KR20160083334A - Visible light communication apparatus using control of target points in 3 dimensions and method thereof - Google Patents

Abstract

The present invention relates to an apparatus and a method for visible light communications capable of controlling a transmission point in a 3D way. The present invention provides an apparatus for visible light communications capable of controlling a transmission point in a 3D way, wherein the apparatus includes: a data modulating unit that modulates a transmission signal; a visible light transmitting unit that transmits a visible light signal corresponding to the modulated transmission signal; and a spatial light modulating unit that is provided at an output terminal of the visible light transmitting unit to spatially optically modulate the transmitted visible light signal to a control signal of a holographic technique and transmit the control signal to a 3D target point situated on the front side of an arbitrary distance and an arbitrary direction. According to the apparatus and method for visible light communications capable of controlling a transmission point in a 3D way, because a security and an accuracy of visible light transmission data can be improved by using a control signal by a hologram technique and a profile of a physically transmitted beam and a size of a 2D beam can be controlled, an interference from another channel can be spatially separated. And, because a signal delivery distance can be controlled by adjusting depth for a transmission forward direction, security can be improved by transmitting selectively transmitting a signal only to the user situated at a target distance on an optical forward propagation direction line.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a visible light communication apparatus capable of three-dimensional control of a transmission point,

The present invention relates to a visible light communication device capable of three-dimensional control of a transmission point and a method thereof, and more particularly, to a visible light communication device and a method thereof capable of three-dimensional control of a transmission point that can increase security.

Recently, as wireless communication has been widely used, problems such as exhaustion of RF band frequency, possibility of confusion among various wireless communication technologies, weak security, and high-speed ubiquitous communication environment have been highlighted. In other words, due to limited RF resource regulations, there is a high possibility of poor accuracy and security due to confusion between RF bands of many similar bands. Therefore, a restricted access of wireless communication is required in an environment requiring confidentiality.

In recent years, visible light communication technology for transmitting and receiving information using visible light signals such as LEDs has been researched as an alternative to overcome these drawbacks. Visible light communication can physically enhance security by utilizing the linearity of light, and there is no crosstalk between them, and there is an advantage that high-speed information transmission and low power driving can be performed.

However, the conventional visible light communication system has a radiation angle due to a certain degree of spread of light, so that the signal can spread over a wide area, so that the security is not perfect. In addition, although the intensity of the signal is reduced at a certain distance or more due to the attenuation of the air due to the linearity, the security is limited because the signal can be accessed by anyone who is substantially within the optical straight line range.

The technology to be a background of the present invention is disclosed in Korean Laid-Open Patent Application No. 2013-0009132 (published on Mar. 13, 2013).

An object of the present invention is to provide a visible light communication device capable of three-dimensionally controlling transmission points capable of increasing the security of transmission data of visible light by three-dimensionally controlling transmission points of visible light signals, and a method thereof.

The present invention relates to an image display apparatus comprising a data modulator for modulating a transmission signal, a visible light transmitter for transmitting a visible light signal corresponding to the modulated transmission signal, and a control unit for controlling the transmitted visible light signal, And a spatial light modulator for spatially modulating light by a signal and transmitting the light on a three-dimensional target point located at an arbitrary distance and direction in front of the transmission point.

Here, the spatial light modulator may adjust the distance to the target point so that the spatially light-modulated beam has a maximum intensity, or it is possible to adjust the intensity of the beam at the target point, Two-dimensional shaping of the size of the beam at the target point may be possible.

The visible light communication apparatus may further include a visible light receiving device located at the target point, the visible light receiving device including: a light receiving section that receives a signal transmitted on the target point; And a data demodulator for recovering the transmission signal.

The present invention also provides a visible light communication method of a visible light communication device capable of three-dimensional control of a transmission point, comprising the steps of: modulating a transmission signal; transmitting a visible light signal corresponding to the modulated transmission signal; And transmitting the visible light signal on the three-dimensional target point located at an arbitrary distance and direction at a front side by spatially modulating the visible light signal with the control signal of the holographic technique and transmitting the visible light signal on the three- .

Here, the visible light communication method may include the steps of adjusting a distance to the target point to maximize intensity of the beam transmitted through the imaginary device, modulating the intensity of the beam at the target point, And performing a two-dimensional shaping of the size of the beam at the target point.

According to an aspect of the present invention, there is provided a visible light communication device capable of three-dimensional control of a transmission point and a method thereof for enhancing the security and accuracy of visible light transmission data using a control signal by a hologram technique, And two-dimensional beam size can be controlled. Therefore, it is possible to spatially separate the interference with other channels. By controlling the depth of the beam in the direction of transmission, the signal transmission distance is controlled, There is an advantage that security can be enhanced by selectively transmitting a signal to only the user who is located.

1 is a block diagram of a visible light communication system capable of three-dimensional control of transmission points according to an embodiment of the present invention.
2 is a configuration diagram showing the visible light transmitting apparatus of FIG.
3 is a flowchart of a visible light transmitting method using the visible light transmitting apparatus of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

The present invention relates to a visible light communication device capable of three-dimensional control of a transmission point and a method thereof, and provides a technique for improving data security and accuracy by applying a holographic technique to a data transmission scheme using visible light communication .

In general, visible light communication is an information transmission technology that realizes the function of lighting and the function of wireless communication at the same time by using the principle of recognizing the light as continuous light if repeatedly turning on and off for several tens to several hundred times per second.

In case of visible light communication, it is possible to access the data if the user exists within a certain distance from the lamp where visible light exists because of the spread of light. In addition, since the signal transmission using the linearity can substantially access the signal to any user who is substantially within the optical linear range, the security is limited. The embodiment of the present invention compensates for this point by transmitting the visible light signal to a target point on an arbitrary three-dimensional space, thereby improving the accuracy and security of data.

1 is a block diagram of a visible light communication system capable of three-dimensional control of transmission points according to an embodiment of the present invention. 2 is a configuration diagram showing the visible light transmitting apparatus of FIG.

A visible light communication system according to an embodiment of the present invention includes a visible light transmission apparatus 100 and a visible light reception apparatus 200. [ The visible light transmitting apparatus 100 includes a data modulator 110, a visible light transmitter 120, and a spatial light modulator (SLM) 130. The visible light transmitter 100 includes a data modulator 110, a visible light transmitter 120, and a spatial light modulator (SLM)

The data modulator 110 modulates an analog or digital signal corresponding to a transmission signal according to a channel characteristic. The data modulation method can be a known method. The transmission signal can be determined according to the object and the application in which the visible light transmission apparatus according to the present embodiment is installed. The object may correspond to a device using an illumination device such as an LED (ex, TV, vehicle, monitor, traffic light, electric lamp).

The visible light transmitting unit 120 transmits the visible light signal corresponding to the modulated transmission signal. The visible light transmitter 120 may be implemented as a general LED lamp. In an embodiment of the present invention, the intensity of the LED light source may be modulated in response to digitally modulated binary bits (a combination signal of 1 and 0) to control driving.

The spatial light modulator 130 is provided at an output terminal of the visible light transmitter 120 and spatially light modulates the transmitted visible light signal with a control signal of a holographic technique to generate a predetermined arbitrary distance d Direction so that the error performance is optimized.

In the conventional case, the visible light signal is simply emitted through the lamp. However, in the present embodiment, the visible light signal may be transmitted so that the intensity of the signal is optimized to a target point located at a certain distance.

In this case, the spatial light modulator 130 adjusts the position of a distance at which the intensity of the transmitted beam is maximized through the adjustment of the internal parameter (depth d) in the control signal generating step of the holographic technique, (Depth d) to the target point shown in Fig. 4A, or to adjust the signal intensity of the beam at the target point.

Further, in the conventional visible light communication, due to the spread of light, there is a certain irradiation angle and the cross-sectional size of the beam increases. However, in this embodiment, the spatial light modulator 130 may be used to adjust the two- Therefore, it is also possible to concentrate the light on the position of the specific space and transmit it.

Here, the embodiment of the present invention may further include a control unit 140 for setting (inputting) the distance, direction, beam cross-sectional size, and signal intensity from the user to spatial modulation and setting parameters and generating a control signal. The spatial light modulator 130 may adjust and control parameters corresponding to the set information.

In this embodiment of the present invention, a physical ray beam is formed by three-dimensionally beam-forming a beam of light using spatial light modulation based on a holographic control technique, and at the same time, signal transmission depth You can control the distance.

Accordingly, signals can be accessed only from the receiving apparatus located at the corresponding distance (d) from the transmitting apparatus 100, and the complement of the visible light transmitting data can be increased. Also, the light can be concentrated at the distance d, thereby increasing the reliability of the transmission signal, reducing the transmission error, and facilitating decoding of the transmission signal. In addition, by using this feature, the brightness of the LED module can be lowered, except for the lighting function, so that visible light communication with enhanced security can be performed with low power driving.

In the case of the visible light receiving apparatus 200 corresponding to the visible light transmitting apparatus 100, in order to be able to access the transmission data, the visible light receiving apparatus 200 is positioned at a position corresponding to the target point as described above. Accordingly, ranging processing such as spatial information and distance information for this purpose may be included. The visible light receiving apparatus 200 further includes a light receiving unit 210 for receiving the signal transmitted on the target point and a data demodulating unit 220 for demodulating the received signal to recover the transmitted signal. The light receiving unit 210 may be implemented with an optical detector or an optical module (camera).

3 is a flowchart of a visible light transmitting method using the visible light transmitting apparatus of FIG. To explain the method, the data modulator 110 modulates an analog or digital signal corresponding to a transmission signal according to a channel characteristic (S310). Then, the visible light transmitter 120 transmits the visible light signal corresponding to the modulated transmission signal using the LED lamp (S32O).

Thereafter, the spatial light modulator 130 spatially modulates the transmitted visible light signal into a control signal of a holographic technique, and optimizes the spatial light modulator on a three-dimensional target point located at a certain distance and direction at a forward position (S330).

In step S330, the spatial light modulator 130 controls the distance d to the target point at which the signal is optimally transmitted through the control unit 140, controls the intensity of the transmission signal at the target point, The size of the signal to be transmitted can be formed two-dimensionally.

By using the method according to the embodiment of the present invention, the spatial light modulator 130 can restore or adjust the transmittance at an optimal brightness value at a specific distance in the light propagation direction, or adjust the intensity of the light at that point .

This is achieved by modulating a signal by setting a variable representing the depth d in a process of generating a control signal of the holographic technique. Therefore, it is possible to transmit a signal only to a user at a specific point by adjusting the 3D depth for a user existing on different depths (distances).

In this way, it is possible to differently adjust the reception position where the signal strength is optimal in the actual space, and to increase the security and accuracy of the data by making the measurement impossible or error increase at the non-corresponding position.

According to the present invention, there is provided a visible light communication device capable of three-dimensional control of a transmission point and a method for enhancing security and accuracy of visible light transmission data using a control signal by a hologram technique, Since the profile of the beam and the two-dimensional beam size can be controlled, the interference with other channels can be spatially separated and the signal transmission distance can be controlled by controlling the depth in the transmission straight direction, There is an advantage that security can be enhanced by selectively transmitting a signal only to a user located at a distance.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: visible light transmitting apparatus 110: data modulating unit
120: visible light transmitter 130: spatial light modulator
140: controller 200: visible light receiver
210: light receiving unit 220:

Claims (6)

A data modulator for modulating a transmission signal;
A visible light transmitter for transmitting a visible light signal corresponding to the modulated transmission signal; And
And a spatial light modulator provided at an output terminal of the visible light transmitter for spatially modulating the transmitted visible light signal with a control signal of a holographic technique and transmitting the spatial light modulator on a three- A visible light communication device capable of three-dimensional control. The method according to claim 1,
Wherein the spatial light modulator comprises:
The distance to the target point can be adjusted so that the intensity of the spatially light-modulated beam is maximized, or the intensity of the beam at the target point can be adjusted or the size of the beam at the target point Dimensional control of a transmission point capable of two-dimensionally forming a three-dimensional image. The method according to claim 1,
And a visible light receiving device located at the target point,
The visible light receiving apparatus includes:
A light receiving unit for receiving a signal transmitted on the target point; And
And a data demodulator for demodulating the received signal and restoring the transmitted signal. A visible light communication method of a visible light communication device capable of three-dimensional control of a transmission point,
Modulating a transmission signal;
Transmitting a visible light signal corresponding to the modulated transmission signal; And
And a step of spatially modulating the transmitted visible light signal by spatially optically modulating the transmitted visible light signal and spatially optically modulating the transmitted visible light signal with a control signal of a holographic technique and transmitting the spatially lighted signal on a three- Communication method. The method of claim 4,
Modulating the intensity of the beam at the target point, adjusting a distance to the target point to maximize the intensity of the spatially light-modulated beam, adjusting the intensity of the beam at the target point, Performing at least one of a process for performing two-dimensional shaping on the transmission point and a process for performing two-dimensional shaping for the transmission point. The method of claim 5,
In the visible light receiving device located at the target point,
And transmitting the signal to the target point, and then demodulating the received signal to restore the transmission signal.

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