CN103944635A - Voice broadcast system based on visible light communication - Google Patents
Voice broadcast system based on visible light communication Download PDFInfo
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- CN103944635A CN103944635A CN201410187357.5A CN201410187357A CN103944635A CN 103944635 A CN103944635 A CN 103944635A CN 201410187357 A CN201410187357 A CN 201410187357A CN 103944635 A CN103944635 A CN 103944635A
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Abstract
The invention discloses a voice broadcast system based on visible light communication. The voice broadcast system based on the visible light communication comprises a visible light emitter and a fixed terminal comprising a photodiode, wherein the fixed terminal is connected with the visible light emitter in a wireless visible light communication mode; the visible light emitter comprises an AD (analog/digital) converter, a parallel-series data conversion module, an LED (light emitting diode) and an LED driving circuit, and the parallel-series data conversion module comprising a first FPGA (field programmable gate array) processer; the fixed terminal comprises a photoelectric receiver, a parallel-series data conversion module, a DA (data/analog) converter and a loudspeaker box and the parallel-series data conversion module comprises a second FPGA processor. The voice broadcast system based on the visible light communication achieves a voice signal wireless communication function through lighting visible light, can be applied to voice information broadcasting in places requiring all-weather lighting such as superstores and subway stations as well as radio broadcasting in places requiring secure communication such as examination rooms, and is convenient to mount and maintain, wide in usage range, energy-saving, environmentally friendly, scientific, reasonable, safe and reliable.
Description
Technical field
The present invention relates to a kind of voice broadcast service system based on visible light communication, belong to the field of Transmitting of Multi-media Information and broadcasting.
Background technology
In recent years, semiconductor (LED) the lighting technology development that is described as " green illumination " is swift and violent, and particularly white light LEDs is just attracting more people's attention, and they are considered to lighting source of future generation.It finally can substitute at present at the widely used incandescent lamp of office and family and fluorescent lamp.The luminescence response characteristic of utilizing the light on and off of LED high speed, modulates the signal on LED visible ray and transmits, and can realize the high effective model of illumination communicating integral.
Sound radio, is generally used for station, market, public venue, mansion, inside, community, and for background music broadcast, paging broadcast and the disastrous broadcast of insertion by force, sound radio is also generally used for the examination hall of language examination and carries out the broadcasting of hearing examination question.
Traditional wired sound broadcast system mainly comprises source of sound, source of sound management and control equipment, power amplifier, output control equipment, sound-reducing equipment and power supply management device, the normal bus structure processed that adopts, adopt the interfaces such as RS-422, Ethernet, adopt wire transmission at playback terminal place.But, there is following shortcoming in traditional wired sound broadcast system: first, transmission line needs special laying, and easily produce effect of parasitic capacitance systematic function, in construction and use procedure, be prone to wire casing, crane span structure incised wound, short circuit internal core, insect, the muroid problem such as nibble, make the rising of system maintenance cost; Secondly, wire transmission is fixed loudspeaker layout, dumb, and sound radio effect is difficult to ensure; Again, the sound radio of wire transmission cannot be used in the occasion that electromagnetic interference is had to strict restriction; Finally, also there is difficult wiring in traditional wired broadcast system, installation is complicated, dilatancy is poor, damage the problems such as metope.
The wireless broadcast system of playing for hearing examination question adopts radio wave to carry out the transmission of voice signal, have without vertical rod stringing, wide coverage, unlimited dilatation, convenient for installation and maintenance, reduced investment, tonequality grace feature clearly, but there is following shortcoming in traditional wireless broadcast system: first, traditional wireless broadcast system cannot use in the occasion that electromagnetic interference is had to strict restriction; Secondly, the voice signal that traditional wireless broadcast system transmits is easily monitored, causes the problems such as examination question leaks, cheats at one's exam.
In recent years the visible ray voice communication system occurring is also in the immature stage, and the main problem existing has: adopt complicated modulation-demodulation technique that system is realized and maintenance cost increase; Transmission speed is low and distance is short, for fear of the obvious flicker of LED lamp, must adopt the technology such as Mai Chesite coding, has increased equally system complexity.
Summary of the invention
The object of the invention is to overcome the deficiency that prior art exists, a kind of voice broadcast service system based on visible light communication is provided, its compact conformation, realizes simply, and convenient for installation and maintenance, the scope of application is wide, and energy-conserving and environment-protective are scientific and reasonable, safe and reliable.
For achieving the above object, the technical solution used in the present invention is:
A voice broadcast service system based on visible light communication, comprises VISIBLE LIGHT EMISSION machine and the fixed terminal with photodiode, and described fixed terminal and VISIBLE LIGHT EMISSION machine, with line-of-sight propagation wireless connections, is characterized in that:
Described VISIBLE LIGHT EMISSION machine comprises AD converter string data modular converter, light-emitting diode and LED driving circuit, described and string data modular converter adopts a FPGA processor, the voice analog signal that described AD converter produces source of sound changes into as parallel digital signal, a described FPGA processor changes into the parallel digital signal changing into through AD converter for serial data stream and realizes UART asynchronous transmission, and described LED driving circuit receives described serial data stream signal and drives the light on and off of light-emitting diode high frequency;
Described fixed terminal comprises optoelectronic receiver, string data conversion module, DA converter and audio amplifier, described string data conversion module adopt the 2nd FPGA processor, described optoelectronic receiver receives the white light signal of described light-emitting diode and changes into the serial data stream into the signal of telecommunication, described the 2nd FPGA processor changes into described serial data stream to realize the asynchronous reception of UART for parallel digital signal, described DA converter changes into described parallel digital signal into voice analog signal, and described audio amplifier is play described voice analog signal.
Described optoelectronic receiver comprises photoelectricity receiving circuit, described photoelectricity receiving circuit is made up of the PIN photodiode connecting successively, trans-impedance amplifier, second level amplifier, third level amplifier and high-speed comparator, and described PIN photodiode is for identifying the light on and off signal of light-emitting diode.
Described LED driving circuit is alternating current source circuit, is composed in parallel by four current feedback operation amplifier circuits.
VISIBLE LIGHT EMISSION machine comprises power management module, and described power management module is converted to the alternating current of 220V the direct current of positive and negative 15V.
Described photoelectricity receiving circuit comprises electric power management circuit, and 9V direct current is converted to positive and negative 5V direct current by described electric power management circuit.
For fear of adopting complicated modulation technique and coding techniques, thereby reduction system complexity, the accuracy that improves transfer of data, parallel serial conversion module of the present invention utilizes FPGA processor that parallel audio digital signal transformed into serial data is flowed and realizes UART asynchronous transmission function.Receive after 8 parallel bit data, according to the timing of fixing baud rate by it from low level, one sends.String modular converter utilize FPGA processor that serial data stream is reverted to parallel audio digital signal and realizes the asynchronous receiving function of UART.After detecting on channel that level changes, can gather according to fixing sampling rate the data of a character frame, and transfer data bit wherein to parallel other processing modules of giving.
Optoelectronic receiver of the present invention comprises photoelectricity receiving circuit, and wherein photoelectricity receiving circuit comprises photodiode, trans-impedance amplifier, second level amplifier, third level amplifier and high-speed comparator.The light on and off signal of described photodiode identification light-emitting diode, produce corresponding current signal, the current signal of photodiode output is converted into voltage signal by described trans-impedance amplifier, described second level amplifier amplifies the voltage signal of trans-impedance amplifier output, the signal of second level amplifier output is further amplified to certain numerical value by described third level amplifier, the signal of third level amplifier output is processed into digital signal level by described high-speed comparator, described digital signal level is exactly the output signal of optoelectronic receiver or the visible light signal receiving, the output of optoelectronic receiver is connected with deserializer.
Voice broadcast service system based on visible light communication provided by the invention, compares with the Public Address system that current application is more, has following beneficial effect:
1. visible light communication can combine with the power for illumination line of force existing in actual environment, in system layout, do not need to increase extra supply of electric power circuit, the transmitter that can set up the voice broadcast service system based on visible light communication by the existing illuminator of simple transformation, reaches the object that makes full use of existing resource, environmental protection and energy saving;
2. visible light communication belongs to wireless transmission, has avoided the maintenance cost that produces because of holding wire fault, also makes the layout of loud speaker be convenient to more flexibly safeguard;
3. LED belongs to green light source, and visible ray is harmless to human-body safety, and the present invention can be used for that megastore, subway station etc. are crowded, the place of the round-the-clock illumination of needs and comprehensive voice broadcast service system;
4. without electromagnetic interference, the present invention can be applicable to aircraft, operating room etc. the occasion of strict restriction to electromagnetic interference;
5. be convenient to realize secure communication, the present invention can be used for needing in the voice broadcast service application scenarios (such as hearing examination hall) of anti-eavesdrop.
6. system is 1 watt constant in the situation that at LED power, and the square-wave signal of different frequency is tested to its attenuation characteristic with distance, and system finally can realize 6 meters of distances, the transfer of data of bandwidth 2.5MHz.Do not need complicated modulation /demodulation, coding and decoding technology, system Realization and maintenance is very convenient.
Brief description of the drawings
Fig. 1 is the structured flowchart that the present invention uses state.
Fig. 2 is VISIBLE LIGHT EMISSION machine syndeton block diagram of the present invention.
Fig. 3 is the syndeton block diagram of fixed receiver of the present invention.
Fig. 4 is the circuit theory diagrams of LED driving circuit of the present invention.
Fig. 5 is the circuit theory diagrams of photoelectricity receiving circuit of the present invention.
Fig. 6 adopts the data frame format of UART asynchronous serial communication agreement for the present invention.
Fig. 7 is that in the present invention, UART sends programming flowchart.
Fig. 8 is UART reception program design frame chart in the present invention.
Embodiment
Below in conjunction with drawings and Examples, the invention will be further described.
Voice broadcast service system based on visible light communication as shown in Figure 1, comprises VISIBLE LIGHT EMISSION machine and the fixed terminal with photodiode, and described fixed terminal and VISIBLE LIGHT EMISSION machine are with line-of-sight propagation wireless connections.
As shown in Fig. 2, described VISIBLE LIGHT EMISSION machine comprises power management module, AD converter string data modular converter and LED driving circuit.Several intermodules utilize wire that corresponding signal is connected successively.
In this case, power management module can adopt AC-DC translation circuit that 220V alternating current is converted to the 15V of government direct current.
In this case, and string data modular converter adopts FPGA to realize the universal asynchronous serial transmission of UART.
Be illustrated in figure 6 the form of UART mono-frame data, each bit meaning of a character frame is as follows.Start bit: first send a logic " 0 " signal, represent the beginning of transmission character.Data bit: and then after start bit, the number of data bit can be 4,5,6,7,8 etc., forms a character.Conventionally adopt ASCII character.Start to transmit from lowest order, by clock location.Parity check bit: data bits add this position after, make the figure place of " 1 " should be even number (even parity check) or odd number (odd), the correctness of carrying out verification data transmission with this, can select when practice not add.Position of rest: it is the end mark of a character data.It can be the high level of 1,1.5,2.Due to data timing on transmission line, and each equipment has its oneself clock, and probably in communication, two equipment rooms have occurred slight asynchronous.Therefore position of rest is not only the end that represents transmission, and provides computer position synchronous chance.The figure place that is applicable to position of rest is more, and the synchronous degrees of tolerance of different clocks is larger, but data transmission rate is simultaneously also slower.
As shown in Figure 7, the programming that UART sends and to receive thinking substantially the same, after receiving 8 parallel bit data, according to fixing baud rate regularly by it from low level, one sends.
As shown in Figure 4, LED drive circuit adopts easy ac current source drives LED, drives diode light on and off frequency can reach 2---3MHz, human eye None-identified.Design alternating current source circuit with the operational amplifier THS3091 of High Output Current, high bandwidth, and use multiple operational amplifiers driving force that further increases in parallel.
As shown in Figure 3, described fixed terminal comprises power management module, optoelectronic receiver, string data conversion module, DA converter and audio amplifier.Several intermodules utilize wire that corresponding signal is connected successively.White light signal becomes the serial data stream of the signal of telecommunication through described optoelectronic receiver, then becomes parallel digital signal through described string data conversion module, then becomes voice analog signal through described DA converter, and described audio amplifier is play described voice analog signal.
In this case, it is chip power supply that power management module can adopt positive 5V voltage stabilizing circuit and DC-DC translation circuit that 9V battery direct current is converted to positive and negative 5V direct current.
In this case, string data conversion module adopt FPGA to realize the universal asynchronous serial received of UART.
UART reception program mentality of designing is after detecting on channel that level changes as shown in Figure 8, can gather according to fixing sampling rate the data of a character frame, and transfers data bit wherein to parallel other processing modules of giving.The input of level detection module is signal input tube pin, and its function is to be responsible for detecting the start bit of data, when detecting that data-signal when 1 becomes 0, just produces a high impulse to controlling receiver module, represents that frame data start; Baud rate time block is the module of configuration baud rate, and in the time that frame data start, this module timing produces high impulse for controlling the sampling of receiver module; Controlling receiver module is nucleus module, mainly the data of 11 of 1 frames for the configuration of serial ports, when for one-way communication, can ignore check digit, after frame data start, the timing rate sampled data that this module produces with baud rate time block, after 8 bit data positions finish receiving, transferred to parallel output, and notified other module reading out datas.
As shown in Figure 5, photoelectricity receiving circuit is realized signal condition function, comprises three-stage amplifier and one-level ultrahigh-speed comparator.First order amplifying circuit is the trans-impedance amplifier that OPA657 chip is built, and rear two-stage amplifying circuit is broadband low noise amplifier, then exports corresponding Transistor-Transistor Logic level signal through TLV3201 ultrahigh-speed comparator below.
In this case, be 1 watt constant in the situation that at LED power, the square-wave signal of different frequency is tested to its attenuation characteristic with distance, system finally can realize 6 meters of distances, the transfer of data of bandwidth 2.5MHz.
The present invention is devoted to the voice signal from microphone or other sources of sound to utilize visible ray to carry out wireless transmission by optical sender, optoelectronic receiver receiving optical signals is reduced into voice signal and gives loud speaker and broadcast, can carry out in places such as subway station, megastore, museum, library, aircraft, operating rooms the broadcast of the emergent broadcasts such as service broadcast, fire alarm such as background music and other business, have that energy-conserving and environment-protective, layout are flexible, easy to maintenance, with low cost, the feature of applied range.
Claims (5)
1. the voice broadcast service system based on visible light communication, comprises VISIBLE LIGHT EMISSION machine and the fixed terminal with photodiode, and described fixed terminal and VISIBLE LIGHT EMISSION machine, with line-of-sight propagation wireless connections, is characterized in that:
Described VISIBLE LIGHT EMISSION machine comprises AD converter string data modular converter, light-emitting diode and LED driving circuit, described and string data modular converter adopts a FPGA processor, the voice analog signal that described AD converter produces source of sound changes into as parallel digital signal, a described FPGA processor changes into the parallel digital signal changing into through AD converter for serial data stream and realizes UART asynchronous transmission, and described LED driving circuit receives described serial data stream signal and drives the light on and off of light-emitting diode high frequency;
Described fixed terminal comprises optoelectronic receiver, string data conversion module, DA converter and audio amplifier, described string data conversion module adopt the 2nd FPGA processor, described optoelectronic receiver receives the white light signal of described light-emitting diode and changes into the serial data stream into the signal of telecommunication, described the 2nd FPGA processor changes into described serial data stream to realize the asynchronous reception of UART for parallel digital signal, described DA converter changes into described parallel digital signal into voice analog signal, and described audio amplifier is play described voice analog signal.
2. the voice broadcast service system based on visible light communication according to claim 1, it is characterized in that: described optoelectronic receiver comprises photoelectricity receiving circuit, described photoelectricity receiving circuit is made up of the PIN photodiode connecting successively, trans-impedance amplifier, second level amplifier, third level amplifier and high-speed comparator, and described PIN photodiode is for identifying the light on and off signal of light-emitting diode.
3. the voice broadcast service system based on visible light communication according to claim 1, is characterized in that: described LED driving circuit is alternating current source circuit, is composed in parallel by four current feedback operation amplifier circuits.
4. according to the voice broadcast service system based on visible light communication described in claim 1,2 or 3, it is characterized in that: VISIBLE LIGHT EMISSION machine comprises power management module, described power management module is converted to the alternating current of 220V the direct current of positive and negative 15V.
5. according to the voice broadcast service system based on visible light communication described in claim 1,2 or 3, it is characterized in that: described photoelectricity receiving circuit comprises electric power management circuit, 9V direct current is converted to positive and negative 5V direct current by described electric power management circuit.
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| CN201410187357.5A CN103944635A (en) | 2014-05-05 | 2014-05-05 | Voice broadcast system based on visible light communication |
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| CN104485996A (en) * | 2015-01-05 | 2015-04-01 | 北京邮电大学 | Omnidirectional voice communication transmit-receive system design based on visible light communication and application method |
| CN104485993A (en) * | 2014-11-25 | 2015-04-01 | 南昌大学 | Vehicular visible light wireless digital voice communication system |
| CN104506334A (en) * | 2015-01-08 | 2015-04-08 | 深圳市芯通信息科技有限公司 | Information broadcasting system and method based on visible light communication |
| CN104601235A (en) * | 2014-12-31 | 2015-05-06 | 青岛黄海学院 | Audio signal visible light transmitting device |
| CN104732898A (en) * | 2015-04-09 | 2015-06-24 | 中国科学院半导体研究所 | Wireless visible-light guide explaining machine |
| CN105225533A (en) * | 2015-09-29 | 2016-01-06 | 成都川睿科技有限公司 | A kind of intelligent transportation communication system based on data first in first out |
| CN107919118A (en) * | 2016-10-09 | 2018-04-17 | 中兴通讯股份有限公司 | Communication control method and device |
| CN109818674A (en) * | 2019-03-25 | 2019-05-28 | 浙江大学城市学院 | A kind of visible light communication wireless broadcast system signal receiving module circuit |
| CN112039620A (en) * | 2020-08-26 | 2020-12-04 | 广州番禺巨大汽车音响设备有限公司 | Digital audio broadcasting processing method and system |
| CN114944870A (en) * | 2022-07-26 | 2022-08-26 | 南昌大学 | UART protocol implementation device based on visible light communication |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104485993A (en) * | 2014-11-25 | 2015-04-01 | 南昌大学 | Vehicular visible light wireless digital voice communication system |
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| CN104601235A (en) * | 2014-12-31 | 2015-05-06 | 青岛黄海学院 | Audio signal visible light transmitting device |
| CN104485996A (en) * | 2015-01-05 | 2015-04-01 | 北京邮电大学 | Omnidirectional voice communication transmit-receive system design based on visible light communication and application method |
| CN104506334A (en) * | 2015-01-08 | 2015-04-08 | 深圳市芯通信息科技有限公司 | Information broadcasting system and method based on visible light communication |
| CN104732898A (en) * | 2015-04-09 | 2015-06-24 | 中国科学院半导体研究所 | Wireless visible-light guide explaining machine |
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| CN114944870A (en) * | 2022-07-26 | 2022-08-26 | 南昌大学 | UART protocol implementation device based on visible light communication |
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Application publication date: 20140723 |