KR101175872B1 - Positioning system and method based on single visible light communication apparatus comprising multiple light sources - Google Patents

Abstract

The present invention relates to a single visible light communication device based positioning system and method including a plurality of light sources to calculate the position of the terminal even when a signal is received from only one visible light communication device.
To this end, according to the present invention, when a visible light communication device including a plurality of light sources transmits a visible light communication signal through a plurality of light sources, the terminal receiving the data collects measurement values for each communication channel from the visible light communication signals received from each light source. And, it is preferable to be configured to calculate the position of the terminal using the measurement value for each communication channel collected by the terminal.
Accordingly, the present invention can accurately calculate the position of the terminal even when a signal is received from only one visible light communication device.

Description

System and method for positioning based on a single visible light communication device including a plurality of light sources {POSITIONING SYSTEM AND METHOD BASED ON SINGLE VISIBLE LIGHT COMMUNICATION APPARATUS COMPRISING MULTIPLE LIGHT SOURCES}

The present invention relates to a single visible light communication device based positioning system and method including a plurality of light sources, and more particularly to a plurality of light sources to calculate the position of the terminal even when a signal is received from only one visible light communication device A single visible optical communication device based positioning system and method.

Conventional positioning system is mainly based on a system using a radio frequency (RF) communication device. Systems using such RF communication devices include satellite based, terrestrial beacon based, wireless LAN (Wi-Fi / WLAN / Wireless LAN) based, RFID based, active RFID based, mobile communication based, Bluetooth based, UWB based , Zigbee-based, WiBro / WiMax-based, and broadcast signal-based systems.

On the other hand, recently, a method for calculating a position using a visible light communication device using a light source such as an LED (Light Emitting Diode) light has been developed and used.

As described above, among the methods of calculating the position using the visible light communication apparatus, there is a method of calculating the position of the user by triangulation by measuring the distance between the transmitting apparatus and the receiving apparatus from the received signal. Precise positioning results are preferred over other methods. However, this method requires at least three to four or more transmission devices for triangulation, and the transmission devices should be widely arranged in consideration of the dilution of precision (DOP). Therefore, in an environment in which it is difficult for a user to receive signals for three to four or more transmitting devices, not only the user's location can be calculated, but also it is not easy to use in an environment in which the transmitting devices are not widely deployed, and multiple transmissions Since the device must be installed, there is a problem that causes a cost problem.

The present invention has been made to solve the above-described problem, by using a visible light communication device comprising a plurality of light sources for signal transmission, it is possible to calculate the position of the terminal even when a signal is received from only one visible light communication device It is an object of the present invention to provide a single visible light communication device based positioning system and method comprising a plurality of light sources.

A single visible light communication device based positioning system including a plurality of light sources according to an embodiment of the present invention for achieving the above object is made, including a plurality of light sources, through the plurality of light sources to provide a visible light communication signal A visible light communication device for transmitting; A terminal for receiving a visible light communication signal transmitted through the plurality of light sources and collecting measurements for each communication channel from the received visible light communication signals; It is preferable to include a position calculation module for calculating the position of the terminal based on the collected communication channel-specific measurements.

On the other hand, a single visible light communication device based positioning method comprising a plurality of light sources according to an embodiment of the present invention, the visible light communication device including a plurality of light sources and the process of transmitting a visible light communication signal through the plurality of light sources; ; Modeling a time at which the visible light communication signal is received by the terminal receiving the visible light communication signal and collecting a measurement value for each communication channel; It is preferable to include the step of estimating the current position of the terminal by using the measurements collected for each communication channel.

According to a single visible light communication device based positioning system and method including a plurality of light sources of the present invention, the position of a terminal can be accurately calculated even when a signal is received from only one visible light communication device. Accordingly, the positioning system can be implemented at low cost.

1 is a view schematically showing the configuration of a single visible light communication device based positioning system including a plurality of light sources according to an embodiment of the present invention.
FIG. 2 is a conceptual diagram illustrating a method of calculating a difference in time taken for a visible light communication signal of two channels transmitted from two light sources of a visible light communication device applied to the present invention to reach a terminal. FIG.
3 is a view showing an exemplary arrangement of light sources in a visible light communication device including a plurality of light sources according to the present invention.
4 is a process for explaining a single visible optical communication device based positioning method including a plurality of light sources according to an embodiment of the present invention.

Hereinafter, a single visible light communication device based positioning system and method including a plurality of light sources according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view schematically showing the configuration of a single visible light communication device based positioning system including a plurality of light sources according to an embodiment of the present invention.

In FIG. 1, the visible light communication device 100 includes a plurality of light sources 102 generating and transmitting visible light communication signals using semiconductor light emitting devices such as LEDs, laser diodes (LDs), and super luminescent diodes (SLDs). Is done.

As described above, the visible light communication signals transmitted through the plurality of light sources 102 may be classified according to communication channels. Incidentally, the time may be synchronized with each other or may be asynchronous, but in the embodiment of the present invention, a case where the time is synchronized with each other will be described.

In addition, the visible light communication device 100 is a terminal so that the position calculation module 300 for calculating the position of the terminal 200 can estimate the current position of the terminal 200 using the position of the visible light communication device 100, The identification information is included in the visible light communication signal sent to the 200 to be transmitted.

Accordingly, when the position calculation module 300 estimates the current position of the terminal 200, based on the identification information received from the visible light communication device 100, the visible light communication device 100 mapped and stored in the corresponding identification information. After confirming the location information, the current location of the terminal 200 can be estimated using the identified location information of the visible light communication device 100. Meanwhile, when the position information of each visible light communication device 300 is not stored in the position calculation module 300, the visible light communication device 100 transmits its identification information to the visible light communication signal transmitted to the terminal 200. It is preferable to include location information together and to transmit it together.

As described above, the visible light communication device 100 includes a plurality of light sources 102, and the visible light communication signals are distinguishable for each communication channel through the plurality of light sources 102, and the time is synchronized with each other. Send the.

As described above, the visible light communication signals transmitted from the plurality of light sources 102 are received by the terminal 200. Since the actual distances to the respective light sources 102 and the terminal 200 are different from each other, each light source In the visible light communication signal transmitted from 102, a difference occurs in the time received by the terminal 200 according to the actual distance difference. Therefore, it is possible to measure the difference in reception time of each signal.

Accordingly, in the exemplary embodiment of the present invention, the visible light communication signals transmitted from the plurality of light sources 102 may be modeled based on the time received by the terminal 200.

As described above, when the times of the visible light signals transmitted from the plurality of light sources 102 are synchronized with each other, it is possible to simultaneously transmit the same visible light signals from the light sources 102a and 102b, i and j. In this case, the terminal 200 may collect measured values by modeling the visible light communication signals transmitted through the i-th and j-th light sources 102a and 102b among the plurality of light sources 102 as shown in Equation 1 below. .

In Equation 1, t ⁱ , t ^j are the time it takes for the signal to arrive from the i, j th light sources 102a, 102b to the terminal 200, as shown in Figure 2, B is the terminal 200 Clock error.

As described above, in the embodiment of the present invention, a method of using a reception time of a visible light communication signal as a measurement will be described as an example. However, the measurement value reveals that the visible light communication device 100 and the terminal 200 may vary depending on which signal is selected from a signal group including a pulse signal, a code, a carrier wave, and a subcarrier to perform communication. For example, in the case of using a carrier, the distance between the light sources is disposed within a distance less than half the wavelength of the carrier, so that the carrier phase is used as a measurement value after removing the unknown number of the carrier, and the terminal 200 is used as a measurement value. The measurement can be modeled by the equation for the distance to.

Here, the terminal 200 is a Global System for Mobile (GSM) phone, Wideband CDMA (W-CDMA) phone, CDMA-2000 phone, Mobile Broad and System (MBS) phone, smart phone, PDA (Personal Digi), tablet PC It may be implemented as a terminal fixedly installed in any one place, such as a mobile terminal or a PC.

On the other hand, the position calculation module 300 calculates the position of the terminal 200 on the basis of the measurement value for each communication channel collected by the terminal 200. At this time, the position calculation module 300 calculates the difference between the channels of the distance from each light source 102 to the terminal 200 on the basis of the measurement value for each communication channel collected by the terminal 200, each calculated The position of the terminal 200 may be calculated using the difference between channels of the distance from the light source 102 to the terminal 200.

As described above, the position calculation module 300 calculates the difference between the channels of the distance from each light source 102 to the terminal 200 based on the measurement values for each communication channel collected by the terminal 200. When the measured values for the visible light signals received from the light sources 102a and 102b, i, obtained through Equation 1, are different from the i-light source 102a and the j-light source 102b, the result as shown in Equation 2 is obtained. You can get it.

As can be seen from Equation 2, the clock error of the terminal 200 is removed through the difference, and multiplied by the luminous flux (C) by the difference measured value from the terminal 200 from the difference value of the measured value obtained from the terminal 200 The difference value of the actual distance to the light sources 102a and 102b can be obtained.

Here, Equation 2 is rearranged with respect to the position of the terminal 200 and the positions of the i and j light sources 102a and 102b.

In Equation 3, (x _i , y _i , z _i ) is the position of the i-th light source 102a of the visible light communication device 100, and (x _j , y _j , z _j ) is the visible light communication device 100. Is the position of the j th light source 102b, and (x, y, z) is the actual position of the terminal 200 (since z is a known value).

Assuming a total of three light sources, one more equation such as Equation 3 can be obtained, and two unknowns are x and y, and two measurement equations. You can get it.

In the same way, when there are two light sources in total, one-dimensional position (azimuth angle), and when there are four or more light sources, three-dimensional positions (x, y, z) can be calculated.

In the embodiment of the present invention, a method of calculating the two-dimensional position (x, y) using the measurements obtained from three light sources will be described as an example.

There are various methods of solving equations such as Equation 3 described above, but the present invention uses methods that use simultaneous and approximate formulas.

When a plurality of light sources 102 of the visible light communication device 100 are arranged as shown in Fig. 3, the position can be expressed as in Equation (4).

In Equation 4,

이고, r은 원 반경이고, θ₁, θ₂, θ₃은 복수의 광원(102) 각각의 방위각이다.

, R is a circle radius, and θ ₁ , θ ₂ , and θ ₃ are the azimuth angles of each of the plurality of light sources 102.

As described above, the position calculation module 300 can obtain the position of the terminal 200 using the obtained position x and y.

As described above, the position calculation module 300 obtains a pair of solutions through Equation 4. When the derived solution is substituted into Equation 3, which is the original equation, the position calculation module 300 does not satisfy the equation. Therefore, the desired solution can be obtained.

As described above, the position calculation module 300 having located x and y is located in the visible light communication device 100 mapped to identification information included in the visible light communication signal received from the visible light communication device 100. Estimate the current position of the terminal 200 based on the location information of the).

As described above, the location calculation module 300 may be included in the terminal 200 and implemented as shown in FIG. 1, or may be implemented separately from the terminal 200 to perform bidirectional communication with the terminal 200. .

FIG. 4 is a process diagram illustrating a single visible optical communication device based positioning method including a plurality of light sources according to an embodiment of the present invention.

First, the visible light communication device 100 including the plurality of light sources 102 periodically transmits a visible light communication signal through the plurality of light sources 102.

Here, the visible light communication device 100 may be distinguished for each communication channel through the plurality of light sources 102 and transmit a visible light communication signal whose time is synchronized with each other.

In addition, the visible light communication device 100 includes its identification information in the visible light communication signal transmitted through the plurality of light sources 102 and transmits it.

As described above, the visible light communication signal transmitted by the visible light communication device 100 through the plurality of light sources 102 is received by the terminal 200 (S10), and the visible light communication transmitted by the visible light communication device 100. Upon receiving the signal, the terminal 200 models the time of receiving the visible light communication signal as shown in Equation 1 and collects measurement values for each communication channel (S12).

Thereafter, the position calculation module 300 based on the measurement value collected for each communication channel in the terminal 200 through the above-described process S12 between channels of the distance from the light source 102 corresponding to each channel to the terminal 200. The difference value is calculated (S14).

In the process S14, the position calculation module 300 may obtain a result as shown in Equation 2 by differentially measuring the measurement values for each communication channel collected through Equation 1.

Through Equation 2, it is possible to obtain the difference value of the actual distance from the plurality of light sources 102 to the terminal 200 from the values obtained by dividing the measured values collected for each communication channel by the terminal 200 from each other.

As described above, the position calculation module 300 that obtains the difference value of the actual distance from the plurality of light sources 102 to the terminal 200 through Equation 2 may determine the position of the terminal 200 and each light source 102. By rearranging for the position of, we obtain the measurement formula as in Equation 3.

Thereafter, the position calculation module 300 calculates the position of the terminal 200 by using the channel-to-channel difference value of the distances from the respective light sources 102 to the terminal 200 obtained through the process S14 (S16). .

In the above step S16, the position calculation module 300 solves the positioning equation obtained through the above step S14, and obtains (in case of using three light sources: x, y).

Thereafter, the current position of the terminal 200 is estimated based on the location of the terminal 200 acquired through the process S16 and the position information of the visible light communication apparatus 100 (S18).

In step S18, the position calculation module 300 based on the identification information included in the visible light communication signal received from the visible light communication device 100, the position information of the visible light communication device 100 mapped to the corresponding identification information. After confirming, the current position of the terminal 200 is estimated using the identified positional information of the visible light communication device 100 and the position of the terminal 200 obtained in the process S16.

As described above, the visible light communication device 100 including the plurality of light sources 102 may be distinguished for each communication channel through the plurality of light sources 102 and transmit a visible light communication signal whose time is synchronized with each other. Accordingly, in the present invention, as shown in FIG. 1, even when a plurality of terminals 200 receive a visible light communication signal from one visible light communication device 100 in a predetermined space, the terminal itself checks its position. That is, a plurality of terminals 200 can calculate a relatively accurate position indoors using only one visible light communication device 100.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken as limitations. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100. visible light communication device, 102. light source,
102a. Light source i randomly selected from light sources included in the visible light communication device,
102b. Light source j randomly selected from light sources included in the visible light communication device;
200. Terminal, 300. Position calculation module

Claims (11)

A visible light communication device including a plurality of light sources and transmitting a visible light communication signal through the plurality of light sources;
A terminal for receiving a visible light communication signal transmitted through the plurality of light sources and collecting measurements for each communication channel from the received visible light communication signals;
A single visible light communication device based positioning system comprising a plurality of light sources comprising a position calculation module for calculating the position of the terminal based on the collected measurement for each communication channel.
The method of claim 1, wherein each visible light communication signal transmitted through the plurality of light sources,
A single visible optical communication device based positioning system comprising a plurality of light sources, characterized in that the signal is distinguishable for each communication channel.
The method of claim 1, wherein the measurement for each communication channel is

Lt; / RTI >
Here, t ⁱ , t ^j is the time it takes for the signal to reach the terminal from the i, j light source,
B is a single visible light communication device based positioning system comprising a plurality of light sources, characterized in that the clock error of the terminal.
The method of claim 1, wherein the position calculation module,
After calculating the channel-to-channel difference value of the distance from each light source to the terminal based on the collected communication channel-specific measurements, the position of the terminal is calculated using the calculated channel-to-channel difference value of the distance from each light source to the terminal. A single visible light communication device based positioning system comprising a plurality of light sources, characterized in that.
The method of claim 4, wherein the channel-to-channel difference value of the distance from each light source to the terminal,

Lt; / RTI >
Here, (x _i , y _i , z _i ) is the position of the i-th light source of the visible light communication device,
(x _j , y _j , z _j ) is the position of the j th light source of the visible light communication device,
(x, y, z) is a single visible light communication device based positioning system comprising a plurality of light sources, characterized in that the actual location of the terminal.
The method of claim 1, wherein the location of the terminal,

Lt; / RTI >
here,

And r is a circle radius, and θ ₁ , θ ₂ , and θ ₃ are azimuth angles of the plurality of light sources, respectively.
Transmitting a visible light communication signal through the plurality of light sources in a visible light communication device including a plurality of light sources;
Modeling a time at which the visible light communication signal is received by the terminal receiving the visible light communication signal and collecting a measurement value for each communication channel;
And a terminal current position estimating step of estimating a current position of the terminal using the measurements collected for each communication channel.
The method of claim 7, wherein the measurement collected for each communication channel,

Lt; / RTI >
Here, t ⁱ , t ^j is the time it takes for the signal to reach the terminal from the i, j light source,
B is a single visible light communication device based positioning method comprising a plurality of light sources, characterized in that the clock error of the terminal.
The method of claim 7, wherein the terminal current position estimation process,
Calculating a channel-to-channel difference value of the distance from each light source to the terminal using the measurements collected for each communication channel;
Calculating the position of the terminal by using the channel-to-channel difference value of the distance from each light source to the terminal;
And estimating a current position of the terminal using the location of the terminal and the position information of the visible light communication device.
The method of claim 9, wherein the channel-to-channel difference value of the distance from each light source to the terminal,

Lt; / RTI >
Here, (x _i , y _i , z _i ) is the position of the i-th light source of the visible light communication device,
(x _j , y _j , z _j ) is the position of the j th light source of the visible light communication device,
(x, y, z) is a single visible light communication device based positioning method comprising a plurality of light sources, characterized in that the actual location of the terminal.
The method of claim 7, wherein the location of the terminal,

Lt; / RTI >
here,

And r is a circle radius, and θ ₁ , θ ₂ , and θ ₃ are azimuth angles of the plurality of light sources, respectively.

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