CN204089821U - A visible light communication system - Google Patents

Abstract

The utility model discloses a kind of visible light communication system, and its controlled processing unit of making a start comprises outer network interface, originating processor, controller of making a start, modulation circuit of making a start, make a start demodulator circuit and reception amplifier.Optical arrays unit comprises drive circuit, infrared remote receiver and 3 groups of LED light sources be made up of white LED light source and RBG light LED light source.Mobile terminal comprises filter plate combination, lens, photoelectric detector, trans-impedance amplifier, auto-gain circuit, low noise amplifier, filter circuit, limiting amplifier, terminal demodulates circuit, terminal control unit, terminal handler, end modification circuit and infrared sending tube.The utility model can reach interregional automatic link transfer and the function communicated of throwing light on, and makes the trans-regional continuity of receiving equipment Continued communication, the compatibility of lighting demand and the energy saving of green communications.

Description

A visible light communication system

technical field

The utility model relates to the field of optical communication, in particular to a visible light communication system.

Background technique

Visible Light Communication (VLC) is a data communication technology that uses visible light in the wavelength range of 780-375nm (frequency 400THz-800THz) as the transmission medium. Existing visible light communication systems always use traditional incandescent lamps and energy-saving lamps as light sources, and send out optical signals through broadcasting, so that receiving users can only communicate within the optical radiation area they are in. If they enter other areas The continuous signal to be received will be lost in an instant, and the range of the light source usually arranged is small, not a large light array area light source, so the range of communication is limited. In addition, in the broadcasting mode, the communication circuit and the lighting circuit are generally in the working state when they are turned on, which will cause unnecessary waste of energy when there is no receiving end. Therefore, when the receiving area of the receiving end changes, the inter-area handover function is lacking, so as to achieve continuous communication and green communication.

With the vigorous development of lighting technology, compared with incandescent lamps and energy-saving lamps, LEDs have the advantages of lower power consumption, lower operating voltage, longer life, smaller size, and more heat resistance. The mainstream lighting source in the market. Utilizing the characteristics of short switching time of LED and easy realization of high-speed modulation to modulate the signal to LED for transmission, visible light communication has the advantages of fast transmission rate and large capacity of ordinary wireless optical communication, and at the same time, the naked eye cannot detect high-speed light and darkness during communication. The flickering transmission signal does not affect daily lighting and has no radiation damage to the human body. It has the advantages of high transmission power, no electromagnetic radiation, no authorization for spectrum use, no mutual interference between signals, and energy saving and environmental protection. It is a kind of The green and environment-friendly wireless communication technology also provides a new option for short-distance wireless communication and promotes the development of next-generation wireless networks.

Utility model content

The technical problem to be solved by the utility model is that the existing visible light communication system based on traditional light sources is difficult to achieve continuous communication and wastes energy, and a visible light communication system is provided.

In order to solve the above problems, the utility model is achieved through the following technical solutions:

A visible light communication system mainly consists of an originating control processing unit, an optical array unit and a mobile terminal. The sending-end control processing unit includes an external network interface, a sending-end processor, a sending-end controller, a sending-end modulation circuit, a sending-end demodulation circuit and a receiving amplifier. The external network interface is connected to the sending processor. The originating controller and the originating processor are connected to each other. The output terminal of the transmitting-end controller is connected to the control terminal of the transmitting-end modulation circuit. The output terminal of the transmitting processor is connected to the input terminal of the transmitting modulation circuit. The output end of the receiving amplifier is connected to the input end of the demodulation circuit at the sending end, and the output end of the demodulation circuit at the sending end is connected to the input end of the processor at the sending end. The light array unit includes a driving circuit, an infrared receiver and 3 groups of LED light sources. The input terminal of the driving circuit is connected to the output terminal of the transmission modulation circuit of the transmission control processing unit. The output end of the drive circuit is divided into three carrier output ends, and each carrier output end is connected to the input end of a group of LED light sources. The output end of the infrared receiver is connected to the input end of the receiving amplifier of the sending end control processing unit. The mobile terminal includes filter combination, lens, photodetector, transimpedance amplifier, automatic gain circuit, low noise amplifier, filter circuit, limiting amplifier, terminal demodulation circuit, terminal controller, terminal processor, terminal modulation circuit and infrared send tube. The filter combination and the lens receive the LED light signal from the LED light source of the light array unit, and the output end of the filter combination and the output end of the lens are both connected with the input end of the photodetector. The output end of the photodetector is connected to the input end of the transimpedance amplifier, and the output end of the transimpedance amplifier is respectively connected to the input end of the automatic gain circuit and the input end of the low noise amplifier. The output end of the automatic gain circuit is connected to the input end of the limiting amplifier after the filter circuit, the output end of the limiting amplifier is connected to the input end of the terminal demodulation circuit, and the output end of the limiting amplifier is connected to the input of the terminal processor through the terminal demodulation circuit end. The output end of the low noise amplifier is connected to the input end of the terminal processor. The terminal controller and the terminal processor are connected to each other. The output end of the terminal processor is connected with the input end of the infrared sending tube through the terminal modulating circuit, and the infrared sending tube sends an infrared light signal to the receiving amplifier of the optical array unit.

In the above solution, each group of LED light sources is composed of white LED light source and RBG light LED light source.

Compared with the prior art, the utility model uses the combination of white LED and RGB LED light source to achieve the function of automatic link transfer and lighting communication between regions, so that the cross-regional continuity of continuous communication of the receiving device and the compatibility of lighting requirements Energy-saving and green communication, while using the RGB LED array light source under the advanced modulation method will greatly increase the number of users and the communication rate. Space-division multiplexing is carried out under the light source layout structure. The adjacent light source areas use white LED lights that send different frequency carriers. Different frequency carriers carry different automatic link transfer information for area switching control, that is, to achieve the control used by adjacent areas. The carrier frequency of the signal is different, so as not to interfere with each other, and then according to the specific size of the layout space, the number of combined light array units of RGB LEDs and white LEDs is increased or decreased, so that the adjacent areas use different carrier frequencies for optical path switching control to achieve Space division multiplexing is used to form large clusters.

Description of drawings

Fig. 1 is a schematic block diagram of a visible light communication system.

Detailed ways

A visible light communication system, as shown in FIG. 1 , is mainly composed of an originating control processing unit, an optical array unit, and a mobile terminal.

The above-mentioned sending-end control processing unit includes an external network interface, a sending-end processor, a sending-end controller, a sending-end modulation circuit, a sending-end demodulation circuit and a receiving amplifier. The external network interface is connected to the sending processor. The originating controller and the originating processor are connected to each other. The output terminal of the transmitting-end controller is connected to the control terminal of the transmitting-end modulation circuit. The output terminal of the transmitting processor is connected to the input terminal of the transmitting modulation circuit. The output end of the receiving amplifier is connected to the input end of the demodulation circuit at the sending end, and the output end of the demodulation circuit at the sending end is connected to the input end of the processor at the sending end.

The above light array unit includes a driving circuit, an infrared receiver and 3 groups of LED light sources. The input terminal of the driving circuit is connected to the output terminal of the transmission modulation circuit of the transmission control processing unit. The output end of the drive circuit is divided into three carrier output ends, and each carrier output end is connected to the input end of a group of LED light sources. The output end of the infrared receiver is connected to the input end of the receiving amplifier of the sending end control processing unit. In a preferred embodiment of the present invention, each group of LED light sources is composed of white light LED light source and RBG light LED light source, and at this time each group of LED light source can emit white light and RBG light. Because the utility model needs to take into account the lighting during the communication process, white LEDs and RGB LEDs are added to the light source part at the front end of the light array unit. Because of the good light efficiency of white LEDs and the good color rendering of RGB-LEDs, the combination of these two light sources can achieve complementary effects in lighting, so the combination of these two light sources can make this The utility model obtains better lighting effects on the premise of realizing communication.

The above-mentioned mobile terminal includes a filter combination, a lens, a photodetector, a transimpedance amplifier, an automatic gain circuit, a low noise amplifier, a filter circuit, a limiting amplifier, a terminal demodulation circuit, a terminal controller, a terminal processor, a terminal modulation circuit and Infrared transmitter tube. The filter combination and the lens receive the LED light signal from the LED light source of the light array unit, and the output end of the filter combination and the output end of the lens are both connected with the input end of the photodetector. The output end of the photodetector is connected to the input end of the transimpedance amplifier, and the output end of the transimpedance amplifier is respectively connected to the input end of the automatic gain circuit and the input end of the low noise amplifier. The output end of the automatic gain circuit is connected to the input end of the limiting amplifier after the filter circuit, the output end of the limiting amplifier is connected to the input end of the terminal demodulation circuit, and the output end of the limiting amplifier is connected to the input of the terminal processor through the terminal demodulation circuit end. The output end of the low noise amplifier is connected to the input end of the terminal processor. The terminal controller and the terminal processor are connected to each other. The output end of the terminal processor is connected with the input end of the infrared sending tube through the terminal modulating circuit, and the infrared sending tube sends an infrared light signal to the receiving amplifier of the optical array unit.

The working process of the downlink of the utility model is as follows: the external network information enters the originating control processing unit through the peripheral interface. The transmitting processor first subpackages its data and performs channel coding, and then generates three mutually independent cross-area optical link switching signals, and divides the baseband modulation bandwidth into three frequency bands. The channel coding and signal of the transmitting processor Both generation and frequency band division adopt existing methods. The modulation circuit at the sending end modulates the coded signal, and modulates three mutually independent handover optical link switching signals onto the three divided carriers and transmits them to the subsequent optical array unit. Under the control of the originating controller, the above modulated signal is divided into two time slots and transmitted alternately and sequentially independently on the corresponding LEDs. The switching signal and communication data signal are put into two connected time slots to form a periodic signal for transmission. After the coded and modulated external network signal is sent to the optical array unit, the RGB LED of the current optical link sends out an optical signal. At this time, the white LED used for the automatic link transfer function does not send out the communication signal of this function; three The independent and modulated handover signals are respectively sent to the white LEDs in the combined light array units of RGB LEDs and white LEDs to send out as optical signals, that is, the white light in the combined light array unit of three RGB LEDs and white LEDs The LEDs send their own three independent carrier signals. The two signals are time-division multiplexed, and the two signals are divided into two consecutive time slots and transmitted alternately in sequence. Each signal is sent to the mobile terminal after passing through the channel. The mobile terminal respectively obtains the independent three-color light carrying external network communication data through the filter, and sends it to the demodulation circuit for corresponding decoding according to the modulation mode after passing through the photoelectric detector, transimpedance amplifier, automatic gain circuit, filter circuit and limiting amplifier. After being tuned, it is sent to the processor of the mobile terminal for channel decoding to restore the original data for the user to use; and the optical signal carrying the handover signal is converged by the lens to the photodetector corresponding to the range of the receiving wavelength, and then passed through the After the transimpedance amplifier and the low-noise amplifier circuit are amplified, the intensity of the optical signal is converted into the intensity of the corresponding electrical signal. The automatic link transfer module in the processor of the mobile terminal analyzes the amplified electrical signal, respectively The intensity of the three carrier signals is compared and analyzed, and the handover signal required by the mobile terminal is extracted at the same time. Under the control of clock synchronization, the controller in the mobile terminal will receive and extract the corresponding time slot for the signal transmitted in the above channel.

The working process of the uplink of the present utility model is as follows: the mobile terminal will send two types of signals, one is the cross-area optical link transfer or the interactive confirmation signal to keep the current optical link unchanged; Data signals to interact with. Both types of signals are generated by the processor of the mobile terminal, and after modulation, the infrared transmitting tube of the mobile terminal sends out infrared light. The two types of signals will also be sent in time slots and different frame headers are added to distinguish data. The infrared light signal is received by the infrared receiver on the optical array unit after passing through the channel, and then sent to the control and processing unit of the sending end after passing through the receiving amplifier circuit and the demodulation circuit. The sender processor of the sender control processing unit discriminates the types of the two signals, and then processes them respectively. The cross-area optical link transfer or the interactive confirmation signal to keep the current optical link unchanged is processed by the originating processor to determine the control of the link, that is, to maintain or transfer, and at the same time decide to use one of the three optical array units for the LED light source link Communication of data signals, and the other two areas of the circuit that do not currently use white LED communication can be in a dormant state under the control of the sender controller of the sender control processing unit; when lighting is not needed, the sender controller can also be controlled to shut down In addition to maintaining the link, the RGB LED array lighting function of the two areas can achieve energy-saving and green communication effects. After the data signal interacting with the data of the external network is processed by the communication data processing module in the sending processor, information is exchanged with the external network through the external network interface.

Claims (2)

1. A visible light communication system, characterized in that: it is mainly composed of an originating control processing unit, an optical array unit and a mobile terminal; wherein The sending end control processing unit includes an external network interface, a sending end processor, a sending end controller, a sending end modulation circuit, a sending end demodulation circuit and a receiving amplifier; the external network interface is connected to the sending end processor; the sending end controller and the sending end processor are connected to each other; the sending end The output end of the controller is connected to the control end of the modulation circuit of the transmission end; the output end of the processor of the transmission end is connected to the input end of the modulation circuit of the transmission end; the output end of the receiving amplifier is connected to the input end of the demodulation circuit of the transmission end, and the output end of the demodulation circuit of the transmission end is connected to the input to the processor; The light array unit includes a driving circuit, an infrared receiver and 3 groups of LED light sources; the input end of the driving circuit is connected to the output end of the sending end modulation circuit of the sending end control processing unit; the output end of the driving circuit is divided into three carrier output ends, each carrier The output ends are respectively connected to the input ends of a group of LED light sources; the output ends of the infrared receiver are connected to the input ends of the receiving amplifier of the sending end control processing unit; The mobile terminal includes filter combination, lens, photodetector, transimpedance amplifier, automatic gain circuit, low noise amplifier, filter circuit, limiting amplifier, terminal demodulation circuit, terminal controller, terminal processor, terminal modulation circuit and infrared The sending tube; the filter combination and the lens receive the LED light signal sent by the LED light source of the light array unit, the output end of the filter combination and the output end of the lens are connected with the input end of the photodetector; the output end of the photodetector is connected across The input end of the impedance amplifier, the output end of the transimpedance amplifier are respectively connected to the input end of the automatic gain circuit and the input end of the low noise amplifier; the output end of the automatic gain circuit is connected to the input end of the limiting amplifier after the filter circuit, and the input end of the limiting amplifier The output end is connected to the input end of the terminal demodulation circuit, the output end of the limiting amplifier is connected to the input end of the terminal processor through the terminal demodulation circuit; the output end of the low noise amplifier is connected to the input end of the terminal processor; the terminal controller and the terminal processing The devices are connected to each other; the output terminal of the terminal processor is connected with the input terminal of the infrared transmitting tube through the terminal modulating circuit, and the infrared transmitting tube sends an infrared light signal to the receiving amplifier of the optical array unit. 2 . The visible light communication system according to claim 1 , wherein each group of LED light sources is composed of white LED light source and RBG light LED light source. 3 .