A visible light communication apparatus, method and system

Abstract

This invention discloses a visible light communication device, method, and system. The device includes: an LED lighting unit and a first controller electrically connected to each other, and a color temperature sensor and a second controller electrically connected to each other. The LED lighting unit includes multiple warm color temperature LEDs and multiple cool color temperature LEDs arranged alternately. The first controller controls the warm and cool color temperature LEDs to flash alternately based on the original information stream. The second controller controls the color temperature sensor to collect the light intensity of the LED lighting unit at a preset sampling frequency, and determines whether the warm or cool color temperature LEDs are currently lit based on the correspondence between light intensity and color temperature, thus reconstructing the information stream. The preset sampling frequency is n times the LED driving frequency, where n is a positive integer. This solves the problems of inaccuracy and inconvenience when using ambient light sensors and cameras to receive information in related technologies.

Description

Technical Field

[0001] This invention relates to the field of wireless optical communication technology, and more particularly to a visible light communication device, method, and system. Background Technology

[0002] With the development of mobile communication technology, mobile phones, as mobile terminals, have become increasingly powerful through continuous innovation. Their hardware integrates various types of sensor modules, including light sensors, motion sensors, and attitude and position sensors. Research is also underway to combine VLC (Visible Light Communication) with mobile terminals. The main technical solutions fall into two categories: one utilizes the ALS (Ambient Light Sensor) on the front of the phone to sample light signals with modulation information and recover the information; the other uses the rolling shutter effect of the phone's camera CMOS to create bright and dark stripes in the image formed by the modulation signal, and then combines this with image processing algorithms to recover the original information.

[0003] However, the problem is that with the widespread adoption of full-screen smartphones, ambient light sensors are placed under the screen. Therefore, the received light is affected by interference from the display, requiring increased integration time and algorithms for compensation. This significantly impacts visible light communication capabilities. Furthermore, the way smartphone cameras are used raises privacy concerns, making users more cautious about using this technology, which hinders its widespread adoption. Summary of the Invention

[0004] This invention provides a visible light communication device, method, and system to solve the problems of inaccuracy and inconvenience in receiving information using ambient light sensors and cameras in related technologies.

[0005] To address the aforementioned technical problems, a first aspect of the present invention provides a visible light communication device, comprising: an LED lighting unit and a first controller electrically connected to each other, and a color temperature sensor and a second controller electrically connected to each other; wherein the LED lighting unit comprises a plurality of warm color temperature LEDs and a plurality of cool color temperature LEDs arranged in an alternating manner;

[0006] The first controller is used to control the warm color temperature LED and the cool color temperature LED to flash alternately based on the original information stream. The second controller is used to control the color temperature sensor to collect the light intensity of the LED lighting unit at a preset sampling frequency, and combine the correspondence between light intensity and color temperature to determine whether the warm color temperature LED or the cool color temperature LED is currently lit in the LED lighting unit, so as to restore the information stream. The preset sampling frequency is n times the driving frequency of each LED, where n is a positive integer.

[0007] According to one embodiment of the present invention, the first controller is further configured to control the warm color temperature LED and the cool color temperature LED to flash alternately based on the test information stream. The second controller is configured to control the color temperature sensor to collect the light intensity of the LED lighting unit for a preset sampling duration, and determine the overall color temperature of the LED lighting unit by combining the correspondence between light intensity and color temperature. The second controller is further configured to restore the information stream based on the overall color temperature and the lighting status of each LED in the LED lighting unit. The preset sampling duration is greater than or equal to the sum of the duration of the warm color temperature LED lighting once and the duration of the cool color temperature LED lighting once.

[0008] According to one embodiment of the present invention, the warm color temperature LEDs and the cool color temperature LEDs are arranged in a matrix, with each row and each column arranged in an ABAB pattern;

[0009] Alternatively, the warm color temperature LEDs and the cool color temperature LEDs are arranged alternately to form a ring;

[0010] Alternatively, the warm color temperature LEDs may be arranged along even-numbered rows and columns, and the cool color temperature LEDs may be arranged along odd-numbered rows and columns, or the cool color temperature LEDs may be arranged along even-numbered rows and columns, and the warm color temperature LEDs may be arranged along odd-numbered rows and columns.

[0011] According to one embodiment of the present invention, the color temperature range of the warm color temperature LED lamp is 2000-3000K, and the color temperature range of the cool color temperature LED lamp is 7000-8000K.

[0012] To address the aforementioned problems, a second aspect of the present invention also proposes a visible light communication method, implemented based on the visible light communication device as described in any embodiment of the present invention, wherein the visible light communication method includes:

[0013] The first controller controls the warm color temperature LED and the cool color temperature LED to flash alternately based on the original information stream;

[0014] The second controller controls the color temperature sensor to collect the light intensity of the LED lighting unit at a preset sampling frequency;

[0015] The system combines the relationship between light intensity and color temperature to determine whether the warm color temperature LED or the cool color temperature LED is currently lit in the LED lighting unit, in order to restore the information flow.

[0016] The preset sampling frequency is n times the driving frequency of each LED, where n is a positive integer.

[0017] According to one embodiment of the present invention, determining whether the warm color temperature LED or the cool color temperature LED is currently lit in the LED lighting unit by combining the correspondence between light intensity and color temperature, in order to restore the information flow, includes:

[0018] If the intensity of red light is greater than that of blue light, then the warm color temperature LED light is turned on.

[0019] If the intensity of red light is less than that of blue light, the cool color temperature LED is turned on.

[0020] According to one embodiment of the present invention, before the first controller controls the warm color temperature LED and the cool color temperature LED to blink alternately based on the original information stream, the method further includes:

[0021] The first controller also controls the warm color temperature LED and the cool color temperature LED to flash alternately based on the test information stream;

[0022] The second controller controls the color temperature sensor to collect the light intensity of the LED lighting unit for a preset sampling time, and determines the overall color temperature of the LED lighting unit by combining the correspondence between light intensity and color temperature. The preset sampling time is greater than or equal to the sum of the duration of the warm color temperature LED light being lit once and the duration of the cool color temperature LED light being lit once.

[0023] According to one embodiment of the present invention, determining whether the warm color temperature LED or the cool color temperature LED is currently lit in the LED lighting unit by combining the correspondence between light intensity and color temperature, in order to restore the information flow, includes:

[0024] If the overall color temperature of the LED lighting unit is a cool color temperature, and the red light intensity is less than the blue light intensity, then the cool color temperature LED light is turned on.

[0025] If the overall color temperature of the LED lighting unit is a cool color temperature, and the red light intensity is greater than or equal to the blue light intensity, then the warm color temperature LED light is turned on.

[0026] If the overall color temperature of the LED lighting unit is warm, and the red light intensity is greater than the blue light intensity, then the warm color temperature LED light is turned on.

[0027] If the overall color temperature of the LED lighting unit is warm, and the red light intensity is less than or equal to the blue light intensity, then the cool color temperature LED light is turned on.

[0028] According to one embodiment of the present invention, determining whether the warm color temperature LED or the cool color temperature LED is currently lit in the LED lighting unit by combining the correspondence between light intensity and color temperature, in order to restore the information flow, includes:

[0029] If the overall color temperature of the LED lighting unit is white, and the red light intensity is less than the blue light intensity, then the cool color temperature LED light is turned on.

[0030] If the overall color temperature of the LED lighting unit is white, and the red light intensity is greater than the blue light intensity, then the warm color temperature LED light is turned on.

[0031] According to one embodiment of the present invention, before the first controller controls the warm color temperature LED and the cool color temperature LED to flash alternately based on the original information stream, the method further includes: the first controller performing 8-bit / 10-bit encoding based on the original information stream;

[0032] Before the second controller restores the information stream, the following is also included:

[0033] The second controller acquires the information stream based on whether the warm color temperature LED is lit or the cool color temperature LED is lit, and performs 8-bit / 10-bit decoding on the acquired information stream to restore the original information stream.

[0034] To address the aforementioned technical problems, a third aspect of the present invention provides a visible light communication system, comprising:

[0035] The signal transmitting terminal includes an electrically connected LED lighting unit and a first controller as described in any embodiment of the present invention, and the signal receiving terminal includes an electrically connected color temperature sensor and a second controller as described in any embodiment of the present invention.

[0036] The signal receiving terminal is at least one of a mobile phone, a tablet computer, or a wearable device.

[0037] According to embodiments of the present invention, a visible light communication device, method, and system are provided, wherein the device includes: an LED lighting unit and a first controller electrically connected to each other, and a color temperature sensor and a second controller electrically connected to each other; wherein the LED lighting unit includes a plurality of warm color temperature LEDs and a plurality of cool color temperature LEDs arranged alternately; the first controller is used to control the warm color temperature LEDs and cool color temperature LEDs to flash alternately based on the original information stream; the second controller is used to control the color temperature sensor to collect the light intensity of the LED lighting unit at a preset sampling frequency, and to determine whether the warm color temperature LEDs or cool color temperature LEDs in the LED lighting unit are currently lit, based on the correspondence between light intensity and color temperature, so as to reconstruct the information stream; wherein the preset sampling frequency is n times the driving frequency of each LED, where n is a positive integer. Thus, by utilizing the adjustable color temperature function of the LED lighting unit to modulate the signal and generate the original information stream, and by sensing the visible light modulation signal from the light source through the color temperature sensor module gradually becoming widespread near the main camera on the back of the mobile phone, the original information stream can be received and recovered. This avoids the limitations imposed by the installation location of ambient light sensors, and also eliminates the need to open the camera, protecting the user's environmental privacy and making it more acceptable to users.

[0038] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a block diagram of the visible light communication device proposed in an embodiment of the present invention;

[0041] Figure 2 This is the correspondence between light intensity and color temperature in the visible light communication device proposed in the embodiments of the present invention;

[0042] Figure 3 This is a lamp arrangement diagram of an LED lighting unit in a visible light communication device proposed in an embodiment of the present invention;

[0043] Figure 4 This is another lamp arrangement diagram of the LED lighting unit in the visible light communication device proposed in this embodiment of the invention;

[0044] Figure 5This is another lamp arrangement diagram of the LED lighting unit in the visible light communication device proposed in the embodiments of the present invention;

[0045] Figure 6 This is a flowchart of the visible light communication method proposed in an embodiment of the present invention;

[0046] Figure 7 This is a flowchart of a visible light communication method proposed in one embodiment of the present invention;

[0047] Figure 8 This is a structural diagram of a visible light communication system proposed in an embodiment of the present invention. Detailed Implementation

[0048] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0050] Optical communication has developed rapidly in the wired field, with related standards, products, and the industry chain becoming increasingly mature. In the wireless field, it has also become a research hotspot due to advancements in key components and materials. Significant progress has been made in VLC (Vibration-Local Communication) based on LEDs (Light-Emitting Diodes) and FSO (Free-space Optical Communication) based on Laser Diodes (Laser Diodes), with some even being practically deployed. LED-based VLC, in particular, has a natural advantage due to its ability to be used in indoor lighting, and standardization efforts have already begun. However, current communication methods are not precise and raise user privacy concerns.

[0051] Figure 1 This is a block diagram of a visible light communication device proposed in an embodiment of the present invention. Figure 1 As shown, the device includes: an LED lighting unit 101 and a first controller 102 that are electrically connected to each other, and a color temperature sensor 103 and a second controller 104 that are electrically connected to each other; wherein, the LED lighting unit 101 includes a plurality of warm color temperature LEDs 1011 and a plurality of cool color temperature LEDs 1012 arranged in an alternating manner.

[0052] The first controller 102 is used to control the warm color temperature LED 1011 and the cool color temperature LED 1012 to flash alternately based on the original information flow. The second controller 104 is used to control the color temperature sensor 103 to collect the light intensity of the LED lighting unit 101 at a preset sampling frequency, and combine the correspondence between light intensity and color temperature to determine whether the warm color temperature LED 1011 or the cool color temperature LED 1012 is currently lit in the LED lighting unit 101, so as to restore the information flow. The preset sampling frequency is n times the driving frequency of each LED, where n is a positive integer.

[0053] For example, the original information stream can be 101100. In this case, it can be pre-set that the cool color temperature LED 1012 represents 0 when it is lit, and the warm color temperature LED 1011 represents 1 when it is lit. In another embodiment, it can also be set that the cool color temperature LED 1012 represents 1 when it is lit, and the warm color temperature LED 1011 represents 0 when it is lit. This example uses the former as an example for illustration.

[0054] After the first controller 102 acquires the original information stream, it can sequentially light up the warm color temperature LED 1011 (hereinafter referred to as warm), the cool color temperature LED 1012 (hereinafter referred to as cool), the warm color temperature LED 1011, the warm color temperature LED 1011, the cool color temperature LED 1012 and the cool color temperature LED 1012 according to the original information stream.

[0055] The color temperature sensor 103 sequentially collects the light intensity of the LED lighting unit 101 according to a preset sampling frequency. Specifically, when the LED lighting unit 101 is lit in the sequence of warm, cool, warm, warm, cool, cool, and so on, since the preset sampling frequency is n times the driving frequency, when the LED lighting unit 101 lights up the warm color temperature LED 1011, the color temperature sensor 103 can first collect the light intensity of the warm color temperature LED 1011, obtain the light intensity of the three RGB channels corresponding to the warm color temperature LED 1011, and then, through... Figure 2The diagram shows the correspondence between light intensity and color temperature (the horizontal axis represents color temperature (K), and the vertical axis represents light intensity (cd). This correspondence is based on data acquisition of color temperature and RGB values ​​from the CIE (Commission International de l'Eclairage, International Commission on Illumination) standard colorimetric system. Since the red light intensity is greater than the blue light intensity, the currently lit LED is determined to be a warm color temperature LED, and information "1" is then reconstructed based on the warm color temperature LED. When the LED lighting unit 101 lights the cool color temperature LED 1012, the color temperature sensor 103 can collect the light intensity of the cool color temperature LED 1012, obtain the light intensity of the three RGB channels corresponding to the cool color temperature LED 1012, and then, through... Figure 2 The relationship between light intensity and color temperature shows that the red light intensity is less than the blue light intensity. Therefore, the currently lit LED is determined to be a cool color temperature LED, and the information "0" is then reconstructed based on the cool color temperature LED. Similarly, the information "1100" can also be reconstructed using the same method. Finally, the second controller 104 recognizes the information emitted by the LED lighting unit 101.

[0056] Understandably, the driving frequencies of warm-temperature LEDs and cool-temperature LEDs can be preset and set to be the same in advance by the first controller 102. Generally, the square wave frequency driving the LEDs is set to be greater than 30Hz, and the probability distributions of 1s and 0s in the original information stream are close to avoid noticeable flickering to the human eye. The preset sampling frequency can be 30Hz, 60Hz, or an integer multiple of 30Hz.

[0057] In other words, within one driving cycle of the first controller 102 driving an LED light to illuminate, the second controller 104 controls the color temperature sensor 103 to sample once or multiple times. When n=1, the second controller 104 controls the color temperature sensor 103 to sample once; when n=multiple times, the second controller 104 controls the color temperature sensor 103 to sample n times. If n times are sampled, the second controller 104 can average the light intensity of the n samples and finally compare the averaged light intensity to determine whether a warm color temperature LED light or a cool color temperature LED light is illuminated.

[0058] It should be noted that the first controller 102 can control the LED lights to turn on and off by outputting a PWM (Pulse Width Modulation) square wave. The light intensity of each LED light can be adjusted by adjusting the duty cycle of the PWM square wave. The larger the duty cycle, the stronger the LED light, and the smaller the duty cycle, the weaker the LED light.

[0059] To enable the second controller 104 to distinguish whether the warm color temperature LED 1011 or the cool color temperature LED 1012 is lit, and to avoid errors caused by the red light intensity equaling the blue light intensity during the light intensity acquisition process, the first controller 102 can control the color temperature of the warm color temperature LED 1011 to be lower and the color temperature of the cool color temperature LED 1012 to be higher. For example, the color temperature range of the warm color temperature LED could be 2000-3000K, and the color temperature range of the cool color temperature LED could be 7000-8000K. This avoids the white light color temperature boundary, making it easier to distinguish after the color temperature sensor 103 acquires the light intensity.

[0060] According to one embodiment of the present invention, in order to avoid bit errors, the following method can also be used: the first controller 102 is further used to control the warm color temperature LED lamp 1011 and the cool color temperature LED lamp 1012 to flash alternately based on the test information flow; the second controller 104 is used to control the color temperature sensor 103 to collect the light intensity of the LED lighting unit for a preset sampling time, and determine the overall color temperature of the LED lighting unit 101 by combining the correspondence between light intensity and color temperature; the second controller is further used to restore the information flow based on the overall color temperature and the lighting status of each LED lamp in the LED lighting unit, and the preset sampling time is greater than or equal to the sum of the duration of the warm color temperature LED lamp lighting once and the duration of the cool color temperature LED lamp lighting once.

[0061] In other words, before the second controller 104 controls the color temperature sensor 103 to formally collect the raw information stream, the overall color temperature of the LED lighting unit 101 can also be collected based on the test information stream.

[0062] In this test information stream, the probability distributions of 1 and 0 are similar. This avoids the human eye perceiving color temperature fluctuations in the mixed light when collecting the sum of the light intensities of warm-color-temperature LEDs and cool-color-temperature LEDs within a preset time period. After collecting the overall light intensity, the overall color temperature of the LED lighting unit 101 can be determined based on the correspondence between light intensity and color temperature.

[0063] For example, if the overall red light intensity is greater than the blue light intensity, the overall color temperature is warm; if the overall red light intensity is less than the blue light intensity, the overall color temperature is cool; and if the overall red light intensity is equal to the blue light intensity, the overall color temperature is white.

[0064] Once the overall color temperature is determined, the information can be accurately restored when the second controller 104 detects the light intensity later, thus avoiding errors.

[0065] For example, if the overall color temperature is warm, and the detected red light intensity is greater than the blue light intensity, then it can be determined that a warm color temperature LED is lit; if the detected red light intensity is less than or equal to the blue light intensity, then it can be determined that a cool color temperature LED is lit. Similarly, if the overall color temperature is white, and the detected red light intensity is less than the blue light intensity, then it can be determined that a cool color temperature LED is lit; if the detected red light intensity is greater than or equal to the blue light intensity, then it can be determined that a warm color temperature LED is lit. This allows for a more accurate reproduction of the original information flow.

[0066] According to one embodiment of the present invention, such as Figure 3 As shown, each warm color temperature LED 1011 and each cool color temperature LED 1012 are arranged to form a matrix, with each row and each column arranged in the form of ABAB; where A can be one of each warm color temperature LED 1011 or each cool color temperature LED 1012, and B can be the other of each warm color temperature LED 1011 or each cool color temperature LED 1012.

[0067] Or, such as Figure 4 As shown, warm color temperature LEDs 1011 and cool color temperature LEDs 1012 are arranged alternately to form a ring;

[0068] Or, such as Figure 5 As shown, each warm color temperature LED 1011 is arranged along even-numbered rows and even-numbered columns, and each cool color temperature LED 1012 is arranged along odd-numbered rows and odd-numbered columns, or each cool color temperature LED 1012 is arranged along even-numbered rows and even-numbered columns, and each warm color temperature LED 1011 is arranged along odd-numbered rows and odd-numbered columns.

[0069] Through such Figures 3 to 5 The arrangement of LEDs in this way makes the arrangement of warm color temperature LEDs and cool color temperature LEDs on the lighting unit 101 more uniform, avoiding obvious flickering that the human eye can perceive.

[0070] Figure 6 This is a flowchart of a visible light communication method proposed in an embodiment of the present invention. This method is implemented based on a visible light communication device as proposed in any embodiment of the present invention, such as... Figure 6 As shown, visible light communication methods include:

[0071] S101, the first controller controls the warm color temperature LED and the cool color temperature LED to flash alternately based on the original information flow;

[0072] S102, the second controller controls the color temperature sensor to collect the light intensity of the LED lighting unit at a preset sampling frequency;

[0073] S103, the second controller combines the correspondence between light intensity and color temperature to determine whether the LED lighting unit is currently lit by warm color temperature LEDs or cool color temperature LEDs, so as to restore the information flow;

[0074] The preset sampling frequency is n times the driving frequency of each LED, where n is a positive integer.

[0075] According to one embodiment of the present invention, determining whether a warm color temperature LED or a cool color temperature LED is currently lit in the LED lighting unit by combining the correspondence between light intensity and color temperature, in order to restore the information flow, includes:

[0076] If the intensity of red light is greater than that of blue light, then the warm color temperature LED light should be turned on.

[0077] If the intensity of red light is less than that of blue light, then the cool color temperature LED light is turned on.

[0078] For example, the original information stream can be 101100. In this case, it can be pre-set that the cool color temperature LED 1012 represents 0 when it is lit, and the warm color temperature LED 1011 represents 1 when it is lit. In another embodiment, it can also be set that the cool color temperature LED 1012 represents 1 when it is lit, and the warm color temperature LED 1011 represents 0 when it is lit. This example uses the former as an example for illustration.

[0079] After the first controller 102 acquires the original information stream, it can sequentially light up the warm color temperature LED 1011 (hereinafter referred to as warm), the cool color temperature LED 1012 (hereinafter referred to as cool), the warm color temperature LED 1011, the warm color temperature LED 1011, the cool color temperature LED 1012 and the cool color temperature LED 1012 according to the original information stream.

[0080] The color temperature sensor 103 sequentially collects the light intensity of the LED lighting unit 101 according to a preset sampling frequency. Specifically, when the LED lighting unit 101 is lit in the sequence of warm, cool, warm, warm, cool, cool, and so on, since the preset sampling frequency is n times the driving frequency, when the LED lighting unit 101 lights up the warm color temperature LED 1011, the color temperature sensor 103 can first collect the light intensity of the warm color temperature LED 1011, obtain the light intensity of the three RGB channels corresponding to the warm color temperature LED 1011, and then, through... Figure 2The diagram shows the correspondence between light intensity and color temperature (horizontal axis is color temperature (K), vertical axis is light intensity (cd)). Since the red light intensity is greater than the blue light intensity, the currently lit LED is determined to be a warm color temperature LED, and information "1" is then reconstructed based on the warm color temperature LED. When the LED lighting unit 101 lights the cool color temperature LED 1012, the color temperature sensor 103 can collect the light intensity of the cool color temperature LED 1012, obtain the light intensity of the three RGB channels corresponding to the cool color temperature LED 1012, and then, through... Figure 2 The relationship between light intensity and color temperature shows that the red light intensity is less than the blue light intensity. Therefore, the currently lit LED is determined to be a cool color temperature LED, and the information "0" is then reconstructed based on the cool color temperature LED. Similarly, the information "1100" can also be reconstructed using the same method. Finally, the second controller 104 recognizes the information emitted by the LED lighting unit 101.

[0081] Understandably, the driving frequencies of warm-temperature LEDs and cool-temperature LEDs can be preset and set to be the same in advance by the first controller 102. Generally, the square wave frequency driving the LEDs is set to be greater than 30Hz, and the probability distributions of 1s and 0s in the original information stream are close to avoid noticeable flickering to the human eye. The preset sampling frequency can be 30Hz, 60Hz, or an integer multiple of 30Hz.

[0082] In other words, within one driving cycle of the first controller 102 driving an LED light to illuminate, the second controller 104 controls the color temperature sensor 103 to sample once or multiple times. When n=1, the second controller 104 controls the color temperature sensor 103 to sample once; when n=multiple times, the second controller 104 controls the color temperature sensor 103 to sample n times. If n times are sampled, the second controller 104 can average the light intensity of the n samples and finally compare the averaged light intensity to determine whether a warm color temperature LED light or a cool color temperature LED light is illuminated.

[0083] It should be noted that the first controller 102 can control the LED lights to turn on and off by outputting a PWM square wave. The light intensity of each LED light can be adjusted by adjusting the duty cycle of the PWM square wave. The larger the duty cycle, the stronger the LED light, and the smaller the duty cycle, the weaker the LED light.

[0084] To enable the second controller 104 to distinguish whether the warm color temperature LED 1011 or the cool color temperature LED 1012 is lit, and to avoid errors caused by the red light intensity equaling the blue light intensity during the light intensity acquisition process, the first controller 102 can control the color temperature of the warm color temperature LED 1011 to be lower and the color temperature of the cool color temperature LED 1012 to be higher. For example, the color temperature range of the warm color temperature LED could be 2000-3000K, and the color temperature range of the cool color temperature LED could be 7000-8000K. This avoids the white light color temperature boundary, making it easier to distinguish after the color temperature sensor 103 acquires the light intensity.

[0085] According to one embodiment of the present invention, such as Figure 7 As shown, before the first controller controls the alternating blinking of warm color temperature LEDs and cool color temperature LEDs based on the original information stream, S101 further includes:

[0086] S001, the first controller is also used to control the alternating flashing of warm color temperature LEDs and cool color temperature LEDs based on the test information flow;

[0087] S002, the second controller is used to control the color temperature sensor to collect the light intensity of the LED lighting unit for a preset sampling time, and to determine the overall color temperature of the LED lighting unit by combining the correspondence between light intensity and color temperature. The preset sampling time is greater than or equal to the sum of the time it takes for the warm color temperature LED to light up once and the time it takes for the cool color temperature LED to light up once.

[0088] In other words, before the second controller 104 controls the color temperature sensor 103 to formally collect the raw information stream, the overall color temperature of the LED lighting unit 101 can also be collected based on the test information stream.

[0089] In this test information stream, the probability distributions of 1 and 0 are similar. This avoids the human eye perceiving color temperature fluctuations in the mixed light when collecting the sum of the light intensities of warm-color-temperature LEDs and cool-color-temperature LEDs within a preset time period. After collecting the overall light intensity, the overall color temperature of the LED lighting unit 101 can be determined based on the correspondence between light intensity and color temperature.

[0090] For example, if the overall red light intensity is greater than the blue light intensity, the overall color temperature is warm; if the overall red light intensity is less than the blue light intensity, the overall color temperature is cool; and if the overall red light intensity is equal to the blue light intensity, the overall color temperature is white.

[0091] Once the overall color temperature is determined, the information can be accurately restored when the second controller 104 detects the light intensity later, thus avoiding errors.

[0092] According to one embodiment of the present invention, determining whether a warm color temperature LED or a cool color temperature LED is currently lit in an LED lighting unit by combining the correspondence between light intensity and color temperature, in order to restore the information flow, includes: if the overall color temperature of the LED lighting unit is cool, and the red light intensity is less than the blue light intensity, determining that the cool color temperature LED is lit; if the overall color temperature of the LED lighting unit is cool, and the red light intensity is greater than or equal to the blue light intensity, determining that the warm color temperature LED is lit; if the overall color temperature of the LED lighting unit is warm, and the red light intensity is greater than the blue light intensity, determining that the warm color temperature LED is lit; if the overall color temperature of the LED lighting unit is warm, and the red light intensity is less than or equal to the blue light intensity, determining that the cool color temperature LED is lit. By obtaining the overall color temperature in this way, the subsequent comparison of light intensity and determination of color temperature can be more accurate.

[0093] According to one embodiment of the present invention, determining whether a warm color temperature LED or a cool color temperature LED is currently lit in an LED lighting unit by combining the correspondence between light intensity and color temperature, in order to restore the information flow, includes: if the overall color temperature of the LED lighting unit is white, and the red light intensity is less than the blue light intensity, determining that a cool color temperature LED is lit; if the overall color temperature of the LED lighting unit is white, and the red light intensity is greater than the blue light intensity, determining that a warm color temperature LED is lit. By obtaining the overall color temperature in this way, determining the color temperature by comparing light intensity later becomes simpler and clearer.

[0094] According to one embodiment of the present invention, before the first controller controls the alternating flashing of warm color temperature LEDs and cool color temperature LEDs based on the original information stream, the method further includes: the first controller performing 8-bit / 10-bit encoding based on the original information stream;

[0095] Before the second controller restores the information flow, it also includes:

[0096] The second controller acquires the information stream based on whether the warm color temperature LED light is lit or the cool color temperature LED light is lit, and performs 8-bit / 10-bit decoding on the acquired information stream to restore the original information stream.

[0097] Understandably, at the LED lighting unit level, the two color temperature LEDs are controlled by two independent PWM circuits, with the corresponding maximum brightness or maximum luminous intensity denoted as P. cold and P warm Then the color temperature of the mixed light can be expressed by the following formula: a*P cold +b*P warm, where \(0 < a < 1\) and \(0 < b < 1\). Here, \(a\) and \(b\) are determined by PWM. For a cold - color - temperature LED lamp, the smaller the duty cycle of the driving square wave, the smaller \(a\), and vice versa; similarly, for a warm - color - temperature LED lamp, the smaller the duty cycle of the driving square wave, the smaller \(b\), and vice versa. For a specific color temperature formed after mixing, there are unique corresponding values for both \(a\) and \(b\), and there are unique corresponding duty cycles for the driving square waves of the cold and warm LEDs respectively. Thus, at the color - temperature sensor end, after collecting the overall color temperature, it can be compared with the specific color temperature set at the LED lighting unit end. If they are the same, the information transmission is correct; if not, no subsequent information transmission is carried out. Among them, the specific color temperature set at the LED lighting unit end can be set according to the occasion atmosphere.

[0098] Perform 8 - bit / 10 - bit encoding on the original information bit stream so that the probabilities of 0 and 1 in the encoded data stream are similar. The advantage of doing this is that it can make the total lighting time of the two - color - temperature LEDs basically the same. When the user sets a certain color temperature, without changing \(a\) and \(b\), the color temperature of the mixed light will not be changed due to data transmission.

[0099] In a specific embodiment, after encoding, the encoded bit stream will control the lighting of LEDs with different color temperatures at a certain rate, and this rate is denoted as the baud rate \(R\). Since the probabilities of 0 and 1 after encoding are similar, and considering that the PWM driving square - wave frequency of the LED is not less than 30 Hz according to the previous text, then 60 bps is required to make the human eye unable to perceive the color - temperature jump of the mixed light.

[0100] First, set the integration time of the color sensor to be relatively long, such as 1 second, to sense the color temperature of the overall mixed light. After obtaining the current mixed - light color - temperature information, reduce the integration time \(T\) of the color sensor s , so that the sampling frequency \(F\) s is an integer multiple of the baud rate, that is: \(F\) s = \(n\times R\), \(n = 1,2,\cdots\); that is, each transmitted information bit corresponds to \(n\) sampling values. \(n\) can be selected according to the capabilities of different color sensors. Each sampling value has three intensity - representing values \((R,G,B)\), and the average sampling value of each information bit can be obtained through the following formula:

[0101] \(S\) R = \((S\) r1 + \(S\) r2 +\cdots+ \(S\) rn ) / n;

[0102] \(S\) G = \((S\) g1 + \(S\) g2 +\cdots+ \(S\) gn ) / n;

[0103] \(S\) B = \((S\) b1+S b2 +…+S bn ) / n;

[0104] Based on the color temperature information obtained in the previous step, a decision is made on the RGB average sample value obtained for each bit slot: if the overall color temperature is warm, and S R >S B The bit is judged to be 1. And S R B If the value is too close to determine the value, it is judged as 0. This is because the intensity of the cool color temperature LED is lower at this time, resulting in S... R S B The intensity may be difficult to judge; if the overall color temperature is cool, and S R B The bit is judged as 0. And S R >S B If the value is too close to determine the value, it is judged as 0. This is because the intensity of warm color temperature LEDs is lower at this time, resulting in S... R S B The intensity may be difficult to judge; if the overall color temperature is pure white, and S R >S B The bit is judged to be 1. And S R B The value is set to 0 because the intensity of LEDs with cool and warm color temperatures is similar at this time. R S B The strength is relatively easy to judge;

[0105] The bitstream obtained at this point still needs to be decoded by 8b / 10b to obtain the original information stream. In addition, a layer of channel coding or checksum can be added to enhance the robustness of information transmission, which will not be elaborated here.

[0106] Figure 8 This is a structural diagram of a visible light communication system proposed in an embodiment of the present invention. Figure 8 As shown, the system includes:

[0107] The system includes a signal transmitting terminal 201 and a signal receiving terminal 202. The signal transmitting terminal 201 comprises an LED lighting unit and a first controller that are electrically connected to each other, as proposed in any embodiment of the present invention. The signal receiving terminal comprises a color temperature sensor 103 and a second controller that are electrically connected to each other, as proposed in any embodiment of the present invention. The signal receiving terminal 202 is at least one of a mobile phone, a tablet computer, or a wearable device. During reception, since the color temperature sensor 102 is mounted next to the main camera on the back of the mobile phone 202, data information can be received by roughly pointing it towards the light source, similar to taking a picture.

[0108] ​​​In summary, the visible light communication device, method, and system proposed in the embodiments of the present invention include: an LED lighting unit and a first controller electrically connected to each other, and a color temperature sensor and a second controller electrically connected to each other; wherein the LED lighting unit includes a plurality of warm color temperature LEDs and a plurality of cool color temperature LEDs arranged alternately; the first controller is used to control the warm color temperature LEDs and cool color temperature LEDs to flash alternately based on the original information stream; the second controller is used to control the color temperature sensor to collect the light intensity of the LED lighting unit at a preset sampling frequency, and to determine whether the warm color temperature LEDs or cool color temperature LEDs are currently lit in the LED lighting unit by combining the correspondence between light intensity and color temperature, so as to restore the information stream; wherein the preset sampling frequency is n times the LED driving frequency, where n is a positive integer. Thus, by utilizing the adjustable color temperature function of the LED lighting unit to modulate the signal and generate the original information stream, and by sensing the visible light modulation signal from the light source through the color temperature sensor module gradually becoming widespread near the main camera on the back of the mobile phone, the original information stream can be received and recovered. This avoids the limitations imposed by the mounting location of ambient light sensors, and also protects user privacy by eliminating the need to turn on the camera, making it more acceptable to users.

[0109] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0110] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A visible light communication device, characterized in that, The method comprises the following steps: LED lighting units and a first controller are electrically connected to each other, and a color temperature sensor and a second controller are electrically connected to each other; wherein the LED lighting units comprise a plurality of warm color temperature LED lamps and a plurality of cold color temperature LED lamps arranged alternately; The first controller is used to control the warm color temperature LED lamps and the cold color temperature LED lamps to flash alternately based on an original information stream, and the second controller is used to control the color temperature sensor to collect light intensity of the LED lighting units at a preset sampling frequency, and determine whether the warm color temperature LED lamps or the cold color temperature LED lamps are currently lit in the LED lighting units based on the corresponding relationship between light intensity and color temperature, so as to restore the information stream; wherein the preset sampling frequency is n times of a driving frequency for driving each LED lamp, and n is a positive integer; Wherein the color temperature sensor collects light intensity of the warm color temperature LED lamps, obtains light intensity of three RGB channels corresponding to the warm color temperature LED lamps, and determines that the currently lit LED lamps are the warm color temperature LED lamps when the red light intensity is greater than the blue light intensity; the color temperature sensor collects light intensity of the cold color temperature LED lamps, obtains light intensity of three RGB channels corresponding to the cold color temperature LED lamps, and determines that the currently lit LED lamps are the cold color temperature LED lamps when the red light intensity is less than the blue light intensity.

2. The visible light communication apparatus according to claim 1, wherein The first controller is also used to control the warm color temperature LED lamps and the cold color temperature LED lamps to flash alternately based on a test information stream, and the second controller is also used to control the color temperature sensor to collect light intensity of the LED lighting units at a preset sampling time length, determine overall color temperature of the LED lighting units based on the corresponding relationship between light intensity and color temperature, and restore the information stream based on the overall color temperature and the lighting state of each LED lamp in the LED lighting units, wherein the preset sampling time length is greater than or equal to the sum of the lighting time of the warm color temperature LED lamps and the lighting time of the cold color temperature LED lamps.

3. The visible light communication apparatus according to claim 1, wherein Each of the warm color temperature LED lamps and each of the cold color temperature LED lamps are arranged to form a matrix, and each row and each column are arranged in an ABAB form; Alternatively, each of the warm color temperature LED lamps and each of the cold color temperature LED lamps are alternately arranged to form a ring; Alternatively, each of the warm color temperature LED lamps is distributed along even rows and even columns, each of the cold color temperature LED lamps is distributed along odd rows and odd columns, or each of the cold color temperature LED lamps is distributed along even rows and even columns, and each of the warm color temperature LED lamps is distributed along odd rows and odd columns.

4. The visible light communication apparatus according to any one of claims 1 to 3, wherein The color temperature range of the warm color temperature LED lamps is 2000-3000K, and the color temperature range of the cold color temperature LED lamps is 7000-8000K.

5. A method of visible light communication, characterized by, The visible light communication method is implemented based on the visible light communication device according to any one of claims 1-4, and the method comprises the following steps: The first controller controls the warm color temperature LED lamps and the cold color temperature LED lamps to flash alternately based on an original information stream; The second controller controls the color temperature sensor to collect light intensity of the LED lighting units at a preset sampling frequency; determine, in combination with the correspondence between the light intensity and the color temperature, whether the warm color temperature LED lamp is currently lit or the cold color temperature LED lamp is currently lit in the LED lighting unit, so as to restore the information flow; wherein the preset sampling frequency is n times of a driving frequency for driving each LED lamp, n being a positive integer; wherein the color temperature sensor collects the light intensity of the warm color temperature LED lamp, obtains the light intensity of the three RGB channels corresponding to the warm color temperature LED lamp, and determines that the currently lit LED lamp is the warm color temperature LED lamp if the red light intensity is greater than the blue light intensity; the color temperature sensor collects the light intensity of the cold color temperature LED lamp, obtains the light intensity of the three RGB channels corresponding to the cold color temperature LED lamp, and determines that the currently lit LED lamp is the cold color temperature LED lamp if the red light intensity is less than the blue light intensity.

6. The visible light communication method of claim 5, wherein, Before the first controller controls the warm color temperature LED lamp and the cold color temperature LED lamp to alternately flash based on the original information flow, the method further comprises: The first controller further controls the warm color temperature LED lamp and the cold color temperature LED lamp to alternately flash based on the test information flow; The second controller controls the color temperature sensor to collect the light intensity of the LED lighting unit for a preset sampling time length, and determines the overall color temperature of the LED lighting unit in combination with the correspondence between the light intensity and the color temperature, the preset sampling time length being greater than or equal to the sum of the time length for the warm color temperature LED lamp to be lit once and the time length for the cold color temperature LED lamp to be lit once.

7. The visible light communication method of claim 6, wherein, The determination, in combination with the correspondence between the light intensity and the color temperature, whether the warm color temperature LED lamp is currently lit or the cold color temperature LED lamp is currently lit in the LED lighting unit, so as to restore the information flow, comprises: if the overall color temperature of the LED lighting unit is the cold color temperature, and the red light intensity is less than the blue light intensity, it is determined that the cold color temperature LED lamp is lit; if the overall color temperature of the LED lighting unit is the cold color temperature, and the red light intensity is greater than or equal to the blue light intensity, it is determined that the warm color temperature LED lamp is lit; if the overall color temperature of the LED lighting unit is the warm color temperature, and the red light intensity is greater than the blue light intensity, it is determined that the warm color temperature LED lamp is lit; if the overall color temperature of the LED lighting unit is the warm color temperature, and the red light intensity is less than or equal to the blue light intensity, it is determined that the cold color temperature LED lamp is lit.

8. The visible light communication method of claim 6, wherein, The determination, in combination with the correspondence between the light intensity and the color temperature, whether the warm color temperature LED lamp is currently lit or the cold color temperature LED lamp is currently lit in the LED lighting unit, so as to restore the information flow, comprises: if the overall color temperature of the LED lighting unit is the white color temperature, and the red light intensity is less than the blue light intensity, it is determined that the cold color temperature LED lamp is lit; if the overall color temperature of the LED lighting unit is the white color temperature, and the red light intensity is greater than the blue light intensity, it is determined that the warm color temperature LED lamp is lit.

9. The visible light communication method of claim 5 or 6, wherein, Before the first controller controls the warm color temperature LED lamp and the cold color temperature LED lamp to alternately flash based on the original information flow, the method further comprises that the first controller performs 8bit / 10bit encoding based on the original information flow; Before the second controller restores the information flow, the method further comprises: The second controller obtains a collection information stream based on the warm color temperature LED being lighted or the cold color temperature LED being lighted, and performs 8bit / 10bit decoding on the collection information stream to restore an original information stream.

10. A visible light communication system, characterized by, The application further relates to a signal transmitting terminal and a signal receiving terminal, wherein the signal transmitting terminal comprises the mutually electrically connected LED lighting unit and the first controller according to any one of claims 1-4, and the signal receiving terminal comprises the mutually electrically connected color temperature sensor and the second controller according to any one of claims 1-4. The signal receiving terminal is at least one of a mobile phone, a tablet computer and a wearable device. ​

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