | 2013-07-24 | 哈尔滨工业大学深圳研究生院 | Method and system of locating wireless sensor network static target |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101135459B1 (en) * | 2010-09-13 | 2012-04-13 | 한국과학기술원 | Spread spectrum signal receiver, Method for multipath super-resolution thereof, and Recording medium thereof |
-
2014
- 2014-08-29 CN CN201410437925.2A patent/CN104243064B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001281330A (en) * | 2000-03-30 | 2001-10-10 | Clarion Co Ltd | Spread spectrum communication distance measurement device |
| WO2007056662A2 (en) * | 2005-11-02 | 2007-05-18 | Sirf Technology, Inc. | System and method for detecting multipath effects in a gps receiver |
| CN101394233A (en) * | 2007-09-21 | 2009-03-25 | 哈尔滨工业大学深圳研究生院 | Pulse wideband multipath signal modeling method and system under indoor view distance environment |
| CN103118429A (en) * | 2013-03-12 | 2013-05-22 | 南京烽火星空通信发展有限公司 | WIFI (Wireless Fidelity) positioning method |
| CN103220781A (en) * | 2013-04-24 | 2013-07-24 | 哈尔滨工业大学深圳研究生院 | Method and system of locating wireless sensor network static target |
Non-Patent Citations (4)
| Title |
|---|
| UWB脉冲信号室内空旷环境路径损耗特性研究;汪洋等;《哈尔滨工业大学学报》;20070128(第01期);73-76 * |
| 扩频测距系统中多径跟踪误差研究;王忠等;《系统工程与电子技术》;19990720(第07期);37-40 * |
| 时空调制扩频通信定位系统抗多径测角测距方法;史庭祥等;《应用科学学报》;20040620(第02期);136-139 * |
| 超声波扩频测距及其信道自适应均衡技术;潘仲明等;《国防科技大学学报》;20021225(第06期);95-98 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104243064A (en) | 2014-12-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104243064B (en) | A kind of spread spectrum TOA distance-finding method under non line of sight multi-path dense scene | |
| US8587478B1 (en) | Localization method of multiple jammers based on TDOA method | |
| CN103713277B (en) | A kind of radiation source localization method of position-based information field | |
| CN104181503A (en) | RSS-based LED positioning system and method | |
| CN101883426A (en) | Ultra-wideband wireless positioning method with high precision | |
| CN106488557A (en) | LDCC PDF based on WiFi signal is classified delay time estimation method | |
| CN104459624A (en) | Ultrasonic indoor positioning method based on time modulation | |
| CN103353597A (en) | Phase-type distance measuring method for ultrahigh frequency RFID (Radio Frequency Identification) positioning | |
| CN103308883B (en) | Arrival angle estimation method based on single antenna | |
| CN106017479B (en) | The three-dimensional real-time tracing method and system of indoor moving target | |
| CN106879068A (en) | The arrival time method of estimation of signal under a kind of strong multi-path environment | |
| CN102608573A (en) | Mutual-fuzzy-accumulation passive location method based on multiple observing points | |
| CN104459675A (en) | Ranging-based object positioning and tracking method and positioning equipment using method | |
| Fawky et al. | Novel pseudo-noise coded chipless RFID system for clutter removal and tag detection | |
| CN105553506A (en) | Fast acquisition method and device of long code spread spectrum signal | |
| Hao et al. | A method for improving UWB indoor positioning | |
| CN105974362A (en) | High-precision passive positioning method for jointly estimating signal parameter and position | |
| Svecova et al. | Object localization using round trip propagation time measurements | |
| CN106383333A (en) | Improved time delay estimation method based on mutual correlation | |
| Cimdins et al. | Modeling the magnitude and phase of multipath uwb signals for the use in passive localization | |
| Barua et al. | Indoor localization with UWB and 2.4 GHz bands | |
| Wu et al. | Optical CDMA-based wireless indoor positioning through time-of-arrival of light-emitting diodes | |
| CN1474196A (en) | High precision anti-multipath narrow band correlated distance detecting system in radio positioning | |
| Onalaja et al. | UWB based pre-localization algorithm for aiding target location in a multipath environment | |
| Mary et al. | Test measurements of improved UWB localization technique for precision automobile parking |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |