CN110166122A - The method and device of brightness adjustment control - Google Patents

The method and device of brightness adjustment control Download PDF

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Publication number
CN110166122A
CN110166122A CN201810704408.5A CN201810704408A CN110166122A CN 110166122 A CN110166122 A CN 110166122A CN 201810704408 A CN201810704408 A CN 201810704408A CN 110166122 A CN110166122 A CN 110166122A
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signal
transmitting terminal
power
positive
modulation
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CN201810704408.5A
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CN110166122B (en
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黄伟
方平
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Priority to PCT/CN2019/072659 priority Critical patent/WO2019157916A1/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/11—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
    • H04B10/114—Indoor or close-range type systems
    • H04B10/116—Visible light communication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/516—Details of coding or modulation

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Optical Communication System (AREA)

Abstract

This application provides a kind of method and apparatus of brightness adjustment control, wherein this method comprises: transmitting terminal carries out light multi-carrier modulation to the data to be transmitted on multichannel subcarrier, obtains bipolar signal；Transmitting terminal carries out polarity processing to bipolar signal, obtains unipolar positive signal and polarity reversing signal；Transmitting terminal modulates the signal parameter of positive signal and polarity reversing signal, obtains the positive signal and polarity reversing signal through ovennodulation；Transmitting terminal by through ovennodulation positive signal and polarity reversing signal be modulated on pulse width modulation (PWM) signal, obtain support brightness adjustment control Hybrid-modulated Signal；Transmitting terminal sends the Hybrid-modulated Signal for supporting brightness adjustment control to receiving end.By the method and apparatus of the brightness adjustment control of the application, the band efficiency of system can be improved.

Description

The method and device of brightness adjustment control
Technical field
This application involves wireless light communication technical fields, and more particularly, to the method and dress of a kind of brightness adjustment control It sets.
Background technique
In recent years, with the fast development of mobile Internet and Internet of Things, the service traffics of mobile subscriber are in explosive increasing It is long.In order to realize the big communication connection connected and low time delay is highly reliable of hot spot high capacity, low-power consumption, with the height of spread spectrum bandwidth Keep pouring in the defeated key technology as next generation mobile communication.Wherein, it is seen that optic communication (visible light Communication, VLC) technology because its have many advantages, such as super large bandwidth, green high-capacity effect, without electromagnetic interference and easily deployment, Important selection as building spectral efficient and high power efficiency super-intensive heterogeneous network.
In visible light communication, other than improving the rate of information throughput and reliability, since VLC is based on existing photograph Bright equipment and realize, need to guarantee user can demand according to user to illumination intensity and local environment to adjust illumination strong Degree, thus the brightness adjustment control for being directed to VLC is also a kind of technology of extremely important and great use value.
In order to meet the needs of indoor VLC high speed data transfer, the light orthogonal frequency for supporting light modulation is introduced in VLC system (optical orthogonal frequency division multiplexing, the O-OFDM) technology of multiplexing, however it is existing Support light modulation O-OFDM modulation technique can not make system band efficiency with higher.
Summary of the invention
The application provides a kind of method and device of brightness adjustment control, and the band efficiency of system can be improved.
In a first aspect, providing a kind of method of brightness adjustment control, comprising: transmitting terminal is to the number to be transmitted on multichannel subcarrier According to light multi-carrier modulation is carried out, bipolar signal is obtained；The transmitting terminal carries out polarity processing to the bipolar signal, obtains Unipolar positive signal and polarity reversing signal；The transmitting terminal modulates the signal of the positive signal and polarity reversing signal Parameter obtains the positive signal and the polarity reversing signal through ovennodulation；The transmitting terminal is by the anode through ovennodulation Property signal and polarity reversing signal be modulated on pulse width modulation (PWM) signal, obtain support brightness adjustment control Hybrid-modulated Signal； The transmitting terminal sends the Hybrid-modulated Signal for supporting brightness adjustment control to receiving end.
The embodiment of the present application can realize light by modulation bipolar signal and its signal parameter of polarity reversing signal Light single-carrier modulated is realized while multi-carrier modulation, since light single-carrier modulated will not influence light overloading wave modulation, light is more The channel efficiency of carrier modulation can remain unchanged, and light single-carrier modulated be realized by way of modulating part signal parameter, again Data can be passed, so that the channel efficiency of system can be improved using the mixing superposition modulated of light multicarrier and light single carrier more.
In some possible implementations, the signal parameter includes the letter of the positive signal and polarity reversing signal Number power and signal period.
In some possible implementations, when the signal parameter is signal power, described in the transmitting terminal modulation The signal parameter of positive signal and polarity reversing signal, comprising: the transmitting terminal is by the positive signal and polarity reversing signal Power corresponding with the first power factor concentration power factor is multiplied respectively, obtain the positive signal through ovennodulation The power of power and the polarity reversing signal, the first power factor collection is preset according to dimming level.
Above-mentioned technical proposal, transmitting terminal realize light list by modulation bipolar signal and its power of polarity reversing signal Carrier modulation improves the band efficiency of system.In addition, not increasing additionally during realizing light single-carrier modulated Modulation power, this improves the power efficiencies of system.
In some possible implementations, when the signal parameter is signal power and signal period, the transmission Modulate the signal parameter of the positive signal and polarity reversing signal in end, comprising: in the positive signal and polarity reversing signal Modulation period in, the transmitting terminal by the power of the positive signal and polarity reversing signal respectively with the second power factor collection In corresponding power factor be multiplied, obtain the power of the positive signal through ovennodulation and the function of the polarity reversing signal Rate, the second power factor collection is preset according to dimming level.
Above-mentioned technical proposal, transmitting terminal pass through modulation bipolar signal and its signal power and signal of polarity reversing signal week Phase realizes light single-carrier modulated, so as to improve the band efficiency of system.In addition, realizing light single-carrier modulated In the process, increase modulation power without additional, this improves the power efficiencies of system.
In some possible implementations, the dimming level meets formula:Wherein, γ is to adjust Light level, poptIt (t) is the mean power of the positive signal and polarity reversing signal modulated by signal parameter, IHFor PWM The high level of voltage signal or the high current of PWM current signal, ILFor the low level or PWM current signal of PWM voltage signal Low current, ε are transformation factor.
In some possible implementations, the method also includes: the transmitting terminal is in the multichannel subcarrier Signal on every subcarriers carries out power control.
In some possible implementations, the transmitting terminal is to the letter on every subcarriers in the multichannel subcarrier Number carry out power control, comprising: the transmitting terminal respectively by every subcarriers signal and change of scale factor set in Corresponding change of scale fac-tor.
Above-mentioned technical proposal, transmitting terminal by by every subcarriers signal and change of scale fac-tor, Lai Shixian Power control can make full use of the range of linearity of light source, so that the precision level of light modulation is higher, can have bigger, more flexible Dimming scope.
In some possible implementations, the transmitting terminal carries out polarity processing to the bipolar signal, obtains list Polar positive signal and polarity reversing signal, comprising: the transmitting terminal obtains the negative loop zero setting of the bipolar signal To the positive signal；Or the positive portions zero setting of the bipolar signal is obtained the reversed polarity letter by the transmitting terminal Number.
Above-mentioned technical proposal transmits the average light power meeting of optical signal due to the O-OFDM signal using direct current biasing It greatly increases, modulation depth can be reduced, the power efficiency of system is caused to reduce.Polarity processing in the embodiment of the present application, which uses, to cut Disconnected processing, avoids the power efficiency that thereby may be ensured that system using direct current biasing.Also, transmitting terminal uses truncation Generated truncation noise only will affect the subcarrier mutually orthogonal with channel distortion experienced, without introducing in channel distortion experienced Noise jamming can reduce the bit error rate of demodulation in this way when receiving end demodulates signal.
In some possible implementations, the transmitting terminal carries out light overloading to the data to be transmitted on multichannel subcarrier Wave modulation, comprising: multichannel subcarrier is layered by the transmitting terminal according to preset rules；The transmitting terminal is to each layer of son Data to be transmitted on carrier wave carries out light multi-carrier modulation.
Above-mentioned technical proposal, transmitting terminal are layered multichannel subcarrier, and system is allowed to make full use of odd number way Carrier wave and even number subcarriers, so as to so that the band efficiency of system is higher.
In some possible implementations, the transmitting terminal carries out light to the data to be transmitted on each layer of subcarrier Multi-carrier modulation, comprising: the transmitting terminal carries out constellation mapping to the data to be transmitted on each layer of subcarrier, described The constellation symbol of mapping meets Hermitian conjugation symmetrical structure；To meeting, Hermitian conjugation is symmetrical to be believed the transmitting terminal Number carry out inverse fast fourier transform；Cyclic prefix is added in the signal by inverse fast fourier transform in the transmitting terminal； The transmitting terminal carries out repetitive extension to the signal that cyclic prefix is added, and obtains bipolar signal.
In some possible implementations, the transmitting terminal by through ovennodulation the positive signal and reversed polarity believe It number is modulated on pulse width modulation (PWM) signal, comprising: the positive signal through ovennodulation is modulated to by the transmitting terminal In the low level or low current of pwm signal；The polarity reversing signal through ovennodulation is modulated to pwm signal by the transmitting terminal On high level or high current.
Second aspect provides a kind of device of brightness adjustment control, comprising: the first modulation module, for multichannel subcarrier On data to be transmitted carry out light multi-carrier modulation, obtain bipolar signal；Processing module, for the bipolar signal into The processing of row polarity, obtains unipolar positive signal and polarity reversing signal；Second modulation module, for modulating the processing mould The signal parameter of the positive signal and polarity reversing signal that block obtains obtains the positive signal through ovennodulation and anti- Polar signal；Generation module, for the positive signal through ovennodulation and polarity reversing signal to be modulated to pulse width tune On pwm signal processed, the Hybrid-modulated Signal for supporting brightness adjustment control is obtained；Communication module, for sending the support to receiving end The Hybrid-modulated Signal of brightness adjustment control.
In some possible implementations, the signal parameter includes the letter of the positive signal and polarity reversing signal Number power and signal period.
In some possible implementations, when the signal parameter is signal power, the second modulation module tool Body is used for: by the power of the positive signal and polarity reversing signal power factor corresponding with the first power factor concentration respectively Be multiplied, obtain the power of the positive signal through ovennodulation and the power of the polarity reversing signal, first power because Subset is preset according to dimming level.
In some possible implementations, when the signal parameter is signal power and signal period, described second Modulation module is specifically used for: within the modulation period of the positive signal and polarity reversing signal, by the positive signal and Power factor corresponding with the second power factor concentration is multiplied the power of polarity reversing signal respectively, it obtains through described in ovennodulation The power of the power of positive signal and the polarity reversing signal, the second power factor collection are default according to dimming level 's.
In some possible implementations, the dimming level meets formula:Wherein, γ is to adjust Light level, poptIt (t) is the mean power of the positive signal and polarity reversing signal modulated by signal parameter, IHFor PWM The high level of voltage signal or the high current of PWM current signal, ILFor the low level or PWM current signal of PWM voltage signal Low current, ε are transformation factor.
In some possible implementations, described device further include: control module, for in the multichannel subcarrier Every subcarriers on signal carry out power control.
In some possible implementations, the control module is specifically used for: by the signal on every subcarriers Power respectively with change of scale fac-tor corresponding in change of scale factor set.
In some possible implementations, the processing module is specifically used for: by the negative value portion of the bipolar signal Zero is split, the positive signal is obtained；Or by the positive portions zero setting of the bipolar signal, obtain the reversed polarity letter Number.
In some possible implementations, first modulation module is specifically used for: according to preset rules that multichannel is sub Carrier wave is layered；Light multi-carrier modulation is carried out to the data to be transmitted on each layer of subcarrier.
In some possible implementations, first modulation module is specifically used for: on each layer of subcarrier The data to be transmitted carries out constellation mapping, and it is symmetrical that the symbol by constellation mapping meets hermitian Hermitian conjugation Structure；Symmetrical signal progress inverse fast fourier transform is conjugated to Hermitian is met；Passing through inverse fast fourier transform Signal in cyclic prefix is added；Repetitive extension is carried out to the signal that cyclic prefix is added, obtains bipolar signal.
In some possible implementations, the generation module is specifically used for: the positive polarity through ovennodulation is believed It number is modulated in the low level or low current of pwm signal；The polarity reversing signal through ovennodulation is modulated to the height of pwm signal On level or high current.
The third aspect, the embodiment of the present application also provides a kind of light adjusting and controlling device, the light adjusting and controlling device includes: one A or multiple processors, one or more memory, one or more light adjusting controllers, one or more baseband processing modules, One or more photodetectors, one or more optical antennas；
Wherein, the memory, for storing program instruction；
The processor, for according to the program instruction stored in the memory execute above-mentioned first aspect described in side Method；
The light adjusting controller, for generating dimming control signal according to the preset dimming level of the processor；
The optical antenna is sent to the photodetector for receiving light intensity signal, and by the light intensity signal；
The photodetector, for converting the electric signal with biasing for light intensity signal, and will be with the electric signal biased It is sent to the baseband processing module, wherein current signal that the electric signal with biasing can be set for band-offset or with the voltage of biasing Signal；
The baseband processing module, for carrying out channel coding, symbol mapping, multi-carrier modulation to baseband signal, and it is raw At physical-layer data frame.Also, the baseband processing module is also used to synchronize processing to the electric signal received, channel is estimated Meter, channel equalization, multicarrier demodulation, symbol de-maps, channel coding.
Fourth aspect, the embodiment of the present application provide a kind of computer storage medium, and program is stored in the storage medium and is referred to It enables, which can realize method described in first aspect when being read and executed by one or more processors.
5th aspect, the embodiment of the present application provides a kind of computer program product comprising instruction, when it is in computer When upper operation, so that computer executes method described in above-mentioned first aspect.
6th aspect, the embodiment of the present application provide a kind of light adjusting system, and the light adjusting system includes described in second aspect Light adjusting and controlling device.
Detailed description of the invention
Fig. 1 is RPO-OFDM modulation technique functional block diagram provided by the embodiments of the present application.
Fig. 2 is the schematic flow chart of the method for brightness adjustment control provided by the embodiments of the present application.
Fig. 3 is a kind of specific implementation frame for the process flow that transmitting terminal provided by the embodiments of the present application generates positive signal Figure.
Fig. 4 is a kind of schematic diagram of preset rules provided by the embodiments of the present application.
Fig. 5 is that transmitting terminal provided by the embodiments of the present application generates the structure chart for supporting the Hybrid-modulated Signal of brightness adjustment control.
Fig. 6 is that the transmitting terminal that another embodiment of the application provides generates the structure for supporting the Hybrid-modulated Signal of brightness adjustment control Figure.
Fig. 7 is the structure chart that the application implements that the Hybrid-modulated Signal of brightness adjustment control is supported in the receiving end provided demodulation.
Fig. 8 is the schematic block diagram of light adjusting and controlling device provided by the embodiments of the present application.
Fig. 9 is the structural schematic diagram of light adjusting and controlling device provided by the embodiments of the present application.
Specific embodiment
Below in conjunction with attached drawing, the technical solution in the application is described.
The technical solution of the embodiment of the present application can be applied to various communication systems, such as: global system for mobile telecommunications (global System of mobile communication, GSM) system, CDMA (code division multiple Access, CDMA) system, wideband code division multiple access (wideband code division multiple access, WCDMA) system System, General Packet Radio Service (general packet radio service, GPRS), long term evolution (long term Evolution, LTE) system, LTE frequency division duplex (frequency division duplex, FDD) system, LTE time division duplex (time division duplex, TDD), Universal Mobile Communication System (universal mobile Telecommunication system, UMTS), global interconnection inserting of microwave (worldwide interoperability For microwave access, WiMAX) communication system, following the 5th generation (5th generation, the 5G) system.Wherein, 5G system can also be known as new wireless (new radio, NR) system.
The invention relates to terminal device can also be known as terminal, be a kind of setting with radio transmission-receiving function It is standby, land can be deployed in, including indoor or outdoors, hand-held or vehicle-mounted；(such as steamer) can also be deployed on the water surface；Also It can dispose in the sky (such as on aircraft, balloon and satellite etc.).Terminal device can be user equipment (user Equipment, UE), wherein UE includes the handheld device with wireless communication function, mobile unit, wearable device or meter Calculate equipment.Illustratively, UE can be mobile phone (mobile phone), tablet computer or the computer with radio transmission-receiving function.Eventually End equipment can also be virtual reality (virtual reality, VR) terminal device, augmented reality (augmented Reality, AR) terminal device, the wireless terminal in Industry Control, it is unmanned in wireless terminal, the nothing in tele-medicine The wireless terminal in wireless terminal, smart city (smart city), wisdom family (smart in line terminal, smart grid Home wireless terminal in) etc..In the embodiment of the present application, realize that the device of the function of terminal device can be terminal device, It is also possible to support terminal device to realize the device of the function in terminal device.
The invention relates to the network equipment can be for the equipment with terminal equipment in communication, the network equipment It can be global system for mobile telecommunications (Global System of Mobile communication, GSM) system or CDMA Base station (Base Transceiver Station, BTS) in (Code Division Multiple Access, CDMA), It can be the base station in wideband code division multiple access (Wideband Code Division Multiple Access, WCDMA) system (NodeB, NB) can also be the evolved base station (Evolutional NodeB, eNB or eNodeB) in LTE system, may be used also To be the wireless controller under cloud Radio Access Network (Cloud Radio Access Network, CRAN) scene, or should The network equipment can for relay station, access point, mobile unit, wearable device and the network equipment in future 5G network or The network equipment etc. in the PLMN network of the following evolution, the embodiment of the present application does not limit.In the embodiment of the present application, network is realized The device of the function of equipment can be the network equipment, be also possible to support the network equipment to realize the dress of the function in the network equipment It sets.
In a wireless communication system, when carrying out wireless communication between communication equipment, the communication equipment for sending data can also claim For data sending terminal, the communication equipment for receiving data can also be known as data receiver.Wherein, data sending terminal can also be known as Perhaps other title data receivers can also be known as receiving end or other titles to transmitting terminal, and the application is with no restrictions.
Illustratively, when terminal device and LA Management Room are communicated, if the network equipment sends number to terminal device The data that the network equipment is sent are received according to, terminal device, then the network equipment is properly termed as transmitting terminal, and terminal device is properly termed as connecing Receiving end；If terminal device is to the data that the network equipment sends data, network equipment receiving terminal apparatus is sent, terminal device can be with Referred to as data sending terminal, the network equipment are properly termed as data receiver.
The hybrid modulation method of the support brightness adjustment control of the embodiment of the present application can be applied to but be not limited to following scene: base In the indoor high-speed visible light communication network and outdoor visible light communication of wireless optical fidelity (lightfidelity, Lifi) technology Network.Wherein, indoor high-speed visible light communication network, which refers to, is mounted on indoor headlamp and mobile phone or other intelligent mobile terminals The LiFi network of composition, outdoor visible light communication network refer to the infrastructure such as the mobile terminals such as vehicle and street lamp, traffic lights, billboard Or the LiFi network formed between vehicle and vehicle.
Indoors and in the visible light communication network under outdoor scene, including indoor illumination, street lamp, traffic lights and vehicle The light sources such as lamp can integrated signal modulator, and mobile phone, vehicle or other intelligent mobile terminals can integrated photodetectors Equal receiving devices.
It should be understood that may be at stationary state between light source and terminal device, motion state also may be at, the application is real It applies example and this is not construed as limiting.
It should also be understood that the terms " system " and " network " is often used interchangeably herein.
It may include transmitting terminal, light wireless communication channel and receiving end in VLC system.Data-signal can pass through hair Sending end sends optical signal, is received again by receiving end via light wireless communication channel and is eventually converted into electric signal output.
It is existing about support brightness adjustment control and with high frequency band efficiency modulation technique in, reversed polarity light orthogonal frequency It is multiplexed (reverse polarity optical orthogonal frequency division multiplexing, RPO- OFDM) modulation technique is that a kind of degree of recognition is relatively high, and can support the modulation technique of larger range light modulation, below will be to RPO- OFDM modulation technique does simple introduction.
Fig. 1 show RPO-OFDM modulation technique functional block diagram.In transmitting terminal, the bit stream that signal source sends over passes through After quadrature amplitude modulation (quadrature amplitude modulation, QAM), QAM modulation symbol can pass through hermitian (Hermitian) it maps, so that QAM modulation symbol meets Hermitian symmetrical structure.Meet Hermitian symmetrical structure Symbol is by inverse fast fourier transform (inverse fast fourier transform, IFFT) and cyclic prefix is added After (cyclic prefix, CP) processing, ambipolar O-OFDM signal is generated, it, can after being handled later by single-polarized signal To obtain containing only the positive polarity O-OFDM signal of positive number signal.
It should be noted that by single polarization, treated that O-OFDM signal may include asymmetric clipping light orthogonal frequency It is multiplexed (asymmetrically clipped optical orthogonal frequency division Multiplexing, ACO-OFDM) signal, overturning orthogonal frequency division multiplexing (flip orthogonal frequency Division multiplexing, F-OFDM) signal, position modulation orthogonal frequency division multiplexing (position modulation Optical orthogonal frequency division multiplexing, PM-OFDM) signal, unipolarity orthogonal frequency Divide multiplexing (unipolar orthogonal frequency division multiplexing, U-OFDM) signal etc..
Similarly, transmitting terminal can obtain containing only according to preset light modulation demand the negative polarity O-OFDM letter of negative signal Number.
Later, positive polarity O-OFDM signal modulation to pulse width can be modulated (pulse width by transmitting terminal Modulation, PWM) signal low level on, by the high level of negative polarity O-OFDM signal modulation to pwm signal, and lead to It crosses light emitting diode (light emitting diode, LED) light source and carries out signal transmission.
Assuming that pwm signal iPWM(t) signal period is TPWM, then pwm signal may be expressed as:
Wherein, IHFor high level pwm signal, and its symbol lengths is T, ILFor low level pwm signal, the pwm signal Duty ratio be D=T/TPWM。
Assuming that by IFFT and CP processing being added and is i by unipolar signal treated O-OFDM signalOOFDM(t), The then RPO-OFDM signal i after signal reversed polarityRPO-OFDM(t) it may be expressed as:
Wherein, m indicates the i of O-OFDM signalOOFDMScale factor is modulated, the signal function of O-OFDM signal is determined for Rate.
In receiving end, photodetector (photodetector, PD) or avalanche photodide (avalanche Photodiode, APD) after detector receives the optical signal of LED light, can convert optical signals into corresponding electric signal and into After row signal processing, available RPO-OFDM receives signal.In the case where conventional letter is synchronous, receiving end can first be carried out Polarity estimation, determines the polarity of O-OFDM signal in PRO-OFDM signal.After the polarity for determining O-OFDM signal, by removing CP After processing, FFT, demapping and demodulation, the recovery of bit stream can be completed.
In above-mentioned technical proposal, since all subcarriers in O-OFDM signal are not efficiently used, system Channel efficiency is not high.
In consideration of it, the embodiment of the present application provides a kind of technical solution, by using light multi-carrier modulation (optical Multi-carrier modulation, OMCM) and light single-carrier modulated (optical single-carrier Modulation, OSCM) mixing superposition modulated, the channel efficiency of system can be improved.
Fig. 2 is the schematic flow chart according to the hybrid modulation method of the support brightness adjustment control of the embodiment of the present application.Fig. 2's Method may include 210-250, and 210-250 is described in detail separately below.
Optionally, when this method is used for uplink, transmitting terminal is terminal device, and receiving end is the network equipment.
Optionally, when this method is used for downlink transfer, transmitting terminal is the network equipment, and receiving end is terminal device.
In 210, transmitting terminal carries out light multi-carrier modulation to the data to be transmitted on multichannel subcarrier, obtains bipolarity letter Number.
The OMCM mode that transmitting terminal is modulated the data to be transmitted on multichannel subcarrier can there are many kinds of, the application Embodiment is not specifically limited in this embodiment.For example, OMCM modulation can be any one in following: ACO-OFDM, wavelet packet point It is multiplexed (wavelet packet division multiplexing, WPDM), Offset Quadrature Amplitude modulates OFDM (OFDM Offset quadrature amplitude modulation, OFDM-OQAM) modulation system.
For convenience, the embodiment of the present application will be illustrated so that OMCM is ACO-OFDM modulation as an example, but the application It is not limited to this.
During a kind of realization, a kind of specific implementation that transmitting terminal generates the process flow of bipolar signal can be such as figure Shown in 3.In Fig. 3, XkFor data to be transmitted, N is the sub-carrier number of ACO-OFDM system, while being also that IFFT calculates points.Letter Singly it is described as follows:
Transmitting terminal can be layered multichannel subcarrier according to preset rules.Optionally, the quantity of layer is less than or equal to The quantity of subcarrier.
Preset rules can there are many kinds of, the embodiment of the present application is not especially limited this.Optionally, preset rules can be with As shown in figure 4, the number of subcarriers of first layer is the 1/2 of total number of subcarriers, the number of subcarriers of the second layer is total subcarrier The 1/4 of quantity, the number of subcarriers of third layer are the 1/8 of total number of subcarriers, wherein every layer of subcarrier all with next layer Subcarrier is orthogonal.It should be understood that Fig. 4 is only example, the restriction to the embodiment of the present application is not constituted.
At this point, in Fig. 3Indicate the data to be transmitted on i-th layer of subcarrier, wherein i=1,2 ..., L, L table Show that subcarrier has been divided into L layers by transmitting terminal.
Then, transmitting terminal can carry out OMCM modulation to the data to be transmitted on each layer of subcarrier.
Specifically, transmitting terminal can carry out constellation mapping to each layer of data to be transmitted.Wherein, constellation mapping can be with Including binary phase shift keying (binary phase shift keying, BPSK), quadrature phase shift keying (quadrature Phase shift keyin, QPSK), 16QAM, 64QAM, 256QAM and 1024QAM etc..
Later, transmitting terminal carries out Hermitian mapping, available satisfaction to each layer of the symbol by constellation mapping Then the ACO-OFDM signal of Hermitian symmetrical structure can carry out IFFT to the signal for meeting Hermitian symmetrical structure It is handled with CP is added.
It should be understood that for the VLC system using intensity modulated technology, O-OFDM signal needs for real signal, transmitting terminal pair The signal for meeting Hermitian symmetrical structure carries out IFFT and handles available real signal.
It should also be understood that signal in transmission process, might have various barriers in the path between transmitting terminal to receiving end Hinder and has various machines and furniture etc. in the presence of object and reflector, such as indoor transmissions environment, it can be to the transmission characteristic of signal Very big influence is caused, will cause reflection, refraction and scattering of signal etc..For receiving end, may receive come from it is more The signal with out of phase and delay of paths, adds CP processing can be to avoid multipath bring inter-carrier interference.
After to the layering of multichannel subcarrier, the length of each layer of ACO-OFDM signal in the time domain is all different, often The length of one layer of ACO-OFDM signal is all the 1/2 of upper layer signal length.
Later, transmitting terminal can carry out time domain repetitive extension to each layer of signal, so that each layer of ACO-OFDM believes It is number isometric in the time domain and mutually orthogonal on frequency domain.
Specifically, transmitting terminal can not the ACO-OFDM signal to first layer do time domain repetitive extension, by the second layer ACO-OFDM signal can be with repetitive extension before twice, before being with repetitive extension by the ACO-OFDM signal of third layer Three times, and so on, then can make that each layer of ACO-OFDM signal is isometric in the time domain, mutually orthogonal on frequency domain.
Each layer of ACO-OFDM signal after repetitive extension is overlapped by transmitting terminal, ambipolar so as to obtain It is layered ACO-OFDM (layered ACO-OFDM, LACO-OFDM) signal.
Above-mentioned technical proposal, transmitting terminal are layered multichannel subcarrier, and LACO-OFDM signal is made full use of Odd number subcarriers and even number subcarriers, it is orthogonal close to direct current biasing light so as to so that the band efficiency of system is higher Frequency division multiplexing (direct current biased optical orthogonal frequency division Multiplexing, DCO-OFDM) band efficiency.
During a kind of realization, transmitting terminal can not also be layered multichannel subcarrier, directly to multichannel subcarrier On data to be transmitted carry out constellation mapping, then to meet Hermitian symmetrical structure signal carry out IFFT with plus CP processing Deng.What the OMCM implementation that transmitting terminal is not layered multichannel subcarrier can be layered with reference pair multichannel subcarrier OMCM implementation, details are not described herein again.
In 220, transmitting terminal carries out polarity processing to bipolar signal, obtains unipolar positive signal and reversed polarity Signal.
In the embodiment of the present application, polarity processing can be any polarity processing mode in addition to using direct current biasing.
Optionally, polarity processing can be truncation.It should be understood that truncation is referred to as slicing processing or clipping Processing.
Specifically, the negative loop zero setting of bipolar signal can be obtained positive signal by transmitting terminal；Similarly, The positive portions zero setting of bipolar signal can be obtained polarity reversing signal by transmitting terminal.
In the case where transmitting terminal is layered multichannel subcarrier, transmitting terminal can believe ambipolar LACO-OFDM Number negative loop zero setting, obtain the LACO-OFDM signal of positive polarity；By the positive portions of ambipolar LACO-OFDM signal Zero setting obtains LACO-OFDM (negative LACO-OFDM, NLACO-OFDM) signal of reversed polarity.
It should be noted that the embodiment of the present application carries out time domain repetitive extension to each layer of ACO-OFDM signal and carries out The sequence of polarity processing is with no restrictions.That is, transmitting terminal can be as above content describes, first to each layer ACO-OFDM signal carries out time domain repetitive extension, then carries out polarity processing.Certainly, transmitting terminal can also be to the signal by IFFT After middle addition CP, polarity processing first is carried out to each layer of ACO-OFDM signal, obtains unipolar ACO-OFDM signal.Then Time domain repetitive extension is carried out to each layer of unipolar ACO-OFDM signal, by the ACO- after each layer of time domain repetitive extension Ofdm signal is overlapped, to generate the LACO-OFDM signal of positive polarity and the NLACO-OFDM signal of reversed polarity.
The context that transmitting terminal carries out polarity processing and time domain repetitive extension to each layer of ACO-OFDM signal is only Context in logic, transmitting terminal can also have other processing steps among two processing steps, the application to this not Make specific limit.
Above-mentioned technical proposal transmits the average light power meeting of optical signal due to the O-OFDM signal using direct current biasing It greatly increases, modulation depth can be reduced, the power efficiency of system is caused to reduce.Single polarization processing in the embodiment of the present application avoids Using direct current biasing, the power efficiency of system thereby may be ensured that.
In addition to this, for each layer of ambipolar ACO-OFDM signal, since each subcarrier of the signal is full Sufficient Hermitian symmetrical structure property and odd number subcarriers signal modulation property, if transmitting terminal is to ambipolar ACO- Ofdm signal carries out truncation, and generated truncation noise only will affect the subcarrier mutually orthogonal with channel distortion experienced, and Noise jamming will not be introduced in channel distortion experienced.
Similarly, if carrying out truncation to ambipolar LACO-OFDM signal, upper layer signal truncation is drawn The truncation noise entered only will affect next layer signal subcarrier, the sub-carrier signal without will affect this layer.And in receiving end When demodulating to signal, upper layer signal can be first demodulated, the upper layer signal can be generated later and make an uproar to the truncation of lower layer signal Sound, such next layer signal can subtract the introduced truncation noise of a upper layer signal, so that it is dry to obtain no truncation noise The signal disturbed.
For convenience, following the description will be in the case where transmitting terminal be layered multichannel subcarrier to this The technical solution that application is implemented is illustrated, it should be appreciated that the application is not limited to this.
In 230, transmitting terminal modulates the signal parameter of positive signal and polarity reversing signal.
In the embodiment of the present application, transmitting terminal can by modulate positive signal and polarity reversing signal signal parameter, Single-carrier modulated is realized while realizing multi-carrier modulation.
Optionally, signal parameter may include the ginseng such as the signal power of positive signal and polarity reversing signal, signal period Amount.
In a kind of possible embodiment, when signal parameter is signal power, transmitting terminal can be by modulating positive polarity LACO-OFDM signal and reversed polarity NLACO-OFDM signal signal power realize single-carrier modulated.At this point, single carrier tune It is made as pulse amplitude modulation (pulse amplitude modulation, PAM).
Specifically, transmitting terminal can the LACO-OFDM signal to positive polarity and reversed polarity NLACO-OFDM signal into Row power change of scale.Optionally, power dimensional variation can be respectively by the LACO-OFDM signal of positive polarity and reversed polarity The power of NLACO-OFDM signal power factor corresponding with the first power factor concentration is multiplied.
Optionally, the first power factor collection can be expressed asWherein, N indicates PAM modulation Order of modulation, that is to say, that within a pwm signal period, transmitting terminal can be by the LACO-OFDM signal of positive polarity and anti- The algorithm for power modulation of polar NLACO-OFDM signal is at several level, then N is just several.For example, transmitting terminal is a pwm signal week , can be by the algorithm for power modulation of LACO-OFDM signal and NLACO-OFDM signal at 4 level in phase, then N=4 at this time.
Optionally, the first power factor collection can be preset.
Optionally, VLC system can carry out the first power factor collection according to dimming level (dimming level) pre- If.Illustratively, dimming level can indicate are as follows:
Wherein, γ indicates dimming level, and E (x) indicates desired expression formula, popt(t) it indicates by signal parameter modulation The mean power of O-OFDM symbol, that is, positive polarity LACO-OFDM signal and reversed polarity NLACO-OFDM signal it is flat Equal power, IHFor the high level of PWM voltage signal or the high current of PWM current signal, ILFor PWM voltage signal low level or The low current of PWM current signal, ε are transformation factor, i.e. voltage/current and the power conversion factor.
The value of ε and the value of N are identical, indicate within a pwm signal period, and transmitting terminal is by the LACO- of positive polarity The algorithm for power modulation of ofdm signal and the NLACO-OFDM signal of reversed polarity at multiple level in, each level is to entire level Contribution.
It should be understood that the embodiment of the present application does not limit the title of dimming level, that is to say, that it can also be expressed as it His title.For example, dimming level can also be expressed as dim factor.
Optionally, the first function can be calculated by certain algorithm according to the light modulation demand at current time in transmitting terminal Rate factor set.
It should be noted that the embodiment of the present application is not specifically limited the algorithm, it is any can be according to current time The algorithm that light modulation demand obtains the first power factor is all covered within the scope of protection of this application.
Optionally, transmitting terminal can modulate the LACO-OFDM signal of positive polarity and the NLACO- of reversed polarity by controller The power of ofdm signal.Wherein, controller can include but is not limited to power controller or light adjusting controller etc..
In alternatively possible embodiment, when signal parameter is signal power and signal period, transmitting terminal can lead to Signal power and the signal period for crossing the LACO-OFDM signal of combined modulation positive polarity and the NLACO-OFDM signal of reversed polarity are real Existing single-carrier modulated.At this point, single-carrier modulated is pulse position modulation (pulse position modulation, PPM).
Specifically, within the modulation period of the NLACO-OFDM signal of the LACO-OFDM signal and reversed polarity of positive polarity, Transmitting terminal can carry out power change of scale to LACO-OFDM signal and NLACO-OFDM signal.Optionally, transmitting terminal can divide The power of LACO-OFDM signal and NLACO-OFDM signal power factor corresponding with the second power factor concentration is not multiplied.
Optionally, what the second power factor was concentrated may include power exponentα1And α2, wherein the LACO-OFDM of positive polarity The corresponding power factor of signal is α1, the corresponding power factor of NLACO-OFDM signal of reversed polarity is α2。
Similar with the first power factor collection, the second power factor collection is also possible to transmitting terminal and obtains according to dimming level is default , or it is also possible to transmitting terminal according to the light modulation demand at current time, it is calculated by certain algorithm.It specifically can be with With reference to the generating mode of the first power factor collection, here, in order to avoid repeating, description is omitted.
It optionally, may include timer in transmitting terminal when transmitting terminal carries out PPM modulation.Wherein, timer can be used When power is being carried out to the LACO-OFDM signal of positive polarity or the NLACO-OFDM signal of reversed polarity in notice transmitting terminal Change of scale.
The embodiment of the present application can use { t1,t2,…,tNIndicate the LACO-OFDM signal or reversed polarity of positive polarity The location information that NLACO-OFDM signal occurs in a PPM symbol period.
Wherein, tiValue be 0 or 1,0 indicate PPM symbol period tiThe symbol of a position is low level, and 1 indicates In the t of PPM symbol periodiThe symbol of a position is high level, i=1,2 ..., N.N indicates the order of modulation of PPM, that is, It says, within a PPM signal period, LACO-OFDM signal or reversed polarity of the transmitting terminal in several position modulation positive polaritys NLACO-OFDM signal, then N is equal to several.
For example, being assumed to be 4PPM signal, if { t1,t2,t3,t4}={ 1,0,0,0 }, then it represents that transmitting terminal is accorded in PPM First position in number period is high level, and is low level in the other positions of PPM symbol period.Due to being carried on high level Be minus polarity signal, what is carried in low level is positive signal.Therefore, transmitting terminal is in first position of PPM symbol period The NLACO-OFDM signal of modulation reversed polarity is set, and in the LACO-OFDM letter of the other positions of PPM symbol period modulation positive polarity Number.At this point, how many period timer can calculate, when having arrived first position of PPM symbol period, can notify to send First position of end PPM symbol period is arrived, then transmitting terminal can be by the power and α of the NLACO-OFDM signal of reversed polarity2 It is multiplied, in other positions transmitting terminal then by the power and α of the LACO-OFDM signal of positive polarity1It is multiplied.Wherein, in 4PPM signal 4 can indicate 4 PPM symbols.
It should be noted that the signal power in low level is identical, the signal function on high level when carrying out PPM modulation Rate is identical, therefore only needs two level, and only there are two power factors for the second power factor concentration: α1And α2。
It should be understood that in the embodiment of the present application, " first " and " second " be not but right just to distinguish different objects The range of the embodiment of the present application is construed as limiting.
Above-mentioned technical proposal, transmitting terminal are realized by modulation bipolar signal and its signal parameter of polarity reversing signal Light single-carrier modulated, so as to improve the band efficiency of system.In addition, during realizing light single-carrier modulated, nothing Modulation power need to additionally be increased, this improves the power efficiencies of system.
Optionally, this method can also include: that transmitting terminal carries out the signal on every subcarriers in multichannel subcarrier Power control.Further, transmitting terminal can also carry out power to each layer of ACO-OFDM signal in layered structure Control.
As an example, transmitting terminal can be by carrying out power control by change of scale to the signal on every subcarriers System, or power control is carried out by change of scale to each layer of ACO-OFDM signal.That is, transmitting terminal can will be every The power of ACO-OFDM on subcarriers respectively with change of scale fac-tor corresponding in change of scale factor set, or will The power of each layer of ACO-OFDM signal respectively with change of scale fac-tor corresponding in change of scale factor set.
Optionally, change of scale factor set { β1,β2,…,βLCan be preset according to dimming level, it can also basis Change of scale factor set is calculated by certain algorithm in the light modulation demand at current time.Wherein, β1Indicate that the first straton carries The change of scale factor of ACO-OFDM signal on wave, β2Indicate the change of scale of the ACO-OFDM signal on second layer subcarrier The factor, and so on, βLIndicate the change of scale factor of the ACO-OFDM signal on second layer subcarrier.
It should be understood that the change of scale factor of the ACO-OFDM signal on different layers may be the same or different, the application This is not limited.
Optionally, transmitting terminal can carry out power control to ACO-OFDM signal by amplifier and attenuator.
When transmitting terminal needs to amplify the power of ACO-OFDM signal, amplifier can be used and amplify；Work as transmitting terminal When needing to reduce the power of ACO-OFDM signal, attenuator can be used and decay.
Optionally, when ACO-OFDM signal is current signal, amplifier can be current amplifier；When ACO-OFDM believes Number be voltage signal when, amplifier can be voltage amplifier.
Optionally, it may include control at least one of the following: OMCM signal that transmitting terminal, which carries out power control to signal, Signal power, OMCM signal polarity reversing signal signal power, OMCM modulation in each straton carrier wave signal power, or The signal power of each straton carrier wave in the reversed polarity modulation of person OMCM modulation.
It should be noted that needing to guarantee that ACO-OFDM believes when transmitting terminal carries out power control to ACO-OFDM signal Number mean power remain unchanged.
As another example, transmitting terminal can carry out power control by controlling the bit wide of pwm signal.
The embodiment of the present application, which does not do transmitting terminal by the specific implementation that the bit wide of control pwm signal carries out power control, to be had Body limits.It should be understood that any can realize that the implementation of power control is all covered in this Shen by controlling the bit wide of pwm signal Within protection scope please.
Above-mentioned technical proposal, transmitting terminal by by every subcarriers signal and change of scale fac-tor, Lai Shixian Power control can make full use of the range of linearity of light source, so that the precision level of light modulation is higher, can have bigger, more flexible Dimming scope.
In 240, the positive signal of process and polarity reversing signal are modulated on pwm signal by transmitting terminal, are supported The Hybrid-modulated Signal of brightness adjustment control.
Transmitting terminal can believe modulated positive polarity after the signal parameter of modulation positive signal and polarity reversing signal Number and polarity reversing signal be modulated in the low level and high level of pwm signal respectively.
That is, transmitting terminal can be by the LACO-OFDM signal modulation of the positive polarity through overpower change of scale to PWM In the low level of signal, by the height electricity of the NLACO-OFDM signal modulation of the reversed polarity through overpower change of scale to pwm signal On flat, so as to obtain supporting the Hybrid-modulated Signal of brightness adjustment control.
In 250, transmitting terminal sends the Hybrid-modulated Signal for supporting brightness adjustment control to receiving end.
The Hybrid-modulated Signal of generation can be changed into optical signal by transmitting terminal, be launched by light wireless communication channel It goes out, so as to complete the transmission of data.
Optionally, after transmitting terminal can amplify the Hybrid-modulated Signal of generation by power amplifier, signal is made to work In the linear work area of LED, for signal after LED becomes light intensity signal, transmitting terminal goes out optical signal launch.
Fig. 5 and Fig. 6 show a kind of possible structural block diagram that transmitting terminal generates the Hybrid-modulated Signal.It should be understood that Fig. 5 It is only example with Fig. 6, does not constitute the restriction to the embodiment of the present application.
It can be seen that, unipolarity can be generated first and be the LACO-OFDM signal of real number for transmitting terminal from Fig. 5 and Fig. 6. Specifically, transmitting terminal first distribute and be layered to multichannel subcarrier according to preset rules, later the signal to each layer QAM modulation has been carried out, and serioparallel exchange is carried out to each layer of QAM modulation symbol, has then carried out Hermitian mapping, with The ACO-OFDM signal for making each layer of output is all real signal.Later, transmitting terminal is to the signal for meeting Hermitian symmetrical structure Carry out time domain repetitive extension.
Meanwhile transmitting terminal can carry out power control to each layer of ACO-OFDM signal based on preset dimming level, By each layer of ACO-OFDM signal, respectively and after corresponding change of scale fac-tor, transmitting terminal can be by each layer ACO-OFDM signal be overlapped, to generate ambipolar LACO-OFDM signal.
Then, transmitting terminal can carry out truncation to ambipolar LACO-OFDM signal, i.e., by ambipolar LACO- The negative loop zero setting of ofdm signal obtains the LACO-OFDM signal of positive polarity；Just by ambipolar LACO-OFDM signal Value part zero setting obtains the NLACO-OFDM signal of reversed polarity.
Further, as shown in figure 5, transmitting terminal can be by modulating the LACO-OFDM signal and reversed polarity of positive polarity The power of NLACO-OFDM signal, to realize that PAM is modulated, wherein the power scale factor of the LACO-OFDM signal of positive polarity is {α1,…,αN/2, the power scale factor of the NLACO-OFDM signal of reversed polarity is { αN/2+1,…,αN}。
As shown in fig. 6, transmitting terminal can be by modulating the LACO-OFDM signal of positive polarity and the NLACO-OFDM of reversed polarity In the power and signal period of signal, to realize PPM modulation, wherein the power scale factor of the LACO-OFDM signal of positive polarity is α1, the power scale factor of the NLACO-OFDM signal of reversed polarity is { α2}。
Next, the LACO-OFDM signal modulation of the positive polarity through overpower change of scale can be arrived PWM's by transmitting terminal It, will be in the NLACO-OFDM signal modulation to the high level of PWM of the reversed polarity through overpower change of scale in low level, it can Generate the Hybrid-modulated Signal for supporting brightness adjustment control.It then, can be with after transmitting terminal carries out digital-to-analogue conversion to the Hybrid-modulated Signal Signal is launched.
Correspondingly, after receiving end receives optical signal using photoelectric detective circuit, optical signal data can be processed into pair Then the electric analoging signal answered demodulates the signal Jing Guo analog-to-digital conversion, so as to the data transmitted.
Specifically, as shown in fig. 7, optical signal can be turned after PD the or APD detector of receiving end receives optical signal After changing corresponding electric signal into and carrying out signal processing, to obtain supporting the Hybrid-modulated Signal of brightness adjustment control.
After receiving end obtains the Hybrid-modulated Signal, signal synchronization can be carried out to the Hybrid-modulated Signal or symbol is same Step.After synchronizing to Hybrid-modulated Signal, receiving end can also carry out channel estimation, channel equalization, relevant parameter information After verification, receiving end can be demodulated Hybrid-modulated Signal.
Optionally, receiving end can carry out the demodulation of Hybrid-modulated Signal according to parameter information.Wherein, the parameter information It can be parameter information needed for progress Hybrid-modulated Signal.
Optionally, which can include but is not limited to: the period of pwm signal, the duty ratio of pwm signal, light modulation The modulation system of the LACO-OFDM signal of positive polarity on horizontal, every subcarriers with it is anti-on order of modulation, every subcarriers The modulation system and order of modulation, the modulation system of OSCM and order of modulation of polar NLACO-OFDM signal.
Optionally, receiving end can obtain the parameter information according to physical layer frame head and corresponding mapping table.
Specifically, transmitting terminal can indicate the modulation system of ACO-OFDM signal with multiple indicators, carry multichannel The number of plies etc. that wave is divided into, such as multiple indicator are N shared, and the preceding M modulation system that can indicate ACO-OFDM signal is 16QAM, the position (M+1) to L are that can indicate that multichannel subcarrier is divided into 64 layers etc..That is indicator and parameter information has correspondence Relationship, the corresponding relationship can form mapping table.Transmitting terminal can using the indicator as the physical layer frame head of data to be transmitted, To which receiving end can obtain parameter information according to physical layer frame head and corresponding mapping table.
During receiving end demodulates Hybrid-modulated Signal, the demodulation of OSCM signal, i.e. PAM can be first carried out The demodulation of modulated signal or PPM modulation signal.
Optionally, receiving end can be carried out using the receiver for capableing of statistical signal power or energy PAM modulated signal or The demodulation of PPM modulation signal.For example, the receiver can be power. recei ver.
Optionally, receiving end can carry out the solution of PAM modulated signal or PPM modulation signal according to average power detector It adjusts.
Receiving end first carries out the demodulation of OSCM signal, it is possible to reduce OSCM signal to the LACO-OFDM signal of positive polarity and The influence of the NLACO-OFDM signal demodulation of reversed polarity.
After the demodulation of OSCM signal is completed in receiving end, the LACO-OFDM signal and reversed polarity of positive polarity can be carried out The signal polarity of NLACO-OFDM signal judges and Signal separator.
Optionally, receiving end can be solved according to the period of the pwm signal got, the duty ratio of pwm signal and OSCM Signal is adjusted, signal polarity judgement and the signal of the LACO-OFDM signal of positive polarity and the NLACO-OFDM signal of reversed polarity are carried out Separation.
After the Signal separator of the NLACO-OFDM signal for the LACO-OFDM signal and reversed polarity for completing positive polarity, receive End can use demodulating algorithm, and according to parameter information, to the LACO-OFDM signal of positive polarity and the NLACO-OFDM of reversed polarity Signal is demodulated.
As an example, if transmitting terminal is layered multichannel subcarrier, demodulating algorithm can be hierarchical alterative Interference elimination method.
Carry out positive polarity LACO-OFDM signal demodulation when, specifically, receiving end can first carry out l (1≤l < L) the demodulation of layer ACO-OFDM signal can be handled, polarity handles and FFT after the demodulation for completing l layer signal by IFFT Processing generates l layer signal to l+1 layers of truncation noise.The truncation noise generated based on l layers, l+1 layer signal can be with before demodulation It will first be subtracted from l layers of truncation noise, then carry out demodulation process, the demodulation of l+1 layer signal can be completed.With same side Method, receiving end can be to the demodulation of each layer of ACO-OFDM signal, so as to complete the LACO-OFDM signal of positive polarity Demodulation.
Similarly, receiving end can also carry out the demodulation of the NLACO-OFDM signal of reversed polarity by this method, so as to To complete to support the demodulation of the Hybrid-modulated Signal of brightness adjustment control.
Above-mentioned technical proposal, in the case where being layered to multichannel subcarrier, the embodiment of the present application is to each layer of signal When carrying out polarity processing, this layer of polarity, which handles introduced noise, will affect next layer of subcarrier, but not in this layer tune Introduce noise jamming on the subcarrier for the signal made, therefore the demodulating algorithm based on hierarchical alterative interference cancellation techniques can be with The lower bit error rate completes the demodulation of OMCM.
The embodiment of the present application can realize light by modulation bipolar signal and its signal parameter of polarity reversing signal Light single-carrier modulated is realized while multi-carrier modulation, since light single-carrier modulated will not influence light overloading wave modulation, light is more The channel efficiency of carrier modulation can remain unchanged, and light single-carrier modulated be realized by way of modulating part signal parameter, again Data can be passed, the band efficiency that system is given can be close to η ≈ log more2N+ηDCO, wherein ηDCOFor DCO-OFDM modulation Channel efficiency, so that the channel efficiency of system can be improved using the mixing superposition modulated of light multicarrier and light single carrier.
Method provided by the embodiments of the present application is described in detail above, in order to realize that above-mentioned the embodiment of the present application mentions Each function in the method for confession, transmitting terminal may include hardware configuration and/or software module, with hardware configuration, software module or Hardware configuration adds the form of software module to realize above-mentioned each function.Some function in above-mentioned each function is with hardware configuration, soft Part module or hardware configuration add the mode of software module to execute, the specific application and design constraint depending on technical solution Condition.
Based on inventive concept same as above method embodiment, the embodiment of the present application provides a kind of brightness adjustment control dress It sets, for realizing the function of transmitting terminal in the above method.Fig. 8 is the schematic block diagram of the embodiment of the present application device.It should be understood that figure Light adjusting and controlling device 800 shown in 8 is only example, the light adjusting and controlling device of the embodiment of the present application can also include other modules or Unit perhaps includes intimate module with the modules in Fig. 8 or does not really want to include all modules in Fig. 8.
First modulation module 810 obtains double for carrying out light multi-carrier modulation to the data to be transmitted on multichannel subcarrier Polar signal
Processing module 820, the bipolar signal for obtaining to the first modulation module 810 carry out polarity processing, obtain list Polar positive signal and polarity reversing signal.
Second modulation module 830, the signal of the positive signal and polarity reversing signal that are obtained for modulation treatment module 820 Parameter.
Generation module 840, for by through ovennodulation positive signal and polarity reversing signal be modulated to pwm signal, obtain To the Hybrid-modulated Signal for supporting brightness adjustment control.
Communication module 850, for sending the hybrid modulation letter for the support brightness adjustment control that generation module 840 generates to receiving end Number.
Optionally, signal parameter may include signal power and the signal period of positive signal and polarity reversing signal.
Optionally, when the signal parameter is signal power, which specifically can be used for: will locate The power of positive signal and polarity reversing signal that reason module 820 obtains respectively power corresponding with the first power factor concentration because Son is multiplied, wherein the first power factor collection is preset according to dimming level.
Optionally, when signal parameter is signal power and signal period, which can specifically be used In: within the modulation period of positive signal and polarity reversing signal that processing module 820 obtains, by positive signal and reversed polarity Power factor corresponding with the second power factor concentration is multiplied the power of signal respectively, wherein the second power factor collection is basis Dimming level is preset.
Optionally, dimming level meets formula:Wherein, γ is dimming level, popt(t) for by letter The positive signal of number parameter modulation and the mean power of polarity reversing signal, IHFor the high level or PWM electric current of PWM voltage signal The high current of signal, ILFor the low level of PWM voltage signal or the low current of PWM current signal, ε is transformation factor.
Optionally, which can also include: control module 860, for every in multichannel subcarrier Signal on subcarriers carries out power control.
Optionally, which specifically can be used for: by the power of the signal on every subcarriers respectively with scale Transformation factor concentrates corresponding change of scale fac-tor.
Optionally, which specifically can be used for: by the negative loop zero setting of bipolar signal, obtain anode Property signal；Or by the positive portions zero setting of bipolar signal, obtain polarity reversing signal.
Optionally, which specifically can be used for: be divided multichannel subcarrier according to preset rules Layer；Light multi-carrier modulation is carried out to the data to be transmitted on each layer of subcarrier.
Optionally, which specifically can be used for: to the data to be transmitted on each layer of subcarrier into Planetary mapping, the symbol by constellation mapping meet Hermitian conjugation symmetrical structure；To meeting Hermitian conjugate pair The signal of title carries out inverse fast fourier transform；Cyclic prefix is added in the signal by inverse fast fourier transform；To adding The signal for entering cyclic prefix carries out repetitive extension, obtains bipolar signal.
Optionally, which is specifically used for: the positive signal through ovennodulation is modulated to the low of pwm signal On level or low current；Polarity reversing signal through ovennodulation is modulated on the high level or high current of pwm signal.
It should be understood that the light adjusting and controlling device 800 can execute the movement of transmitting terminal in method provided by the embodiments of the present application, Here, in order to avoid repeating, description is omitted.
The embodiment of the present application also provides a kind of light adjusting and controlling devices for supporting VLC.The light adjusting and controlling device can be branch The terminal device for holding VLC is also possible to support the network equipment of VLC.
As shown in figure 9, the light adjusting and controlling device 900 may include: that one or more processors 910, one or more are deposited Reservoir 920, one or more light adjusting controllers 930, one or more baseband processing modules 940, one or more photodetections Device 960, one or more optical antennas 970.
Wherein, memory 920, for storing program instruction.
Processor 910, the method that can be used for realizing above-mentioned brightness adjustment control according to the program instruction stored in memory 920 In power.
Light adjusting controller 930 can be used for generating corresponding dimming control signal according to light modulation demand.
Optical antenna 970 can be used for receiving light intensity signal, and the light intensity signal be sent to photodetector 960.
Photodetector 960 can be used for converting light intensity signal to the electric signal with biasing, and will be with the telecommunications biased Number it is sent to baseband processing module 940, wherein the electric signal with biasing can be for current signal that band-offset is set or with the electricity of biasing Press signal.
Baseband processing module 940 can be used for carrying out baseband signal channel coding, symbol mapping, multi-carrier modulation, and Generate physical-layer data frame.Also, the baseband processing module 940 can be also used for synchronizing place to the electric signal received The base band signal process such as reason, channel estimation, channel equalization, multicarrier demodulation, symbol de-maps, channel coding.
Optionally, which can also include one or more RF transceivers 990, for receiving or Send radio frequency signal.
It should be noted that processor 910, memory 920, light adjusting controller 930, baseband processing module 940, photoelectricity are visited It surveys device 960 to connect with RF transceiver 990 by bus, to realize that data mutually pass.The bus can be divided into address bus, Data/address bus, control bus etc..
In addition, the case where being the network equipment for the light adjusting and controlling device 900, which can also be wrapped Include one or more communication interfaces 980.The communication interface 980 can be used for receiving the support light modulation of other network equipments transmission The Hybrid-modulated Signal of control, and the Hybrid-modulated Signal for supporting brightness adjustment control is sent to baseband processing module 940.The communication Interface 980 can be optical fiber link interface, Ethernet interface, microwave link interface and/or copper interfaces etc..
Optionally, the light adjusting and controlling device 900 can also include one or more light source drives 9100 and one or Multiple light sources 950.Wherein, light source drive 9100 can be used for generating DC current or DC voltage, and the number that will be received It is overlapped processing according to frame and DC current or DC voltage, generates the electric signal with biasing, and the electric signal with biasing is sent out To light source 950.Light source 950 can be used for generating light intensity signal according to the electric signal with biasing.
Based on the same technical idea, the embodiment of the present application also provides a kind of computer readable storage mediums, including refer to It enables, when instruction is run on computers, computer is made to execute method performed by above-mentioned light adjusting and controlling device.
In the embodiment of the present application, processor can be central processing unit (central processing unit, CPU), General processor network processing unit (network processor, NP), digital signal processor (digital signal Processing, DSP), microprocessor, microcontroller, programmable logic device (programmable logic device, ) or their any combination PLD.
In the embodiment of the present application, memory can be volatile memory (volatile memory), such as deposit at random Access to memory (random-access memory, 9RAM)；Memory also may include nonvolatile memory (non- Volatile memory), such as flash memory (flash memory), hard disk (hard disk drive, HDD) or solid-state Hard disk (solid-state drive, SSD)；Memory can also be the combination of the memory of mentioned kind.Memory can be Can be used in carry or store have instruction or data structure form desired program code and can be by computer access Any other medium, but not limited to this.
It should be understood that in various embodiments of the present invention, magnitude of the sequence numbers of the above procedures are not meant to execute suitable Sequence it is successive, the execution of each process sequence should be determined by its function and internal logic, the implementation without coping with the embodiment of the present invention Process constitutes any restriction.
It is apparent to those skilled in the art that for convenience and simplicity of description, the system of foregoing description, The specific work process of device and unit, can refer to corresponding processes in the foregoing method embodiment, and details are not described herein.
In several embodiments provided herein, it should be understood that disclosed systems, devices and methods, it can be with It realizes by another way.For example, the apparatus embodiments described above are merely exemplary, for example, the unit It divides, only a kind of logical function partition, there may be another division manner in actual implementation, such as multiple units or components It can be combined or can be integrated into another system, or some features can be ignored or not executed.Another point, it is shown or The mutual coupling, direct-coupling or communication connection discussed can be through some interfaces, the indirect coupling of device or unit It closes or communicates to connect, can be electrical property, mechanical or other forms.
The unit as illustrated by the separation member may or may not be physically separated, aobvious as unit The component shown may or may not be physical unit, it can and it is in one place, or may be distributed over multiple In network unit.It can select some or all of unit therein according to the actual needs to realize the mesh of this embodiment scheme 's.
It, can also be in addition, each functional unit in each embodiment of the application can integrate in one processing unit It is that each unit physically exists alone, can also be integrated in one unit with two or more units.
It, can be wholly or partly by software, hardware, firmware or it is any in method provided by the embodiments of the present application Combination is to realize.When implemented in software, it can entirely or partly realize in the form of a computer program product.The meter Calculation machine program product includes one or more computer instructions.Load and execute on computers the computer program instructions When, it entirely or partly generates according to process or function described in the embodiment of the present invention.The computer can be general-purpose computations Machine, special purpose computer, computer network, the network equipment, user equipment or other programmable devices.The computer instruction can To store in a computer-readable storage medium, or computer-readable deposit from a computer readable storage medium to another Storage media transmission, for example, the computer instruction can pass through from a web-site, computer, server or data center Wired (such as coaxial cable, optical fiber, Digital Subscriber Line (digital subscriber line, DSL)) or wireless (for example, it is red Outside, wirelessly, microwave etc.) mode transmitted to another web-site, computer, server or data center.The calculating Machine readable storage medium storing program for executing can be any usable medium or include one or more usable mediums that computer can access The data storage devices such as integrated server, data center.The usable medium can be magnetic medium (for example, floppy disk, hard Disk, tape), optical medium (for example, digital video disk (digital video disc, DVD)) or semiconductor medium (example Such as, SSD) etc..
The above, the only specific embodiment of the application, but the protection scope of the application is not limited thereto, it is any Those familiar with the art within the technical scope of the present application, can easily think of the change or the replacement, and should all contain Lid is within the scope of protection of this application.Therefore, the protection scope of the application should be based on the protection scope of the described claims.

Claims (23)

1. a kind of method of brightness adjustment control characterized by comprising
Transmitting terminal carries out light multi-carrier modulation to the data to be transmitted on multichannel subcarrier, obtains bipolar signal；
The transmitting terminal carries out polarity processing to the bipolar signal, obtains unipolar positive signal and reversed polarity letter Number；
The transmitting terminal modulates the signal parameter of the positive signal and polarity reversing signal, obtains the anode through ovennodulation Property signal and polarity reversing signal；
The positive signal through ovennodulation and polarity reversing signal are modulated to pulse width modulation (PWM) signal by the transmitting terminal On, obtain the Hybrid-modulated Signal for supporting brightness adjustment control；
The transmitting terminal sends the Hybrid-modulated Signal for supporting brightness adjustment control to receiving end.
2. the method according to claim 1, wherein the signal parameter includes the positive signal and antipole The signal power of property signal and signal period.
3. according to the method described in claim 2, it is characterized in that, when the signal parameter be signal power when, the transmission Modulate the signal parameter of the positive signal and polarity reversing signal in end, comprising:
The transmitting terminal is corresponding with the first power factor concentration respectively by the power of the positive signal and polarity reversing signal Power factor is multiplied, and the first power factor collection is preset according to dimming level.
4. according to the method described in claim 2, it is characterized in that, when the signal parameter is signal power and signal period When, the transmitting terminal modulates the signal parameter of the positive signal and polarity reversing signal, comprising:
Within the modulation period of the positive signal and polarity reversing signal, the transmitting terminal is by the positive signal and antipole Property signal power corresponding with the second power factor concentration power factor is multiplied respectively, the second power factor collection is basis Dimming level is preset.
5. the method according to claim 3 or 4, which is characterized in that the dimming level meets formula:
Wherein, γ is dimming level, poptIt (t) is the positive signal modulated by signal parameter and polarity reversing signal Mean power, IHFor the high level of PWM voltage signal or the high current of PWM current signal, ILFor the low level of PWM voltage signal Or the low current of PWM current signal, ε are transformation factor.
6. the method according to any one of claims 1 to 5, which is characterized in that the method also includes:
The transmitting terminal carries out power control to the signal on every subcarriers in the multichannel subcarrier.
7. according to the method described in claim 6, it is characterized in that, the transmitting terminal is to every way in the multichannel subcarrier Signal on carrier wave carries out power control, comprising:
The transmitting terminal by the power of the signal on every subcarriers respectively with corresponding scale in change of scale factor set Transformation factor is multiplied.
8. method according to any one of claim 1 to 7, which is characterized in that the transmitting terminal believes the bipolarity Number carry out polarity processing, obtain unipolar positive signal and polarity reversing signal, comprising:
The negative loop zero setting of the bipolar signal is obtained the positive signal by the transmitting terminal；Or
The positive portions zero setting of the bipolar signal is obtained the polarity reversing signal by the transmitting terminal.
9. method according to any one of claim 1 to 8, which is characterized in that the transmitting terminal is on multichannel subcarrier Data to be transmitted carry out light multi-carrier modulation, comprising:
The multichannel subcarrier is layered by the transmitting terminal according to preset rules；
The transmitting terminal carries out light multi-carrier modulation to the data to be transmitted on each layer of subcarrier.
10. according to the method described in claim 9, it is characterized in that, the transmitting terminal is to be passed on each layer of subcarrier Transmission of data carries out light multi-carrier modulation, comprising:
The transmitting terminal carries out constellation mapping, the symbol by constellation mapping to the data to be transmitted on each layer of subcarrier Number meet hermitian Hermitian conjugation symmetrical structure；
The transmitting terminal is conjugated symmetrical signal progress inverse fast fourier transform to Hermitian is met；
Cyclic prefix is added in the signal by inverse fast fourier transform in the transmitting terminal；
The transmitting terminal carries out repetitive extension to the signal that cyclic prefix is added, and obtains the bipolar signal.
11. method according to any one of claim 1 to 10, which is characterized in that the transmitting terminal will be through ovennodulation The positive signal and polarity reversing signal are modulated on pulse width modulation (PWM) signal, comprising:
The positive signal through ovennodulation is modulated in the low level or low current of pwm signal by the transmitting terminal；
The polarity reversing signal through ovennodulation is modulated on the high level or high current of pwm signal by the transmitting terminal.
12. a kind of light adjusting and controlling device characterized by comprising
First modulation module obtains bipolarity letter for carrying out light multi-carrier modulation to the data to be transmitted on multichannel subcarrier Number；
Processing module obtains unipolar positive signal and reversed polarity for carrying out polarity processing to the bipolar signal Signal；
Second modulation module, the signal for modulating the positive signal and polarity reversing signal that the processing module obtains are joined Amount, obtains the positive signal and the polarity reversing signal through ovennodulation；
Generation module, for the positive signal through ovennodulation and polarity reversing signal to be modulated to pulse width modulation (PWM) On signal, the Hybrid-modulated Signal for supporting brightness adjustment control is obtained；
Communication module, for sending the Hybrid-modulated Signal for supporting brightness adjustment control to receiving end.
13. device according to claim 12, which is characterized in that the signal parameter includes the positive signal and anti- The signal power of polar signal and signal period.
14. device according to claim 13, which is characterized in that when the signal parameter is signal power, described the Two modulation modules are specifically used for:
By the power of the positive signal and polarity reversing signal power factor phase corresponding with the first power factor concentration respectively Multiply, the first power factor collection is preset according to dimming level.
15. device according to claim 13, which is characterized in that when the signal parameter is signal power and signal period When, second modulation module is specifically used for:
Within the modulation period of the positive signal and polarity reversing signal, by the function of the positive signal and polarity reversing signal Power factor corresponding with the second power factor concentration is multiplied rate respectively, and the second power factor collection is pre- according to dimming level If.
16. device according to claim 14 or 15, which is characterized in that the dimming level meets formula:
Wherein, γ is dimming level, poptIt (t) is the positive signal modulated by signal parameter and polarity reversing signal Mean power, IHFor the high level of PWM voltage signal or the high current of PWM current signal, ILFor the low level of PWM voltage signal Or the low current of PWM current signal, ε are transformation factor.
17. device described in any one of 2 to 16 according to claim 1, which is characterized in that described device further include:
Control module, for carrying out power control to the signal on every subcarriers in the multichannel subcarrier.
18. device according to claim 17, which is characterized in that the control module is specifically used for:
By the power of the signal on every subcarriers respectively with change of scale factor phase corresponding in change of scale factor set Multiply.
19. device described in any one of 2 to 18 according to claim 1, which is characterized in that the processing module is specifically used for:
By the negative loop zero setting of the bipolar signal, the positive signal is obtained；Or
By the positive portions zero setting of the bipolar signal, the polarity reversing signal is obtained.
20. device described in any one of 2 to 19 according to claim 1, which is characterized in that first modulation module is specifically used In:
Multichannel subcarrier is layered according to preset rules；
Light multi-carrier modulation is carried out to the data to be transmitted on each layer of subcarrier.
21. device according to claim 20, which is characterized in that first modulation module is specifically used for:
Constellation mapping is carried out to the data to be transmitted on each layer of subcarrier, the symbol by constellation mapping meets Hermitian Hermitian is conjugated symmetrical structure；
Symmetrical signal progress inverse fast fourier transform is conjugated to Hermitian is met；
Cyclic prefix is added in the signal by inverse fast fourier transform；
Repetitive extension is carried out to the signal that cyclic prefix is added, obtains bipolar signal.
22. device described in any one of 2 to 21 according to claim 1, which is characterized in that the generation module is specifically used for:
The positive signal through ovennodulation is modulated in the low level or low current of pwm signal；
The polarity reversing signal through ovennodulation is modulated on the high level or high current of pwm signal.
23. a kind of computer readable storage medium, including instruction, when run on a computer, so that the computer is held Method of the row as described in any one of claims 1 to 11.
CN201810704408.5A 2018-02-13 2018-06-30 Dimming control method and device Active CN110166122B (en)

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CN112751613A (en) * 2020-12-31 2021-05-04 南京信息工程大学 Adjustable light self-adaptive bias O-OFDM transmission method based on PWM
CN113691480A (en) * 2021-08-25 2021-11-23 哈尔滨工业大学 Multi-carrier sending method and receiving method based on multi-layer orthogonal modulation
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CN105812056A (en) * 2016-04-28 2016-07-27 清华大学 Visible light communication method and device aiming at dimming control

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CN104753604A (en) * 2013-12-27 2015-07-01 富士通株式会社 Optical Communication System, Method For Controlling Optical Communication, And Optical Transmitter
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CN112511238A (en) * 2020-12-28 2021-03-16 南京信息工程大学 Adaptive bias layered optical OFDM method based on IM/DD
CN112751613A (en) * 2020-12-31 2021-05-04 南京信息工程大学 Adjustable light self-adaptive bias O-OFDM transmission method based on PWM
CN112751613B (en) * 2020-12-31 2022-02-15 南京信息工程大学 Adjustable light self-adaptive bias O-OFDM transmission method based on PWM
CN113691480A (en) * 2021-08-25 2021-11-23 哈尔滨工业大学 Multi-carrier sending method and receiving method based on multi-layer orthogonal modulation
CN113691480B (en) * 2021-08-25 2024-03-19 哈尔滨工业大学 Multi-carrier transmitting method and receiving method based on multi-layer orthogonal modulation
CN117978286A (en) * 2024-04-01 2024-05-03 南京信息工程大学 Preprocessing ABLO-OFDM method, device, medium and equipment integrating high-precision dimming
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