CN116846472B - Visible light communication method between television screen and smart phone - Google Patents

Abstract

The invention discloses a visible light communication method between a TV screen and a smart phone, and relates to the field of visible light communication. The TV screen is divided into a template layer, a core layer, a redundant layer and an additional layer to realize parallel transmission of information; on the screen Define multiple pixel blocks and rely on the template layer pixel blocks to modulate the pixel block distribution, demodulation rules and splicing rules. The core layer transmits the main information, the redundant layer is the backup of the core layer, and the additional layer provides additional information; the smartphone camera captures The TV screen information is demodulated and spliced based on the template layer information; if the core information is damaged, redundant information is used to repair it and finally displayed on the mobile phone. The core advantage lies in the realization of efficient, stable and reliable visible light communication.

Description

A visible light communication method between a TV screen and a smartphone

Technical field

The present invention relates to the field of visible light communication, and more specifically, to a visible light communication method between a television screen and a smart phone.

Background technique

With the rapid development of smart phones and Internet technology, information delivery systems play an increasingly important role in people's daily lives. Traditional information transmission systems mainly rely on wired or radio wave communications. However, these communication methods may be affected by problems such as interference and signal attenuation in certain environments, thereby reducing the rate and quality of information transmission. Therefore, studying a new type of information delivery system has important practical significance.

In recent years, visible light communication technology has gradually become a communication method that has attracted much attention.

VLC mainly uses the visible light band, which is the light wave that the human eye can perceive (approximately from 400 nanometers to 700 nanometers) to transmit data. It modulates digital signals into light wave signals for transmission. Compared with other wireless communication technologies, VLC has a potential high-bandwidth advantage because the frequency band of visible light is very wide. In practical applications, VLC can usually reach a transmission rate of hundreds of Mbps or even Gbps, but its transmission distance is shorter, usually between a few meters and tens of meters.

Currently, the application of visible light communication between smartphones and TVs is still in the exploratory stage, and the challenge of how to efficiently transmit digital information on dense screen pixels needs to be solved. Such applications are meaningful in certain scenarios. For example, when the network condition is poor and the information to be transmitted is not efficient enough to be displayed on TV alone, or it cannot be guaranteed that everyone can watch it again, using visible light communication and Communication on mobile phones has meaning. For example, when it involves some relatively confidential information that is inconvenient to display directly on a large screen, visible light communication signals can be transmitted through the TV screen, and only authorized people can use their smartphones to demodulate the signal after entering a password. getting information.

Contents of the invention

The technical problem to be solved by the present invention is to provide a visible light communication method between a television screen and a smart phone to solve the problems mentioned in the background art.

In order to achieve the above objects, the present invention adopts the following technical solutions:

A visible light communication method between a TV screen and a smartphone, including the following steps:

S1: Divide the TV screen into template layer, core layer, redundant layer and additional layer. The template layer is located in the center of the TV screen, the core layer is set around the template layer, the redundant layer is set around the core layer, and the additional layer is set around the redundant layer. set up;

S2: Divide multiple pixel blocks on the TV screen. Each pixel block is composed of multiple adjacent pixels. The size of the pixel block is determined based on the TV screen resolution and the smartphone camera resolution so that the camera can clearly distinguish each pixel. piece;

Only one pixel block is set in the template layer;

Multiple pixel blocks are distributed in the core layer, redundant layer and additional layer;

S3: Modulate the pixel block distribution information, pixel block demodulation rule information, and pixel block information splicing rules of the TV screen to the template layer pixel blocks;

Modulate the core information onto the core layer, where different pixel blocks on the core layer transmit multiple pieces of different information in parallel;

Modulate the redundant information onto the redundant layer, where the redundant information is the same as the core information, and different pixel blocks on the redundant layer transmit multiple pieces of different information in parallel;

Modulating additional information onto an additional layer, wherein different pixel blocks on the additional layer transmit multiple pieces of different information in parallel;

S4: The smartphone uses the camera to receive the TV screen information. The smartphone decodes the received information on the template layer pixel blocks, and based on the decoded pixel block distribution information, pixel block demodulation rule information, and pixel block information splicing rules, Multiple pieces of different information transmitted in parallel by different pixel blocks on the core layer are demodulated and spliced to obtain core information. Multiple pieces of different information transmitted in parallel by different pixel blocks on the redundant layer are demodulated and spliced to obtain redundant information. The additional layers are Multiple pieces of different information transmitted in parallel from different pixel blocks are demodulated and spliced to obtain additional information;

S5: The smartphone compares the decoded core information with the redundant information. When the core information is damaged or incomplete, the redundant information is used to supplement or repair the core information;

S6: According to the pixel block information splicing rules, the smartphone combines the redundant information with the supplemented or repaired core information to form the final information and displays it on the smartphone screen.

In some embodiments, during the modulation process, the information to be transmitted in the core layer or the redundant layer or the additional layer is encoded to obtain a continuous digital signal sequence. This sequence is divided into multiple subsequences, where each subsequence corresponds to a pixel. blocks are transferred.

In some embodiments, the modulation process further includes:

Use PWM or OOK to modulate each subsequence so that each digital bit is converted to a specific brightness or color;

Using OFDM technology, the PWM or OOK modulated subsequences are allocated to different frequency subcarriers, and different frequency subcarriers are mapped to different pixel blocks for transmission.

In some embodiments, forward error correction coding is applied to each pixel block in the core layer to improve the reliability of information transmission.

In some embodiments, the forward error correction coding is Reed-Solomon coding or LDPC coding.

In some embodiments, the information conveyed by the television screen includes but is not limited to text, image, sound and video information.

In some embodiments, the smartphone first stores the information transferred in the core layer, redundant layer and additional layer to the memory or hard disk, and first demodulates the information in the template layer. After the demodulation of the information in the template layer is completed, The information transmitted by the core layer, redundant layer and additional layer is then retrieved for demodulation.

In some embodiments, the method further includes: the smart phone also needs to enter a password before demodulation. This is especially useful when sensitive information cannot be displayed directly on a large screen.

The advantages of the present invention over the prior art are:

1. Traditional visible light communication technology may encounter difficulties in identifying individual pixels due to the resolution limitations of smartphone cameras and the pixel density of TV screens. The invention introduces the concept of pixel blocks. Each pixel block is composed of multiple adjacent pixels. This design enables the smart phone to clearly distinguish and decode the information of each pixel block, thus greatly improving the accuracy and stability of communication. sex.

2. In the present invention, by dividing the TV screen into template layer, core layer, redundant layer and additional layer, and placing key information in the center of the screen, this design improves the reliability of information transmission. Especially the redundancy layer, its existence ensures that even when there is a problem with data transmission at the core layer, the lost or damaged data can be repaired and supplemented through the redundancy layer, thus greatly enhancing the reliability of data transmission.

3. The present invention uses multiple pieces of information to be transmitted in parallel, and this design provides an efficient information transmission method. By dividing the information into multiple sub-sequences and transmitting them in parallel, the transmission speed is increased. Combined with the template area information, the demodulation can be carried out smoothly. This design can significantly improve the data transmission efficiency and success rate in practical applications. .

4. The present invention sets up a template area, which contains the distribution information of pixel blocks, pixel block demodulation rules and splicing rules. This means that for different template settings, the smart phone can perform corresponding demodulation according to the template information transmitted by it, so that the present invention has high universality in different devices and application scenarios.

Description of the drawings

Figure 1 is a schematic flow diagram of the method of the present invention;

Figure 2 is a layered schematic diagram of a television screen according to the present invention.

Detailed ways

Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

The present invention is a visible light communication method between a TV screen and a smart phone, as shown in Figure 1, including the following steps:

S1: As shown in Figure 2, the present invention divides the TV screen into a template layer (the small square in the center in Figure 2), a core layer, a redundant layer and an additional layer. The template layer is located in the center of the TV screen and the core layer surrounds it. The template layer is set, the redundant layer is set around the core layer, and the additional layer is set around the redundant layer;

S2: Divide multiple pixel blocks on the TV screen. Each pixel block is composed of multiple adjacent pixels. The size of the pixel block is determined based on the TV screen resolution and the smartphone camera resolution so that the camera can clearly distinguish each pixel. piece;

Only one pixel block is set in the template layer;

Multiple pixel blocks are distributed in the core layer, redundant layer and additional layer;

S3: Modulate the pixel block distribution information, pixel block demodulation rule information, and pixel block information splicing rules of the TV screen to the template layer pixel blocks;

Modulate the core information onto the core layer, where different pixel blocks on the core layer transmit multiple pieces of different information in parallel;

Modulate the redundant information onto the redundant layer, where the redundant information is the same as the core information, and different pixel blocks on the redundant layer transmit multiple pieces of different information in parallel;

Modulating additional information onto an additional layer, wherein different pixel blocks on the additional layer transmit multiple pieces of different information in parallel;

S4: The smartphone uses the camera to receive the TV screen information. The smartphone decodes the received information on the template layer pixel blocks, and based on the decoded pixel block distribution information, pixel block demodulation rule information, and pixel block information splicing rules, Multiple pieces of different information transmitted in parallel by different pixel blocks on the core layer are demodulated and spliced to obtain the core information. Multiple pieces of different information transmitted in parallel by different pixel blocks on the redundant layer are demodulated and spliced to obtain redundant information. Different pieces of information on the additional layer are demodulated and spliced to obtain redundant information. Multiple pieces of different information transmitted in parallel by pixel blocks are demodulated and spliced to obtain additional information;

S5: The smartphone compares the decoded core information with the redundant information. When the core information is damaged or incomplete, the redundant information is used to supplement or repair the core information;

S6: According to the pixel block information splicing rules, the smartphone combines the redundant information with the supplemented or repaired core information to form the final information and displays it on the smartphone screen.

In some embodiments, during the modulation process, the information to be transmitted in the core layer or the redundant layer or the additional layer is encoded to obtain a continuous digital signal sequence. This sequence is divided into multiple subsequences, where each subsequence corresponds to a pixel. blocks are transferred.

In some embodiments, the modulation process further includes:

Use PWM or OOK to modulate each subsequence so that each digital bit is converted to a specific brightness or color;

Using OFDM technology, the PWM or OOK modulated subsequences are allocated to different frequency subcarriers, and different frequency subcarriers are mapped to different pixel blocks for transmission.

in:

PWM (Pulse Width Modulation) is pulse width modulation, which is a technology that converts between analog signals and digital signals.

OOK (On-Off Keying) is on-off keying or on-off modulation.

OFDM (Orthogonal Frequency Division Multiplexing) is orthogonal frequency division multiplexing. It is a digital modulation technology that divides a single data stream into multiple smaller data streams. Each data stream is modulated on its own independent subcarrier. . All these subcarriers are orthogonal, meaning there is no interference between them. OFDM can effectively resist multipath fading and is widely used in wireless communications such as Wi-Fi and LTE.

In some embodiments, forward error correction coding is applied to each pixel block in the core layer to improve the reliability of information transmission.

In some embodiments, the forward error correction encoding is Reed-Solomon encoding or LDPC encoding

In some embodiments, the information conveyed by the television screen includes, but is not limited to, text, image, sound, and video information.

In some embodiments, the smartphone first stores the information transferred in the core layer, redundant layer and additional layer to the memory or hard disk, and first demodulates the information in the template layer. After the demodulation of the information in the template layer is completed, The information transmitted by the core layer, redundant layer and additional layer is then retrieved for demodulation.

In some embodiments, the method further includes: the smartphone needs to enter a password before demodulating.

Since the present invention transmits information directly in a local area, it does not need to rely on the Internet or build a cloud platform, and the information will not be directly displayed on the screen. Therefore, the possible application scenarios of the present invention include:

1) In specific emergencies, such as during earthquakes, typhoons or other disasters, when traditional communication infrastructure is affected and cannot work properly, TV stations can send emergency messages or instructions through their screens, and smartphone users only need to You can quickly receive these messages by pointing your phone at the screen.

2) Merchants can play advertisements with preferential information on TV screens in shopping malls, subway stations or other public places. Customers can receive these offers directly on their mobile phones without scanning QR codes or downloading any apps.

3) In academic seminars or lectures, researchers may need to share their latest research results. In order to prevent unauthorized persons from viewing or stealing these studies in advance, information can be transmitted through a large screen, but participants need to enter a password given by the researcher before they can receive and view it.

4) In banks or other financial institutions, customers may need to confirm large transfers or specific financial operations. To ensure the security of these operations, financial institutions can display confirmation information on their large screens, and customers need to enter their corresponding passwords on their mobile phones before they can view and confirm it, to prevent other customers from seeing their information.

It can be seen that the present invention has relatively broad application prospects.

The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can, within the technical scope disclosed in the present invention, implement the technical solutions of the present invention. Equivalent substitutions or changes of the inventive concept thereof shall be included in the protection scope of the present invention.

Claims (8)

1. A visible light communication method between a TV screen and a smart phone, characterized in that it includes the following steps: S1: Divide the TV screen into template layer, core layer, redundant layer and additional layer. The template layer is located in the center of the TV screen, the core layer is set around the template layer, the redundant layer is set around the core layer, and the additional layer is set around the redundant layer. set up; S2: Divide multiple pixel blocks on the TV screen. Each pixel block is composed of multiple adjacent pixels. The size of the pixel block is determined based on the TV screen resolution and the smartphone camera resolution so that the camera can clearly distinguish each pixel. piece; Only one pixel block is set in the template layer; Multiple pixel blocks are distributed in the core layer, redundant layer and additional layer; S3: Modulate the pixel block distribution information, pixel block demodulation rule information, and pixel block information splicing rules of the TV screen to the template layer pixel blocks; Modulate the core information onto the core layer, where different pixel blocks on the core layer transmit multiple pieces of different information in parallel; Modulate the redundant information onto the redundant layer, where the redundant information is the same as the core information, and different pixel blocks on the redundant layer transmit multiple pieces of different information in parallel; Modulating additional information onto an additional layer, wherein different pixel blocks on the additional layer transmit multiple pieces of different information in parallel; S4: The smartphone uses the camera to receive the TV screen information. The smartphone decodes the received information on the template layer pixel blocks, and based on the decoded pixel block distribution information, pixel block demodulation rule information, and pixel block information splicing rules, Multiple pieces of different information transmitted in parallel by different pixel blocks on the core layer are demodulated and spliced to obtain core information. Multiple pieces of different information transmitted in parallel by different pixel blocks on the redundant layer are demodulated and spliced to obtain redundant information. The additional layers are Multiple pieces of different information transmitted in parallel from different pixel blocks are demodulated and spliced to obtain additional information; S5: The smartphone compares the decoded core information with the redundant information. When the core information is damaged or incomplete, the redundant information is used to supplement or repair the core information; S6: According to the pixel block information splicing rules, the smartphone combines the redundant information with the supplemented or repaired core information to form the final information and displays it on the smartphone screen. 2. The visible light communication method between the TV screen and the smart phone according to claim 1, characterized in that during the modulation process, the information to be transmitted in the core layer or the redundant layer or the additional layer is encoded to obtain a continuous digital signal. Sequence, this sequence is divided into multiple sub-sequences, where each sub-sequence corresponds to a pixel block for transmission. 3. The visible light communication method between the TV screen and the smart phone according to claim 2, characterized in that the modulation process further includes: Use PWM or OOK to modulate each subsequence so that each digital bit is converted to a specific brightness or color; Using OFDM technology, the PWM or OOK modulated subsequences are allocated to different frequency subcarriers, and different frequency subcarriers are mapped to different pixel blocks for transmission. 4. The visible light communication method between the TV screen and the smart phone according to claim 1, characterized in that, for each pixel block in the core layer, forward error correction coding is applied to improve the reliability of information transmission. 5. The visible light communication method between the television screen and the smart phone according to claim 4, wherein the forward error correction code is Reed-Solomon code or LDPC code. 6. The visible light communication method between the TV screen and the smart phone according to claim 1, wherein the information transmitted by the TV screen includes but is not limited to text, image, sound and video information. 7. The visible light communication method between the TV screen and the smart phone according to claim 1, characterized in that the smart phone first stores the information transmitted in the core layer, the redundant layer and the additional layer into the memory or hard disk, and first demodulates the information. After the information in the template layer is demodulated, the information transmitted by the core layer, redundant layer and additional layer is retrieved for demodulation. 8. The visible light communication method between the TV screen and the smart phone according to claim 1, characterized in that the method further includes: the smart phone also needs to input a password before demodulation.