CN103763029A - Polarization multiplexing system and data transmitting and receiving method in process of visible light communication - Google Patents

Abstract

The invention relates to the field of visible light communication and discloses a polarization multiplexing system and a data transmitting and receiving method in the process of visible light communication. A visible light communication system comprises a plurality of polarizers and analyzers, wherein the number of the analyzers is equal to that of the polarizers, and the analyzers correspond to the polarizers in a one-to-one mode. At the transmitting end, LED lamps correspond to the polarizers in a one-to-one mode, visible light emitted by the different LED lamps passes through the corresponding polarizers, and linearly polarized light in different polarization directions is obtained and transmitted. At the receiving end, the polarization direction between each analyzer and the corresponding polarizer forms a preset angle, each analyzer detects the visible light transmitted by the corresponding polarizer, a multichannel transmitting signal can be recovered through the digital signal processing algorithm according to the light intensities detected by the different analyzers, and therefore the data transmission rate of the visible light communication system can be multiplied.

Description

Polarisation multiplex system in visible light communication, data input and data output method

Technical field

The present invention relates to visible light communication field, particularly the polarisation multiplex system in visible light communication, data input and data output method.

Background technology

LED(Light-Emitting Diode, light-emitting diode) as a kind of solid state light emitter, there is the advantages such as luminous efficiency is high, size is little, the life-span is long, by replacing traditional lighting apparatus, become environmental protection lighting light source of future generation.As a kind of semiconductor photonic device, the fast response characteristic of LED makes it have the feature of High Speed Modulation, and velocity modulation that can cannot perception with human eye by signal is carried out transfer of data to LED light source.LED-based These characteristics, has produced the new technology of a kind of degree of depth coupled illumination and transfer of data, i.e. visible optical communication technique (Visible Light Communication is called for short VLC).VLC technology as a kind of light wireless communication technology have transmitting power high, high without frequency spectrum application, bandwidth, without electromagnetic interference and the advantage such as safe and reliable, can be used as the supplementing of twireless radio-frequency communication technology of frequency spectrum growing tension.

The basic principle that realizes visible LED communication is to transmit data to carry out certain modulation to institute is luminous, such as pulse width modulation (Pulse Width Modulation, referred to as PWM), pulse position modulation (Pulse Position Modulation, referred to as PPM), or pulse amplitude modulation (Pulse Amplitude Modulation, referred to as PAM).The light energy of this modulation is transmitted by space channel and is received by the photodetector on destination apparatus (transducer), and photodetector demodulates sent data again through subsequent treatment after light signal is converted to the signal of telecommunication.Can be the common portable equipment that is attached with in design this function, as mobile phone, digital camera, notebook computer etc.But, in transmission of visible light channel in visible light communication, there are scattering, diffusion etc., make when utilizing visible ray to communicate to exist the impacts such as the intersymbol interference, the light intensity that are caused by multipath transmisstion be weak, and there is the impact of surround lighting (background noise), above-mentioned modulation system can not overcome intersymbol interference, its availability of frequency spectrum is not high yet, be difficult to realize at a high speed (such as, be greater than the rate of information throughput of 100 megabits per second) communication.

Light wave is transverse electro-magnetic wave, has polarization characteristic.As shown in Figure 1, natural daylight, by after polarizer P, only has the direction of vibration light consistent with the direction of thoroughly shaking of polarizer to pass through smoothly, that is to say, by the light wave of polarizer P, in the plane perpendicular to the direction of propagation, along certain specific direction vibration, this light is polarised light.By the polarised light of polarizer P, then by polarizer Q, if the direction of thoroughly shaking of two polarizers is parallel, can pass through; If the direction of thoroughly shaking of two polarizers is vertical, can not see through Q.According to this characteristic of polarised light, there are in practice a lot of purposes.

Summary of the invention

The object of the present invention is to provide polarisation multiplex system in a kind of visible light communication, data input and data output method, the transmission rate of visible light communication system is significantly improved.

For solving the problems of the technologies described above, embodiments of the present invention provide the polarisation multiplex system in a kind of visible light communication, comprise transmitting terminal and receiving terminal, and the visible ray that adopts LED lamp to send carries the information that needs transmission;

Described transmitting terminal has at least 2 polarizers; Described LED lamp is corresponding one by one with the described polarizer; The visible ray that different LED lamp sends, by the corresponding polarizer, obtains the linearly polarized light of different polarization direction, and is sent to described receiving terminal;

Described receiving terminal has the analyzer with described polarizer similar number, and described analyzer is corresponding one by one with the described polarizer; The direction of thoroughly shaking between described analyzer and the corresponding polarizer becomes preset angles, and each analyzer detects the visible ray sending through the corresponding polarizer.

Embodiments of the present invention also provide the data transmission method for uplink of the polarisation multiplex system in a kind of visible light communication, comprise following steps:

Signal is divided into at least 2 tunnels;

Each road signal is carried out respectively to low-pass filtering and amplification, and add direct current biasing, driving LED lamp sends visible ray;

The visible ray that each paths of LEDs lamp sends sends by the corresponding polarizer.

Embodiments of the present invention also provide the data receive method of the polarisation multiplex system in a kind of visible light communication, comprise following steps:

Each analyzer of receiving terminal detects the visible ray that transmitting terminal sends;

The visible ray that each road analyzer is detected, changes into the signal of telecommunication by optical-electrical converter;

To each road signal of telecommunication amplify respectively with low-pass filtering treatment after, sample;

Signal to sampling carries out off-lined signal processing, estimates respectively the transmitted signal on each road of transmitting terminal.

Embodiment of the present invention in terms of existing technologies, visible light communication system adopts multiple polarizers, and with the analyzer of polarizer similar number, analyzer is corresponding one by one with the polarizer, the visible ray that this system adopts LED lamp to send carries the information that needs transmission, and LED lamp is corresponding one by one with the polarizer, and the visible ray that different LED lamp sends is by the corresponding polarizer, obtain the linearly polarized light of different polarization direction, and be sent to receiving terminal; At receiving terminal, the direction of thoroughly shaking between analyzer and the corresponding polarizer becomes preset angles, and each analyzer detects the visible ray sending through the corresponding polarizer, the light intensity detecting according to different detectors, through digital signal processing algorithm, can recover multichannel and transmit, thereby can improve exponentially the message transmission rate of visible light communication system.

In addition, described preset angles is 0 degree, makes analyzer parallel with the direction of thoroughly shaking between the corresponding polarizer, and the visible light signal that can make receiving terminal detect is strong as far as possible.

In addition, described transmitting terminal has 2 polarizers, is respectively first polarizer and second polarizer, and the analyzer that described receiving terminal is corresponding is respectively the first analyzer and the second analyzer;

The direction of thoroughly shaking between described the first analyzer and described first polarizer becomes the first angle [alpha] ₁₁, the direction of thoroughly shaking between described the second analyzer and described second polarizer becomes the second angle [alpha] ₂₂, the direction of thoroughly shaking between described the first analyzer and described second polarizer becomes the 3rd angle [alpha] ₁₂, the direction of thoroughly shaking between described the second analyzer and described first polarizer becomes the 4th angle [alpha] ₂₁, and cos ²α ₁₁cos ²α ₂₂≠ cos ²α ₁₂cos ²α ₂₁.

Adopt 2 polarizers and corresponding analyzer to carry out visible light communication, realize two-way multiplexing, thereby can improve exponentially the transmission rate of visible light communication system.

In addition, described α ₁₁, α ₂₂value be 0 degree, described α ₁₂, α ₂₁value be 90 degree.The direction of thoroughly shaking of the two-way polarizer is orthogonal, and the direction of thoroughly shaking of analyzer is parallel with the direction of thoroughly shaking of the polarizer, can simplify calculating, thereby improves the information processing rate of visible light communication system, for high speed visible light communication lays the foundation.

In addition, the described polarizer and described analyzer are polarizer, can realize the separation of light without devices such as complicated optical splitters, thereby lay the first stone for the commercialization of high speed visible light communication system.

Accompanying drawing explanation

Fig. 1 is the polarisation of light behavioral illustrations schematic diagram according to prior art;

Fig. 2 is according to the schematic diagram of the polarisation multiplex system in the visible light communication of first embodiment of the invention;

Fig. 3 is the schematic diagram that is related to thoroughly shaking between deviation angle α between direction and normalization intensity in transmission of thoroughly shake direction and the polarizer of analyzer;

Fig. 4 is according to the schematic diagram of the polarisation multiplex system in the visible light communication of second embodiment of the invention;

Fig. 5 is the analogue system block diagram of the polarisation multiplex system in two-way visible light communication.

Embodiment

For making the object, technical solutions and advantages of the present invention clearer, below in conjunction with accompanying drawing, the embodiments of the present invention are explained in detail.But, persons of ordinary skill in the art may appreciate that in the each execution mode of the present invention, in order to make reader understand the application better, many ins and outs have been proposed.But, even without these ins and outs and the many variations based on following execution mode and modification, also can realize the each claim of the application technical scheme required for protection.

The first execution mode of the present invention relates to the polarisation multiplex system in a kind of visible light communication, comprises transmitting terminal and receiving terminal, and the visible ray that adopts LED lamp to send carries the information that needs transmission; As shown in Figure 2, transmitting terminal has at least 2 polarizers; LED lamp is corresponding one by one with the polarizer; The visible ray that different LED lamp sends, by the corresponding polarizer, obtains the linearly polarized light of different polarization direction, and is sent to receiving terminal.Receiving terminal has the analyzer with polarizer similar number, and analyzer is corresponding one by one with the polarizer; The direction of thoroughly shaking between analyzer and the corresponding polarizer becomes preset angles, and each analyzer detects the visible ray sending through the corresponding polarizer.Pass through the polarizer, the information difference that the visible ray that can make each LED lamp send carries, and the visible ray that can be easy to different LED lamp to send by analyzer at receiving terminal is distinguished, thereby realize palarization multiplexing, significantly improve the transmission rate of visible light communication system.

According to Malus' law (1809), if the visible light intensity that LED lamp sends is I ₀, the direction of thoroughly shaking between analyzer and the corresponding polarizer becomes α angle (namely, the direction of thoroughly shaking of analyzer departs from the angle of the direction of thoroughly shaking of the polarizer), and the polarization light intensity detecting after analyzer is I, so I and I ₀between relation can be represented by the formula:

$I=\frac{1}{2}{\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="HDA0000453741000000013.png,HDA0000453741000000022.png"\; state="\{\{state\}\}">I</figure-callout>}}_0{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\mathrm{\&alpha;}$

Refer to shown in Fig. 3, it is the relation between the deviation angle α and the normalization intensity in transmission that thoroughly shake between direction of thoroughly shake direction and the polarizer of analyzer, as can be seen from the figure, α is less, intensity in transmission is larger, that is to say, the direction of thoroughly shaking that the direction of thoroughly shaking of analyzer departs from the polarizer approaches parallel, and the polarization light intensity detecting after analyzer is larger.Therefore, as a kind of preferred version of present embodiment, be to select analyzer parallel with the direction of thoroughly shaking between the corresponding polarizer, namely, making preset angles is 0, the visible light signal that can make like this receiving terminal detect is strong as far as possible.

In addition, it is worth mentioning that, the polarizer in present embodiment and analyzer all can adopt polarizer to realize, and can realize the separation of light without devices such as complicated optical splitters, thereby lay the first stone for the commercialization of high speed visible light communication system.

Compared with prior art, the visible light communication system of present embodiment adopts multiple polarizers, and with the analyzer of polarizer similar number, analyzer is corresponding one by one with the polarizer, the visible ray that this system adopts LED lamp to send carries the information that needs transmission, and LED lamp is corresponding one by one with the polarizer, and the visible ray that different LED lamp sends is by the corresponding polarizer, obtain the linearly polarized light of different polarization direction, and be sent to receiving terminal; At receiving terminal, the direction of thoroughly shaking between analyzer and the corresponding polarizer becomes preset angles, and each analyzer detects the visible ray sending through the corresponding polarizer, the light intensity detecting according to different detectors, through digital signal processing algorithm, can recover multichannel and transmit, namely, by the relation between the light intensity and the light intensity of transmitting terminal transmitting visible ray that detect, can recover the visible light intensity that transmitting terminal sends.Because signal carries by visible light intensity, therefore can recover respectively multichannel transmitted signal, thereby can improve exponentially the message transmission rate of visible light communication system.

The second execution mode of the present invention relates to the polarisation multiplex system in a kind of visible light communication.The second execution mode and the first execution mode are roughly the same, and main distinction part is: in the first embodiment, adopt N the polarizer and corresponding analyzer to carry out visible light communication, realize N road multiplexing.And in second embodiment of the invention, adopt 2 polarizers and corresponding analyzer to carry out visible light communication, realize two-way multiplexing.

Specifically, as shown in Figure 4, transmitting terminal has 2 polarizers, is respectively first polarizer 1 and second polarizer 2, and the analyzer that receiving terminal is corresponding is respectively the first analyzer 3 and the second analyzer 4.After the two paths of LED lamp of transmitting terminal, use two polarizers, in Fig. 41 and 2; At receiving terminal, before two-way Photoelectric Detection, use two polarizers, i.e. 3 in figure and 4; Suppose that the visible light intensity that two paths of LED lamp sends is respectively X ₁and X ₂, polarizer 3 is for detection of the visible ray from polarizer 1 transmission, and the polarization light intensity detecting is Y ₁; Polarizer 4 is for detection of the visible ray from polarizer 2 transmissions, and the polarization light intensity detecting is Y ₂.

If the direction of thoroughly shaking between the first analyzer and first polarizer becomes the first angle [alpha] ₁₁, the direction of thoroughly shaking between the second analyzer and second polarizer becomes the second angle [alpha] ₂₂, the direction of thoroughly shaking between the first analyzer and second polarizer becomes the 3rd angle [alpha] ₁₂, the direction of thoroughly shaking between the second analyzer and first polarizer becomes the 4th angle [alpha] ₂₁, so, according to Malus' law, the polarization light intensity that polarizer 3 and 4 detects and before polarizer 1 and 2 relation between visible light intensity as follows:

${\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1=\frac{1}{2}{\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">X</figure-callout>}}_1{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{11}+\frac{1}{2}{\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">X</figure-callout>}}_2{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{12}$

${\mathrm{<figure-callout\; id="2"\; label="Y"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">Y</figure-callout>}}_2=\frac{1}{2}{\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">X</figure-callout>}}_2{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{22}+\frac{1}{2}{\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">X</figure-callout>}}_1{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{21}$

From above formula, receiving terminal detects Y ₁and Y ₂afterwards, if known α ₁₁, α ₁₂, α ₂₂, α ₂₁, and cos ²α ₁₁cos ²α ₂₂≠ cos ²α ₁₂cos ²α ₂₁, can uniquely solve X ₁and X ₂the visual intensity namely can unique definite two-way transmitting terminal sending respectively, owing to carrying the information that needs transmission by visible light intensity, the information that therefore can send at the unique definite transmitting terminal of receiving terminal, realize the two-way palarization multiplexing of visible ray, thereby can improve exponentially the transmission rate of visible light communication system.

In addition, it is worth mentioning that, the direction of thoroughly shaking of the two-way polarizer is orthogonal, and the direction of thoroughly shaking of analyzer is parallel with the direction of thoroughly shaking of the polarizer, can simplify calculating.According to polarisation of light characteristic, can detect the linearly polarized light that obtains seeing through polarizer 1 by polarizer 3, and because polarizer 4 becomes 90 degree with the direction of thoroughly shaking of polarizer 1, by polarizer 4, can't detect the linearly polarized light through polarizer 1; In like manner, can detect the linearly polarized light that obtains seeing through polarizer 2 by polarizer 4, by polarizer 3, can't detect the linearly polarized light of transmission-polarizing sheet 2.That is to say, make α ₁₁, α ₂₂value be 0 degree, α ₁₂, α ₂₁value be 90 degree, obtain:

${\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1=\frac{1}{2}{X}_1{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^{2}0+\frac{1}{2}{X}_2{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^{2}90$

${\mathrm{<figure-callout\; id="2"\; label="Y"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">Y</figure-callout>}}_2=\frac{1}{2}{X}_2{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^{2}90+\frac{1}{2}{X}_1{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^{2}0$

Namely, ${\mathrm{<figure-callout\; id="1"\; label="Y"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">Y</figure-callout>}}_1=\frac{1}{2}{X}_1,$ ${\mathrm{<figure-callout\; id="2"\; label="Y"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">Y</figure-callout>}}_2=\frac{1}{2}{X}_2.$

As Fig. 5 has provided the analogue system block diagram of the multiplexing visible light communication system of two-way cross-polarization, first signal is divided into two-way, after system transmitting terminal low pass filtered involves amplifier amplification, add certain direct current biasing rear drive LED lamp, the visible ray that has carried information is produced to linearly polarized light by polarizer and launch.The linearly polarized light that two-way is orthogonal and the natural daylight of surrounding environment (noise), form omnidirectional natural daylight and transfer to receiving terminal.At receiving terminal, adopt lens to carry out after optically focused, by the polarizer for analyzing parallel with the polarizer of transmitting terminal (namely the angle thoroughly shaking between direction of the polarizer of thoroughly shake direction and the transmitting terminal of the polarizer of receiving terminal is 0 degree), respectively the polarised light of two-way carry information is detected, adopt photodiode to carry out direct detection the polarised light detecting, to the signal of telecommunication detecting again through amplification with low-pass filtering treatment after, sample.Finally adopt off-lined signal to process according to the relation between the light intensity detecting and the light intensity of transmitting terminal transmitting visible ray, recover the visible light intensity that transmitting terminal sends; Because signal carries by visible light intensity, therefore can recover respectively two-way transmitted signal.Because two-way multiplexed signals transmits simultaneously, the transmission rate that therefore adopts the multiplexing visible light communication system of two-way to carry out transfer of data is the twice that does not adopt the message transmission rate of the visible light communication system of palarization multiplexing.In addition, owing to adopting orthogonal two-route wire polarised light to carry signal, the light intensity that each road of receiving terminal detects is the half of the visible ray of transmitting terminal transmission, and by the polarizer of receiving terminal, article one, on branch road, the polarised light transmitting on another branch road can not be detected, when carrying out off-lined signal processing, only need to double simply to recover the visible light intensity that transmitting terminal sends, be highly susceptible to calculating, thereby improve the information processing rate of visible light communication system, for high speed visible light communication lays the foundation.

The 3rd execution mode of the present invention relates to the polarisation multiplex system in a kind of visible light communication.The 3rd execution mode and the first execution mode are roughly the same, and main distinction part is: in the first embodiment, adopt N the polarizer and corresponding analyzer to carry out visible light communication, realize N road multiplexing.And in third embodiment of the invention, adopt 3 polarizers and corresponding analyzer to carry out visible light communication, realize three tunnels multiplexing.

Specifically, transmitting terminal has 3 polarizers, and receiving terminal has 3 corresponding analyzers.At transmitting terminal, use three polarizers respectively the transmission visible ray of each branch road to be polarized; At receiving terminal, use three corresponding polarizers to carry out analyzing; Suppose that the visible light intensity that transmitting terminal sends is respectively X ₁, X ₂, X ₃, the light intensity that three polarizers of receiving terminal detect is respectively Y ₁, Y ₂, Y ₃, the deviation angle thoroughly shaking between direction of the polarizer of thoroughly shake direction and the j branch road of the analyzer of i branch road is α _ij, wherein,, there is following relation in i=1,2 or 3, j=1,2 or 3 between the light intensity that the light intensity that receiving terminal detects so and transmitting terminal send:

$\left[\begin{array}{c}{Y}_1\\ Y_2\\ {\mathrm{<figure-callout\; id="3"\; label="Y"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">Y</figure-callout>}}_3\end{array}\right]=P\left[\begin{array}{c}{X}_1\\ X_2\\ {\mathrm{<figure-callout\; id="3"\; label="X"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">X</figure-callout>}}_3\end{array}\right]=\left[\begin{array}{ccc}\frac{1}{2}{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{11}& \frac{1}{2}{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{12}& \frac{1}{2}{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{13}\\ \frac{1}{2}{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{21}& \frac{1}{2}{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{22}& \frac{1}{2}{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{23}\\ \frac{1}{2}{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{31}& \frac{1}{2}{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{32}& \frac{1}{2}{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&alpha;}}_{33}\end{array}\right]\left[\begin{array}{c}{X}_1\\ X_2\\ {\mathrm{<figure-callout\; id="3"\; label="X"\; filenames="HDA0000453741000000021.png"\; state="\{\{state\}\}">X</figure-callout>}}_3\end{array}\right]$

If P exists inverse matrix in above formula, can solve according to following formula so the light intensity of the visible ray of transmitting terminal transmission:

$\left[\begin{array}{c}{X}_1\\ X_2\\ X_3\end{array}\right]=P^{-1}\left[\begin{array}{c}{Y}_1\\ Y_2\\ Y_3\end{array}\right]$

The deviation angle α thoroughly shaking between direction of the polarizer of thoroughly shake direction and the j branch road of the analyzer of i branch road is reasonably set _ij, make matrix P have inverse matrix, can recover the visual intensity that transmitting terminal sends at receiving terminal, thereby it is multiplexing to realize three tunnels, can trebly improve the rate of information throughput of visible light communication system.In theory, i or j value are N(N>=2), α is rationally set _ij, make P have inverse matrix, just can recover the visible light intensity that transmitting terminal sends at receiving terminal, thereby it is multiplexing to realize N road, can N doubly improve the rate of information throughput of visible light communication system.

Four embodiment of the invention relates to the method for the data transmission of the polarisation multiplex system in a kind of visible light communication, and first the method is divided into signal at least 2 tunnels; Then, each road signal is carried out respectively to low-pass filtering and amplification, and add direct current biasing, driving LED lamp sends visible ray; Then the visible ray that, each paths of LEDs lamp sends sends by the corresponding polarizer.

Be not difficult to find, present embodiment is the embodiment of the method corresponding with the first execution mode, present embodiment can with the enforcement of working in coordination of the first execution mode.The correlation technique details of mentioning in the first execution mode is still effective in the present embodiment, in order to reduce repetition, repeats no more here.Correspondingly, the correlation technique details of mentioning in present embodiment also can be applicable in the first execution mode.

Four embodiment of the invention relates to the method for the data receiver of the polarisation multiplex system in a kind of visible light communication, and first each analyzer of receiving terminal detects the visible ray that transmitting terminal sends in the method; Then, the visible ray that each road analyzer is detected, changes into the signal of telecommunication by optical-electrical converter; Then, to each road signal of telecommunication amplify respectively with low-pass filtering treatment after, sample; Then, the signal of sampling is carried out to off-lined signal processing, estimate respectively the transmitted signal on each road of transmitting terminal.

Be not difficult to find, present embodiment is the embodiment of the method corresponding with the first execution mode, present embodiment can with the enforcement of working in coordination of the first execution mode.The correlation technique details of mentioning in the first execution mode is still effective in the present embodiment, in order to reduce repetition, repeats no more here.Correspondingly, the correlation technique details of mentioning in present embodiment also can be applicable in the first execution mode.

The step of the whole bag of tricks is divided above, just in order being described clearly, can to merge into a step or some step is split while realizing, and is decomposed into multiple steps, as long as comprise identical logical relation, all in the protection range of this patent; To adding inessential modification in algorithm or in flow process or introducing inessential design, but the core design that does not change its algorithm and flow process is all in the protection range of this patent.

Persons of ordinary skill in the art may appreciate that the respective embodiments described above are to realize specific embodiments of the invention, and in actual applications, can to it, do various changes in the form and details, and without departing from the spirit and scope of the present invention.

Claims (7)

1. the polarisation multiplex system in visible light communication, comprises transmitting terminal and receiving terminal, and the visible ray that adopts LED lamp to send carries the information that needs transmission, it is characterized in that,

Described transmitting terminal has at least 2 polarizers; Described LED lamp is corresponding one by one with the described polarizer; The visible ray that different LED lamp sends, by the corresponding polarizer, obtains the linearly polarized light of different polarization direction, and is sent to described receiving terminal;

Described receiving terminal has the analyzer with described polarizer similar number, and described analyzer is corresponding one by one with the described polarizer; The direction of thoroughly shaking between described analyzer and the corresponding polarizer becomes preset angles, and each analyzer detects the visible ray sending through the corresponding polarizer.

2. the polarisation multiplex system in visible light communication according to claim 1, is characterized in that, described preset angles is 0 degree.

3. the polarisation multiplex system in visible light communication according to claim 1, it is characterized in that, described transmitting terminal has 2 polarizers, is respectively first polarizer and second polarizer, and the analyzer that described receiving terminal is corresponding is respectively the first analyzer and the second analyzer;

The direction of thoroughly shaking between described the first analyzer and described first polarizer becomes the first angle [alpha] ₁₁, the direction of thoroughly shaking between described the second analyzer and described second polarizer becomes the second angle [alpha] ₂₂, the direction of thoroughly shaking between described the first analyzer and described second polarizer becomes the 3rd angle [alpha] ₁₂, the direction of thoroughly shaking between described the second analyzer and described first polarizer becomes the 4th angle [alpha] ₂₁, and cos ²α ₁₁cos ²α ₂₂≠ cos ²α ₁₂cos ²α ₂₁.

4. the polarisation multiplex system in visible light communication according to claim 3, is characterized in that, described α ₁₁, α ₂₂value be 0 degree, described α ₁₂, α ₂₁value be 90 degree.

5. according to the polarisation multiplex system in the visible light communication described in claim 1 to 4 any one, it is characterized in that, the described polarizer and described analyzer are polarizer.

6. a data transmission method for uplink for the polarisation multiplex system in visible light communication, is characterized in that, comprises following steps:

Signal is divided into at least 2 tunnels;

Each road signal is carried out respectively to low-pass filtering and amplification, and add direct current biasing, driving LED lamp sends visible ray;

The visible ray that each paths of LEDs lamp sends sends by the corresponding polarizer.

7. a data receive method for the polarisation multiplex system in visible light communication, is characterized in that, comprises following steps:

Each analyzer of receiving terminal detects the visible ray that transmitting terminal sends;

The visible ray that each road analyzer is detected, changes into the signal of telecommunication by optical-electrical converter;

To each road signal of telecommunication amplify respectively with low-pass filtering treatment after, sample;

Signal to sampling carries out off-lined signal processing, estimates respectively the transmitted signal on each road of transmitting terminal.

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