CN104038288B - A kind of visible light communication system based on natural optic communication - Google Patents

Abstract

The invention discloses a kind of visible light communication system based on natural optic communication, including receive nature light, the intensity of the described natural light that detection receives the brightness detecting module of output detections result；Receive nature light, according to the testing result of described brightness detecting module output, select the natural optical modulator module of the described natural light with the modulation of described testing result corresponding modulation system；Wherein, described testing result and described modulation system one_to_one corresponding.The present invention is modulated with natural light for carrier, compared to artificial light sources lighting apparatus more environment protecting and power-savings such as LED, and there is not the problem bringing harm to human body.Simultaneously by way of using the natural light of nature optical modulator module directly modulation, it is to avoid the limited problem of the modulation bandwidth that causes due to LED characteristic in visible light communication.

Description

A Visible Light Communication System Based on Natural Light Communication

technical field

The present invention relates to the technical field of visible light communication, and more specifically, to a visible light communication system based on natural light communication.

Background technique

With the rapid development of visible light communication technology, white light LED (Light-Emitting Diode, Light Emitting Diode) visible light communication technology has been widely used.

White LEDs are mainly divided into two categories: RGB LEDs (red-green-blue LEDs) and pseudo-white LEDs. Compared with RGB LEDs, pseudo-white LEDs occupy the main lighting market because of their low complexity and low cost. Pseudo-white LEDs are composed of a blue light-emitting chip and a layer of yellow phosphor that cooperate with each other. The blue light is filtered by a yellow filter to form a pseudo-white light. However, the modulation bandwidth of pseudo-white LEDs is limited to a few MHz due to the long response time of the phosphor.

After extensive research on existing visible light communication technologies, the inventors found that LEDs are used as transmitting antennas in existing visible light communication technologies, that is, artificial light source lighting devices such as LEDs are used as visible light transmitting terminals in the prior art. However, because the artificial light source LED emits rays, light source flicker and high illuminance will seriously affect the human visual nerve, and even disrupt the human body's biological clock and circadian rhythm, long-term use of LED light source will bring harm to the human body. At the same time, LEDs are affected by the response time, causing their modulation bandwidth to be limited.

Contents of the invention

In view of the above problems, the present invention provides a visible light communication system based on natural light communication, which realizes visible light communication based on natural light, is environmentally friendly and overcomes the problem of limited LED modulation bandwidth. The technical solution is as follows:

The present invention provides a visible light communication system based on natural light communication, including:

A natural light detection module that receives natural light, detects the intensity of the received natural light and outputs the detection result;

receiving natural light, and selecting a modulation mode corresponding to the detection result to modulate the natural light modulation module according to the detection result output by the natural light detection module;

Wherein, the detection result is in one-to-one correspondence with the modulation mode.

Preferably, the natural light modulation module includes an electronically controlled liquid crystal and a natural light modulation unit; wherein the electrically controlled liquid crystal includes a liquid crystal layer, and when different electrical signals are applied to each area of the liquid crystal layer, the arrangement direction and position of the liquid crystal molecules change accordingly ;

The natural light modulation unit is used to select a modulation method corresponding to the detection result according to the detection result output by the natural light detection module;

The electronically controlled liquid crystal is used to control each region on the liquid crystal layer to apply different electrical signals according to the modulation mode selected by the natural light modulation unit, so as to control the modulation and loading of data information into the natural light, and complete the adjustment of the natural light modulation.

Preferably, the modulation method includes a binary on-off keying OOK modulation method, a pulse amplitude modulation 4PAM modulation method or an orthogonal frequency division multiplexing technology OFDM modulation method.

Preferably, the natural light detection module includes an electrical signal detection module and at least one electrical signal generation module; wherein,

The electrical signal generating module is configured to receive the natural light and generate an electrical signal according to the received natural light; wherein, the intensity of the received natural light corresponds to the intensity of the generated electrical signal;

The electric signal detection module is used to detect the strength of the electric signal generated by the electric signal generation module, and output the strength of the electric signal as the detection result.

Preferably, detecting the strength of the electric signal generated by the electric signal generating module by the electric signal detection module includes: calculating the strength of the electric signal by the electric signal detection module according to a preset algorithm, and determining the strength of the electric signal intensity level; among them,

When the electrical signal detection module determines that the intensity level of the electrical signal is excellent, the natural light modulation module selects an OFDM modulation method;

When the electrical signal detection module determines that the intensity level of the electrical signal is good, the natural light modulation module selects a 4PAM modulation method;

When the electrical signal detection module determines that the intensity level of the electrical signal is poor, the natural light modulation module selects an OOK modulation method.

Preferably, the electrical signal generating module includes a photodetector.

Preferably, the natural light detection module further includes at least one light sensor for detecting the incident angle of the natural light, so as to determine the relative position of the natural light source and the natural light detection module.

Preferably, the light sensor is a sun sensor.

Applying the above technical solution, the present invention provides a visible light communication system based on natural light communication. In the present invention, the natural light detection module receives natural light, detects the intensity of the received natural light and outputs the detection result, and then the natural light modulation module according to the natural light detection module For the output detection result, select a modulation mode corresponding to the detection result to modulate the natural light. Therefore, the present invention uses natural light as a carrier for modulation, which is more environmentally friendly and energy-saving than artificial light source lighting equipment such as LEDs, and does not cause harm to the human body. At the same time, by using the natural light modulation module to directly modulate natural light, the problem of limited modulation bandwidth caused by LED characteristics in visible light communication is avoided.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

FIG. 1 is a schematic structural diagram of a visible light communication system based on natural light communication provided by the present invention;

2 is a schematic structural diagram of a natural light modulation module in a visible light communication system based on natural light communication provided by the present invention;

FIG. 3 is another structural schematic diagram of a visible light communication system based on natural light communication provided by the present invention;

4 is a schematic structural diagram of a natural light detection module in a visible light communication system based on natural light communication provided by the present invention;

FIG. 5 is another structural schematic diagram of a natural light detection module in a visible light communication system based on natural light communication provided by the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The visible light communication system based on natural light communication protected by the present invention may be a specific physical device, which includes a natural light detection module and a natural light modulation module. The natural light detection module and the natural light modulation module may also be two independent physical devices, and the two are used together. The visible light communication system based on natural light communication provided by the present invention can be specifically arranged on objects such as glass that can realize light transmission, so as to receive and modulate natural light emitted by natural light sources such as the sun.

Embodiment one

Please refer to FIG. 1 , which shows a schematic structural diagram of a visible light communication system based on natural light communication provided by the present invention, including: a natural light detection module 100 and a natural light modulation module 200 . in,

The natural light detection module 100 is used for receiving natural light, detecting the intensity of the received natural light and outputting the detection result.

In this embodiment, the natural light detection module 100 can be independently installed around or in the center of the glass or at any other position to receive natural light and detect the intensity of the received natural light, and then output the detected detection results to the natural light modulation module 200.

The natural light modulation module 200 is used to receive natural light, and select a modulation method corresponding to the detection result to modulate the natural light according to the detection result output by the natural light detection module 100 .

Wherein, there is a one-to-one correspondence between the detection result and the modulation mode.

In this embodiment, the natural light modulation module 200 can be independently installed around or in the center of the glass or at any other position, and it is connected with the natural light detection module 100 in communication.

Of course, the present invention can also integrate the natural light detection module 100 and the natural light modulation module 200 into a physical device, which is installed around or in the center of the glass or at any other position.

In the present invention, the intensity level of natural light can be preset. After the natural light detection module 100 detects the intensity of natural light, it determines the current intensity level of natural light according to the detected intensity value of natural light, and outputs the current intensity level of the electric signal as the detection result. At the same time, different modulation modes can also be set in advance according to the strength levels of different electrical signals. After receiving the detection result output by the natural light detection module 100, the natural light modulation module 200 selects a modulation method corresponding to the detection result to modulate the natural light.

Applying the above-mentioned technical solution of the present invention, the present invention receives natural light through the natural light detection module 100, detects the intensity of the received natural light and outputs the detection result, and then the natural light modulation module 200 selects the detection result output by the natural light detection module 100 according to the The modulation mode corresponding to the detection result modulates the natural light. Therefore, the present invention uses natural light as the carrier for modulation, which is more environmentally friendly and energy-saving than artificial light source lighting equipment such as LEDs, and does not cause harm to the human body. At the same time, by using the natural light modulation module to directly modulate natural light, the problem of limited modulation bandwidth due to LED characteristics in visible light communication is avoided.

Based on the above embodiments, refer to FIG. 2 , which shows a schematic structural diagram of a natural light modulation module in a visible light communication system based on natural light communication provided by the present invention. in,

The natural light modulation module 200 includes an electronically controlled liquid crystal 210 and a natural light modulation unit 220 . Wherein, the electronically controlled liquid crystal 210 includes a liquid crystal layer 211 , and when different electrical signals are applied to each area of the liquid crystal layer 211 , the arrangement direction and position of the liquid crystal molecules change accordingly.

In this embodiment, the liquid crystal layer 211 in the electronically controlled liquid crystal 210 is used as a light modulation material, and the liquid crystal layer 211 adopts a nematic liquid crystal mixed field effect working mode. Applying different electrical signals to various regions on the liquid crystal layer 211 can cause changes in the arrangement direction and position of the liquid crystal molecules, thereby resulting in changes in the optical properties of the electrically controlled liquid crystal 210 .

The natural light modulation unit 220 is configured to select a modulation method corresponding to the detection result according to the detection result output by the natural light detection module 100 .

In this embodiment, the detection result may include the intensity level of the electrical signal. Wherein, the intensity level of the electrical signal can be divided into three levels: excellent, good, and poor. The modulation method may include OOK (On-OffKeying, binary on-off keying) modulation method, 4PAM (Pulse Amplitude Modulation, pulse amplitude modulation) modulation method, and OFDM (Orthogonal Frequency Division Multiplexing, orthogonal frequency division multiplexing technology) modulation method.

At this time, the electronically controlled liquid crystal 210 is specifically used to control each region on the liquid crystal layer 211 to apply different electrical signals according to the modulation mode selected by the natural light modulation unit 220, so as to control the modulation and loading of data information into the natural light and complete the modulation of the natural light.

In order to better realize the description of the present invention, please refer to FIG. 3 , which shows another schematic structural diagram of a visible light communication system based on natural light communication provided by the present invention. in,

The outside of the visible light communication system based on natural light communication protected by the present invention includes a glass substrate 300 . The glass substrate 300 is AR high-transparency anti-reflection glass, the peak transmittance can reach 99%, and the reflectance is <1%. The hardness of the AR glass film layer is required to be equivalent to that of glass, greater than 7H, and has strong impact resistance.

Setting the natural light detection module 100 on the glass substrate 300 may include setting the natural light detection module 100 around the glass substrate 300 , or setting the natural light detection module 100 at any position on the glass substrate 300 . Preferably, a plurality of natural light detection modules 100 are evenly arranged on the periphery and the center of the glass substrate 300 . The natural light detection module 100 receives natural light from the sun, detects the intensity of the received natural light and outputs the detection result to the natural light modulation module 200 .

The natural light modulation unit 220 in the natural light modulation module 200 selects a modulation method corresponding to the detection result according to the detection result output by the natural light detection module 100. At this time, the electronically controlled liquid crystal 210 controls each area on the liquid crystal layer according to the modulation method selected by the natural light modulation unit 220. Different electrical signals are used to control the alignment and position of liquid crystal molecules, and to modulate the intensity of natural light passing through the liquid crystal layer 211 to load information. Through the natural light modulation module 200 , the natural light is modulated after passing through the glass substrate 300 .

On the basis of the above embodiments, refer to FIG. 4 , which shows a schematic structural diagram of a natural light detection module in a visible light communication system based on natural light communication provided by the present invention. in,

The natural light detection module 100 includes an electrical signal detection module 110 and at least one electrical signal generation module 120 . in,

The electrical signal generating module 120 is used for receiving natural light, and generating an electrical signal according to the received natural light. Wherein, the intensity of the received natural light is in one-to-one correspondence with the intensity of the generated electrical signal.

In this embodiment, the intensity of natural light is directly proportional to the intensity of the electrical signal. The stronger the intensity of the natural light, the higher the intensity of the electrical signal generated by the electrical signal generating module 120 , and the lower the intensity of the natural light, the lower the intensity of the electrical signal generated by the electrical signal generating module 120 . Therefore, the intensity of received natural light can be detected by detecting the intensity of the generated electrical signal.

In the actual application process, the electrical signal generating module 120 will receive interference from other lights in the natural environment. In order to ensure the accuracy of the electrical signal detected by the electrical signal generating module 120, preferably, multiple electrical signal generating modules are included 120, respectively detecting natural light from different angles.

In the present invention, preferably, the electrical signal generating module 120 may be a photodetector that converts optical signals into electrical signals. Therefore, the greater the intensity of natural light, the stronger the intensity of the electrical signal converted by the photodetector.

The electric signal detection module 110 is used to detect the strength of the electric signal, and output the strength of the electric signal as the detection result.

In this embodiment, the electrical signal detection module 110 calculates the intensity of the electrical signal according to a preset algorithm, and determines the intensity level of the electrical signal. In the actual application process, conditions such as the size of the light intensity in the natural environment, the requirements of the target transmission rate, and the limitation of the bit error rate need to be considered. Strength, and then determine the strength level of the electrical signal to ensure the accuracy of the system.

At this time, the natural light modulation unit 220 is specifically configured to select a modulation method corresponding to the intensity level of the electrical signal determined by the electrical signal detection module 110 .

Specifically, it may include:

When the electrical signal detection module 110 determines that the intensity level of the electrical signal is excellent, the natural light modulation unit 220 selects the OFDM modulation mode;

When the electrical signal detection module 110 determines that the intensity level of the electrical signal is good, the natural light modulation unit 220 selects the 4PAM modulation mode;

When the electrical signal detection module 110 determines that the intensity level of the electrical signal is poor, the natural light modulation unit 220 selects the OOK modulation mode.

On the basis of the above embodiments, please refer to FIG. 5 , which shows another schematic structural diagram of a natural light detection module in a visible light communication system based on natural light communication provided by the present invention. Wherein, the natural light detection module 100 further includes at least one light sensor 130 . Wherein, the light sensor 130 is used to detect the incident angle of natural light, so as to determine the relative position of the natural light source and the natural light detection module 100 .

In this embodiment, the light sensor 130 is a sun sensor.

Specifically, the light sensor 130 detects the incident angle of the natural light, and the relative position of the natural light source relative to the natural light detection module 100 can be determined by judging the incident angle of the natural light. Furthermore, the direction of introducing natural light is adjusted according to the determined relative position of the natural light source relative to the natural light detection module 100, so as to ensure sufficient introduction of natural light.

It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. For the same and similar parts in each embodiment, refer to each other, that is, Can.

Finally, it should also be noted that in this text, relational terms such as first and second etc. are only used to distinguish one entity or operation from another, and do not necessarily require or imply that these entities or operations, any such actual relationship or order exists. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

A visible light communication system based on natural light communication provided by the present invention has been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the present invention. method and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. In summary, the content of this specification should not be understood as Limitations on the Invention.

Claims (8)

1. A visible light communication system based on natural light communication, characterized in that, comprising: A natural light detection module that receives natural light, detects the intensity of the received natural light and outputs the detection result; receiving natural light, and selecting a modulation mode corresponding to the detection result to modulate the natural light modulation module according to the detection result output by the natural light detection module; Wherein, the detection result is in one-to-one correspondence with the modulation mode. 2. The system according to claim 1, wherein the natural light modulation module includes an electronically controlled liquid crystal and a natural light modulation unit; wherein the electrically controlled liquid crystal includes a liquid crystal layer, and different regions of the liquid crystal layer are applied with different The direction and position of the liquid crystal molecules change accordingly when the electrical signal is applied; The natural light modulation unit is used to select a modulation method corresponding to the detection result according to the detection result output by the natural light detection module; The electronically controlled liquid crystal is used to control each region on the liquid crystal layer to apply different electrical signals according to the modulation mode selected by the natural light modulation unit, so as to control the modulation and loading of data information into the natural light, and complete the adjustment of the natural light modulation. 3. The system according to claim 2, wherein the modulation method comprises a binary on-off keying (OOK) modulation method, a pulse amplitude modulation (4PAM) modulation method or an orthogonal frequency division multiplexing technology (OFDM) modulation method. 4. The system according to claim 1, wherein the natural light detection module comprises an electrical signal detection module and at least one electrical signal generation module; wherein, The electrical signal generation module is configured to receive the natural light and generate an electrical signal according to the received natural light; wherein, the intensity of the received natural light corresponds to the intensity of the generated electrical signal; The electric signal detection module is used to detect the strength of the electric signal generated by the electric signal generation module, and output the strength of the electric signal as the detection result. 5. The system according to claim 4, wherein the detection by the electrical signal detection module of the strength of the electrical signal generated by the electrical signal generation module comprises: the electrical signal detection module calculates the strength of the electrical signal according to a preset algorithm. the strength of the electrical signal, and determine the strength level of the electrical signal; wherein, When the electrical signal detection module determines that the intensity level of the electrical signal is excellent, the natural light modulation module selects the OFDM modulation method; When the electrical signal detection module determines that the intensity level of the electrical signal is good, the natural light modulation module selects a 4PAM modulation method; When the electrical signal detection module determines that the intensity level of the electrical signal is poor, the natural light modulation module selects an OOK modulation method. 6. The system of claim 4, wherein the electrical signal generating module comprises a photodetector. 7. The system according to claim 4, wherein the natural light detection module further comprises at least one light sensor for detecting the incident angle of the natural light to determine the relative position of the natural light source and the natural light detection module . 8. The system of claim 7, wherein the light sensor is a sun sensor.