CN102547570B - A kind of pseudorange difference location method and device - Google Patents

Abstract

The invention discloses a kind of pseudorange difference location method, belong to user positioning technology field.Described method comprises: choose calibration point, measures the coordinate of described calibration point and the TDOA value of correspondence in advance; Choose three described calibration points according to position to be positioned, obtain the TDOA value of described three calibration points, calculate corresponding TDOA non line of sight correction value; The TDOA non line of sight correction value of position to be positioned is calculated according to the TDOA non line of sight correction value of described three calibration points; According to coordinate figure and the TDOA non line of sight correction value calculating TDOA value of position to be positioned; Or according to TDOA value and the TDOA non line of sight correction value coordinates computed value of position to be positioned.The present invention can measure a small amount of calibration point in advance with larger distance interval, based on the TDOA value of calibration point, adopt pseudo range difference model virtual to produce the higher grid point characteristic information of density, while alleviating location non-market value, effectively reduce the collection capacity of gridding information.

Description

A kind of pseudorange difference location method and device

Technical field

The present invention relates to user positioning technology field, particularly a kind of pseudorange difference location method and device.

Background technology

Mobile terminal positioning service (LBS, LocationBasedService), be the mobile communications network by operator, obtain the positional information (latitude and longitude coordinates) of mobile subscriber, under the support of electronic map platform, for user provides respective service a kind of value-added service.Such as, this positioning service can find the current geographic position of cellphone subscriber, the title in hotel, movie theatre, library, gas station etc. then in the kilometer range of searching mobile phone user current position 1 and address.The platform of this service can cross over mobile terminal, website, call center, other mobile devices etc.Generally speaking LBS by the Internet or wireless network, between fixed-line subscriber and mobile subscriber, will complete location and service two large functions.

Existing wireless location method mainly contains information arrival time (TOA, TimeOfArrival) locate, the time of advent poor (TDOA, TimeDifferenceofArrival) location, the angle of arrival (AOA, AngleOfArrival) are located, based on architecture, mesh fitting location etc.

TOA localization method is mainly extrapolated the geographical coordinate at mobile terminal place to the distance of more than three or three base stations by mobile terminal.Concrete reckoning process is as follows: suppose that mobile terminal is R1, R2, R3 to the distance of base station BS 1, BS2, BS3, and according to positioning principle, mobile terminal one is positioned with base station BS i position for the center of circle, Ri be radius circumferentially.With position, three base stations for the center of circle, mobile terminal is that radius draws circle to three base station distance, then as shown below, then the intersection point of three circles is the position at mobile terminal place.Specifically can be shown in Figure 1.

Concrete equation in coordinates formula is as formula (1).

$\left\{\begin{array}{c}{R}_1=\sqrt{{(x_1-x)}^2+{(y_1-y)}^2}\\ R_2=\sqrt{{(x_2-x)}^2+{(y_2-y)}^2}\\ R_3=\sqrt{{(x_3-x)}^2+{(y_3-y)}^2}\end{array}\right.$ Formula (1)

Wherein xi, yi are base station coordinates, and x, y are mobile terminal coordinate.In actual radio localization method, arriving the time ti (TOA) of base station i by measuring the signal sent from destination mobile terminal, the distance R of target MS and base station can be obtained _i=c × t _i, wherein c is electromagnetic wave propagation velocity aloft, i.e. c=3 × 10 ⁸m/s, i=1,2,3, Simultaneous Equations, as shown in above-mentioned equation group, can obtain mobile terminal coordinate position (x, y).

TDOA location is identical with the general principle that TOA locates, and just simplifies some operands in the calculation, is more suitable for practical application.Formula (in 1) (R _i=c × t _i) be a desirable distance accounting equation, and actual measurement to pseudorange in also should there is the clock jitter Δ t of a receiver and base station, namely equation is expressed as ρ _i=R _i+ c Δ t (ρ _i=c × t _i).Mobile terminal is obtained R after the distance of base station BS 1 and BS2 is subtracted each other ₂₁=R ₂-R ₁, from geometric knowledge, terminal will be positioned at two base stations be focus, permanent in R with two focal lengths difference ₂₁a pair hyperbola on, as shown below.With reason R ₃₁=R ₃-R ₁can be obtained another to hyperbola.After two teams' hyperbolae intersect, intersection point is the position at mobile terminal place.Specifically refer to Fig. 2.

Concrete equation in coordinates formula is as formula (2).

$\left\{\begin{array}{c}{(\sqrt{{(x-x_2)}^2+{(y-y_2)}^2}-\sqrt{{(x-x_1)}^2+{(y-y_1)}^2})}^2=R_{21}^2\\ {(\sqrt{{(x-x_3)}^2+{(y-y_3)}^2}-\sqrt{{(x-x_1)}^2+{(y-y_1)}^2})}^2=R_{31}^2\end{array}\right.$ Formula (2)

Similar with TOA localization method, base station BS 1 and the range difference between base station BS 2 and travelling carriage can be drawn by measurement, namely by measuring the time difference t arriving mobile terminal from the signal while of two base stations ₂₁determine, or measure the time difference t from travelling carriage arrival two base stations ₂₁.Because above-mentioned equation both sides square, two solutions can be obtained after separating above-mentioned equation group, owing to only having a solution to represent the actual position of travelling carriage, therefore some prioris (as radius of society etc.) are needed to tell true solution, with deblurring degree (ambiguity solution).

AOA location is based on azimuth determination localization method, and the method is measured the incidence angle of travelling carriage emitting radio waves, thus forms a radial line from receiver to travelling carriage, i.e. rhumb line.Utilize the AOA measured value that two or more receivers provide, determine the intersection point of many rhumb line by AOA location algorithm, be the estimated position of travelling carriage to be positioned, as shown in Figure 3.

Suppose that the angle of arrival that base station BS 1 and BS2 record the signal that travelling carriage sends respectively is respectively θ 1 and θ 2, then formula (3) is set up.

$\tan \left({\mathrm{\θ}}_i\right)=\frac{x_0-x_i}{y_0-y_i},i=\mathrm{1,2}$ Formula (3)

By solving above-mentioned formula (3) nonlinear equation, location of mobile station (x0, y0) can be obtained.

In existing wireless location system, due to nonideal channel circumstance, make multipath transmisstion between travelling carriage and base station, non-line-of-sight propagation ubiquity; In a cdma network, also there is multi-access inference, these factors all can make the various signal characteristic measured values detected occur error, thus affect positioning precision.The error effect that in various error source, non-line-of-sight propagation causes is the most remarkable, especially in city proper, and the region of indoor radio propagation circumstance complication.

In geometry location method, it is the necessary condition obtaining signal characteristic measured value accurately that line-of-sight propagation (LOS, LineOfSight) is propagated.Gps system also propagates based on the LOS of electric wave the accurate location just achieved target just.But the cellular network area of coverage is generally city and the suburbs, also these regions just, the larger region of location requirement, realize LOS and propagate normally very difficult between travelling carriage and multiple base station; Even if when without multipath and have employed high accuracy Service of Timing, non-line-of-sight propagation (NLOS, NotLineOfSight) propagation also can cause TOA or TDOA measure error especially in the region of the propagation environment of radio wave complexity such as urban district, and this error will reach hundreds of rice.Therefore, NLOS propagate be main cause affect various positioning precision of cellular network, and how to reduce NLOS propagate the error caused just become raising positioning precision key.

Due to the CID (CellID-base station numbering) that each base station has it unique, when mobile terminal starts shooting networking at every turn, the information in engineering mode is stored in the specific region of mobile terminal internal memory.By architecture, obtain some parameters such as the CID in engineering mode by specific program exactly, and by corresponding with the area at place, base station for the CID object finally realizing mobile position estimation.Specific program mentioned here can be the JAVA program run on mobile terminals, and the important feature due to Java language can run in any operating system.In the last few years, there is the mobile terminal of many support JAVA, and made mobile terminal become a JVM (Java Virtual Machine).CID, LAC (LocationAreaCode local area code) in mobile terminal internal memory, CH (Channel channel number), TA (TimeAdvance time trail), RxL (signal receiving strength) and TxPwr (PowerLevel shows the power emission intensity of mobile terminal in call) is obtained by J2ME (Java2PlatformMicroEdition (Java2 Platform MicroEdition)) program.After obtaining these data, also need the support of a database.This database is corresponding between CID, LAC with concrete base station location, can investigate and prosecute corresponding base station location by CID, LAC in this database.Now, base station location just determines, but the location that distance realizes travelling carriage also has a certain distance.Now, need to use these values of CH, TA, RxL, TxPwr as parameter.Can be converted by TA and obtain the distance of travelling carriage distance base station; For the base station using directional antenna, can determine by CH the sector that travelling carriage is residing at present; And RxL, TxPwr are as auxiliary data, particular location is revised.Specifically refer to Fig. 4.

(wherein A is radio frequency signal attenuation coefficient to distance L=TA*500+RxL*A+TxPwr*B; B is transmitting power attenuation coefficient). so, just by mobile position estimation in a certain sector, a certain base station, and the distance of travelling carriage and base station is also rough has calculated.Thus, just can obtain the track residing for travelling carriage, namely in Fig. 4 shown in curve.If indicated on city map by Fig. 4, be easy to the position obtained residing for travelling carriage.Specifically refer to Fig. 5.

In prior art, also has a kind of mesh fitting localization method.Requirement according to positioning precision carries out stress and strain model to geographic area, record the coordinate at four summits place of each grid, by data acquisition, by the characteristic parameter (comprising TDOA, field intensity etc.) at each summit place and the coordinate one_to_one corresponding input database of this point.During location, the characteristic parameter immediately received by mobile terminal carries out similarity comparison respectively with four apex feature parameters of each grid in database, and the similarity on four summits is integrated into the similarity of a grid.Obtained the coordinate of mobile terminal by specific algorithm in the grid that similarity is maximum.The method needs to carry out a large amount of grid data collections and test, and workload is very big.

Realizing in process of the present invention, inventor finds that prior art at least exists following problem:

The existing localization method based on TDOA/TOA/AOA, because of by the factor such as non line of sight to affect position error comparatively large, especially in the radio propagation such as urban district, indoor complex environment, the impact of non line of sight factor on positioning precision is particularly evident.For solving non-market value, prior art adopts mesh fitting mode to position, grid is divided into by locating area, in advance collection apparatus (as TDOA value) positioned to different grid and store, when user locates, the location feature collected being mated with the grid search-engine data prestored, finding the immediate grid of location feature as locating the customer location obtained.In mesh fitting localization method, obtain high-precision positioning result need carry out a large amount of grid software test, and workload is too loaded down with trivial details.

Summary of the invention

In order to solve in existing localization method, positioning precision is not high, the problem that workload is loaded down with trivial details, embodiments provides a kind of pseudorange difference location method and device.Described technical scheme is as follows:

A kind of pseudorange difference location method, described method comprises:

Choose calibration point, measure the coordinate of described calibration point and the TDOA value of correspondence in advance;

Choose three described calibration points according to position to be positioned, obtain the TDOA value of described three calibration points, calculate corresponding TDOA non line of sight correction value;

The TDOA non line of sight correction value of position to be positioned is calculated according to the TDOA non line of sight correction value of described three calibration points;

According to coordinate figure and the TDOA non line of sight correction value calculating TDOA value of position to be positioned; Or according to TDOA value and the TDOA non line of sight correction value coordinates computed value of position to be positioned.

Describedly choose three described calibration points according to position to be positioned, obtain the TDOA value of described three calibration points, calculate corresponding TDOA non line of sight correction value, comprising:

Three described calibration point A, B, C are chosen according to position to be positioned;

Obtain n the TDOA value T respectively that described three calibration points A, B, C record _a1, T _a2... T _an; T _b1, T _b2... T _bn; T _c1, T _c2... T _cn;

According to formula

$N_{A1}=\sqrt{{(x_{\mathrm{1,1}}-x)}^2+{(y_{\mathrm{1,1}}-y)}^2+{(z_{\mathrm{1,1}}-z)}^2}-\sqrt{{(x_{\mathrm{1,2}}-x)}^2+{(y_{\mathrm{1,2}}-y)}^2+{(z_{\mathrm{1,2}}-z)}^2}-c\·T_{A1}$

$N_{A2}=\sqrt{{(x_{\mathrm{2,1}}-x)}^2+{(y_{\mathrm{2,1}}-y)}^2+{(z_{\mathrm{2,1}}-z)}^2}-\sqrt{{(x_{\mathrm{2,2}}-x)}^2+{(y_{\mathrm{2,2}}-y)}^2+{(z_{\mathrm{2,2}}-z)}^2}-c\·T_{A2}$

……

$N_{\mathrm{Cn}}=\sqrt{{(x_{n,1}-x)}^2+{(y_{n,1}-y)}^2+{(z_{n,1}-z)}^2}-\sqrt{{(x_{n,2}-x)}^2+{(y_{n,2}-y)}^2+{(z_{n,2}-z)}^2}-c\·T_{\mathrm{Cn}}$

Calculate corresponding TDOA non line of sight correction value N _a1, N _a2... N _an; N _b1, N _b2... N _bn; N _c1, N _c2... N _cn.

Described position to be positioned is grid point;

Describedly choose three described calibration point A, B, C according to position to be positioned, comprising:

Described three calibration points A, B, C meet following condition: the Delta Region that three calibration points surround comprises described grid point coordinate, and three calibration points are minimum to the Distance geometry of this grid point; Or, the central point in the region that described multiple grid point surrounds to three calibration points apart from minimum.

The described TDOA non line of sight correction value according to described three calibration points calculates the TDOA non line of sight correction value of position to be positioned, comprising:

According to the coordinate of described three calibration points A, B, C and the TDOA non line of sight correction value solution formula of correspondence

$\left\{\begin{array}{c}{a}_n\·x_A+b_n\·y_A+c_n=N_{\mathrm{An}}\\ a_n\·x_B+b_n\·y_B+c_n=N_{\mathrm{Bn}}\\ a_n\·x_C+b_n\·y_C+c_n=N_{\mathrm{Cn}}\end{array}\right.$

And formula N _n=a _nx+b _ny+c _nsimultaneous, calculates the TDOA non line of sight correction value N of position to be positioned ₁, N ₂... N _n.

The described coordinate figure according to position to be positioned and TDOA non line of sight correction value calculate TDOA value; Or according to TDOA value and the TDOA non line of sight correction value coordinates computed value of position to be positioned, comprising:

When described position to be positioned is grid point, according to formula

$T_1=(\sqrt{{(x_{\mathrm{1,1}}-x)}^2+{(y_{\mathrm{1,1}}-y)}^2+{(z_{\mathrm{1,1}}-z)}^2}-\sqrt{{(x_{\mathrm{1,2}}-x)}^2+{(y_{\mathrm{1,2}}-y)}^2+{(z_{\mathrm{1,2}}-z)}^2}-N_1)/c$

$T_2=\sqrt{{(x_{\mathrm{2,1}}-x)}^2+{(y_{\mathrm{2,1}}-y)}^2+{(z_{\mathrm{2,1}}-z)}^2}-\sqrt{{(x_{\mathrm{2,2}}-x)}^2+{(y_{\mathrm{2,2}}-y)}^2+{(z_{\mathrm{2,2}}-z)}^2}-N_2)/c$

……

$T_n=\sqrt{{(x_{n,1}-x)}^2+{(y_{n,1}-y)}^2+{(z_{n,1}-z)}^2}-\sqrt{{(x_{n,2}-x)}^2+{(y_{n,2}-y)}^2+{(z_{n,2}-z)}^2}-N_n)/c$

Coordinates computed is the TDOA value T of the grid point of (x, y) ₁, T ₂... T _n;

When described position to be positioned is customer location, be T according to above-mentioned formulae discovery TDOA value ₁, T ₂... T _ncorresponding coordinate (x, y).

The method also comprises:

When described position to be positioned is grid point, by described grid point coordinate and corresponding TDOA value T ₁, T ₂... T _nstore;

When user locates, by the TDOA value of customer location of mensuration and the TDOA value T of grid point ₁, T ₂... T _nmatch, determine customer location.

A kind of pseudorange difference positioner, this device comprises calibration point predicting unit, calibration point TDOA non line of sight correction value computing unit, position to be positioned non line of sight correction value computing unit and positioning result computing unit, wherein,

Described calibration point predicting unit, for choosing calibration point, and measures the coordinate of described calibration point and the TDOA value of correspondence in advance;

Described calibration point TDOA non line of sight correction value computing unit, for choosing three described calibration points according to position to be positioned, obtains the TDOA value of described three calibration points, calculates corresponding TDOA non line of sight correction value;

Described position to be positioned non line of sight correction value computing unit, for calculating the TDOA non line of sight correction value of position to be positioned according to the TDOA non line of sight correction value of described three calibration points;

Described positioning result computing unit, for calculating TDOA value according to the coordinate figure of position to be positioned and TDOA non line of sight correction value; Or according to TDOA value and the TDOA non line of sight correction value coordinates computed value of position to be positioned.

Described calibration point TDOA non line of sight correction value computing unit comprises calibration point further and chooses subelement, calibration point TDOA value acquisition subelement and a TDOA non line of sight correction value computation subunit, wherein,

Described calibration point chooses subelement, for choosing three described calibration points according to position to be positioned;

Described calibration point TDOA value obtains subelement, for obtaining n the TDOA value of described three calibration points A, B, C;

A described TDOA non line of sight correction value computation subunit, for calculating TDOA non line of sight correction value corresponding to described three calibration points A, B, C.

Described position to be positioned non line of sight correction value computing unit comprises linear interpolation calculation of parameter subelement and the 2nd TDOA non line of sight correction value computation subunit further, wherein,

Described linear interpolation calculation of parameter subelement, for according to the coordinate of described three calibration points A, B, C and the TDOA non line of sight correction value of correspondence, calculates line style difference parameter a _n, b _n, c _n;

Described 2nd TDOA non line of sight correction value computation subunit, for calculating the TDOA non line of sight correction value N of position to be positioned ₁, N ₂... N _n.

Described positioning result computing unit comprises grid point TDOA value computation subunit and customer location coordinate computation subunit further, wherein,

Described grid point TDOA value computation subunit, for the TDOA value T of coordinate (x, y) the computing grid point according to grid point ₁, T ₂... T _n;

Described customer location coordinate computation subunit, the TDOA value for obtaining according to test is T ₁, T ₂... T _ncomputed user locations coordinate (x, y).

The beneficial effect that the technical scheme that the embodiment of the present invention provides is brought is:

The embodiment of the present invention is by choosing a small amount of calibration point in advance and measuring the coordinate of calibration point and the TDOA value of correspondence, three suitable calibration points are chosen according to position to be positioned, calculate corresponding TDOA non line of sight correction value, the TDOA non line of sight correction value of position to be positioned is calculated according to the TDOA non line of sight correction value of calibration point, calculate corresponding TDOA value according to the coordinate that position to be positioned is known and preserve, or calculating corresponding coordinate according to the TDOA value measuring the position to be positioned obtained.The scheme that the embodiment of the present invention provides, a small amount of calibration point can be measured in advance with larger distance interval, based on the TDOA value of calibration point, pseudo range difference model virtual is adopted to produce the higher grid point characteristic information of density, while alleviating location non-market value, effectively reduce the collection capacity of gridding information.Or, corresponding accurate coordinate can be calculated by the TDOA value measuring the position to be positioned obtained.The scheme that the embodiment of the present invention provides, can effectively reduce the amount of calculation in user's position fixing process, accelerates the speed of user location, improves user experience.

Accompanying drawing explanation

In order to be illustrated more clearly in the technical scheme in the embodiment of the present invention, below the accompanying drawing used required in describing embodiment is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 is TOA localization method schematic diagram in prior art of the present invention;

Fig. 2 is TDOA localization method schematic diagram in prior art of the present invention;

Fig. 3 is AOA localization method schematic diagram in prior art of the present invention;

Fig. 4 is base station positioning method schematic diagram in prior art of the present invention;

Fig. 5 be in prior art of the present invention base station and map in conjunction with localization method schematic diagram;

Fig. 6 is the pseudorange difference location method principle flow chart that the embodiment of the present invention 1 provides;

Fig. 7 A is calibration point system of selection 1 schematic diagram that the embodiment of the present invention 1 provides;

Fig. 7 B is calibration point system of selection 2 schematic diagram that the embodiment of the present invention 1 provides;

Fig. 8 is the pseudorange difference positioning device structure schematic diagram that the embodiment of the present invention 4 provides;

Fig. 9 is calibration point TDOA non line of sight correction value computing unit 200 structural representation that the embodiment of the present invention 5 provides;

Figure 10 is position to be positioned non line of sight correction value computing unit 300 structural representation that the embodiment of the present invention 6 provides;

Figure 11 is positioning result computing unit 400 structural representation of the pseudorange difference positioner that the embodiment of the present invention 7 provides.

Embodiment

For making the object, technical solutions and advantages of the present invention clearly, below in conjunction with accompanying drawing, embodiment of the present invention is described further in detail.

The principle of the embodiment of the present invention is to choose a small amount of calibration point in advance and measures the coordinate of calibration point and the TDOA value of correspondence, three suitable calibration points are chosen according to position to be positioned, calculate corresponding TDOA non line of sight correction value, the TDOA non line of sight correction value of position to be positioned is calculated according to the TDOA non line of sight correction value of calibration point, calculate corresponding TDOA value according to the coordinate that position to be positioned is known and preserve, or calculating corresponding coordinate according to the TDOA value measuring the position to be positioned obtained.Here, divide into two kinds of modes realized.One is position to be positioned is grid point, and the coordinate of such grid point is known, can obtain TDOA value corresponding to grid point, the TDOA value of these grid points and coordinate information are together stored by the coordinate of grid point.When user location, compared with the TDOA value of the grid point prestored by the TDOA value of the customer location by mensuration, judge the grid at customer location place, carry out the coordinate of computed user locations according to the coordinate of grid point.In another kind of implementation, directly can measure the TDOA value of user location, then be calculated the elements of a fix of customer location by this TDOA value.

The scheme that the embodiment of the present invention provides, a small amount of calibration point can be measured in advance with larger distance interval, based on the TDOA value of calibration point, pseudo range difference model virtual is adopted to produce the higher grid point characteristic information of density, while alleviating location non-market value, effectively reduce the collection capacity of gridding information.Or, corresponding accurate coordinate can be calculated by the TDOA value measuring the position to be positioned obtained.The scheme that the embodiment of the present invention provides, can effectively reduce the amount of calculation in user's position fixing process, accelerates the speed of user location, improves user experience.

Embodiment 1

The embodiment of the present invention 1 provides a kind of pseudorange difference location method, and as shown in Figure 6, the method comprises the steps:

Step 10, chooses calibration point, measures the coordinate of calibration point and the TDOA value of correspondence in advance.

User location is the work of a system, and primary work to select a small amount of calibration point for the datum mark as locating area at whole locating area.Choosing of calibration point can be carried out according to the actual needs, according to the size of the workload that can bear, chooses the quantity of calibration point.

After selected calibration point, need to measure the coordinate of calibration point and the TDOA value of correspondence in advance.The mensuration of coordinate can be carried out according to localization methods such as GPS, and the mensuration of TDOA value needs to measure multiple TDOA value, and stores after being associated with corresponding multiple TDOA values by the coordinate of calibration point.

Step 20, chooses three calibration points according to position to be positioned, obtains the TDOA value of three calibration points, calculates corresponding TDOA non line of sight correction value.

Here, be divided into two kinds of implementations, in the first implementation, first network for location lattice point, namely position to be positioned is grid point.Here grid point, be according to actual needs region to be positioned is divided into multiple grid, each grid has 4 grid points.The create-rule of grid can be grid point equidistantly to distribute, also can carry out irregular division according to information such as indoor room coordinates.At this moment, need to choose three calibration points (due to when grid division, the coordinate of grid point can be obtained by locate modes such as GPS, and such as, on actual map, the coordinate in any place is all known) according to the coordinate of grid point.

The method choosing calibration point according to the coordinate of grid point is also divided into two kinds of modes, in first kind of way, three calibration points A, B, C meet following condition: the Delta Region that three calibration points surround comprises grid point coordinate, and three calibration points are minimum to the Distance geometry of this grid point.In the second way, the central point in the region that multiple grid point surrounds to three calibration points apart from minimum.As shown in Figure 6, in Fig. 7 A, grid point 1 to 4 is four points in a grid.Grid point 1,3,4 selects calibration point 1,2,4, and grid point 3 selects calibration point 1,3,4.In Fig. 7 B, grid point 1 to 4 all selects calibration point 1,2,4.

In the second implementation, position to be positioned is exactly directly the result of user location, like this, just can select three calibration points according to user position roughly.

After calibration point has been selected, three calibration points that setting is selected have been A, B, C, first will obtain n the TDOA value T respectively that three calibration points A, B, C record _a1, T _a2... T _an; T _b1, T _b2... T _bn; T _c1, T _c2... T _cn.Wherein, T _a1represent that what record at calibration point A is (x from coordinate _1,1, y _1,1, z _1,1) base station and coordinate be (x _1,2, y _1,2, z _1,2) the signal transmission delay of base station poor, other is by that analogy.Calculate corresponding TDOA non line of sight correction value N _a1, N _a2... N _an; N _b1, N _b2... N _bn; N _c1, N _c2... N _cn.Computing formula is as formula (4):

$N_{A1}=\sqrt{{(x_{\mathrm{1,1}}-x)}^2+{(y_{\mathrm{1,1}}-y)}^2+{(z_{\mathrm{1,1}}-z)}^2}-\sqrt{{(x_{\mathrm{1,2}}-x)}^2+{(y_{\mathrm{1,2}}-y)}^2+{(z_{\mathrm{1,2}}-z)}^2}-c\·T_{A1}$

$N_{A2}=\sqrt{{(x_{\mathrm{2,1}}-x)}^2+{(y_{\mathrm{2,1}}-y)}^2+{(z_{\mathrm{2,1}}-z)}^2}-\sqrt{{(x_{\mathrm{2,2}}-x)}^2+{(y_{\mathrm{2,2}}-y)}^2+{(z_{\mathrm{2,2}}-z)}^2}-c\·T_{A2}$ Formula (4)

……

$N_{\mathrm{Cn}}=\sqrt{{(x_{n,1}-x)}^2+{(y_{n,1}-y)}^2+{(z_{n,1}-z)}^2}-\sqrt{{(x_{n,2}-x)}^2+{(y_{n,2}-y)}^2+{(z_{n,2}-z)}^2}-c\·T_{\mathrm{Cn}}$

In formula (4), eliminate part formula, in fact, need here to calculate all N _a1, N _a2... N _ann _a3, N _b1, N _b2... N _bn, N _c1, N _c2... N _cnall values.C in formula is the light velocity.

Step 30, calculates the non line of sight correction value of position to be positioned according to the TDOA non line of sight correction value of three calibration points.

Here, according to step 20 calculate arrive three calibration points TDOA non line of sight correction value, line style differential technique can be adopted to calculate the non line of sight correction value of position to be positioned.Namely the non line of sight correction value solution formula (5) of the coordinate of calibration point A, B, C and correspondence is first utilized to obtain line style difference parameter a _n, b _n, c _n:

$\left\{\begin{array}{c}{a}_n\·x_A+b_n\·y_A+c_n=N_{\mathrm{An}}\\ a_n\·x_B+b_n\·y_B+c_n=N_{\mathrm{Bn}}\\ a_n\·x_C+b_n\·y_C+c_n=N_{\mathrm{Cn}}\end{array}\right.$ Formula (5)

Afterwards, two kinds of implementations are divided into equally, in a kind of mode, position to be positioned is grid point, and at this moment, the coordinate due to grid point is known, thus the coordinate (x, y) of grid point can be substituted into the non line of sight correction value N that formula (6) obtains grid point accurately ₁, N ₂... N _n.

N _n=a _nx+b _ny+c _nformula (6)

In another mode, position to be positioned is customer location, now, because customer location coordinate is unknown, is thus set to (x, y), substitutes into formula (6) equally, can obtain the non line of sight correction value N of this customer location ₁, N ₂... N _n, but this correction value is not also accurately, also needs further to calculate ability passable.

Step 40, the coordinate figure according to position to be positioned calculates TDOA value; Or according to the TDOA value coordinates computed value of position to be positioned.

In step 40, be divided into two kinds of implementations equally.When position to be positioned is grid point time, be the TDOA value T of the grid point of (x, y) according to formula (7) coordinates computed ₁, T ₂... T _n.

$T_1=(\sqrt{{(x_{\mathrm{1,1}}-x)}^2+{(y_{\mathrm{1,1}}-y)}^2+{(z_{\mathrm{1,1}}-z)}^2}-\sqrt{{(x_{\mathrm{1,2}}-x)}^2+{(y_{\mathrm{1,2}}-y)}^2+{(z_{\mathrm{1,2}}-z)}^2}-N_1)/c$

$T_2=\sqrt{{(x_{\mathrm{2,1}}-x)}^2+{(y_{\mathrm{2,1}}-y)}^2+{(z_{\mathrm{2,1}}-z)}^2}-\sqrt{{(x_{\mathrm{2,2}}-x)}^2+{(y_{\mathrm{2,2}}-y)}^2+{(z_{\mathrm{2,2}}-z)}^2}-N_2)/c$ Formula (7)

……

$T_n=\sqrt{{(x_{n,1}-x)}^2+{(y_{n,1}-y)}^2+{(z_{n,1}-z)}^2}-\sqrt{{(x_{n,2}-x)}^2+{(y_{n,2}-y)}^2+{(z_{n,2}-z)}^2}-N_n)/c$

At this moment, corresponding TDOA value T can be calculated according to the coordinate (x, y) of grid point ₁, T ₂... T _n, be mapped the coordinate of this grid point and TDOA value storage.Time customer location is in actual applications located, according to the TDOA value of the customer location measured, mate with the TDOA value of the grid point stored the grid determined at customer location, and calculate user's positioning result.

In another mode, position to be positioned is customer location, at this moment, according to the non line of sight correction value N of this customer location that the result of calculation of step 30 obtains ₁, N ₂... N _nnot accurately, but can this non line of sight correction value N ₁, N ₂... N _nsubstitute into formula (7), and, the TDOA value T of the customer location that when locating according to actual user, measurement obtains ₁, T ₂... T _nsubstitute into formula (7), just can obtain customer location coordinate (x, y) accurately through calculating, this coordinate is exactly the final coordinate of customer location.

To sum up, can know, in the scheme that the embodiment of the present invention 1 provides, in fact two kinds of implementations are divided into, be exactly first measure the coordinate of grid point and a corresponding TDOA value, then when actual location customer location, by measure to the TDOA value of customer location and the TDOA value of the grid point of storage match, determine the grid residing for customer location, and the coordinate of coordinate determination customer location according to grid point.In another kind of mode, do not need grid point, directly according to coordinate and the corresponding TDOA value of calibration point, calculate corresponding TDOA value non line of sight correction value, calculate according to the TDOA value of this non line of sight correction value in conjunction with the customer location of practical measurement again, obtain the coordinate of customer location.

No matter which kind of mode, its core is all to adopt the method for pseudorange difference correction result to revise the TDOA value non line of sight correction value obtained in computational process, difference is exactly that the thinking of forward is first to set up grid, come consumer positioning position by the coupling of grid point, after reverse thinking is directly the TDOA value of customer location to be calculated, obtain position coordinates.

Embodiment 2

In the embodiment of the present invention 2, the mode first measuring grid point in above-described embodiment 1 of have employed exactly to carry out the method for user location, wherein,

First select calibration point at interval of certain distance, measure TDOA value corresponding to calibration point coordinate and calibration point place in advance.

Then the grid point coordinate needed for location is generated with pre-defined rule.Pre-defined rule can be grid point equidistantly to distribute, also can carry out irregular division according to information such as indoor room coordinates.

Prestore according to required grid point coordinate and calibration point coordinate, base station coordinates, calibration point the TDOA value of TDOA value, generating mesh point afterwards.Create-rule is as follows:

Find out three calibration points A, B, C, meet following condition: the Delta Region that three calibrations surround comprises grid point coordinate, and three calibration points are minimum to the Distance geometry of this grid point; Or grid element center o'clock to three calibration points apart from minimum.Note calibration point coordinate is respectively (x _a, y _a), (x _b, y _b), (x _c, y _c).

If A, B, C 3 n recorded TDOA value is respectively T _a1, T _a2... T _an; T _b1, T _b2... T _bn; T _c1, T _c2... T _cn(wherein, T _a1represent that what record at calibration point A is (x from coordinate _1,1, y _1,1, z _1,1) base station and coordinate be (x _1,2, y _1,2, z _1,2) the signal transmission delay of base station poor).Calculate corresponding TDOA non line of sight correction value N _a1, N _a2... N _an; N _b1, N _b2... N _bn; N _c1, N _c2... N _cn.The process calculated as described in Example 1.

Coordinates computed is the non line of sight correction value N of the grid point of (x, y) ₁, N ₂... N _n.

Coordinates computed is the TDOA value T of the grid point of (x, y) ₁, T ₂... T _n.Then mate the TDOA value of grid point here according to the TDOA value measuring the customer location obtained, once determine customer location coordinate.The process of all calculating and formula all as described in Example 1, repeat no more herein.

Embodiment 3

In the embodiment of the present invention 3, the mode not measuring grid point in above-described embodiment 1 of have employed exactly to carry out the method for user location, wherein,

First select calibration point at interval of certain distance, measure TDOA value corresponding to calibration point coordinate and calibration point place in advance.

Then three calibration points A, B, C are found out according in above-mentioned two embodiments according to the mode of grid point searching calibration point, meet following condition: the Delta Region that three calibrations surround comprises the customer location coordinate estimated, and three calibration points are minimum to the Distance geometry of this location point.Note calibration point coordinate is respectively (x _a, y _a), (x _b, y _b), (x _c, y _c).

If A, B, C 3 n recorded TDOA value is respectively T _a1, T _a2... T _an; T _b1, T _b2... T _bn; T _c1, T _c2... T _cn(wherein, T _a1represent that what record at calibration point A is (x from coordinate _1,1, y _1,1, z _1,1) base station and coordinate be (x _1,2, y _1,2, z _1,2) the signal transmission delay of base station poor).Calculate corresponding TDOA non line of sight correction value N _a1, N _a2... N _a3; N _b1, N _b2... N _b3; N _c1, N _c2... N _cn.

Coordinates computed is the non line of sight correction value N of the customer location of (x, y) ₁, N ₂... N _n.Here (x, y) is unknown.Then according to the TDOA value T of customer location coordinate (x, y) ₁, T ₂... T _ncarry out the coordinate of computed user locations.Computational process as described in Example 1, can adopt line style differential technique to calculate the non line of sight correction value of position to be positioned.Namely the non line of sight correction value solution formula (5) of the coordinate of calibration point A, B, C and correspondence is first utilized to obtain line style difference parameter a _n, b _n, c _n.Then customer location coordinate is set to (x, y), substitutes into formula (6), the non line of sight correction value N of this customer location can be obtained ₁, N ₂... N _n.Again by the TDOA value T of customer location coordinate (x, y) ₁, T ₂... T _nbring formula (7) into, combined calculation can obtain the coordinate of customer location.

Embodiment 4

The embodiment of the present invention 4 provides a kind of pseudorange difference positioner, as shown in Figure 8, this device comprises calibration point predicting unit 100, calibration point TDOA non line of sight correction value computing unit 200, position to be positioned non line of sight correction value computing unit 300 and positioning result computing unit 400, specific as follows:

Calibration point predicting unit 100, for choosing calibration point, and measures the coordinate of calibration point and the TDOA value of correspondence in advance.

Choosing of calibration point can be carried out as required, chooses a small amount of calibration point in region to be positioned.

Calibration point TDOA non line of sight correction value computing unit 200, for choosing three calibration points according to position to be positioned, obtaining the TDOA value of three calibration points, calculating corresponding TDOA non line of sight correction value.

Position to be positioned non line of sight correction value computing unit 300, for calculating the TDOA non line of sight correction value of position to be positioned according to the TDOA non line of sight correction value of three calibration points.

Positioning result computing unit 400, for calculating TDOA value according to the coordinate figure of position to be positioned and TDOA non line of sight correction value; Or according to TDOA value and the TDOA non line of sight correction value coordinates computed value of position to be positioned.

Embodiment 5

As shown in Figure 9, the calibration point TDOA non line of sight correction value computing unit 200 of the pseudorange difference positioner in above-described embodiment 4 comprises calibration point further and chooses subelement 201, calibration point TDOA value acquisition subelement 202 and a TDOA non line of sight correction value computation subunit 203, specific as follows:

Calibration point chooses subelement 201, for choosing three described calibration points according to position to be positioned.

Calibration point TDOA value obtains subelement 202, for obtaining n the TDOA value of three calibration points A, B, C.

One TDOA non line of sight correction value computation subunit 203, for calculating TDOA non line of sight correction value corresponding to three calibration points A, B, C.

Embodiment 6

As shown in Figure 10, the position to be positioned non line of sight correction value computing unit 300 of the pseudorange difference positioner in above-described embodiment 4 comprises linear interpolation calculation of parameter subelement 301 and the 2nd TDOA non line of sight correction value computation subunit 302 further, specific as follows:

Linear interpolation calculation of parameter subelement 301, for according to the coordinate of three calibration points A, B, C and the TDOA non line of sight correction value of correspondence, calculates line style difference parameter a _n, b _n, c _n.

2nd TDOA non line of sight correction value computation subunit 302, for calculating the TDOA non line of sight correction value N of position to be positioned ₁, N ₂... N _n.

Embodiment 7

As shown in figure 11, the positioning result computing unit 400 of the pseudorange difference positioner in above-described embodiment 4 comprises grid point TDOA value computation subunit 401 and customer location coordinate computation subunit 402 further, specific as follows:

Grid point TDOA value computation subunit 401, for the TDOA value T of coordinate (x, y) the computing grid point according to grid point ₁, T ₂... T _n.

Customer location coordinate computation subunit 402, the TDOA value for obtaining according to test is T ₁, T ₂... T _ncomputed user locations coordinate (x, y).

To sum up, can know, the pseudorange difference positioner that the embodiment of the present invention provides in fact also carries out for two kinds of implementations, a kind of is the TDOA value of first network for location lattice point, when actual location customer location, mating with the TDOA value of grid point according to measuring the TDOA value of customer location obtained, determining the grid residing for customer location, carrying out user location.Another mode, direct exactly according to measuring the TDOA value of customer location obtained, the location of customer location coordinate is carried out in conjunction with the coordinate of calibration point and TDOA value.This wherein all needs the TDOA non line of sight correction value being come computing grid point or customer location by the TDOA non line of sight correction value of calibration point, takes this mode further by pseudorange difference, carrys out coordinates computed or calculate TDOA value by coordinate by TDOA value.

In sum, the embodiment of the present invention is by choosing a small amount of calibration point in advance and measuring the coordinate of calibration point and the TDOA value of correspondence, three suitable calibration points are chosen according to position to be positioned, calculate corresponding TDOA non line of sight correction value, the TDOA non line of sight correction value of position to be positioned is calculated according to the TDOA non line of sight correction value of calibration point, calculate corresponding TDOA value according to the coordinate that position to be positioned is known and preserve, or calculating corresponding coordinate according to the TDOA value measuring the position to be positioned obtained.The scheme that the embodiment of the present invention provides, a small amount of calibration point can be measured in advance with larger distance interval, based on the TDOA value of calibration point, pseudo range difference model virtual is adopted to produce the higher grid point characteristic information of density, while alleviating location non-market value, effectively reduce the collection capacity of gridding information.Or, corresponding accurate coordinate can be calculated by the TDOA value measuring the position to be positioned obtained.The scheme that the embodiment of the present invention provides, can effectively reduce the amount of calculation in user's position fixing process, accelerates the speed of user location, improves user experience.

One of ordinary skill in the art will appreciate that all or part of step realizing above-described embodiment can have been come by hardware, the hardware that also can carry out instruction relevant by program completes, described program can be stored in a kind of computer-readable recording medium, the above-mentioned storage medium mentioned can be read-only memory, disk or CD etc.

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (3)

1. a pseudorange difference location method, is characterized in that, described method comprises:

Choose calibration point, measure the coordinate of described calibration point and the TDOA value of correspondence in advance;

Choose three described calibration points according to position to be positioned, obtain the TDOA value of described three calibration points, calculate corresponding TDOA non line of sight correction value; Comprise:

Three described calibration point A, B, C are chosen according to position to be positioned;

Obtain n the TDOA value T respectively that described three calibration points A, B, C record _a1, T _a2t _an; T _b1, T _b2t _bn; T _c1, T _c2t _cn;

According to formula

$\begin{array}{c}{N}_{A1}=\sqrt{{(x_{\mathrm{1,1}}-x)}^2+{(y_{\mathrm{1,1}}-y)}^2+{(z_{\mathrm{1,1}}-z)}^2}-\sqrt{{(x_{\mathrm{1,2}}-x)}^2+{(y_{\mathrm{1,2}}-y)}^2+{(z_{\mathrm{1,2}}-z)}^2}-c\·T_{A1}\\ N_{A2}=\sqrt{{(x_{\mathrm{2,1}}-x)}^2+{(y_{\mathrm{2,1}}-y)}^2+{(z_{\mathrm{2,1}}-z)}^2}-\sqrt{{(x_{\mathrm{2,2}}-x)}^2+{(y_{\mathrm{2,2}}-y)}^2+{(z_{\mathrm{2,2}}-z)}^2}-c\·T_{A2}\\ ......\\ N_{\mathrm{Cn}}=\sqrt{{(x_{n,1}-x)}^2+{(y_{n,1}-y)}^2+{(z_{n,1}-z)}^2}-\sqrt{{(x_{n,2}-x)}^2+{(y_{n,2}-y)}^2+{(z_{n,2}-z)}^2}-c\·T_{\mathrm{Cn}}\end{array}$

Calculate corresponding TDOA non line of sight correction value N _a1, N _a2n _an; N _b1, N _b2n _bn; N _c1, N _c2n _cn;

The TDOA non line of sight correction value of position to be positioned is calculated according to the TDOA non line of sight correction value of described three calibration points; Comprise:

According to the coordinate of described three calibration points A, B, C and the TDOA non line of sight correction value solution formula of correspondence

$\left\{\begin{array}{c}{a}_n\·x_A+b_n\·y_A+c_n=N_{\mathrm{An}}\\ a_n\·x_B+b_n\·y_B+c_n=N_{\mathrm{Bn}}\\ a_n\·x_C+b_n\·y_C+c_n=N_{\mathrm{Cn}}\end{array}\right.$

And formula N _n=a _nx+b _ny+c _nsimultaneous, calculates the TDOA non line of sight correction value N of position to be positioned ₁, N ₂n _n;

Described position to be positioned is grid point;

Describedly choose three described calibration point A, B, C according to position to be positioned, comprising:

Described three calibration points A, B, C meet following condition: the Delta Region that three calibration points surround comprises described grid point coordinate, and three calibration points are minimum to the Distance geometry of this grid point; Or, the central point in the region that multiple grid point surrounds to three calibration points apart from minimum;

According to coordinate figure and the TDOA non line of sight correction value calculating TDOA value of position to be positioned; Or according to TDOA value and the TDOA non line of sight correction value coordinates computed value of position to be positioned.

2. the method for claim 1, is characterized in that, the described coordinate figure according to position to be positioned and TDOA non line of sight correction value calculate TDOA value; Or according to TDOA value and the TDOA non line of sight correction value coordinates computed value of position to be positioned, comprising:

When described position to be positioned is grid point, according to formula

$\begin{array}{c}{T}_1=(\sqrt{{(x_{\mathrm{1,1}}-x)}^2+{(y_{\mathrm{1,1}}-y)}^2+{(z_{\mathrm{1,1}}-z)}^2}-\sqrt{{(x_{\mathrm{1,2}}-x)}^2+{(y_{\mathrm{1,2}}-y)}^2+{(z_{\mathrm{1,2}}-z)}^2}-N_1)/c\\ T_2=(\sqrt{{(x_{\mathrm{2,1}}-x)}^2+{(y_{\mathrm{2,1}}-y)}^2+{(z_{\mathrm{2,1}}-z)}^2}-\sqrt{{(x_{\mathrm{2,2}}-x)}^2+{(y_{\mathrm{2,2}}-y)}^2+{(z_{\mathrm{2,2}}-z)}^2}-N_2)/c\\ ......\\ T_n=(\sqrt{{(x_{n,1}-x)}^2+{(y_{n,1}-y)}^2+{(z_{n,1}-z)}^2}-\sqrt{{(x_{n,2}-x)}^2+{(y_{n,2}-y)}^2+{(z_{n,2}-z)}^2}-N_n)/c\end{array}$

Coordinates computed is the TDOA value T of the grid point of (x, y) ₁, T ₂t _n;

When described position to be positioned is customer location, be T according to above-mentioned formulae discovery TDOA value ₁, T ₂t _ncorresponding coordinate (x, y).

3. method as claimed in claim 1 or 2, it is characterized in that, the method also comprises:

When described position to be positioned is grid point, by described grid point coordinate and corresponding TDOA value T ₁, T ₂t _nstore;

When user locates, by the TDOA value of customer location of mensuration and the TDOA value T of grid point ₁, T ₂t _nmatch, determine customer location.