CN205883246U - Visible light communication system based on adjust luminance and add up - Google Patents

Abstract

The utility model discloses a visible light communication system based on adjust luminance and add up, the LED screen remote signal transmission system comprises a transmitting end and a receiving end. Transmitting terminal and receiving terminal pass through wireless optical communication and connect. The transmitting terminal includes data code module, pulse position modulation module, light source drive module, the module of adjusting luminance, RGB LED light source. The receiving terminal includes photoelectric detection module, strides and hinders enlarged module, mould data acquisition original mold piece, pulse position and adjudicate module, pulse position demodulation module and data decoding module. The utility model discloses adopt the synthetic white light of joint dimming method at the transmitting terminal, select for use suitable light path to carry out information transfer under the environment of difference, accomplish remote communication in space or subsurface communication when realizing the white light illumination, amount to to compare the judgement method in the receiving terminal adoption, adjudicate the signal that the sampling obtained, reduced the condition of mistaken verdict, improved the reliability of system.

Description

A kind of visible light communication system cumulative based on light modulation

Technical field

This utility model relates to communication technical field, is specifically related to a kind of visible light communication system cumulative based on light modulation.

Background technology

In current visible light communication (VLC) system, white light source great majority used are by blue-ray LED mixed fluorescent powder Produce required white light.Due to first drive when driving LED luminescence be blue light source be fluorescent material and then, and blue light Driving response speed than fluorescent material fast a lot, therefore there will be the situation that modulation bandwidth diminishes, notably may cause color Difference.

Additionally, the judgement mode used in existing visible light communication system, great majority and the judgement side in digital communication department Formula is similar, the threshold value of receiving end signal and setting will carry out contrast judgement, when receiving end signal more than threshold value judgement is One value, is judged to another value less than this decision value.But, the judgement mode of this setting fixed threshold value, tend to lead Cause the erroneous judgement of data, thus have a strong impact on the communication efficiency of system.Accordingly, it is considered to the reliability of communication system, give and receive System provides a bigger dynamic range of signals, it is ensured that the stability of receiving end signal, is devoted to the research of judgement mode also Increasingly receive much concern.

Utility model content

Technical problem to be solved in the utility model is the problem that existing visible light communication exists that reliability is the best, it is provided that A kind of visible light communication system cumulative based on light modulation.

For solving the problems referred to above, this utility model is achieved through the following technical solutions:

A kind of visible light communication system cumulative based on light modulation, including transmitting terminal and receiving terminal.Transmitting terminal and receiving terminal lead to Cross wireless light communication to connect.Described transmitting terminal includes data coding module, pulse position modulation module, light source driver module, tune Optical module, RGB LED light source.Above-mentioned RGB LED light source is made up of red LED light source, green LED light source and blue led light source； The input of data coding module accesses transmission data, and the outfan of data coding module connects the defeated of pulse position modulation module Enter end；The outfan of pulse position modulation module is connected with the input of light source driver module；The outfan of light source driver module It is connected with the LED light source of one of which color；The light modulation end of the LED light source of the outfan of light-adjusting module and three kinds of colors connects. Described receiving terminal includes Photoelectric Detection module, across resistance amplification module, modulus sampling module, pulse position judging module, pulse position Put demodulation module and data decoding module.The outfan of Photoelectric Detection module connects the input across resistance amplification module, puts across resistance The outfan of big module connects the input of modulus sampling module, and the outfan of modulus sampling module connects pulse position judgement mould The input of block, the outfan of pulse position judging module connects the input of pulse position demodulation module, and pulse position demodulates The outfan of module connects the input of data decoding module, and transmission data sent by the outfan of data decoding module.

Above-mentioned visible light communication system still further comprises optical lens；This optical lens includes being arranged on RGB LED light Transmitting terminal supplementary lens behind source and be arranged on the receiving terminal supplementary lens before Photoelectric Detection module.

Compared with prior art, this utility model has a characteristic that

1, use associating light-dimming method synthesis white light, select suitable light path to carry out information transmission in different environments, Space telecommunication or subsurface communication is completed while realizing white-light illuminating；

2, the white light color rendering properties of RGB LED light source synthesis is good and light efficiency is higher, and also can be to three kinds of colors Light path is modulated respectively or selects a few road to be modulated, and namely can be loaded in any light path by data message and pass Defeated；

3, employing is accumulative compares decision method, and the signal obtaining sampling makes decisions, and reduces the situation of mistaken verdict, Improve the reliability of system；

4, the use of optical lens, can be directed at launch light beam and focus on receive light beam thus strengthen receive optical signal strong Degree, provides certain guarantee for telecommunication；

Accompanying drawing explanation

Fig. 1 is a kind of visible light communication system system block diagram cumulative based on light modulation.

Detailed description of the invention

A kind of visible light communication system cumulative based on light modulation, as it is shown in figure 1, include transmitting terminal, optical lens and reception End.

Described transmitting terminal include data coding module, pulse position modulation module, light source driver module, light-adjusting module and RGB LED light source.Above-mentioned RGB LED light source is by three primary colors LED light source i.e. red LED light source, green LED light source and blue led Light source is constituted.The input of data coding module accesses transmission data, and the outfan of data coding module connects pulse position and adjusts The input of molding block.The outfan of pulse position modulation module is connected with light source driver module.Light source driver module with wherein A kind of color light source connect.The outfan of light-adjusting module is connected with the light modulation end of three primary colors LED light source.

RGB LED light source has tunable optical characteristic, and can obtain color rendering properties by the luminous flux of regulation these three light Good reference color temperature wide white light.Decayed in an atmosphere by analysis HONGGUANG and little feature is lost, at free space compared with slow trapping When communicating, the outfan of pulse position modulation module connects light source driver module, and light source driver module connects RGB LED light The wherein red light source in source, the outfan of light-adjusting module connects the redgreenblue light source of RGB LED light source.Transmitting terminal unit is adopted Use fixing red-light source, and the light source regulating other two kinds of colors synthesizes the white light meeting lighting requirement, meanwhile will adjust Information processed is loaded in HONGGUANG light path the communication completing up to more than 100 meters, realizes both can having carried out in free space white with this Optical illumination is capable of again the purpose of telecommunication.The feature little by analyzing blue light absorption loss under water, enters under water During row communication, the outfan of pulse position modulation module connects light source driver module, and light source driver module outfan connects RGB The wherein blue-light source of LED light source, the outfan of light-adjusting module connects the redgreenblue light source of RGB LED light source.Transmitting terminal Unit uses fixing blue light source, and the light source regulating other two kinds of colors synthesizes the white light meeting lighting requirement, same with this Time modulation intelligence be loaded in blue light paths complete subsurface communication, realize the most not only to carry out white-light illuminating but also can with this Realize the purpose of communication.

Light source driver module connects in RGB LED light source three tunnel a wherein road light source, arrives for drive load modulation intelligence The LED light source of the same colour of RGB LED light source.Light-adjusting module is fixed a road light source and is changed the direct current of other two-way LED source The level of biasing, synthesizes white light.During regulation optical signal, the change of light signal strength be greater than human eye institute it is observed that maximum dodge The bright time.When the average specific in the pulse duration within one cycle of light emission Frame is less than 50%, then Frame is believed Number level is less than the non-homogeneous signal of 50%, owing to creating the non-homogeneous signal frequency less than 50%, then may result in Some information can not send or system transfer rate reduce, but the use of light regulating technology can well avoid with Upper problem, dims the most useful for the power of visible light communication system and the saving of energy.By above-mentioned light modulation side Formula, so that the white light light of synthesis is higher more stable.HONGGUANG is learnt by analyzing the characteristics such as the absorption loss of light, attenuation degree Attenuation degree is minimum in an atmosphere, therefore when free-space communication, signal loading is launched in HONGGUANG light path, with this The size of the luminous intensity regulation blue light and the luminous intensity of green-light source of fixing red-light source in light-adjusting module makes light source Synthesis white light, finally completes telecommunication and the white-light illuminating of free space.Light absorbs when propagating under water and damages by analysis Loss-rate is relatively big, and only the attenuation quotient in water of the light in the blue green light wavelength band of wavelength 480nm ± 30nm is minimum, penetrate Ability is the strongest, when communicating the most under water, will launch in signal loading to blue light paths, fixes in light-adjusting module with this The luminous intensity regulation HONGGUANG of blue light source and the luminous intensity synthesis white light of green-light source, finally complete subsurface communication and white light Illumination.

Data coding module and pulse position modulation module carry out block encoding and modulation to data message to be sent, with Just can be loaded on RGB LED light source.In this utility model preferred embodiment, data coding module uses has error correction merit The coded system of energy, pulse position modulation module uses pulse position modulation mode, data coding module and pulse position modulation Module is realized by FPGA.

The work process of transmitting terminal is as follows: data message is sent to FPGA signal processing module by signal source module.? In FPGA signal processing module encoding signal and modulate, the signal after modulating coding becomes pulse position signal, so Rear drive is loaded into a road light source of three primary light source, regulates the level of direct current biasing in other two-way circuit of light sources, regulates three Primary light source synthesis white light.Pulse position signal loading is launched in HONGGUANG light path, completes the remote of free space Communication and illumination, will launch in pulse position signal loading to blue light paths during subsurface communication, complete subsurface communication and photograph Bright, therefore the method for this light modulation synthesis white light visible ray can apply simultaneously to free space white-light illuminating and communicate and white light under water Illuminate and communicate.

Described receiving terminal includes Photoelectric Detection module, across resistance amplification module, modulus sampling module, pulse position judgement mould Block, pulse position demodulation module and data decoding module.The outfan of Photoelectric Detection module connects the input across resistance amplification module End, the outfan across resistance amplification module connects the input of modulus sampling module, and the outfan of modulus sampling module connects pulse The input of position judging module, the outfan of pulse position judging module connects the input of pulse position demodulation module, arteries and veins The outfan rushing position demodulation module connects the input of data decoding module, and transmission number sent by the outfan of data decoding module According to.

The signal of telecommunication sent due to Photoelectric Detection still has simulation letter through the signal that TIA amplification is namely amplified across resistance Number form, therefore the effect of modulus sampling module is that the signal receiving receiving terminal is sampled, with more accurately side Formula amount of sampling dissolves through the signal after resistance amplification module.Signal can be divided before judgement by the signal of sampling In further detail, the final position determining light pulse by the accumulative method compared, it is more accurate, from necessarily so to make to adjudicate Reduce the situation that code element is made mistakes in degree, improve the reliability of system.In this utility model preferred embodiment, modulus is adopted Original mold block includes voltage conversion circuit and AD sampling A/D chip.The voltage of the voltage signal owing to obtaining after across resistance amplification module Not necessarily disclosure satisfy that the needs of AD sampling A/D chip, before sampling, therefore use voltage conversion circuit, by voltage signal It is converted into the voltage range required for AD sampling A/D chip, more suitable signal is sampled.

The work process of receiving terminal is as follows: optical signal is changed into the signal of telecommunication by Photoelectric Detection module, and this signal of telecommunication is faint Current signal again through the amplification of TIA circuit and change into voltage signal, in order to meet the voltage request of sampling A/D chip, First carry out voltage conversion before being sampled by signal through amplifying across resistance in AD sample circuit, be converted into sampling Voltage range required by chip, still has the form of analogue signal yet with the signal before sending into sampling A/D chip, because of Signal can be sampled and quantify by this, can be divided in further detail by signal before judgement by the signal of sampling, Signal sampling obtained is sent to pulse position judging module, carries out signal to sampled value in pulse position judging module The method that accumulative summation is compared finds out the position at light pulse place, recovers PPM signal, the most demodulated final with decoding Recover original signal and complete communication.

Optical lens includes transmitting terminal supplementary lens and receiving terminal supplementary lens.In long-distance optical communication, to optics Designing necessary, it not only to consider the situation that the light sink-efficiency that causes under remote focus condition is low, and to consider near The situation that the angle of divergence that focused light source size causes is big.In this utility model preferred embodiment, transmitting terminal supplementary lens is poly- Optical lens, is placed in transmitting terminal RGB LED light source front end and is fixed by support.Receiving terminal supplementary lens is Fresnel Lenses, is placed in and connects Receiving end Photoelectric Detection module front end is fixed by support.Although have employed collecting lens before the light source of transmitting terminal, but optical signal Owing to beam divergence becomes more and more fainter, meanwhile the alignment of light beam becomes more and more difficult, therefore passes through according to light Fresnel Lenses through reflected refraction repeatedly, at light-ray condensing to, forms gonglion on each groove of lens Principle, therefore before the Photoelectric Detection module of receiving terminal use Fresnel Lenses.Will be through Fresnel with experiment by calculating The light of lens just focuses on the position of the focus at Photoelectric Detection module place, it is possible to well realize optically focused.Thus sending out Penetrating end uses lens can be that telecommunication provides deeper guarantee with receiving terminal.

In sum, this utility model utilizes the tunable optical characteristic selecting light source, uses the method synthesis of light modulation to meet and shines Bright required white light, it is possible to be applicable to free space and subsurface communication lighting demand；The accumulative of receiving terminal employing compares judgement side Formula, the position for judgement light pulse provides and accurately judges that, largely avoids the situation that signal decision is made mistakes, and improves The reliability of system.

Claims (2)

1. based on the visible light communication system that light modulation is cumulative, including transmitting terminal and receiving terminal；It is characterized in that:

Described transmitting terminal includes data coding module, pulse position modulation module, light source driver module, light-adjusting module, RGB LED Light source；Above-mentioned RGB LED light source is made up of red LED light source, green LED light source and blue led light source；Data coding module Input accesses transmission data, and the outfan of data coding module connects the input of pulse position modulation module；Pulse position The outfan of modulation module is connected with the input of light source driver module；The outfan of light source driver module and one of which color LED light source connect；The light modulation end of the LED light source of the outfan of light-adjusting module and three kinds of colors connects；

Described receiving terminal includes Photoelectric Detection module, across resistance amplification module, modulus sampling module, pulse position judging module, arteries and veins Rush position demodulation module and data decoding module；The outfan of Photoelectric Detection module connects the input across resistance amplification module, across The outfan of resistance amplification module connects the input of modulus sampling module, and the outfan of modulus sampling module connects pulse position and sentences The certainly input of module, the outfan of pulse position judging module connects the input of pulse position demodulation module, pulse position The outfan of demodulation module connects the input of data decoding module, and transmission data sent by the outfan of data decoding module.

A kind of visible light communication system cumulative based on light modulation the most according to claim 1, it is characterised in that: the most further Including optical lens；This optical lens includes the transmitting terminal supplementary lens after being arranged on RGB LED light source and is arranged on light electric-examination Survey the receiving terminal supplementary lens before module.