Visible light communication system and method therefor

• US 20070058987A1
• Filed: 08/31/2006
• Published: 03/15/2007
• Est. Priority Date: 09/13/2005
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Suzuki, Katsuyoshi
• Granted Patent: US 7,949,259 B2
• Time in Patent Office: Days
• US Class Current: 398/183
• CPC Class Codes: H04B 10/1141 One-way transmission
• CPC Class Codes: H04B 10/116 Visible light communication

Abstract

In a visible light communication system, a transmission device includes a data modulation section which assigns 1-bit information to each of visible lights of RGB, and modulates transmission data into 3-bit modulation data. An LED light emission section transmits a multiplexed visible light signal, in which the RGB visible lights are multiplexed in accordance with the modulation data.

Claims

1. A visible light communication system including a transmission device which transmits a visible light signal and a reception device which receives the visible light signal, the transmission device comprising:

light emission means for emitting visible lights of red, green and blue;

data modulation means for assigning 1-bit information to each of the visible lights and modulating transmission data into 3-bit modulation data; and

transmission control means for driving and controlling the light emission means in accordance with the modulation data which is output from the data modulation means, and transmitting a multiplexed visible light signal, in which the visible lights are multiplexed, from the light emission means.

2. The visible light communication system according to claim 1, wherein the reception device includes:

light reception means for receiving the multiplexed visible light signal which is transmitted from the light emission means, separating the received multiplexed visible light signal into the visible lights, and outputting reception data which is obtained by the separation; and

means for demodulating the transmission data from the reception data which is output from the light reception means.

3. The visible light communication system according to claim 1, wherein the light emission means includes:

light-emitting diode elements which emit visible lights of red, green and blue; and

driving means for driving the light-emitting diode elements in accordance with a control of the transmission control means, and emitting the visible lights at the same time or selectively.

4. The visible light communication system according to claim 1, wherein the reception means includes data reproduction means for reproducing the transmission data.

5. A visible light communication system including a transmission device which transmits a visible light signal and a reception device which receives the visible light signal, the transmission device comprising:

light emission means for emitting visible lights of red, green and blue;

data modulation means for assigning 1-bit information to each of the visible lights and modulating transmission data into 3-bit modulation data; and

transmission means for driving and controlling the light emission means in accordance with the modulation data and inverted bit data of the modulation data, and transmitting a multiplexed visible light signal, which corresponds to the modulation data and the inverted bit data of the modulation data, from the light emission means.

6. The visible light communication system according to claim 5, wherein the reception device includes:

means for receiving the multiplexed visible light signal which is transmitted from the light emission means; and

means for extracting and demodulating the multiplexed visible light signal which corresponds to the modulation data.

7. The visible light communication system according to claim 5, wherein the light emission means includes:

light-emitting diode elements which emit visible lights of red, green and blue; and

driving means for driving the light-emitting diode elements, and emitting the visible lights at the same time or selectively.

8. A visible light communication system including a transmission device which transmits transmission data by a visible light signal and a reception device which receives the visible light signal, the reception device comprising:

filter means for receiving visible light signals of red, green and blue from the transmission device, and extracting each of the visible light signals;

means for demodulating the transmission data from the visible light signal that is extracted by the filter means; and

means for reproducing the demodulated transmission data.

9. The visible light communication system according to claim 8, wherein the filter means is a replaceable optical filter member.

10. The visible light communication system according to claim 8, wherein the filter means is composed of a device having a function of selectively extracting the visible light signals of red, green and blue, and

the visible light communication system includes control means for controlling the filter means and causing the filter means to selectively extract a visible light signal, which is an object of reception, from the received visible light signals.

11. A transmission method which is applied to a visible light communication system including a transmission device which transmits a multiplexed visible light signal in which visible light signals of red, green and blue are multiplexed, and a reception device which receives the multiplexed visible light signal, comprising:

a step of assigning 1-bit information to each of the visible light signals and modulating transmission data into 3-bit modulation data; and

a step of modulating the visible light signals in accordance with the modulation data, and transmitting the multiplexed visible light signal in which the visible lights are multiplexed.

12. A transmission method which is applied to a visible light communication system including a transmission device which transmits visible light signals of red, green and blue, and a reception device which receives the visible light signals, comprising:

a step of assigning 1-bit information to each of the visible light signals and modulating transmission data of a 3-bit string; and

a step of transmitting a multiplexed visible light signal corresponding to the modulation data and inverted bit data of the modulation data.

13. A transmission method which is applied to a visible light communication system including a transmission device which transmits transmission data by visible light signals of red, green and blue, and a reception device which receives the visible light signals, comprising:

a step of receiving the visible light signals of red, green and blue from the transmission device, and extracting each of the visible light signals;

a step of demodulating the transmission data corresponding to the extracted visible light signal; and

a step of reproducing the demodulated transmission data.