CN105119655A - Visible light communication method based on QAM and MPPM and system thereof - Google Patents
Visible light communication method based on QAM and MPPM and system thereof Download PDFInfo
- Publication number
- CN105119655A CN105119655A CN201510551507.0A CN201510551507A CN105119655A CN 105119655 A CN105119655 A CN 105119655A CN 201510551507 A CN201510551507 A CN 201510551507A CN 105119655 A CN105119655 A CN 105119655A
- Authority
- CN
- China
- Prior art keywords
- signal
- mppm
- qam
- module
- visible light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Optical Communication System (AREA)
Abstract
The invention discloses a visible light communication method based on QAM and MPPM. The method comprises the following steps: 1, a data stream forms a QAM signal; 2, the data stream performed with multi-pulse position modulation to form an MPPM signal; 3, the QAM signal controls an LED driving voltage to regulate and control a light intensity amplitude; the MPPM signal controls the on-off of LED driving current; 4, a blue light receiving passage and a yellow light receiving passage exist in a receiving subsystem; 5, the MPPM signal and the QAM signal are decoded to form corresponding binary data streams; and the binary data streams form a final obtained signal through a data combiner. The invention further discloses a visible light communication system for achieving the visible light communication method based on QAM and MPPM. The visible light communication system comprises a transmitting subsystem, a transmission subsystem and the receiving subsystem. The transmission rate of the visible light communication system is effectively improved.
Description
Technical field
The present invention relates to visible light communication technology, in particular to visible light communication method and the system thereof of a kind of QAM and MPPM, the present invention is the dual modulation technology that a kind of quadrature amplitude modulation technology combines with multi-pulse position modulation technology and the method realizing data transmit-receive.
Background technology
In recent years, the semiconductor illumination technique being described as " green illumination " develops rapidly.LED has the advantages such as efficiency is high, price is low, the life-span is long, environmental protection will replace the conventional illumination sources such as incandescent lamp, be widely used in the fields such as illumination, display.Meanwhile, white light LEDs has more the characteristics such as modulating performance is good, response sensitivity is high, signal can be loaded in LED lamp with the high frequency of human eye None-identified and transmit.Make white light LEDs expand to the communications field from lighting field, and then expedite the emergence of out Emerging wireless communications technology---the visible light communication technology that can realize illumination and communicating integral.
Infraredly to compare with radio communication with traditional, visible light communication have transmitting power high, without electromagnetic interference, without the need to applying for the advantages such as the confidentiality of frequency spectrum resource and information.But visible light communication still faces many challenges, be on the one hand wherein: communication system exists multiple LED light source, and different point-source of lights correspond to different light paths, and between light path, the delay of Signal transmissions can produce intersymbol interference; Meanwhile, when system data transmission rate is higher, due to the restriction of LED bandwidth, the impact of a signal can be caused to expand on adjacent signals, produce intersymbol interference and error rate of system is promoted greatly.
On the other hand, white light LEDs is mainly divided into two classes, fluorescent material LED and red, green and blue LED, and its principle of fluorescent material LED utilizes blue chip to excite yellow fluorescent powder to produce white light.As shown in Figure 6, be the curve of spectrum of fluorescent material LED, the spectral characteristic of known fluorescent material LED is divided into blue light components and yellow part.Wherein, blue light components is by power supply Direct driver, and response speed is than very fast, and bandwidth is very high; And fluorescent material belongs to secondary driving, response speed is slow, and bandwidth is narrower, and therefore the light of different spectrum also exists difference in response speed.In the response time of fluorescent material, the message transmission rate of system is limited according to the white light then rate-constrained that communicates; According to filter elimination yellow part, the blue light for response fast communicates, then limit the communication distance of system.
Summary of the invention
Primary and foremost purpose of the present invention is that the above-mentioned shortcoming overcoming prior art is with not enough, a kind of visible light communication method of QAM and MPPM is provided, this visible light communication method takes full advantage of spectral characteristic and the response characteristic of white light LEDs, achieves a kind of dual modulation technology combined based on QAM and the MPPM of fluorescent material LED.
Another object of the present invention is to overcome the above-mentioned shortcoming of prior art and deficiency, a kind of system realizing the visible light communication method of described QAM and MPPM is provided, this system is at light transmitting terminal, by controlling the light of different spectrum, utilize filter to distinguish different spectral signals at optical receiver end, realize multidiameter delay communication.The time dimension of driving pulse sequence adopts MPPM multi-pulse position modulation, corresponding with the blue light components of spectrum; In its amplitude dimension enterprising employing QAM quadrature amplitude modulation, corresponding with the yellow part of spectrum.Different two paths of data information is realized in different spectrally parallel transmission with this.Optimize visible light communication system channel performance further, do not increasing under bandwidth of a device prerequisite, significantly improve quality and the message transmission rate of radio communication.
Principle of the present invention: QAM quadrature amplitude modulation is exactly to mutually orthogonal and the two-way carrier signal that frequency is identical carries out double-sideband modulation with two separate digital baseband signals, the modulated signal obtained is spectrum orthogonal in same bandwidth, so can be used for realizing homophase and the parallel digital information transmission of orthorhombic phase two-way.Drastically increase the ROA of LED frequency spectrum, improve the message transmission rate of visible light communication system.But along with the increase of order of modulation, the Distance geometry phase difference between signaling point can be more and more less, make interference between symbol become increasing, the result finally caused is that the difficulty of whole system demodulation increases, and the interference free performance of system declines.So, although nominal increase QAM modulation exponent number can improve the rate of information throughput, because of the increase of the error rate, communication quality is declined, thus make QAM obtain order of modulation to be restricted.What MPPM multiple-pulse position Modulation and Amplitude Modulation adopted is optics group coding form, the power utilization of increase system, strong interference immunity, burst pulse shaper on its encoder can limit the bandwidth of MPPM pulse thus reduce the interference that this MPPM pulse causes adjacent frequency inband signaling, namely reduces intersymbol interference; Meanwhile, also can weaken by delay time slot between adjacent pulse the impact that intersymbol interference brings system.
Primary and foremost purpose of the present invention is achieved through the following technical solutions: a kind of visible light communication method based on QAM and MPPM, comprises the following steps:
Step 1, data flow, through conventional coding, interweave, and the preliminary treatment of the baseband systems such as serioparallel exchange forms binary code stream; Described binary code forms QAM signal after flowing through quadrature amplitude modulation;
Step 2, data flow, through conventional coding, interweave, and the preliminary treatment of the baseband systems such as serioparallel exchange forms binary code stream; Described binary code forms MPPM signal after flowing through multi-pulse position modulation;
Step 3, transmission subsystem are the free space of transmitting optical signal; Described optical signals white light LEDs is launched; Described white light LEDs is by QAM and MPPM two signal Synchronization Control, and QAM signal passes through control LED driving voltage and then the regulation and control of realization to light intensity amplitude; The break-make of MPPM signal controlling LED drive current;
Step 4, in receiving subsystem exist two photo-signal channels; Described photo-signal channel is divided into blue light receive path and gold-tinted receive path; Described blue light receive path obtains blue light signals by blue color filter, through signal transacting reduction MPPM signal; Described gold-tinted receive path obtains gold-tinted signal by yellow filter, through signal transacting reduction QAM signal;
Step 5, described MPPM signal form corresponding binary data stream with QAM signal after decoding and processing; Described binary data flows through data combiner and is formed and finally obtain signal.
In step 1, described quadrature amplitude modulation comprises the following steps:
Step 11, described binary code flow through serial/parallel converter and export two-way parallel stream sequence; The speed of described two-way parallel stream sequence is kept to the half of described binary code stream;
Step 12, described two-way parallel stream sequence are respectively through 2 level to L level conversion, and form the baseband signal of L level, wherein, L is positive integer;
The baseband signal of step 13, described L level forms X (t) and Y (t) signal through base band shaping filter;
The homophase carrier wave that step 14, described X (t) are identical with frequency respectively with Y (t) signal and orthorhombic phase carrier wave carry out multiplication operation, the two paths of signals finally obtained are carried out the QAM signal of oneself modulation that sum operation just obtains.
In step 2, described multi-pulse position modulation comprises the following steps:
Step 21, described binary code stream are mapped to the binary bit stream that code length is n equidistant time slot, and wherein, n is positive integer;
Step 22, in the binary bit stream of a described n time slot, m time slot sends light pulse, obtain modulated MPPM signal, wherein, m is positive integer.
In step 4, described signal transacting comprises the following steps:
Step 41, described blue light signals and gold-tinted signal, after amplification, filtering process, carry out the demodulation process of blue light signals and gold-tinted signal;
Step 42, described demodulation process are respectively QAM demodulation process and MPPM demodulation process; The principle of described QAM demodulation process and MPPM demodulation process is respectively the inverse process of claim 2 and claim 3.
Another object of the present invention can be achieved through the following technical solutions: a kind of visible light communication system realizing the described visible light communication method based on QAM and MPPM, comprise: launch subsystem, transmission subsystem and receiving subsystem, it is characterized in that, described transmitting subsystem has: QAM modulation module, MPPM modulation module, LED drive circuit and LED lamp; Described transmission subsystem is used for the visible light signal that LED lamp sends to be transferred to photoelectricity testing part; Described receiving subsystem has: the first photoelectricity testing part, the second photoelectricity testing part, QAM demodulation module, MPPM demodulation module and data combiner; Described QAM modulation module, MPPM modulation module are connected with LED drive circuit respectively; Described LED drive circuit, LED lamp are connected successively with photoelectricity testing part; Described photoelectricity testing part comprises the first photoelectricity testing part and the second photoelectricity testing part; Described first photoelectricity testing part is connected with QAM demodulation module, and described second photoelectricity testing part is connected with MPPM demodulation module; Described QAM modulation module and MPPM modulation module produce QAM data flow and MPPM data flow respectively; Described QAM data flow and this two paths of data stream of MPPM data flow are sent to LED drive circuit, and are coupled with direct current signal by BaisTee module, with driving LED light fixture utilizing emitted light signal; Described light signal enters receiving subsystem through opto-electronic conversion; There is in described receiving subsystem blue light receive path and gold-tinted receive path; Described blue light receive path obtains blue light signals by blue color filter, then is reduced into MPPM signal through MPPM demodulation module; Described gold-tinted receive path obtains gold-tinted signal by yellow filter, then is reduced into QAM signal through QAM demodulation module; Described MPPM signal forms corresponding binary data stream with QAM signal after decoding and processing; Described binary data flows through data combiner and is formed and finally obtain signal.
Described LED drive circuit comprises: information source, variable resistor, high-speed buffer, BiasTee module, DC current source and current-limiting resistance, and described information source, variable resistor, high-speed buffer, BiasTee module are connected successively with current-limiting resistance; The positive pole of described DC current source is connected with information source, the negative pole of described DC current source and BiasTee model calling; Described BiasTee module comprises electric capacity and inductance; One end of described inductance is connected with the negative pole of DC current source, and the other end of described inductance is connected with the negative pole of electric capacity, and the positive pole of described electric capacity is connected with high-speed buffer; The signal of telecommunication that described information source exports is transferred to BiasTee module through high-speed buffer, and the signal that the DC signal that described DC current source exports and high-speed buffer transmit is coupled in BiasTee module, generates coupled electrical signal; Described coupled electrical signal outputs to LED drive circuit by current-limiting resistance.
Described QAM modulation module comprises: serial/parallel converter, 2 level are to L level conversion, base band shaping filter, multiplier and adder; The serial/parallel converter connected successively by two-way, 2 level divide formation two paths of data stream to L level conversion, base band shaping filter and multiplier; And in the two paths of data stream input summer formed; Described binary code flows through serial/parallel converter and exports two-way parallel stream sequence; The speed of described two-way parallel stream sequence is kept to the half of described binary code stream; Described two-way parallel stream sequence to L level conversion, forms the baseband signal of L level respectively through 2 level; The baseband signal of described L level forms X (t) and Y (t) signal through base band shaping filter; The homophase carrier wave that described X (t) is identical with frequency respectively with Y (t) signal and orthorhombic phase carrier wave carry out multiplication operation through described multiplier; The two paths of signals finally obtained is carried out sum operation through described adder, obtains the QAM signal of oneself modulation.
Described MPPM modulation module comprises: serioparallel exchange module, register, MPPM encoder, parallel serial conversion module and clock system; Described serioparallel exchange module, register, MPPM encoder are connected successively with parallel serial conversion module; Described clock system is connected with parallel-serial conversion mould with described serioparallel exchange module, register, MPPM encoder respectively; Described binary code stream is mapped to the binary bit stream that code length is n time slot; In the binary bit stream of a described n time slot, m time slot sends light pulse, obtain modulated MPPM signal.
The demodulating process of described QAM demodulation module is the inverse process of QAM modulation module; The demodulating process of described MPPM demodulation module is the inverse process of described MPPM modulation module.
Another object of the present invention also can be achieved through the following technical solutions: a kind of visible light communication system realizing the described visible light communication method based on QAM and MPPM, comprise and launch subsystem, transmission subsystem and receiving subsystem, the data flow of described transmitting subsystem is divided into D
qAMwith D
mPPMtwo-way.
Described D
qAMdata flow, through conventional coding, interweaves, and the preliminary treatment of the baseband systems such as serioparallel exchange forms binary code stream; Described binary code flows through serial/parallel converter and exports two-way parallel stream sequence; The speed of described two-way parallel stream sequence is kept to the half of described binary code stream; Described two-way parallel stream sequence to L level conversion, forms the baseband signal of L level respectively through 2 level; The baseband signal of described L level forms X (t) and Y (t) signal through base band shaping filter; The homophase carrier wave that described X (t) is identical with frequency respectively with Y (t) signal and orthorhombic phase carrier wave carry out multiplication operation.The two paths of signals finally obtained is carried out the QAM signal of oneself modulation that sum operation just obtains.The regulation and control to light intensity amplitude by control LED driving voltage and then realization of QAM signal.
Described D
mPPMdata flow, through conventional coding, interweaves, and the preliminary treatment of the baseband systems such as serioparallel exchange forms binary code stream; Described binary code stream is mapped to the binary bit stream that code length is n time slot; In the binary bit stream of a described n time slot, m time slot sends light pulse, obtain modulated MPPM signal.MPPM signal controls the break-make of LED drive current by pulse switch.
Described transmission subsystem is free space transmission light signal; The result of described optical signals QAM and MPPM dual modulation produces; The time shaft of described light signal represents the signal that MPPM modulates; The amplitude axis of described light signal represents the signal of QAM modulation.Due to the blue light components fast response time of LED light spectrum, the light signal of its correspondence mainly reflects that MPPM modulates; Yellow part due to response speed slow, the light signal of its correspondence only reflects QAM modulation.And then achieve QAM and the MPPM signal parallel transmission of blue light components and yellow part.
Described receiving subsystem is divided into blue light receive path and gold-tinted receive path.
First described blue light receive path obtains the blue light components of white light LEDs by blue color filter; Described blue light components carries out opto-electronic conversion through photoelectricity testing part and forms the signal of telecommunication; The described signal of telecommunication delivers to QAM and MPPM demodulation module after amplification, filtering process accordingly; The quadrature amplitude modulation signal of input is carried out demodulation process by described QAM demodulation module; The multi-pulse position modulation signal of input is carried out demodulation process by described MPPM demodulation module, is finally transferred to data combiners block again.
First described gold-tinted receive path obtains the yellow part of white light LEDs by yellow filter; Described yellow part carries out opto-electronic conversion through photoelectricity testing part and forms the signal of telecommunication; The described signal of telecommunication amplifies through corresponding, delivers to MPPM demodulation module after filtering process; The multi-pulse position modulation signal of input is carried out demodulation process by described MPPM demodulation module, is finally input to data combiners block again; The data obtained with described blue light receive path merge, and obtain final data.
The present invention includes quadrature amplitude modulation and multi-pulse position modulation; Quadrature amplitude modulation is a kind of technology utilizing carrier amplitude and phase combining modulation efficiently, drastically increase the availability of frequency spectrum, but along with the increase of order of modulation, Distance geometry phase difference between signaling point can be more and more less, make interference between symbol become increasing, and then limit the order of modulation of quadrature amplitude modulation; And its power utilization of multi-pulse position modulation is high, band efficiency is good, strong interference immunity, can weaken by delay time slot between adjacent pulse the impact that intersymbol interference brings system.
Commercial white light LEDs generally excites yellow fluorescent powder by blue LED die and produces white light, and its spectral distribution presents blue light components and yellow part, and yellow part greatly limit the message transmission rate of visible light communication system time of delay.So the present invention proposes the light controlling different spectrum, utilize filter to distinguish different spectral signals at optical receiver end, realize multidiameter delay communication.The time dimension of driving pulse sequence adopts multi-pulse position modulation, its amplitude is carried out mate the quadrature amplitude modulation with yellow part, realize different two paths of data information in different spectrally parallel transmission with this.While weakening the intersymbol interference that quadrature amplitude modulation brings, optimize visible light communication system channel performance further, achieve and do not increasing under bandwidth of a device prerequisite, significantly improve quality and the message transmission rate of radio communication.
Compared with prior art, the present invention has the following advantages and beneficial effect:
1, the present invention more effectively make use of the spectrum of fluorescent material LED, by realizing blue light components in white light LEDs spectrum and the QAM signal of yellow part and the parallel transmission of MPPM signal, improves visible light communication system transmission rate.
2, the present invention can effectively utilize fluorescent material LED to respond yellow part slowly, avoids the transmission range adopting filter elimination yellow part and influential system data.
Accompanying drawing explanation
Fig. 1 is the schematic diagram that the present invention realizes the visible light communication system of QAM and MPPM dual modulation method.
Fig. 2 a is that the present invention realizes QAM modulation theory diagram.
Fig. 2 b is that the present invention realizes QAM demodulation principle block diagram.
Fig. 3 a is that the present invention realizes MPPM modulation principle block diagram.
Fig. 3 b is that the present invention realizes MPPM demodulation principle block diagram.
Fig. 4 is the relation curve of LED modulation signal and power output.
Fig. 5 is LED drive circuit schematic diagram.
Fig. 6 is fluorescent material LED light spectral distribution curve.
Embodiment
Below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail, but embodiments of the present invention are not limited thereto.
Embodiment
As shown in Figure 1, a kind of visible light communication system realizing visible light communication method based on QAM and MPPM, comprising: launch subsystem, transmission subsystem and receiving subsystem.In transmitting subsystem, data flow is encoded respectively, interweaves, and the preliminary treatment of the baseband systems such as serioparallel exchange forms binary code stream; Described binary code stream, respectively through after QAM modulation module and MPPM modulation module modulation treatment, carrys out driving LED light fixture utilizing emitted light signal by LED drive circuit.
As shown in Figure 2 a, be QAM modulation module principle block diagram, data flow, through conventional coding, interweaves, and the preliminary treatment of the baseband systems such as serioparallel exchange forms binary code stream; Described binary code flows through serial/parallel converter and exports two-way parallel stream sequence; The speed of described two-way parallel stream sequence is kept to the half of described binary code stream; Described two-way parallel stream sequence to L level conversion, forms the baseband signal of L level respectively through 2 level; The baseband signal of described L level forms X (t) and Y (t) signal through base band shaping filter; The homophase carrier wave that described X (t) is identical with frequency respectively with Y (t) signal and orthorhombic phase carrier wave carry out multiplication operation.The two paths of signals finally obtained is carried out the QAM signal of oneself modulation that sum operation just obtains.The regulation and control to light intensity amplitude by control LED driving voltage and then realization of QAM signal.As for the inverse process that its principle of QAM demodulation module is QAM modulation module, as shown in Figure 2 b, be QAM demodulation module theory diagram.
As shown in Figure 3 a, be MPPM modulation module theory diagram, data flow, through conventional coding, interweaves, and the preliminary treatment of the baseband systems such as serioparallel exchange forms binary code stream; Described binary code stream is mapped to the binary bit stream that code length is n time slot; In the binary bit stream of a described n time slot, m time slot sends light pulse, obtain modulated MPPM signal.The break-make of MPPM signal controlling LED drive current.As for the inverse process that its principle of MPPM demodulation module is MPPM modulation module, as shown in Figure 3 b, be MPPM demodulation module theory diagram.
As shown in Figure 4, for the relation curve of LED modulation signal and power output, the luminous power exported to make LED lamp remains on linear modulating range, needs to arrange suitable bias current on the basis of modulation signal, and the light signal that LED lamp is exported can not distortion.As shown in Figure 5, be the schematic diagram of LED drive circuit.Realized T-shaped biased by BaisTee module, being coupled direct current signal and AC signal thus ensure that signal can not be lost in LED lamp.LED lamp implements Synchronization Control by QAM and MPPM two signals by LED drive circuit, the regulation and control to light intensity amplitude by control LED driving voltage and then realization of QAM signal; The break-make of MPPM signal controlling LED drive current.As shown in Figure 6, be fluorescent material LED light spectral distribution curve.Visible LED light spectral distribution curve is divided into blue light components and yellow part.Due to the blue light components fast response time of LED light spectrum, the light signal reflection MPPM modulation of its correspondence; Yellow part due to response speed slow, the light signal reflection QAM modulation of its correspondence.And then achieve QAM and the MPPM signal parallel transmission of blue light components and yellow part.
Light signal is by after transmission subsystem, and be converted to the signal of telecommunication through photoelectricity testing part and enter receiving subsystem, in receiving subsystem, the passage of signal transacting is divided into blue light receive path and gold-tinted receive path two parts.First blue light receive path obtains the blue light components of white light LEDs by blue color filter; Described blue light components carries out opto-electronic conversion through photoelectricity testing part and forms the signal of telecommunication; The described signal of telecommunication amplifies through corresponding, delivers to QAM and MPPM demodulation module after filtering process; The quadrature amplitude modulation signal of input is carried out demodulation process by described QAM demodulation module; The multi-pulse position modulation signal of input is carried out demodulation process by described MPPM demodulation module, is finally transferred to data combiners block again.First gold-tinted receive path obtains the yellow part of white light LEDs by yellow filter; Described yellow part carries out opto-electronic conversion through photoelectricity testing part and forms the signal of telecommunication; The described signal of telecommunication amplifies through corresponding, delivers to MPPM demodulation module after filtering process; The multi-pulse position modulation signal of input is carried out demodulation process by described MPPM demodulation module, is finally transferred to data combiners block again; The data obtained with described blue light receive path merge, and obtain final data.
Above-described embodiment is only one embodiment of the present invention; but embodiments of the present invention are not restricted to the described embodiments; other are any do not deviate from Spirit Essence of the present invention and principle under do change, modification, substitute, combine, simplify the substitute mode that all should be equivalence, be included within protection scope of the present invention.
Claims (10)
1., based on a visible light communication method of QAM and MPPM, it is characterized in that, comprise the following steps:
Step 1, data flow, through conventional coding, interweave, and the preliminary treatment of the baseband systems such as serioparallel exchange forms binary code stream; Described binary code forms QAM signal after flowing through quadrature amplitude modulation;
Step 2, data flow, through conventional coding, interweave, and the preliminary treatment of the baseband systems such as serioparallel exchange forms binary code stream; Described binary code forms MPPM signal after flowing through multi-pulse position modulation;
Step 3, transmission subsystem are the free space of transmitting optical signal; Described optical signals white light LEDs is launched; Described white light LEDs is by QAM and MPPM two signal Synchronization Control, and QAM signal passes through control LED driving voltage and then the regulation and control of realization to light intensity amplitude; The break-make of MPPM signal controlling LED drive current;
Step 4, in receiving subsystem, there is photo-signal channel be simultaneously divided into blue light receive path and gold-tinted receive path; Described blue light receive path obtains blue light signals by blue color filter, through signal transacting reduction MPPM signal; Described gold-tinted receive path obtains gold-tinted signal by yellow filter, through signal transacting reduction QAM signal;
Step 5, described MPPM signal form corresponding binary data stream with QAM signal after decoding and processing; Described binary data flows through data combiner and is formed and finally obtain signal.
2. the visible light communication method based on QAM and MPPM according to claim 1, is characterized in that, in step 1, described quadrature amplitude modulation comprises the following steps:
Step 11, described binary code flow through serial/parallel converter and export two-way parallel stream sequence; The speed of described two-way parallel stream sequence is kept to the half of described binary code stream;
Step 12, described two-way parallel stream sequence are respectively through 2 level to L level conversion, and form the baseband signal of L level, wherein, L is positive integer;
The baseband signal of step 13, described L level forms X (t) and Y (t) signal through base band shaping filter;
The homophase carrier wave that step 14, described X (t) are identical with frequency respectively with Y (t) signal and orthorhombic phase carrier wave carry out multiplication operation, the two paths of signals finally obtained are carried out the QAM signal of oneself modulation that sum operation just obtains.
3. the visible light communication method based on QAM and MPPM according to claim 1, is characterized in that, in step 2, described multi-pulse position modulation comprises the following steps:
Step 21, described binary code stream are mapped to the binary bit stream that code length is n equidistant time slot, and wherein, n is positive integer;
Step 22, in the binary bit stream of a described n time slot, m time slot sends light pulse, obtain modulated MPPM signal, wherein, m is positive integer.
4. the visible light communication method based on QAM and MPPM according to claim 1, is characterized in that, in step 4, described signal transacting comprises the following steps:
Step 41, described blue light signals and gold-tinted signal, after amplification, filtering process, carry out the demodulation process of blue light signals and gold-tinted signal;
Step 42, described demodulation process are respectively QAM demodulation process and MPPM demodulation process; The principle of described QAM demodulation process and MPPM demodulation process is respectively the inverse process of claim 2 and claim 3.
5. one kind realizes the visible light communication system of the visible light communication method based on QAM and MPPM according to claim 1, comprise: launch subsystem, transmission subsystem and receiving subsystem, it is characterized in that, described transmitting subsystem has: QAM modulation module, MPPM modulation module, LED drive circuit and LED lamp; Described transmission subsystem is used for the visible light signal that LED lamp sends to be transferred to photoelectricity testing part; Described receiving subsystem has: the first photoelectricity testing part, the second photoelectricity testing part, QAM demodulation module, MPPM demodulation module and data combiner; Described QAM modulation module, MPPM modulation module are connected with LED drive circuit respectively; Described LED drive circuit, LED lamp are connected successively with photoelectricity testing part; Described photoelectricity testing part comprises the first photoelectricity testing part and the second photoelectricity testing part; Described first photoelectricity testing part is connected with QAM demodulation module, and described second photoelectricity testing part is connected with MPPM demodulation module; Described QAM modulation module and MPPM modulation module produce QAM data flow and MPPM data flow respectively; Described QAM data flow and this two paths of data stream of MPPM data flow are sent to LED drive circuit, and are coupled with direct current signal by BaisTee module, with driving LED light fixture utilizing emitted light signal; Described light signal enters receiving subsystem through opto-electronic conversion; There is in described receiving subsystem blue light receive path and gold-tinted receive path; Described blue light receive path obtains blue light signals by blue color filter, then is reduced into MPPM signal through MPPM demodulation module; Described gold-tinted receive path obtains gold-tinted signal by yellow filter, then is reduced into QAM signal through QAM demodulation module; Described MPPM signal forms corresponding binary data stream with QAM signal after decoding and processing; Described binary data flows through data combiner and is formed and finally obtain signal.
6. visible light communication system according to claim 5, it is characterized in that, described LED drive circuit comprises: information source, variable resistor, high-speed buffer, BiasTee module, DC current source and current-limiting resistance, and described information source, variable resistor, high-speed buffer, BiasTee module are connected successively with current-limiting resistance; The positive pole of described DC current source is connected with information source, the negative pole of described DC current source and BiasTee model calling; Described BiasTee module comprises electric capacity and inductance; One end of described inductance is connected with the negative pole of DC current source, and the other end of described inductance is connected with the negative pole of electric capacity, and the positive pole of described electric capacity is connected with high-speed buffer; The signal of telecommunication that described information source exports is transferred to BiasTee module through high-speed buffer, and the signal that the DC signal that described DC current source exports and high-speed buffer transmit is coupled in BiasTee module, generates coupled electrical signal; Described coupled electrical signal outputs to LED drive circuit by current-limiting resistance.
7. visible light communication system according to claim 5, is characterized in that, described QAM modulation module comprises: serial/parallel converter, 2 level are to L level conversion, base band shaping filter, multiplier and adder; The serial/parallel converter connected successively by two-way, 2 level divide formation two paths of data stream to L level conversion, base band shaping filter and multiplier; And in the two paths of data stream input summer formed; Described binary code flows through serial/parallel converter and exports two-way parallel stream sequence; The speed of described two-way parallel stream sequence is kept to the half of described binary code stream; Described two-way parallel stream sequence to L level conversion, forms the baseband signal of L level respectively through 2 level; The baseband signal of described L level forms X (t) and Y (t) signal through base band shaping filter; The homophase carrier wave that described X (t) is identical with frequency respectively with Y (t) signal and orthorhombic phase carrier wave carry out multiplication operation through described multiplier; The two paths of signals finally obtained is carried out sum operation through described adder, obtains the QAM signal of oneself modulation.
8. visible light communication system according to claim 5, is characterized in that, described MPPM modulation module comprises: serioparallel exchange module, register, MPPM encoder, parallel serial conversion module and clock system; Described serioparallel exchange module, register, MPPM encoder are connected successively with parallel serial conversion module; Described clock system is connected with parallel-serial conversion mould with described serioparallel exchange module, register, MPPM encoder respectively; Described binary code stream is mapped to the binary bit stream that code length is n time slot; In the binary bit stream of a described n time slot, m time slot sends light pulse, obtain modulated MPPM signal.
9. visible light communication system according to claim 5, is characterized in that, the demodulating process of described QAM demodulation module is the inverse process of QAM modulation module.
10. visible light communication system according to claim 5, is characterized in that, the demodulating process of described MPPM demodulation module is the inverse process of described MPPM modulation module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510551507.0A CN105119655A (en) | 2015-08-31 | 2015-08-31 | Visible light communication method based on QAM and MPPM and system thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510551507.0A CN105119655A (en) | 2015-08-31 | 2015-08-31 | Visible light communication method based on QAM and MPPM and system thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105119655A true CN105119655A (en) | 2015-12-02 |
Family
ID=54667563
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510551507.0A Pending CN105119655A (en) | 2015-08-31 | 2015-08-31 | Visible light communication method based on QAM and MPPM and system thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105119655A (en) |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105530052A (en) * | 2015-12-30 | 2016-04-27 | 广东顺德中山大学卡内基梅隆大学国际联合研究院 | Visible light communication system based on MPPM (Multi-Pulse Position Modulation) and RS (Reed Solomon) codes |
| CN105680941A (en) * | 2016-02-26 | 2016-06-15 | 中国科学技术大学 | Underwater LED (Light-Emitting Diode) long distance communication system based on visible light |
| CN105721064A (en) * | 2016-01-18 | 2016-06-29 | 桂林电子科技大学 | Coding and decoding method and device by combining channel coding and multidimensional pulse position modulation |
| CN106130638A (en) * | 2016-08-20 | 2016-11-16 | 华南理工大学 | PAM Yu MPPM dual modulation method and system for visible light communication |
| CN106788725A (en) * | 2016-12-16 | 2017-05-31 | 山东大学 | A kind of visible light communication gamut key modulation method based on multiple-pulse position |
| CN107612618A (en) * | 2017-09-28 | 2018-01-19 | 天津大学 | One kind is based on the new hybrid modulation method of visible light communication |
| WO2018041252A1 (en) * | 2016-09-02 | 2018-03-08 | Huawei Technologies Co., Ltd. | Method of dimming for visible light communications |
| CN108075829A (en) * | 2017-12-13 | 2018-05-25 | 桂林电子科技大学 | A kind of variable slot pulse position modulation device, method and laser communication system |
| CN108366031A (en) * | 2017-08-14 | 2018-08-03 | 广东顺德中山大学卡内基梅隆大学国际联合研究院 | In conjunction with the reversed polarity multi-pulse position modulation optical OFDM system of brightness adjustment control |
| CN109150306A (en) * | 2017-06-16 | 2019-01-04 | 深圳清华大学研究院 | Visible light communication system and method |
| CN109831925A (en) * | 2016-09-29 | 2019-05-31 | 加利福尼亚大学董事会 | Visible light communication system on chip |
| CN111082864A (en) * | 2019-11-20 | 2020-04-28 | 安徽中骄智能科技有限公司 | Integrated circuit of visible light communication system transmitting module |
| CN112787720A (en) * | 2021-01-21 | 2021-05-11 | 南京航空航天大学 | Spatial X-ray communication method and device based on hybrid modulation |
| CN113193913A (en) * | 2021-04-26 | 2021-07-30 | 江南大学 | Visible light communication system and method based on MPPM and adaptive bias |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101710890A (en) * | 2009-12-15 | 2010-05-19 | 华东理工大学 | Pulse and OFDMD double-data modulation method |
| CN103457661A (en) * | 2013-09-09 | 2013-12-18 | 东南大学 | LED array visible light communication system and method |
| CN103457904A (en) * | 2013-08-23 | 2013-12-18 | 上海交通大学 | 16QAM high-speed data transmission system based on substrate integrated waveguide interconnection |
| CN103763829A (en) * | 2014-01-20 | 2014-04-30 | 南京邮电大学 | Light source dimming method based on OFDM signal |
| US20140233966A1 (en) * | 2012-12-21 | 2014-08-21 | Zte (Usa) Inc. | Recovering data from quadrature phase shift keying modulated optical signals |
| CN104158632A (en) * | 2014-09-03 | 2014-11-19 | 重庆邮电大学 | Method of modulating variable pulse amplitude position and improving error rate for visible light communication system |
| CN104821871A (en) * | 2015-03-11 | 2015-08-05 | 南京航空航天大学 | 16 quadrature amplitude modulation (QAM) demodulation synchronization method |
-
2015
- 2015-08-31 CN CN201510551507.0A patent/CN105119655A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101710890A (en) * | 2009-12-15 | 2010-05-19 | 华东理工大学 | Pulse and OFDMD double-data modulation method |
| US20140233966A1 (en) * | 2012-12-21 | 2014-08-21 | Zte (Usa) Inc. | Recovering data from quadrature phase shift keying modulated optical signals |
| CN103457904A (en) * | 2013-08-23 | 2013-12-18 | 上海交通大学 | 16QAM high-speed data transmission system based on substrate integrated waveguide interconnection |
| CN103457661A (en) * | 2013-09-09 | 2013-12-18 | 东南大学 | LED array visible light communication system and method |
| CN103763829A (en) * | 2014-01-20 | 2014-04-30 | 南京邮电大学 | Light source dimming method based on OFDM signal |
| CN104158632A (en) * | 2014-09-03 | 2014-11-19 | 重庆邮电大学 | Method of modulating variable pulse amplitude position and improving error rate for visible light communication system |
| CN104821871A (en) * | 2015-03-11 | 2015-08-05 | 南京航空航天大学 | 16 quadrature amplitude modulation (QAM) demodulation synchronization method |
Non-Patent Citations (5)
| Title |
|---|
| HAITHAM S. KHALLAF,ETAL.: "Proposal of a Hybrid QAM-MPPM Technique for Optical Communications Systems", 《TRANSPARENT OPTICAL NETWORKS(ICTON),2014 16TH INTERNATIONAL CONFERENCE ON》 * |
| HOSSAM M. H. SHALABY: "Maximum Achievable Constrained Power Efficiencies of MPPM-LQAM Techniques", 《IEEE PHOTONICS TECHNOLOGY LETTERS》 * |
| JIAN CHEN,ETAL.: "MPPM Dimming Control for OFDM-Based Visible Light Communication Systems", 《COMMUNICATION SYSTEMS(ICCS),2014 IEEE INTERNATIONAL CONFERENCE ON》 * |
| 刘晔等: "无线光通信中改进型多脉冲位置调制的性能研究", 《2008通信理论与技术新发展——第十三届全国青年通信学术会议论文集（下）》 * |
| 谭家杰等: "多脉冲位置调制解调的CPLD实现研究", 《衡阳师范学院学报》 * |
Cited By (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105530052A (en) * | 2015-12-30 | 2016-04-27 | 广东顺德中山大学卡内基梅隆大学国际联合研究院 | Visible light communication system based on MPPM (Multi-Pulse Position Modulation) and RS (Reed Solomon) codes |
| CN105721064A (en) * | 2016-01-18 | 2016-06-29 | 桂林电子科技大学 | Coding and decoding method and device by combining channel coding and multidimensional pulse position modulation |
| CN105721064B (en) * | 2016-01-18 | 2018-05-04 | 桂林电子科技大学 | The coding and decoding method and device of channel combined multidimensional pulse position modulation |
| CN105680941B (en) * | 2016-02-26 | 2018-04-10 | 中国科学技术大学 | A kind of underwater LED long haul communications systems based on visible ray |
| CN105680941A (en) * | 2016-02-26 | 2016-06-15 | 中国科学技术大学 | Underwater LED (Light-Emitting Diode) long distance communication system based on visible light |
| CN106130638A (en) * | 2016-08-20 | 2016-11-16 | 华南理工大学 | PAM Yu MPPM dual modulation method and system for visible light communication |
| WO2018041252A1 (en) * | 2016-09-02 | 2018-03-08 | Huawei Technologies Co., Ltd. | Method of dimming for visible light communications |
| US10298333B2 (en) | 2016-09-02 | 2019-05-21 | Futurewei Technologies, Inc. | Method of dimming for visible light communications |
| CN109831925A (en) * | 2016-09-29 | 2019-05-31 | 加利福尼亚大学董事会 | Visible light communication system on chip |
| CN106788725A (en) * | 2016-12-16 | 2017-05-31 | 山东大学 | A kind of visible light communication gamut key modulation method based on multiple-pulse position |
| CN106788725B (en) * | 2016-12-16 | 2019-02-22 | 山东大学 | A kind of visible light communication gamut key modulation method based on multiple-pulse position |
| CN109150306B (en) * | 2017-06-16 | 2020-06-30 | 深圳清华大学研究院 | Visible light communication system and method |
| CN109150306A (en) * | 2017-06-16 | 2019-01-04 | 深圳清华大学研究院 | Visible light communication system and method |
| CN108366031B (en) * | 2017-08-14 | 2021-04-06 | 广东顺德中山大学卡内基梅隆大学国际联合研究院 | Reverse polarity multi-pulse position modulation light OFDM system combined with dimming control |
| CN108366031A (en) * | 2017-08-14 | 2018-08-03 | 广东顺德中山大学卡内基梅隆大学国际联合研究院 | In conjunction with the reversed polarity multi-pulse position modulation optical OFDM system of brightness adjustment control |
| CN107612618A (en) * | 2017-09-28 | 2018-01-19 | 天津大学 | One kind is based on the new hybrid modulation method of visible light communication |
| CN107612618B (en) * | 2017-09-28 | 2019-11-15 | 天津大学 | One kind being based on the novel hybrid modulation method of visible light communication |
| CN108075829A (en) * | 2017-12-13 | 2018-05-25 | 桂林电子科技大学 | A kind of variable slot pulse position modulation device, method and laser communication system |
| CN111082864A (en) * | 2019-11-20 | 2020-04-28 | 安徽中骄智能科技有限公司 | Integrated circuit of visible light communication system transmitting module |
| CN112787720A (en) * | 2021-01-21 | 2021-05-11 | 南京航空航天大学 | Spatial X-ray communication method and device based on hybrid modulation |
| CN113193913A (en) * | 2021-04-26 | 2021-07-30 | 江南大学 | Visible light communication system and method based on MPPM and adaptive bias |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105119655A (en) | Visible light communication method based on QAM and MPPM and system thereof | |
| CN106160873B (en) | A kind of phase-shift coding method and realization device based on pulse amplitude modulation system | |
| EP2339762B1 (en) | Visible light communication transmitter and visible light communication system | |
| KR101408816B1 (en) | Visible light communication transmitter and visible light communication system | |
| Roberts et al. | IEEE 802.15. 7 physical layer summary | |
| CN102412953B (en) | Visible light local area network duplex communication method | |
| Komiyama et al. | Study of visible light communication system using RGB LED lights | |
| US7877018B2 (en) | Method and apparatus for correcting color imbalance of visible light in wavelength division parallel visible light communications | |
| CN105049118A (en) | Visible light communication method based on double-modulation technology and visible light communication system thereof | |
| CN103986516A (en) | Visible light communication system and method | |
| CN105281836B (en) | A kind of visible light communication system and method based on preemphasis circuit | |
| CN106130638A (en) | PAM Yu MPPM dual modulation method and system for visible light communication | |
| CN105162517A (en) | Visible light communication method and visible light communication system thereof based on pulse amplitude regulation | |
| CN104243034A (en) | Visible-light communication system and visible-light communication method | |
| CN106452582A (en) | Close-range high-speed bidirectional data transmission system based on wavelength division multiplexing RGB-LED light source | |
| CN106100730A (en) | Carrierless amplitude phase modulating system based on super Nyquist precoding and modulator approach | |
| Idris et al. | A survey of modulation schemes in visible light communications | |
| Choi et al. | Visible light communications with color and dimming control by employing VPPM coding | |
| CN103840876B (en) | visible light communication method and system | |
| Adwani et al. | Li-Fi: information transferring through LED's | |
| CN205430247U (en) | Visible light communication system based on QAM and MPPM | |
| CN205986878U (en) | A PAM and dual modulation hardware systems of MPPM for visible light communication | |
| CN115037365B (en) | High-speed expandable encoder of high-power free space optical communication system | |
| Xiao et al. | High-Speed visible light communication chipset based multi-color MIMO system | |
| CN108337047B (en) | Time domain hybrid modulation method based on visible light communication system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20151202 |
|
| WD01 | Invention patent application deemed withdrawn after publication |