Compound eye visible light multiple access communication method

Abstract

The application provides a compound eye type visible light multiple access communication method, and belongs to the technical field of visible light communication. The communication method fully utilizes the characteristics of a complex channel environment, designs a light receiving end composed of multiple PDs in a VLC system into a compound eye type multiple PD receiving layout mode, and provides a corresponding communication method according to the designed compound eye type PD receiving layout mode. Compared with using a single PD to realize data transmission of the VLC system, the application can fully utilize the characteristics of the complex channel environment, design the light receiving end composed of multiple PDs into the compound eye type receiving layout mode, not only can sufficiently utilize the visible light signals in the complex space scene, improve the received light signal strength, but also can multiplex the visible light communication channel, realize data communication transmission of multiple LEDs, and further improve the data transmission rate of the VLC system.

Description

Technical Field

[0001] This invention belongs to the field of visible light communication technology and relates to a communication method for visible light signals, specifically a compound eye type visible light multiple access communication method. Background Technology

[0002] In recent years, lighting technology based on light-emitting diodes (LEDs) has developed rapidly. Due to its excellent lighting and modulation characteristics, it has begun to replace traditional incandescent light sources and is gradually being applied in various fields. Among them, visible light communication (VLC) technology fully utilizes the dual functions of LED lighting and communication. It transmits information by emitting high-speed, imperceptible on / off signals from LEDs, possessing advantages that traditional radio frequency communication technologies cannot match, such as abundant spectrum resources, no electromagnetic radiation, and environmental friendliness.

[0003] For communication needs in space scenarios with complex channel environments and unchanging channel characteristics, visible light communication (VLC) technology can effectively overcome the difficulties of complex electromagnetic environments compared to wired communication and traditional radio frequency (RF) communication technologies, enabling information exchange between devices within the space. However, in current VLC systems, the maximum data communication rate of a single photodiode (PD) for communication transmission cannot meet the demands of higher-speed communication. Using multiple PDs for multi-source VLC communication, however, can effectively improve the overall communication performance of the VLC system. Therefore, to improve the communication rate of VLC systems, it is necessary to fully consider the characteristics of the applied space scenario and design a suitable multi-PD receiving layout to maximize the data transmission rate of the VLC system. Summary of the Invention

[0004] The technical problem this invention aims to solve is that when performing visible light communication in spatial scenarios with complex channel environments and unchanged channel characteristics, the maximum data transmission rate of a single PD (Distributed Photodetector) system cannot meet the requirements of high-speed transmission. Therefore, it is necessary to design a suitable multi-PD receiving layout based on the characteristics of the applied spatial scenario to achieve the reception and demodulation of visible light signals from multiple light sources, thereby improving the data transmission rate of the VLC system.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A compound-eye visible light multiple access communication method is disclosed. This method fully utilizes the complex characteristics of the channel environment by designing the optical receiver in a VLC system, composed of multiple photodetectors (PDs), into a compound-eye receiver layout. Based on this design, a communication method is provided that can fully receive and utilize visible light signals transmitted from multiple light sources within a spatial scene, thereby multiplexing the channel and improving the overall data transmission rate of the VLC system. The specific details of the compound-eye visible light multiple access communication method are as follows:

[0007] Assume a VLC system has K LED light sources as light emitters, responsible for transmitting visible light signals to K users, and M compound-eye PDs as light receivers, used to receive the light signals from the K users after passing through a complex space, and demodulate the transmitted data from each user, thereby realizing data communication transmission among the K users. The steps are as follows:

[0008] Step 1: Deployment of Compound Eye PD Receiver

[0009] The receiver of the VLC system consists of M PD sensors. These M PDs are designed in specific shapes suitable for the actual channel environment, such as circles or squares. At the same time, the receiving direction of each PD is arranged around the arc surface, which is similar to the compound eye structure of an insect, so as to fully receive the visible light signal after passing through the complex channel environment.

[0010] Step 2: Generation of the original compound eye pattern set

[0011] For a VLC system containing K LED light sources, there are a total of N combinations of on / off states, where N = 2^N. K That is, the on state of an LED represents that it transmits data as "1", and the off state represents that it transmits data as "0". In a complex channel environment, experiments were conducted to create on / off state combinations {X1, X2, ..., X...} consisting of the on / off states of K LED light sources. k ,...,X K} n , where X k X represents the on / off state of the k-th LED light source, and X k Let k ∈ {0,1}, k ∈ {1,2,...,K}, and n represent the nth 0-1 state combination of the K LED light sources at the transmitter, where n ∈ {1,2,...,N}. The electrical signals received by the M PDs after each experimental LED on / off state combination are stored through a compound-eye PD receiver. It is denoted as the primitive compound eye pattern S n Then the original compound eye pattern S n This corresponds to the on / off state of each of the K LED light sources, i.e., the 01 data sent, where n∈{1,2,...,N}. Finally, the N LED on / off states are combined to correspond to the N original compound eye patterns S received. n The set is the original compound eye pattern set S, where S = {S1, S2, ..., S...} N}

[0012] Step 3: Transmission of visible light signals

[0013] Let the transmitted data of K LED light sources be d1, d2, ..., d K Where d1, d2, ..., d K ∈{0,1}, will send data d1,d2,...,d K The baseband signal is applied to each of the K LED light sources, thereby enabling the transmission of optical signals from the K LED light sources.

[0014] Step 4: Reception and Demodulation of Visible Light Signals

[0015] For signal reception in a compound-eye PD receiver, the electrical signals I1, I2, ..., I received by M PDs per unit time are... M Let R be the receiving compound eye pattern, where R = {I1, I2, ..., I...} M}, and receive the compound eye pattern R and the original compound eye pattern S n They have the same set shape. The demodulation process for the received compound eye pattern R per unit time is as follows.

[0016] First, the electrical signal values ​​I1, I2, ..., I in the received compound eye pattern R are... M Each is compared with N original compound eye patterns S n Electrical signal values ​​at the same PD position Perform Euclidean distance E n The calculation is expressed as:

[0017]

[0018] Where n∈{1,2,...,N}.

[0019] Secondly, find N Euclidean distance results E1, E2, ..., E N The minimum value in the range is calculated, and the compound eye pattern used to obtain this minimum value is the original compound eye pattern uniquely corresponding to the received compound eye pattern R within that unit time. Since the original compound eye pattern S... n A unique combination of the on / off states of K LED light sources {X1, X2, ..., X...} k ,...,X K} nThis corresponds to the 0 and 1 data transmitted by each of the K LED light sources. Therefore, within a unit of time, by receiving the compound eye pattern R, the 0 and 1 data transmitted by each of the K LED light sources can be demodulated, and thus all the transmitted data d1, d2, ..., d from the K LED light sources can be demodulated. K This enables data transmission from K LED light sources in a VLC system.

[0020] The beneficial effects of this invention are as follows:

[0021] Compared to using a single PD to achieve data transmission in a VLC system, this invention fully utilizes the complex characteristics of the channel environment by designing the optical receiver composed of multiple PDs into a compound eye receiving layout. This not only makes full use of visible light signals in complex spatial scenarios and improves the intensity of the received optical signals, but also allows for the reuse of visible light communication channels to achieve data communication transmission between multiple LEDs, thereby further improving the data transmission rate of the VLC system. Attached Figure Description

[0022] Figure 1 These are top (left) and side (right) views of a compound-eye PD receiver with a square layout in the compound-eye visible light multiple access communication method of the present invention.

[0023] Figure 2 This is a flowchart illustrating the compound-eye visible light multiple access communication method of the present invention. In the diagram: 1 represents four LED light sources, 2 represents the transmission of light signals from the LED light sources, 3 represents the reception of visible light signals from the four LED light sources through a compound-eye PD receiver, and 4 represents the demodulation of the received visible light signals. Detailed Implementation

[0024] The specific embodiments of the present invention are described in detail below with reference to the technical solution (and accompanying drawings).

[0025] Assume a VLC system has four LED light sources as light emitters, responsible for transmitting visible light signals to four users, and 16 compound-eye PDs as light receivers, used to receive the visible light signals from the four users through complex space and demodulate the transmitted data, thus realizing data communication transmission between the four users. The process of the compound-eye visible light multiple access communication method is as follows.

[0026] Step 1: Deployment of Compound Eye PD Receiver

[0027] The VLC system's receiver consists of 16 PD sensors arranged in a 4x4 square layout. The receiving directions of each PD are arranged around a curved surface, similar to the compound eye structure of an insect. This arrangement allows for efficient reception of visible light signals after passing through complex channel environments. A top view (left) and a side view (right) of the compound eye PD receiver layout are attached. Figure 1 As shown in the image.

[0028] Step 2: Generation of the original compound eye pattern set

[0029] For a VLC system containing four LED light sources, see attached... Figure 2 As shown in section 1, there are a total of 16 possible combinations of on / off states. Specifically, an on LED indicates a transmitted data value of "1", and an off LED indicates a transmitted data value of "0". In a complex channel environment, experiments were conducted to create on / off state combinations {X1, X2, X3, X4} consisting of the on / off states of four LEDs. n X1, X2, X3, and X4 represent the on / off states of the four LED light sources, and X1, X2, X3, X4 ∈ {0, 1}. n represents the nth 0 / 1 state combination of the four LEDs at the transmitter, and n ∈ {1, 2, ..., 16}. The compound-eye PD receiver stores the electrical signals received by the 16 PDs after each experimental LED on / off state combination. It is denoted as the primitive compound eye pattern S n Then the original compound eye pattern S n This corresponds to the on / off state of each of the four LED light sources, i.e., the 01 data sent, where n∈{1,2,...,16}. Finally, the 16 LED on / off states are combined to correspond to the 16 original compound eye patterns S received. n The set is the original compound eye pattern set S, where S = {S1, S2, ..., S...} 16}

[0030] Step 3: Transmission of visible light signals

[0031] Let the transmitted data from the four LED light sources be d1, d2, d3, and d4, where d1, d2, d3, and d4 ∈ {0, 1}. The transmitted data d1, d2, d3, and d4 are used as baseband signals and applied to the four LED light sources respectively, thus realizing the transmission of optical signals from the four LED light sources, as shown in the attached diagram. Figure 2 As shown in point 2.

[0032] Step 4: Reception and Demodulation of Visible Light Signals

[0033] For signal reception of the compound-eye PD receiver, its arrangement is as follows: Figure 2As shown in section 3, the electrical signals I1, I2, ..., I received by the 16 PDs at the receiving end per unit time are represented. 16 Let R be the receiving compound eye pattern, where R = {I1, I2, ..., I...} 16}, and receive the compound eye pattern R and the original compound eye pattern S n They have the same square shape. For the received compound eye pattern R per unit time, see attached... Figure 2 As shown in section 4, the demodulation process is as follows.

[0034] First, according to equation (1), the electrical signal values ​​I1, I2, ..., I in the received compound eye pattern R are... 16 Each of the 16 original compound eye patterns S n Electrical signal values ​​at the same PD position Perform Euclidean distance E n The calculation yielded 16 Euclidean distance results: E1, E2, ..., E 16 .

[0035] Secondly, the minimum value among the 16 Euclidean distance results is found. The compound eye pattern used to calculate this minimum value is the original compound eye pattern uniquely corresponding to the received compound eye pattern R within that unit of time. Since the original compound eye pattern S... n A unique combination of the on / off states of four LED light sources: {X1, X2, X3, X4} n This corresponds to the 01 data sent by each of the four LED light sources. Therefore, within a unit of time, by receiving the compound eye pattern R, the 01 data sent by each of the four LED light sources can be demodulated, and then all the transmitted data d1, d2, d3, d4 of the four LED light sources can be demodulated, thus realizing the data transmission of the four LED light sources in the VLC system.

[0036] The above-described embodiments are merely illustrative of the implementation methods of the present invention, but should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A compound-eye visible light multiple access communication method, characterized in that, The aforementioned communication method fully utilizes the complex characteristics of the channel environment by designing the optical receiver in the VLC system, which consists of multiple PDs, into a compound-eye multi-PD receiver layout. Based on this compound-eye PD receiver layout, a corresponding communication method is provided. This method can fully receive and utilize visible light signals transmitted from multiple light sources within the spatial scene, thereby multiplexing the channel and improving the overall data transmission rate of the VLC system. Specifically, as follows: Assuming there is in the VLC system Each LED light source acts as a light emitter, responsible for Visible light signal transmission for each user, and A compound-eye-shaped PD serves as the optical receiver, used to receive... The optical signals from each user after passing through a complex space are then demodulated to extract the transmitted data from each user, thereby achieving... Data communication transmission for individual users; the steps are as follows: Step 1: Arrangement of compound-eye PD receiver; Step 2: Generation of the original compound eye pattern set; Step 3: Transmission of visible light signals; Step 4: Reception and Demodulation of Visible Light Signals For signal reception in a compound eye PD receiver, the signal reception per unit time will be... The electrical signals received by each PD Recorded as receiving compound eye pattern ,in And receive compound eye patterns With the original compound eye pattern Having the same set shape; for receiving compound eye patterns per unit time The demodulation process is as follows: First, receive the compound eye pattern. Electrical signal values ​​in respectively with The original compound eye pattern Electrical signal values ​​at the same PD position Perform Euclidean distance The calculation is expressed as: (1) in, ; Secondly, searching Euclidean distance results The minimum value in the range is then used to calculate the compound eye pattern used to obtain the minimum value, which is the compound eye pattern received per unit time. The unique corresponding primitive compound eye pattern; due to the primitive compound eye pattern Able to uniquely represent Combination of on / off states of individual LED light sources That is, corresponding Each LED light source sends its own 0 and 1 data; therefore, within a unit of time, by receiving the compound eye pattern... Able to demodulate The 0 and 1 data sent by each LED light source are then demodulated. All transmitted data from each LED light source To implement in VLC system Data transmission of individual LED light sources.

2. The compound-eye visible light multiple access communication method according to claim 1, characterized in that, In step one: The receiver of the VLC system is... Composed of PD sensors, this Each PD is designed with a specific shape suitable for the actual channel environment, including circles, squares or other shapes. At the same time, the receiving direction of each PD is arranged around the arc surface, which is a layout similar to the compound eye structure of an insect, so as to fully receive the visible light signal after passing through the complex channel environment. In step two: for those containing A VLC system with 1 LED light source represents a total of 10 combinations of on / off states. One, of which That is, the LED's on state indicates that it is transmitting data "1", and its off state indicates that it is transmitting data "0". Experiments were conducted in complex channel environments, by... The combination of on / off states formed by the on / off states of individual LED light sources ,in Indicates the first The on / off state of each LED light source, and , , Indicates the transmitting end The first LED light source A combination of 0 and 1 states, and ; After storing the LED on / off state combination for each test using a compound-eye PD receiver The electrical signals received by each PD And recorded it as the primitive compound eye pattern. The original compound eye pattern Corresponding to The on / off state of each LED light source, i.e., the 01 data sent, where , ; Finally Each LED on / off state combination corresponds to the received The original compound eye pattern The set is a primitive compound eye pattern set. ,in ; In step three: Let The data transmitted by each LED light source are as follows: ,in, Data will be sent. As baseband signals, respectively loaded to On each LED light source, thereby achieving The light signal is sent from each LED light source.

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