CN106125046A - A kind of RSS/AOA 3-D positioning method based on CDMA modulation - Google Patents

Abstract

The present invention discloses a kind of RSS/AOA 3-D positioning method based on CDMA modulation.The present invention is based on CDMA modulation technique, use RSS/AOA 3-D positioning method, encoded by the optical signal with LED lamp id information utilizing CDMA modulation technique that LED lamp is launched, owing to CDMA spread spectrum coding has orthogonality, can tell, at receiving terminal, id information and the signal power size that LED is sent.The band of position of receiving terminal is determined by id information；The signal power size of the optical signal by receiving estimates roughly the position of receiving terminal；By measuring the azimuth between receiving terminal and LED lamp and the elevation angle, the position of receiving terminal is carried out a more accurate calculating.In the 3-D positioning method of the present invention, CDMA modulation technique solves well owing to multipath effect and multiple reference point interfere the problem that caused positioning precision declines.Under the conditions of same infrastructure, it is possible to while meeting lighting demand, also it is provided that the positioning service that precision is of a relatively high, has broad application prospects.

Description

A kind of RSS/AOA 3-D positioning method based on CDMA modulation

Technical field

The present invention relates to visible light communication technology, particularly to a kind of RSS/AOA three-dimensional localization side based on CDMA modulation Method.

Background technology

Autonomous robot controls, private services, and location recognition, first aid and navigation assistance increase sharply etc..Wherein position An indispensable technology.Up to date, the research of alignment system have been focused into GPS (GPS), RF-ID, infrared, ultrasound wave, and WLAN.Global positioning system be always treated as a kind of effective in outdoor environment to various right The means of image tracing, but, global positioning system signal is in some regions, as can not in the interior zone in tunnel or building Use.Due to multipath effect and the impact of radio interference, it is difficult for being positioned at accurately in indoor environment.Indoor positioning system The research of system has been carried out using radio frequency, infrared ray, ultrasound wave, and WLAN, and these systems also have bigger The defect of each side, as there is extra infrastructure, measurement error is big, and following range is narrow, and electromagnetism interference is weak, safety Low, response time is long, and low extensibility.Due to these reasons, the indoor using optics visible ray radio communication recently are fixed Position system (owvlc) is popularized as effective alternative means.It is applicable to indoor based on light emitting diode (LED) owvlc Location because what its received signal power was determined by photoelectric current, and photoelectric current be by received signal power produce, and it The most significantly being affected by transmission range and angle, therefore, OWVLC can provide location estimation more accurately to compare existing system. But, what the intersymbol interference that traditional triangle polyester fibre method existence causes due to multipath effect and multiple reference point was caused determines Position accuracy is not enough, and error in data is big, it is impossible to meet the drawback of base lighting requirement

Summary of the invention

In order to overcome the disadvantages mentioned above of prior art with not enough, it is an object of the invention to propose one and adjust based on CDMA The high accuracy indoor visible light communication alignment system of the RSS/AOA 3-D positioning method of system, by utilizing CDMA to spread in modulating The orthogonality of code, what each LED sent has the optical signal of id information through specific PN code Direct-Spread, filters via self adaptation Wave circuit can tell the id information of each LED and corresponding signal power size.Its region is determined by described id information, Its position is estimated roughly in the weighting being utilized signal power size by RSS triangle polyester fibre method, by AOA localization method profit Its position is accurately calculated, it is achieved indoor accurate position with azimuth and the elevation angle.By merging the three-dimensional of the RSS/AOA of CDMA modulation Localization method can realize the high accuracy indoor visible light communication alignment system of Asynchronous Reception.

The purpose of the present invention is achieved through the following technical solutions.

A kind of RSS/AOA 3-D positioning method based on CDMA modulation, comprises the following steps:

Step 1, the primary signal with LED lamp id information is carried out CDMA modulation；

Step 2, signal after ovennodulation drive LED lamp to send the light with id information by LED drive circuit Signal；

Step 3, receiving terminal receive multiple optical signal with id information launched from different LED lamp simultaneously, pass through Signal is processed by amplifying circuit, auto-adaptive filter circuit and CDMA despreading module；Owing to spreading the orthogonality of code, receiving terminal Each optical signal with different LED lamp id information can be told thus restore id information and the measurement of LED lamp Each optical signal power size, carries out "ball-park" estimate by RSS triangle polyester fibre method to the position of receiving terminal；

Step 4, the azimuth measured between described receiving terminal and each LED lamp and the elevation angle, by AOA localization method The position of receiving terminal is carried out an accurate calculating, draws the position coordinates of receiving terminal, thus realize being accurately positioned.

Further, described step 1 comprises the following steps:

Step 11, the BPSK baseband modulation that carries out the primary signal with LED lamp id information, form baseband modulation letter Number, a width of A of band of baseband modulation signal₁；

Step 12, baseband modulation signal is carried out spread processing through PN code generator, formed and carry a width of A₂Spread spectrum letter Number, and A₂Much larger than A₁。

Further, in its described step 3 and step 4, location is the region being determined receiving terminal place by id information, logical Cross RSS triangle polyester fibre method and the position of receiving terminal is carried out rough position estimation, by the AOA localization method position to receiving terminal Put and calculate accurately.

Further, described step 3 comprises the following steps:

Step 31, described receiving terminal receive the optical signal with id information of multiple different LED lamp transmitting and by it It is changed into the signal of telecommunication；The signal of telecommunication forms the signal before despreading by auto-adaptive filter circuit process；

Step 32, described CDMA despreading module capture PN code sequence, adjusts the phase place of local PN code by synchronous circuit, from And produce the PN code identical with transmitting terminal, the signal before described despreading is carried out despreading process；Owing to spreading the orthogonality of code, institute The id information of LED lamp can be restored with receiving terminal and measure the size of signal power；Determined by id information and connect Receiving end region；By the signal power size of the optical signal of each LED lamp received, receiving terminal position is carried out "ball-park" estimate；Obtained rough location estimation is the weighting of the signal power size receiving each signal, its mathematics Formula is:

$r_{Rj}=\frac{\underset{k=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\χ}}_k{P}_{k,j}({\mathrm{\Φ}}_{k,j},{\mathrm{\θ}}_{k,j})r_{sk}}{\underset{k=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\χ}}_k{P}_{k,j}({\mathrm{\Φ}}_{k,j},{\mathrm{\θ}}_{k,j})}$

Wherein, r_RjFor the coordinate of jth receiving terminal, χ_kFor the binary weights that kth light fixture is additional, P_{K, j}For with regard to jth Receiving terminal receives the signal power size of kth light fixture, r_skIdeal coordinates for kth light fixture.Φ_k,jIt is that LED lamp is launched The angle of emergence of optical signal, θ_k,jIt it is the angle of incidence of the optical signal that receiving terminal receives.

Further, described step 4 comprises the following steps:

Step 41, measurement draw the azimuthal angle beta between each LED lamp and receiving terminal_kWith angle of elevation alpha_k；

Step 42, utilizing geometrical relationship to calculate the accurate coordinates of receiving terminal, its mathematic(al) representation is:

$\left[\begin{array}{c}X\\ Y\\ Z\end{array}\right]=\left[\begin{array}{c}{X}_k\\ Y_k\\ Z_k\end{array}\right]+\left[\begin{array}{c}{D}_{k,j}{\mathrm{sin\α}}_k{\mathrm{cos\β}}_k\\ D_{k,j}{\mathrm{sin\α}}_k{\mathrm{sin\β}}_k\\ D_{k,j}{\mathrm{cos\α}}_k\end{array}\right]$

Wherein X, Y, Z are the coordinates of receiving terminal,X_k, Y_k, Z_kIt it is the coordinate of kth light fixtureD_{K, j}=| r_Rj-r_sk|,

And D_{K, j}Then can be calculated by geometrical relationship, its mathematic(al) representation is

$D_{k,j}=\frac{D\sqrt{1+{\left({\mathrm{tan\β}}_k\right)}^2}}{{\mathrm{sin\α}}_k\left({\mathrm{tan\β}}_1{\mathrm{tan\β}}_2\right)}$

D=| r_sk1-r_sk2|；A D is there is between each light fixture and receiving terminal_{K, j}But as long as calculating one of them D between light fixture and receiving terminal_{K, j}, the position of receiving terminal can be calculated.

Described based on CDMA modulation RSS/AOA 3-D positioning method visible light communication indoor orientation method use be System includes: signal emission part, transmission channel, signal receiving part divide.BPSK baseband-modem module, CDMA spread spectrum module, LED drive Galvanic electricity road and LED lamp are sequentially connected with the described signal emission part of composition；Optical signal receiving terminal, amplifying circuit, adaptive-filtering Circuit and CDMA despreading module are sequentially connected with the described signal receiving part of composition and divide；Described transmission channel is the three-dimensional interior space.Tool There are the primary signal of the LED lamp id information BPSK baseband-modem module by described signal emission part and CDMA spread spectrum module After carrying out baseband modulation and spread spectrum, LED lamp is driven to convert electrical signals to the optical signal with id information and launch； Described optical signal passes through 3 D auto space propagation arriving signal receiving portion.Described optical signal receiving terminal receives through three-dimensional room After the optical signal with id information of interior space propagation, it is reduced to the signal of telecommunication；The described signal of telecommunication is amplified through amplifying circuit Process, then remove noise by auto-adaptive filter circuit, then pass through CDMA despreading module despreading.Final acquisition has each The signal of telecommunication of id information and signal power size.Described id information determines its region, rough by the weighting of signal power Estimate its position, accurately calculate its position by azimuth and the elevation angle, it is achieved be accurately positioned.

Compared with prior art, the present invention has the following advantages and beneficial effect:

(1) innovatively CDMA modulation technique is applied in VLC system, on the premise of not increasing bandwidth of a device, becomes Improve speed and the quality of radio communication again.

(2) novelty merge to get up to be incorporated in VLC system by RSS localization method and AOA localization method, decreasing While required infrastructure (quantity of LED lamp), also improve the accuracy of location.

Accompanying drawing explanation

Fig. 1 is the indoor environment schematic diagram simulated.

Fig. 2 is the theory diagram realizing CDMA modulation and demodulation.

Fig. 3 is the theory diagram of the hybrid three-dimensional localization method realizing RSS/AOA.

Fig. 4 is the principle schematic of the hybrid three-dimensional localization method realizing RSS/AOA.

Detailed description of the invention

Below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail, but the implementation of the present invention is not It is limited to this.

Embodiment 1

As it is shown in figure 1, the system model of a kind of RSS/AOA visible light communication localization method based on CDMA modulation.This is 1. the room of one 4m*4m*3.5m rice, be the LED lamp participating in location in figure；2. it is the LED lamp of contributing noise；3. be from The position of the receiving terminal dissipated.12 LED lamp are divided into four row four and arrange and be distributed on the ceiling evenly and at intervals, with every four LED lamp, as a positioning unit, realizes RSS localization method by four light fixtures, then by its in aforementioned four light fixture In two realize AOA localization method, thus realize being accurately positioned of receiving terminal

Further, as in figure 2 it is shown, described BPSK baseband-modem module is the original letter with LED lamp id information Number it is converted into baseband modulation signal, a width of A of band of baseband modulation signal₁；Described CDMA spread spectrum module passes through PN code generator pair Baseband modulation signal carries out spread processing, converts thereof into spread-spectrum signal；The a width of A of band of spread-spectrum signal₂, A₂Much larger than A₁；At this In case, use direct sequence spread spectrum skill, and use PN code for spread spectrum code；Described spread-spectrum signal is through LED drive circuit LED lamp is driven to launch the optical signal with id information；Described optical receiving end receives has LED through what free space arrived Have the optical signal of id information and be converted to the signal of telecommunication；Described amplifying circuit amplifies the signal of telecommunication；Signal warp after described amplification Cross auto-adaptive filter circuit and remove noise, form the signal before despreading；Described CDMA despreading module capture PN code sequence, by same Step circuit adjusts the phase place of local PN code, thus produces the PN code identical with transmitting terminal, solves the signal before described despreading Expansion processes.Thus restore the id information of LED lamp and measure the size of signal power.

Further, as shown in Figure 3, Figure 4, the region at receiving terminal place is first determined according to the id information of signal.Then Utilize RSS triangle polyester fibre method that the position of receiving terminal is carried out a rough estimation；Its mathematical formulae is:

$r_{Rj}=\frac{\underset{k=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\χ}}_k{P}_{k,j}({\mathrm{\Φ}}_{k,j},{\mathrm{\θ}}_{k,j})r_{sk}}{\underset{k=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\χ}}_k{P}_{k,j}({\mathrm{\Φ}}_{k,j},{\mathrm{\θ}}_{k,j})}$

Wherein, r_RjCoordinate for jth receiving terminal.χ_kFor the binary weights that kth light fixture is additional；P_{K, j} For receiving the signal power size of kth light fixture with regard to jth receiving terminal；r_skFor the ideal coordinates of kth light fixture,Φ_k,jIt it is the side of the angle of emergence of the optical signal that LED lamp is launched, the i.e. direction of propagation of optical signal and LED lamp To angle, wherein LED lamp direction vectorRepresent；θ_k,jIt is the angle of incidence i.e. light of the optical signal that receiving terminal receives Signal propagation direction and the angle in receiving terminal direction, wherein receiving terminal direction vectorRepresent.

Utilize above-mentioned formula, calculate the position coordinates that receiving terminal is rough, coordinate information is sent back LED lamp, docking The positional information of receiving end is updated.

Further, on the rough position obtained by RSS localization method, AOA localization method is utilized to be closed by geometry It is that the position to receiving terminal carries out an accurate calculating.Measure the azimuth between receiving terminal and two light fixtures and the elevation angle, Utilize following equation that receiving terminal position is calculated accurately.

(1)---D=| r_sk1-r_sk2|

$\left(2\right)---D_{k,j}=\frac{D\sqrt{1+{\left({\mathrm{tan\β}}_k\right)}^2}}{{\mathrm{sin\α}}_k\left({\mathrm{tan\β}}_1{\mathrm{tan\β}}_2\right)}$

$\left(3\right)---\left[\begin{array}{c}X\\ Y\\ Z\end{array}\right]=\left[\begin{array}{c}{X}_k\\ Y_k\\ Z_k\end{array}\right]+\left[\begin{array}{c}{D}_{k,j}{\mathrm{sin\α}}_k{\mathrm{cos\β}}_k\\ D_{k,j}{\mathrm{sin\α}}_k{\mathrm{sin\β}}_k\\ D_{k,j}{\mathrm{cos\α}}_k\end{array}\right]$

Wherein X, Y, Z are the coordinates of receiving terminal,X_k, Y_k, Z_kIt it is the coordinate of kth light fixtureD_{K, j}=| r_Rj-r_sk| it is the vector between LED lamp and receiving terminal, β_kIt is between LED lamp and receiving terminal Azimuth, α_kIt it is the elevation angle between each LED lamp and receiving terminal.

Position vector D between two LED lamp realizing AOA localization method is calculated first by formula (1)；Then Formula (2) is used to calculate the vectorial D between one of them LED lamp and receiving terminal_{K, j}；Finally use formula (3) to calculate to connect The coordinate r of receiving end_Rj,

Thus realize being accurately positioned of receiving terminal.The accurate coordinate obtained is sent to LED lamp, updates receiving terminal Positional information.

Further, after certain time interval, then re-use RSS localization method the position of receiving terminal is carried out "ball-park" estimate, carries out AOA localization method the most again and calculates the position of receiving terminal, updates the position of receiving terminal Information.Constantly repeat above procedure, thus achieve a butt joint receiving end indoor positioning accurately and tracking.

Above-described embodiment is only a kind of implementation of the present invention, but the implementation of the present invention is not by above-described embodiment Restriction, the change made under other any spirit without departing from the present invention and principle, modify, substitute, combine, simplify all Should be equivalence method of replacing, be included in protection scope of the present invention it.

Claims (5)

1. a RSS/AOA 3-D positioning method based on CDMA modulation, it is characterised in that comprise the following steps:

Step 1, the primary signal with LED lamp id information is carried out CDMA modulation；

Step 2, signal after ovennodulation drive LED lamp to send the optical signal with id information by LED drive circuit；

Step 3, receiving terminal receive multiple optical signal with id information launched from different LED lamp simultaneously, by amplifying Signal is processed by circuit, auto-adaptive filter circuit and CDMA despreading module；Owing to spreading the orthogonality of code, receiving terminal can Tell each optical signal with different LED lamp id information thus restore the id information of LED lamp and measure each Optical signal power size, carries out "ball-park" estimate by RSS triangle polyester fibre method to the position of receiving terminal；

Step 4, the azimuth measured between described receiving terminal and each LED lamp and the elevation angle, docked by AOA localization method The position of receiving end carries out an accurate calculating, draws the position coordinates of receiving terminal, thus realizes being accurately positioned.

A kind of RSS/AOA 3-D positioning method based on CDMA modulation the most according to claim 1, it is characterised in that institute State step 1 to comprise the following steps:

Step 11, the BPSK baseband modulation that carries out the primary signal with LED lamp id information, form baseband modulation signal, base The a width of A of band with modulated signal₁；

Step 12, baseband modulation signal is carried out spread processing through PN code generator, formed and carry a width of A₂Spread-spectrum signal, and And A₂Much larger than A₁。

A kind of RSS/AOA 3-D positioning method based on CDMA modulation the most according to claim 1, it is characterised in that its In described step 3 and step 4, location is the region being determined receiving terminal place by id information, by RSS triangle polyester fibre method pair The position of receiving terminal carries out rough position estimation, is calculated the position of receiving terminal accurately by AOA localization method.

A kind of RSS/AOA 3-D positioning method based on CDMA modulation the most according to claim 1, it is characterised in that institute State step 3 to comprise the following steps:

Step 31, described receiving terminal receive the optical signal with id information of multiple different LED lamp transmitting and are changed For the signal of telecommunication；The signal of telecommunication forms the signal before despreading by auto-adaptive filter circuit process；

Step 32, described CDMA despreading module capture PN code sequence, is adjusted the phase place of local PN code, thus produces by synchronous circuit The raw PN code identical with transmitting terminal, carries out despreading process to the signal before described despreading；Owing to spreading the orthogonality of code, so connecing Receiving end can restore the id information of LED lamp and measure the size of signal power；Receiving terminal is determined by id information Region；By the signal power size of the optical signal of each LED lamp received, receiving terminal position is carried out roughly Estimation；Obtained rough location estimation is the weighting of the signal power size receiving each signal, its mathematical formulae For:

$r_{Rj}=\frac{\underset{k=1}{\overset{N}{\Σ}}{\mathrm{\χ}}_k{P}_{k,j}({\mathrm{\Φ}}_{k,j},{\mathrm{\θ}}_{k,j})r_{sk}}{\underset{k=1}{\overset{N}{\Σ}}{\mathrm{\χ}}_k{P}_{k,j}({\mathrm{\Φ}}_{k,j},{\mathrm{\θ}}_{k,j})}$

Wherein, r_RjFor the coordinate of jth receiving terminal, χ_kFor the binary weights that kth light fixture is additional, P_{K, j}For receiving with regard to jth End receives the signal power size of kth light fixture, r_skIdeal coordinates for kth light fixture.Φ_k,jIt is that the light that LED lamp is launched is believed Number the angle of emergence, θ_k,jIt it is the angle of incidence of the optical signal that receiving terminal receives.

A kind of RSS/AOA 3-D positioning method based on CDMA modulation the most according to claim 1, it is characterised in that described Step 4 comprises the following steps:

Step 41, measurement draw the azimuthal angle beta between each LED lamp and receiving terminal_kWith angle of elevation alpha_k；

Step 42, utilizing geometrical relationship to calculate the accurate coordinates of receiving terminal, its mathematic(al) representation is:

$\left[\begin{array}{c}X\\ Y\\ Z\end{array}\right]=\left[\begin{array}{c}{X}_k\\ Y_k\\ Z_k\end{array}\right]+\left[\begin{array}{c}{D}_{k,j}{\mathrm{sin\α}}_k{\mathrm{cos\β}}_k\\ D_{k,j}{\mathrm{sin\α}}_k{\mathrm{sin\β}}_k\\ D_{k,j}{\mathrm{cos\α}}_k\end{array}\right]$

Wherein X, Y, Z are the coordinates of receiving terminal,X_k, Y_k, Z_kIt it is the coordinate of kth light fixtureD_{K, j} =| r_Rj-r_sk|,

And D_{K, j}Then can be calculated by geometrical relationship, its mathematic(al) representation is

$D_{k,j}=\frac{D\sqrt{1+{\left({\mathrm{tan\β}}_k\right)}^2}}{{\mathrm{sin\α}}_k\left({\mathrm{tan\β}}_1{\mathrm{tan\β}}_2\right)}$

D=| r_sk1-r_sk2|；A D is there is between each light fixture and receiving terminal_{K, j}But as long as calculating one of them light fixture And the D between receiving terminal_{K, j}, the position of receiving terminal can be calculated.