KR101379968B1 - Apparatus, system and method for communicating data using light - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to visible light communication, and more particularly, to a visible light communication device, a system, and a method. Visible light communication apparatus according to an embodiment of the present invention includes a modulator for modulating a transmission signal; A signal processor for processing a received signal; And an LED light emitting / receiving unit, wherein the LED light emitting / receiving unit includes a high power LED, and when operating in a transmission mode, the high power LED blinks according to a modulated transmission signal output from the modulation unit. In operation, the received signal corresponding to the received optical signal is transmitted to the signal processor.

Description

Visible light communication device, system and method {APPARATUS, SYSTEM AND METHOD FOR COMMUNICATING DATA USING LIGHT}

TECHNICAL FIELD The present invention relates to visible light communication, and more particularly, to a visible light communication device, a system, and a method.

Recently, LED is attracting attention as an illumination light source. The price of LEDs has declined 10 times every 10 years, and performance has improved 20 times. The advantages of LED light sources include low power consumption and long life. Incandescent bulbs convert only 10% of the power to light, while LEDs convert 90% to light, resulting in significantly lower power consumption. In addition, the lifetime of LEDs is as long as 100,000 hours, while the life of conventional bulbs is up to 4,000 hours. Another advantage of LED light sources is that they are environmentally friendly. Conventional light sources use heavy metals such as mercury and lead, but LEDs follow RoHS (Restriction of Hazardous Substances) regulations that do not use such heavy metals. Visible light wireless communication technology is a technology that enables communication using an infrastructure in which incandescent and fluorescent lights are replaced with LED lights, and is a new convergence technology that adds communication functions to lighting devices.

The biggest advantage of visible light communication is that there are no legal restrictions on the use of frequencies for communication. Converting the wavelength of visible light into frequency corresponds to approximately 385THz-789THz. As a result, there is no fear of crosstalk with existing communication using RF frequency, and it is free from harmful applications. The communication link can be visually recognized to directly determine whether it is listening or listening. The Korea Telecommunication Technology Association (TTA) has established a visible light communication service working group since May 2007 to lead the national standard. In November 2007, the VLC IG (Visual Light Communication Interest Group) was established in IEEE 802.15, laying the groundwork for international standards. In Japan, the VLCC (Visible Light Communication Consortium) was formed to exchange technologies for visible light wireless communication in the form of a consortium. LED is used as lighting by using the property of converting electricity into light. LED lighting communication fusion principle is based on the basic principle of sending and receiving LED and PD (Photo Diode) flickering, it is possible to simultaneously communicate while maintaining the lighting function. The speed of switching from electricity to light is about 30nm to 250nm, and this fast on-off can be communicated by modulating communication. If a person blinks more than 100 per second, the person does not recognize the blink and recognizes it as continuously on. Although there is a flicker by communication, the lighting function is maintained because it is recognized as being turned on continuously.

However, in order to apply the visible light wireless communication to various fields, it is necessary to overcome the limitations of the transmission frequency to increase the data transmission rate and transmission rate and to miniaturize the device / system.

Disclosure of Invention The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide a visible light communication device, a system, and a method which can simplify the configuration.

Another object of the present invention is to provide a visible light communication device, a system, and a method capable of increasing a transmission speed and a transmission rate.

Visible light communication apparatus according to an embodiment of the present invention includes a modulator for modulating a transmission signal; A signal processor for processing a received signal; And an LED light emitting / receiving unit, wherein the LED light emitting / receiving unit includes a high power LED, and when operating in a transmission mode, the high power LED blinks according to a modulated transmission signal output from the modulation unit. In operation, the received signal corresponding to the received optical signal is transmitted to the signal processor.

According to an embodiment of the present invention, a visible light communication system includes: a first LED module configured to include one or more LEDs configured to output data provided from a first electronic device to visible light; A second LED module configured to include one or more LEDs for detecting an optical signal from the visible light output from the first LED module and outputting the optical signal as an electrical signal, and transmitting the electrical signal to a second electronic device; Include.

Here, the first and second LED modules may be connected to the first and second electronic devices through a USB interface, respectively, and bidirectional communication is possible. In addition, a forward bias voltage is applied to the LED in the second LED module to detect the optical signal, and the LED in the second LED module outputs the electrical signal in a differential waveform. The second LED module further includes an integrator for integrating the differential signal of the differential waveform.

According to an embodiment of the present invention, a visible light communication method includes: outputting data provided from a first electronic device to visible light using a first LED module including one or more LEDs; Receiving the visible light using a second LED module comprising one or more LEDs; And converting an optical signal included in the visible light into an electrical signal and transmitting the electrical signal to a second electronic device.

According to the present invention, an LED outputting a differential waveform in response to a high frequency signal is used as a light receiving device, thereby increasing transmission speed and transmission rate.

In addition, since there is no need for an element or a circuit for providing a reverse bias voltage, there is an effect that the structure of the apparatus and system can be simplified and downsized.

1 is a view showing a visible light communication system according to a first embodiment of the present invention.
2 is a view for explaining an example of the LED light emitting unit.
3 is a view showing a visible light communication system according to a second embodiment of the present invention.
4 is a diagram illustrating an example of the first and second LED modules of FIG. 3.
5 is a view showing a visible light communication system according to a third embodiment of the present invention.
6 is a diagram illustrating an example of the LED module of FIG. 5.
7 is a diagram illustrating a visible light communication system according to a fourth embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. In the following description, the same constituent elements are given the same names and the same symbols for convenience of explanation.

The terminology used in the present invention was selected as a general term that is widely used at present, but in some cases, the term is arbitrarily selected by the applicant, and in this case, the meaning of the term is described in detail in the description of the present invention. The present invention should be understood as meanings other than terms.

First Embodiment

1 shows a visible light communication system according to a first embodiment of the present invention. As shown in FIG. 1, the visible light communication system according to the first embodiment includes a transmitter 10 and a receiver 20.

The transmitter 10 is a line coder 11 for outputting data such as text, voice, video, etc. in a pulse form, and a modulator for modulating the signal output from the line coder 11 to be visible light (12), an LED light emitting unit 13 for emitting visible light including a signal modulated by the modulator 12. Here, the line coding unit 11 performs coding in order to output binary data strings such as text, voice, video, and the like as Fuss waveforms. The reason for performing such line coding is to adjust the transmission characteristics and constraints on the transmission line during data transmission, or to facilitate the smooth synchronous reproduction or error detection of the receiving side. For example, the LED light emitting unit 13 may be configured to include one high power (1W or more) LED or may be configured in an array form including a plurality of high power LEDs. In addition, the LED light emitting unit 13 may transmit a signal by controlling the amount of light or blinking of the visible light output, and may be applied to other methods of carrying a signal on the visible light as well as this method. Even when transmitting a signal by controlling the blinking of visible light, when the on / off of the LED light emitting unit 13 is about 200 Hz or more, since it is not recognized by the human eye, the LED light emitting unit 13 is simultaneously transmitted. It is not a problem to use as a lighting element. Therefore, the transmission device 10 may also be configured in the form of indoor and outdoor lighting, billboards, signs, displays / TV, stand lighting.

The receiving device 20 may be a portable terminal such as a lighting device, a mobile phone, a PDA, a tablet PC, a notebook computer, a game machine, or an audio / video device, a PC, or other electronic device. The receiver 20 is not limited thereto, and may be an electronic device requiring data reception or capable of data reception. The receiver 20 includes an LED light receiver 21 and a signal processor 22. Here, the LED light receiving unit 21 receives the visible light output from the LED light emitting unit 13 to generate an electrical signal. The LED light-receiving unit 21 may be configured to include, for example, one high-power (1W or more) LED or an array including a plurality of high-power LEDs, and a wide frequency band (hundreds of Hz to several MHz). Differential waveform signals may be output in response to visible light including the signals. In addition, since the LED light receiver 21 may be used as an illumination element while not receiving visible light, the receiver 20 may be used as an illumination device. The signal processor 22 is configured to include an integration circuit for integrating the differential waveform electrical signals output from the LED light receiver 21 and a demodulator for demodulating the electrical signals. In particular, since the LED light receiver 21 outputs a differential waveform signal, the signal processor 22 performs an integrator function of integrating the differential waveform signal. Accordingly, the signal processor 22 integrates and demodulates the differential waveform electrical signal and outputs data such as text, voice, and video.

In the above-described drawings and the description thereof, the transmitting apparatus 10 and the receiving apparatus 20 are described separately, but the transmitting apparatus 10 and the receiving apparatus 20 may be integrally formed (hereinafter, referred to as visible light communication). Device (not shown). In this case, since light emission and light reception can be performed using the same LED, the LED light emitting unit 13 and the LED light receiving unit 21 are combined to be called an LED light emitting / receiving unit (not shown). Accordingly, the visible light transmitting / receiving device includes a line coding unit 11, a modulator 12, an integrator 22, and an LED light emitting / receiving unit. In this case, the visible light transmission / reception device performs visible light communication with another visible light communication device.

2 shows an example of the first LED light emitting / receiving unit 1 and the second LED light emitting / receiving unit 21. As shown in FIG. 2, the first LED light emitting / receiving unit 1 includes a driving transistor Q1, a switch SW1, a high power LED D1, and a resistor R1. In the drawing, an example in which a Bipolar Junction Transistor (BJT) is used as an example of the driving transistor Q1 is illustrated, but is not limited thereto. Other driving transistors (eg, MOSFETs) may be used. The output of the modulator 12 is input to the input terminal (base terminal in the case of BJT) of the driving transistor Q1. The first node N1 is connected to the input terminal of the signal processor 22. The resistor R1 may be omitted depending on the operation of the signal processor 22. That is, the first node N1 may be connected only to the switch SW1 and the signal processor 22. When the first LED light emitting / receiving unit 1 operates as the LED light emitting unit 13 (that is, when operating in the transmission mode), the switch SW1 switches the output terminal of the driving transistor Q1 to the LED D1. Connect to In this case, the LED D1 flashes in accordance with the signal transmitted via the line coding unit 11, the modulator 12, and the driving transistor Q1. In this case, the LED D1 also functions as illumination. When the first LED light-receiving unit 1 operates as the LED light-receiving unit 21 (that is, when operating in the reception mode), the switch SW1 connects the first node N1 to the LED D1. do. In this case, a signal generated by the LED D1 by light reception is transmitted to the signal processor 22 via the first node N1. In this case, the LED D1 corresponds to an off state. In the case where the first LED light-receiving portion 1 operates as the LED light-receiving portion 21, it is not required to apply a reverse bias to the LED D1. Therefore, since a separate circuit / element for applying reverse bias is not required, the configuration of the apparatus can be simplified and miniaturized.

The second LED light emitting / receiving unit 2 includes a driving transistor Q2, a switch SW2, an LED D2, and a resistor R2. When the first LED light-receiving part 1 operates as the LED light-emitting part 13, the second LED light-receiving part 20 should operate as the LED light-receiving part 21, and the first LED light-receiving part 1 Operation and configuration of the second LED light emitting / receiving unit 2 except that the second LED light emitting / receiving unit 20 should operate as the LED light emitting unit 13 when the LED light receiver 21 operates as the LED light receiving unit 21. Since the operation and configuration of the first LED light emitting / receiving unit 1 are the same, a detailed description thereof will be omitted for convenience of description.

Second Example

3 shows a visible light communication system according to a second embodiment of the present invention. The second embodiment is for visible light communication between two electronic devices. In FIG. 3, two PCs are used as examples, but may be other electronic devices, for example, a mobile terminal such as a mobile phone, a PDA, a tablet PC, a notebook, a game machine, or an audio / video device, a PC, or other electronic devices. have. Also, the two electronic devices communicating may be of different kinds / models / versions.

As shown in FIG. 3, the first LED module 40 is connected to the transmitting electronic device 30, and the second LED module 50 and the amplifier 60 are connected to the receiving electronic device 70. . The first LED module 40 and the second LED module 50 communicate with the electronic devices 30 and 70, respectively, using a local area network such as Ethernet. In addition, like the transmitter 10 and the receiver 20 of the first embodiment, the first and second LED modules 40 and 50 can be used as lighting devices. The electronic devices 30 and 70 may be configured to first check each other's IDs or identification information to determine whether they are compatible, whether access / data transmission / reception is allowed, and then transmit / receive data .

4 shows an example of the first and second LED modules 40 and 50. As shown in FIG. 4, the first LED module 40 includes a signal receiving / processing unit 41, a control unit 42, an LED driver 43, an LED light emitting unit 44, a power supply unit (not shown), and the like. It is configured to include. The signal receiving / processing unit 41 receives and processes a signal from the transmitting-side electronic device 30 and outputs the signal. The LED driver 43 stores the signal output from the signal receiving / processing unit 41 in visible light. The LED light emitting unit 44 is controlled to be output. Here, the LED light emitting unit 44 may be configured in the form of one high-power (3-5V, 1000mA-3000mA) LED or in the form of an array (array) comprising a plurality of high-power LED. In addition, the LED light emitting unit 44 may transmit a signal by controlling the amount of light or blinking of the visible light output, and may be used as an illumination device even when transmitting a signal by controlling the blinking of the visible light. The control unit 42 controls the operations of the signal receiving / processing unit 41, the LED driver 43, and the LED light emitting unit 44.

As shown in FIG. 4, the second LED module 50 includes a controller 51, an LED light receiver 52, and a signal processor 53. The LED light receiver 52 detects the optical signal transmitted from the first LED module 40 and outputs an electrical signal, and the signal processor 53 demodulates the electrical signal output from the LED light receiver 52. Output Here, the LED light-receiving unit 52 may include an array of high-power (3-5V, 1000mA-3000mA) LEDs or a plurality of high-power LEDs, and may include a wide frequency band In response to visible light including a signal of a few MHz) can be output a differential waveform signal. The LED light-receiving unit 52 may also respond to square wave signals of 5 MHz or more and output differential electric signals. The signal processor 53 receives and processes the timely signal of the differential wave form. For example, if the LED light receiving unit 52 functions as a differentiator for outputting a differential waveform signal, the signal processing unit 53 performs an integrator function for integrating the differential waveform signal. Although not shown in the drawing, since the reverse bias is not applied to the LED in the LED light receiving unit 52 as the LED light receiving unit 21 of FIG. 2, the second LED module 50 is required to apply the reverse bias. No circuit / elements are required.

The LED light emitting unit 44 and the LED light receiving unit 52 of the second embodiment may be configured in the same manner as the LED light emitting unit 13 and the LED light receiving unit 21 shown in FIG. 2.

Third Example

5 shows a visible light communication system according to a third embodiment of the present invention. The third embodiment is for visible light communication between two electronic devices. The electronic devices 80 and 110 may be portable terminals such as a mobile phone, a PDA, a tablet PC, a notebook computer, a game machine, or an audio / video device, a PC, or other electronic devices. In addition, the two electronic devices 80 and 110 communicating with each other may be of different kinds / models / versions.

As shown in FIG. 5, a first LED module 90 is connected to the electronic device 80, and a second LED module 1000 is connected to the electronic device 110. The first LED module 90 and the second LED module 100 communicate with the electronic devices 80 and 110, respectively, using a local area network such as Ethernet, or the electronic device 80 through a USB interface. , 110). When the first and second LED modules 90 and 100 are configured to include a USB interface, the first and second LED modules 90 and 100 may be detachable from the electronic devices 80 and 110. As such, when the first and second LED modules 90 and 100 are connected through a USB interface, the Plug and Play function is supported, so that the electronic devices 80 and 110 are connected to the first and second LED modules 90 and 100. And 2 LED modules 90 and 100 and detect a hot swapping function, so that the first and second LED modules 90 and 100 are turned on even when the electronic devices 80 and 110 are turned on. It is possible to connect or disconnect). In addition, since the electronic devices 80 and 110 may supply power to the first and second LED modules 90 and 100 through a USB interface, the first and second LED modules 90 and 100 may be separated. It can be operated without a power source. Like the first and second LED modules 40 and 50 of the second embodiment, the first and second LED modules 90 and 100 may be used as lighting devices.

In addition, the electronic devices 80 and 110 are configured to first check each other's IDs or identification information to determine whether they are compatible, whether access / data transmission / reception is allowed, and then transmit / receive data The first and second LED modules 90 and 100 may be configured to allow bidirectional communication. Each of the first and second LED modules 90 and 100 is configured to allow both transmission and reception of data for bidirectional communication.

6 illustrates an example of the first LED module 90. 6 shows only the first LED module 90, the second LED module 100 is configured in the same manner as the first LED module 90. As shown in FIG. 6, the first LED module 90 includes a signal transceiver 91, an LED light emitter / receiver 92, a controller 93, and an LED driver 94. The signal transceiver 91 is configured to transmit and receive data with the electronic device 80. The LED light-receiving unit 92 may include one high power (3-5V, 1000 mA-3000 mA) LED or an array including a plurality of high power LEDs. In addition, the LED light emitting / receiving unit 92 may transmit an optical signal or receive an optical signal from the second LED module 100 through the amount or blink of visible light. The LED light-receiving unit 92 may be used as a lighting device while not being used for receiving an optical signal. When the LED light-receiving unit 92 receives an optical signal from the second LED module 100, the LED light-receiving unit 92 outputs an undifferential waveform signal. In this case, the signal transceiver 91 serves as an integrator for integrating the differential waveform signal. In addition, since the reverse bias is not applied to the LEDs in the LED light emitting / receiving unit 92 as in the LED light receiving unit 21 of FIG. 2, the first LED module 90 is a circuit necessary for applying the reverse bias. Does not require elements. The second LED module 100 is the same as the first LED module 90.

Fourth Example

7 shows a visible light communication system according to a fourth embodiment. As shown in FIG. 7, the visible light communication system according to the fourth embodiment includes a transmitter 120 and a receiver 130.

The transmitter 120 is configured to include a voice / audio signal unit 121, a frequency generator 122, a PWM modulator 123, and an LED light emitter 124. The voice / audio signal unit 121 generates and outputs a voice or audio signal or receives and outputs a voice or audio signal input from the outside. The frequency generator 122 generates and outputs a triangular wave between 100 KHz and 200 KHz. The PWM modulating unit 123 compares an analog signal output from the audio / audio signal unit 121, for example, an analog signal of less than 5 KHz, and a triangle wave output from the frequency generator 122, ) Outputs a signal. Here, the PWM modulator 123 may control the amount of light of the LED by changing the ratio of on (on) and off (off). For example, if a constant pulse is generated by adjusting the ratio of on time and off time (duty ratio), the LED light emitting unit 124 recognizes an average value of the on time of the pulse and applies a reduced voltage. Likewise, light can be generated. In this case, the LED light emitting unit 124 transmits a signal by controlling the amount of light (brightness). The LED light emitting unit 124 may be configured in the form of a single high power (3-5V, 1000mA-3000mA) LED or in the form of an array (array) comprising a plurality of high-power LED.

The receiver 130 includes an LED light receiver 131, a signal processor 132, an amplifier 133, and a speaker 134. Here, the LED light receiving unit 131 receives the visible light output from the LED light emitting unit 13 to generate an electrical signal. The LED light receiving unit 131 may be configured as an array including one high-power LED (3-5 V, 1000 mA-3000 mA) or an array including a plurality of high-power LEDs, and may be a wide frequency band A differential waveform signal can be output in response to visible light including a MHz (MHz) signal. The signal processor 132 includes an integrator (eg, a low pass filter of 5 KHz) and a PWM demodulator for demodulating the electrical signal, which integrates an electric signal of a differential waveform output from the LED light receiver 124. In particular, if the LED light receiver 124 functions as a differential (eg, a high pass filter) that outputs a differential waveform signal, the signal processor 132 may function as an integrator that integrates the differential waveform signal. To perform. The amplifier 133 amplifies the signal output from the signal processor 132 and outputs voice or audio through the speaker 134.

The LED light emitting unit 124 and the LED light receiving unit 131 may have the same structure as the LED light emitting unit 13 and the LED light receiving unit 21 shown in FIG. 2 and may be used as an illumination device. In particular, since the reverse bias is not applied to the LED in the LED light-receiving unit 31, a circuit / element or the like necessary for applying the reverse bias is not required.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

1, 2: LED light emitting unit
10, 120: transmitter 20, 130: receiver
11: line coding section 12: modulation section
124: LED light emitting unit 131: LED light receiving unit
22, 53 132: signal processor 40, 50, 90, 100: LED module
30, 70, 80, 110: electronic device 41: signal receiving / processing unit
42, 51, 93: control unit 43, 94: LED drive unit
121: voice / audio signal unit 122: frequency generator
123: PWM modulator 133: Amplifier
134: speaker 151: differentiator
152: frequency modulator

Claims (17)

A modulator for modulating a transmission signal;
A signal processor for processing a received signal; And
And a high power LED, when operating in a transmission mode, flashes the high power LED according to a modulated transmission signal output from the modulator, and when operating in a reception mode, receives the reception signal corresponding to the received optical signal. Including a LED light emitting / receiving unit for transmitting to the signal processor,
When the LED light emitting / receiving unit operates in the receiving mode, a reverse bias is not applied to the high power LED,
And the LED light emitting / receiving unit outputs a differential waveform signal corresponding to the received optical signal, and the signal processing unit includes an integrator for integrating the differential signal and a demodulator for demodulating the integrated signal. The method according to claim 1,
And the signal processing unit integrates and demodulates the received signal. delete The method according to claim 1,
And the LED light emitting / receiving unit is not provided with a circuit for applying a reverse bias to the high power LED. The method according to any one of claims 1, 2, and 4,
The LED light emitting / receiving unit
A driving transistor configured to receive the modulated transmission signal; And
The reception signal output from the high power LED when the LED light / receiver is operating in the transmission mode, and the output of the driving transistor to the high power LED; Visible communication device comprising a switch for transmitting to the signal processor. The method according to claim 1,
And said high power LED is operating as illumination when said LED light emitting / receiving unit is operating in said transmission mode, and said high power LED is off when said LED light emitting / receiving unit is operating in said receiving mode. A first LED module configured to include one or more high power LEDs for outputting data provided from the first electronic device to visible light;
And a second LED module configured to detect an optical signal from the visible light output from the first LED module and transmit the optical signal to a second electronic device, wherein the second LED module outputs the optical signal as an undifferential electric signal. It is configured to include a signal processing unit for integrating the above LED and the electrical signal and demodulate the integrated signal,
And the optical signal is detected without applying a reverse bias voltage to the LED in the second LED module. 8. The method of claim 7,
And said first electronic device is a lighting device. 8. The method of claim 7,
The second electronic device is a visible light communication system, characterized in that the portable terminal. 8. The method of claim 7,
And the first and second LED modules are respectively connected to the first and second electronic devices through a USB interface. 8. The method of claim 7,
The first and second LED modules are visible light communication system, characterized in that bi-directional communication. delete 8. The method of claim 7,
The second module
A resistance element for outputting the electrical signal output from the LED to the signal processor;
A transistor for controlling the LED;
And a switch for selectively coupling one of said resistor and said transistor to said LED. Outputting data provided from the first electronic device to visible light using a first LED module including one or more high power LEDs;
Receiving the visible light using a second LED module comprising one or more LEDs;
Converting an optical signal included in the visible light into an electric signal of a differential waveform, integrating the electric signal, demodulating the integrated signal, and transmitting the integrated signal to a second electronic device;
And detecting the optical signal without applying a reverse bias voltage to the LED in the second LED module. 15. The method of claim 14,
And the first and second LED modules are respectively connected to the first and second electronic devices through a USB interface. 15. The method of claim 14,
The first and second LED modules are visible light communication method characterized in that bi-directional communication. delete

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