CN105450577B - A kind of filter bank multi-carrier visible light communication system and method based on direct current biasing - Google Patents
A kind of filter bank multi-carrier visible light communication system and method based on direct current biasing Download PDFInfo
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- CN105450577B CN105450577B CN201510882159.5A CN201510882159A CN105450577B CN 105450577 B CN105450577 B CN 105450577B CN 201510882159 A CN201510882159 A CN 201510882159A CN 105450577 B CN105450577 B CN 105450577B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2626—Arrangements specific to the transmitter only
- H04L27/2627—Modulators
- H04L27/264—Pulse-shaped multi-carrier, i.e. not using rectangular window
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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
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/06—Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection
- H04L25/061—Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection providing hard decisions only; arrangements for tracking or suppressing unwanted low frequency components, e.g. removal of dc offset
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Abstract
The invention discloses a kind of filter bank multi-carrier visible light communication system and method based on direct current biasing, the system includes transmitting terminal and receiving terminal, its core is respectively the processing of synthesis filter group and analysis filter group processing module, by using the sub-band synthesis filter of real-valued coefficient, meet the requirement for sending that signal is real value, and by using direct current biasing, further meet the requirement for sending that signal is positive value, to which filter bank multi-carrier technology is successfully applied to visible light communication.Compared to the existing visible light communication system based on OFDM multicarriers, there are two apparent advantages for system tool provided by the invention：It on the one hand need not be to transmission data block additional cycles prefix, to save transmission power and improve spectrum utilization efficiency；On the other hand carried system can support asynchronous transfer mode well, to increase the flexibility of system design, reduce the requirement synchronized to system sending and receiving end, advantageously reduce system cost of implementation.
Description
Technical field
The invention belongs to visible light communication field more particularly to a kind of filter bank multi-carrier based on direct current biasing are visible
Optical communication system and method.
Background technology
Currently, visible light communication (VLC, Visible as one of the 5th generation cellular mobile communication (5G) key technology
Light Communication) just as the research hotspot of mobile communication field.Compared to existing radio-frequency range communication system,
Visible light communication, which has, exempts from that frequency spectrum is authorized, latent capacity is high, Electro Magnetic Compatibility is good, safe and secret, harmless and carry simultaneously
For many advantages such as illuminations.
Visible light communication can be divided into relevant (Coherent) visible light communication and incoherent according to the coherence of transceiver
(Non-Coherent) visible light communication.Technology and methods and radio communication used in relevant visible light communication are almost consistent, and
IM/DD (intensity modulated/directly detection) communication plan is then very different with radio communication.It is logical compared to relevant visible light
Letter, incoherent visible light communication need not modulate and restore reference carrier, it is easier to realize, equipment cost is lower, be it is a kind of very
Competitive communication plan.Incoherent visible light communication it is main be achieved in that the detection of intensity modulated/directly (IM/DD,
Intensity Modulation/Direct Detection), i.e., the intensity of the optical signal sent out modulates information in light source
(Intensity) it is transmitted on, the variation of light intensity is detected using photodetector to restore original information in receiving terminal.
Therefore, IM/DD communication modes require signal to be sent to be necessary for real number and be nonnegative number, to meet the physical significance of luminous intensity.
It is worth noting that, IM/DD communication plans can be applied in the visible light wireless communication based on light emitting diode (LED),
It can also apply in the visible light wire communication based on optical fiber.Transmission letter corresponding to the system communicated using IM/DD modes
Road is generally known as IM/DD channels.
In view of the importance of IM/DD communication modes, technology contents of the invention are defined in IM/DD communication modes, are announced
System and method be suitable for IM/DD channels, including radio communication channel and wire communication channel.
Fully to excavate the potentiality of visible light communication, the typical case as multicarrier (MC, Multi-Carrier) technology realizes
Scheme, orthogonal frequency division multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) technology by
It is widely used in visible light communication.Under the scope of IM/DD communication modes, carried successively there are many typical optical OFDM system
Go out, including direct current biasing light OFDM (DCO-OFDM, Direct Current Optical OFDM), asymmetric amplitude limit light OFDM
(ACO-OFDM, Asymmetrically Clipped Optical OFDM), amplitude modulate Discrete Multitone (PAM-DMT, Pulse
Amplitude Modulation Discrete Multi Tone), reversion OFDM (Flip-OFDM) and enhance unipolarity
OFDM (eU-OFDM, enhanced Unipolar OFDM) etc..
Although these above-mentioned optical OFDM systems achieve preferable performance, however, they still have asking for some general character
Topic.Typical problem includes：1) these optical OFDM systems be required for when data transmission additional cycles prefix (CP,
Cyclic Prefix), in order to eliminate intersymbol interference, still, on the one hand the introducing of CP increases transmission power, on the other hand
Sending time is extended, to reduce spectrum efficiency；2) ofdm system needs each subcarrier stringent synchronization, does not support asynchronous
Transmission mode, this so that these optical OFDM systems are very strict to synchronous requirement in the case of for multi-user communication, this
Very big challenge can be brought to the design of sending and receiving end, also limit the flexibility of system.
Therefore, it is necessary to a kind of technical solutions that can overcome above-mentioned smooth OFDM defects.
As another exemplary implementation of multi-transceiver technology, filter bank multi-carrier (FBMC, Filter Bank
Multi-Carrier) technology also receives the extensive concern of industry in recent years, and as the alternative of replacement OFDM in 5G researchs
Scheme.This can preferably overcome the drawbacks described above of OFDM just because of FBMC：FBMC need not add CP, each subcarrier
Data flow on (also referred to as subband) is without stringent synchronization.However, although the research of FBMC is in Radio-Frequency Wireless Communication
Carry out extensively, in visible light communication, coherent communication that is seldom, and being only limitted under wire channel is reported in the research about FBMC
In mode.Under IM/DD communication modes, either wired or wireless communication is showed no correlative theses or patent literature.
How FBMC systems are designed under IM/DD channels, while overcoming the defect of optical OFDM system, be still one and urgently to be resolved hurrily ask
Topic.
Invention content
For existing optical OFDM system under IM/DD communication modes need additional CP with to synchronize require stringent defect, this
Invention provides a kind of filter bank multi-carrier visible light communication system and method based on direct current biasing, can overcome existing system
The defect of system.
To achieve the above object of the invention, the technical scheme is that：A kind of filter bank multi-carrier based on direct current biasing
Wave visible light communication system, including transmitting terminal and receiving terminal；
The transmitting terminal, including：
Interface and cache module, for being received from applications and caching the message bit stream to be transmitted；
Digital baseband preprocessing module generates multiplexing symbol stream for being pre-processed to message bit stream；
Synthesis filter group processing module, for carrying out synthesis filter group to the multiplexing symbol stream to be transmitted
Processing a so that son for being loaded into filter group respectively per stream of modulation symbols all the way takes, and is superimposed generation multicarrier all the way
Digital signal streams；
Numeral/analog conversion module generates mould for carrying out digital-to-analog conversion to the digital signal streams to be transmitted
Quasi- signal；
Biasing and drive circuit module, for being amplified to analog signal, while additional direct current biasing so that pass through
The normal work section of analog signal and light source after amplification and biasing matches；
Light source, for shining under the driving of the simulation electrical domain signal by amplification and biasing, to which electrical domain letter will be simulated
Number light intensity signal is converted to, and is sent in visible light communication channel；
The receiving terminal includes：
Photoelectric converter and its drive circuit module, for converting the light intensity signal received by photoelectric converter
For electric signal；
Amplification filter module makes its signal width for the electrical domain signal after opto-electronic conversion to be amplified and filtered
Degree is in the operation interval for being followed by analog-to-digital converting module, while filtering out DC component and out-of-band noise；
Analog-to-digital converting module carries out analog/digital conversion for that will amplify filtered analog electrical signal, generates
Digital electrical domain signal is handled convenient for receiver；
Analysis filter group processing module will be more all the way for carrying out analysis filter group processing to digital electrical domain signal
Carrier signal is decomposed into the symbol stream of multidiameter delay transmission again；
Balance module, the every of multidiameter delay symbol stream for being exported to analysis filter group carry out equalization operation all the way,
Eliminate the influence that channel distortions generate signal；
Digital baseband post-processing module, for being post-processed by balanced multidiameter delay symbol stream, recovering original
The message bit stream all the way come；
Caching and interface module, for cache information bit stream and are sent to external object application.
Further, the digital baseband preprocessing module specifically includes：
Modulation module generates stream of modulation symbols for carrying out pulse amplitude modulation to bit stream；
Serioparallel exchange module high speed symbol stream will be converted into multichannel all the way for carrying out serioparallel exchange to stream of modulation symbols
Parallel low-rate modulation symbol stream；
The digital baseband post-processing module specifically includes：
Parallel serial conversion module, the multidiameter delay low speed symbol stream for exporting analysis filter group carry out parallel-serial conversion,
Form the symbol stream of high speed all the way；
Symbol judgement module carries out symbol judgement, pulse width of the output by judgement for the high speed symbol stream to input
Spend stream of modulation symbols；
Demodulation module solves planisphere mapping for being demodulated to the pulse amplitude modulation symbol stream after judgement, from
And stream of modulation symbols is demodulated into corresponding bit stream.
Further, before the modulation module of digital baseband preprocessing module, coding module and interleaving block is added；
Coding module increases the reliability of transmission for carrying out channel coding to message bit stream；
Interleaving block increases for being interleaved processing to the message bit stream after coding and resists continuous burst error energy
Power；
After the demodulation module of digital baseband post-processing module, de-interleaving block and decoder module is added；
De-interleaving block, for being deinterleaved operation to demodulated bit stream；
Decoder module, for being decoded to the bit stream after deinterleaving, to recover original information bits
Stream.
Further, the synthesis filter group processing module uses the channels the M cosine-modulation with Perfect Reconstruction property
Filter group, specifically includes：The parallel P times of up-sampler in the roads M is up-sampled for carrying out P times to stream of modulation symbols, to generate P
Group image spectra；The roads M parallel subband synthesis filter, frequency response per road sub-band synthesis filter only with front and back adjacent two-way subband
The frequency response of synthesis filter is overlapping, for carrying out sub-band filter to the stream of modulation symbols after up-sampling, takes out corresponding one group of mirror
Picture frequency is composed；Adder generates single channel digital signal streams, is somebody's turn to do for being added to the multiple signals stream after sub-band filter
Road signal contains M way band signals, to constitute filter bank multi-carrier signal；
The analysis filter group processing module uses the channels the M cosine modulated filters group with Perfect Reconstruction property,
It specifically includes：The roads M parallel subband analysis filter, per the corresponding subband integrated filter of the frequency band of road Subband Analysis Filter
Device is identical, for carrying out sub-band filter to the digital electrical domain multi-carrier signal received, takes out in signal and corresponds to the Substrip analysis
Certain section of frequency band of filter, to generate the roads M parallel subband signal；The parallel P times of down-sampler in the roads M, for by subband point
The multichannel subband signal of analysis filtering carries out P times of down-sampling, reduces sampling rate, to which subband spectrum is expanded to entire frequency band,
Generate the parallel low speed symbol stream in the roads M.
Further, in the multi-user mode, each user is used alone in M branch in the synthesis filter group
A part of adjacent branch, a part of adjacent branch in M branch in the analysis filter group is used alone, and
The serial number of the synthesis filter group branch used by a user and analysis filter group branch corresponds.
Further, the subband in the sub-band synthesis filter and the analysis filter group in the synthesis filter group
Analysis filter is all made of real-valued coefficients.
Further, the light source is light emitting diode (LED) or laser diode (LD)；The photoelectric converter is light
Electric diode (PD).
Further, the size of the additional direct current biasing is taken as being attached the k of the standard deviation of the signal of direct current biasing
Times, the interval of k is [Isosorbide-5-Nitrae].
The present invention also provides a kind of the filter bank multi-carrier visible light communication method based on direct current biasing, specific steps
It is as follows：
S1, message bit stream to be transmitted is received from applications；
S2, message bit stream to be transmitted is subjected to numeral pretreatment, including pulse amplitude modulation and serioparallel exchange, generated
The parallel stream of modulation symbols in the roads M；
S3, stream of modulation symbols is subjected to synthesis filter group processing, generates filter bank multi-carrier digital signal；
S4, digital signal is subjected to digital-to-analog conversion, generates analog electrical signal；
S5, direct current biasing is added to analog electrical signal and drives light source luminescent；
S6, the optical signal received is converted into analog electrical signal with photoelectric converter；
S7, analog electrical signal is amplified and is filtered, filter out DC component；
S8, analog/digital conversion is carried out to analog electrical signal, generates digital signal；
S9, analysis filter group processing is carried out to digital signal, generates multidiameter delay symbol stream；
S10, multidiameter delay symbol stream is influenced per equilibrium treatment, elimination channel distortions are carried out all the way；
S11, digital post-processing, including parallel-serial conversion, symbol judgement, solution are carried out to the multidiameter delay symbol stream by equilibrium
It adjusts, recovers original information bits stream；
S12, the message bit stream recovered is sent to intended application.
Further, between step S2 pulse amplitude modulations and serioparallel exchange, coding is added and interweaves, for information
Bit stream carries out channel coding, and is interleaved processing to the message bit stream after coding；After step S11 demodulation, add
Enter deinterleaving and decoding, for being deinterleaved operation to demodulated bit stream, and to the bit after deinterleaving
Stream is decoded, and recovers original information bits stream.To increase the reliability of transmission.
Advantageous effect：
The invention discloses a kind of visible light communication systems based on filter bank multi-carrier suitable for IM/DD communication modes
System and method, compared to existing visible light communication system and method based on OFDM, technical scheme of the present invention has and has as follows
Beneficial effect：
It (1) need not be to data additional cycles prefix, to save transmission power, simultaneously in technical scheme of the present invention
Improve spectrum efficiency；
(2) technical scheme of the present invention supports the symbol stream asynchronous transmission on each subcarrier (i.e. subband), to increase
The flexibility of system design, simplifies the stringent synchronization requirement between transceiver, advantageously reduces the cost of implementation of system.
Description of the drawings
In order to illustrate more clearly of technical scheme of the present invention and embodiment, below in technical solution description and embodiment
Attached drawing to be used is needed to be briefly described.
Fig. 1 is carries the transmitting terminal and receiving terminal frame of the filter bank multi-carrier visible light communication system based on direct current biasing
Figure；
Fig. 2 is carries the flow chart of the filter bank multi-carrier visible light communication method based on direct current biasing；
Fig. 3 is carries the digital baseband of transmitting terminal in the filter bank multi-carrier visible light communication system based on direct current biasing
Preprocessing module block diagram；
Fig. 4 is carries the integrated filter of transmitting terminal in the filter bank multi-carrier visible light communication system based on direct current biasing
Device group processing module block diagram；
Fig. 5 filters to propose the analysis of receiving terminal in the filter bank multi-carrier visible light communication system based on direct current biasing
Device group processing module block diagram；
Fig. 6 is carries the digital baseband of receiving terminal in the filter bank multi-carrier visible light communication system based on direct current biasing
Post-processing module block diagram；
Fig. 7 is to propose the filter bank multi-carrier visible light communication system mesarcs filter based on direct current biasing in embodiment
Wave device hp(n) time domain impulse response；
Fig. 8 is to propose comprehensive filter in the filter bank multi-carrier visible light communication system based on direct current biasing in embodiment
The frequency domain amplitude response of each sub-band synthesis filter in wave device group；Meanwhile each height in analysis filter group in carried system
Frequency domain amplitude response with analysis filter is also identical with Fig. 8；
Fig. 9 is the frequency domain amplitude response of each subcarrier in DCO-OFMD multi-carrier visible light communication systems in embodiment；
Figure 10 is in embodiment, under Gaussian white noise channel and synchronous transfer module, using carrying based on direct current biasing
Filter bank multi-carrier visible light communication system and existing DCO-OFDM visible light communication systems bit error rate curve with than
Special signal-to-noise ratio changes simulation comparison figure；
Figure 11 is in embodiment, under multipath channel and synchronous transfer module, using proposing the filtering based on direct current biasing
The bit error rate curve of device group multi-carrier visible light communication system and existing DCO-OFDM visible light communication systems is with bit noise
Than changing simulation comparison figure；
Figure 12 is in embodiment, under Gaussian white noise channel and asynchronous transfer mode, using carrying based on direct current biasing
Filter bank multi-carrier visible light communication system and existing DCO-OFDM visible light communication systems bit error rate curve with than
Special signal-to-noise ratio changes simulation comparison figure；
Figure 13 is in embodiment, under multipath channel and asynchronous transfer mode, using proposing the filtering based on direct current biasing
The bit error rate curve of device group multi-carrier visible light communication system and existing DCO-OFDM visible light communication systems is with bit noise
Than changing simulation comparison figure；
Wherein：Expression DCO-OFDM system emulations result,Indicate that the carried system and method for the present invention is imitative
True result.
Specific implementation mode
In the following with reference to the drawings and specific embodiments, the present invention is furture elucidated, it should be understood that these embodiments are merely to illustrate
It the present invention rather than limits the scope of the invention, after having read the present invention, those skilled in the art are to of the invention each
The modification of kind equivalent form falls within the application range as defined in the appended claims.
One embodiment of the present of invention gives a kind of filter bank multi-carrier visible light communication system based on direct current biasing
System, for overcoming the existing inherent shortcoming using OFDM multi-carrier mode systems.The system comprises transmitting terminals and receiving terminal；
The transmitting terminal (please referring to Fig.1) includes：
Interface and cache module, for being received from applications and caching the message bit stream to be transmitted；
Digital baseband preprocessing module (please refer to Fig.1 and Fig. 3) generates more for being pre-processed to message bit stream
Road stream of modulation symbols；It specifically includes：Modulation module, for carrying out 4 system pulse amplitude modulation (4-PAM, 4- to message bit stream
Pulse Amplitude Modulation), generate stream of modulation symbols；Serioparallel exchange module, for being carried out to stream of modulation symbols
High speed symbol stream all the way is converted into the low-rate modulation symbol stream of multidiameter delay by serioparallel exchange；
Synthesis filter group processing module (please refer to Fig.1 and Fig. 4), for the multiplexing symbol stream to be transmitted
Carry out synthesis filter group processing so that a son for being loaded into filter group respectively per stream of modulation symbols all the way takes, and folds
Add generation multiple carrier digital signal stream all the way；The synthesis filter group selection uses more than the channels M with Perfect Reconstruction property
Synthesis filter group in string modulated filter group (CMFB, Cosine Modulated Filter Banks)；The parameter M
Value is M=16 (accordingly, up-sampling factor P=16)；M-th, m=1,2 ..., M in the synthesis filter group, son
Coefficient expressions with synthesis filter are：
Wherein, Nf=128, hp(n) it is ptototype filter, value is as shown in fig. 7, fm(n), m=1,2 ..., M, frequency domain
Amplitude response is as shown in figure 8, as shown in Figure 8, the frequency response of each subband is band logical, and only adjacent intersubband, which exists, to be overlapped, no
For adjacent intersubband there is no overlapping (in other words, the maximum amplitude value of overlapping part is minimum, is less than -60dB), this is to be proposed
System supports the major reason of asynchronous transfer mode.And in the existing system based on OFDM multicarriers, each subcarrier has
Very long " hangover " effect (referring to Fig. 9) all exists with other all subcarriers and overlaps (the maximum amplitude value of overlapping part
For -13dB, it is much larger than -60dB), once destroying the orthogonality between subcarrier using asynchronous transfer mode, will cause serious
Inter-sub-carrier interference deteriorates system transmission performance.
Numeral/analog conversion module generates mould for carrying out digital-to-analog conversion to the digital signal streams to be transmitted
Quasi- signal；
Biasing and drive circuit module, for being amplified to analog signal, while additional direct current biasing so that pass through
The normal work section of analog signal and light source after amplification and biasing matches；The direct current biasing value is to be attached direct current
K times of the standard deviation of the signal of biasing；The parameter k values are k=3.5；
Light source, for shining under the driving of the simulation electrical domain signal by amplification and biasing, to which electrical domain letter will be simulated
Number light intensity signal is converted to, and is sent in visible light communication channel；The light source is light emitting diode (LED)；
The receiving terminal (please referring to Fig.1) includes：
Photoelectric converter and its drive circuit module, for converting the light intensity signal received by photoelectric converter
For electric signal；The photoelectric converter is photodiode (PD)；
Amplification filter module makes its signal width for the electrical domain signal after opto-electronic conversion to be amplified and filtered
Degree is in the operation interval for being followed by analog-to-digital converting module, while filtering out DC component and out-of-band noise；
Analog-to-digital converting module carries out analog/digital conversion for that will amplify filtered analog electrical signal, generates
Digital electrical domain signal is handled convenient for receiver；
Analysis filter group processing module (please refer to Fig.1 and Fig. 5), for carrying out analysis filtering to digital electrical domain signal
Multi-carrier signal all the way, is decomposed into the symbol stream of multidiameter delay transmission by the processing of device group again；The analysis filter group selection
Using aforementioned M (M=16, accordingly, down-sampling factor P=16) channel cosine modulated filters group with Perfect Reconstruction property
In analysis filter group；M-th, m=1,2 ..., M in the analysis filter group, the coefficient table of Subband Analysis Filter
It is up to formula：
Wherein, Nf=128, hp(n) value is as shown in Figure 7；hm(n), m=1,2 ..., M, frequency domain amplitude response and fm
(n), m=1,2 ..., M, frequency domain amplitude response it is identical, can refer to Fig. 8.
Balance module：The every of multidiameter delay symbol stream for being exported to analysis filter group carries out equalization operation all the way,
Eliminate the influence that channel distortions generate signal；Equilibrium is equal using single tap based on force zero (ZF, Zero Forcing) criterion
Weighing apparatus, value are the inverse of the channel frequency domain response corresponding to each subband center frequency point；
Digital baseband post-processing module (please refer to Fig.1 and Fig. 6), for being flowed by balanced multidiameter delay symbol
Row post-processing, recovers original message bit stream all the way；It specifically includes：Parallel serial conversion module is used for analysis filter group
The multidiameter delay low speed symbol stream of output carries out parallel-serial conversion, forms the symbol stream of high speed all the way；Symbol judgement module, for pair
The high speed symbol stream of input carries out symbol judgement, 4 system pulse amplitude modulation symbol streams of the output by judgement；Demodulation module,
For being demodulated to the pulse amplitude modulation symbol stream after judgement, that is, planisphere mapping is solved, to demodulate stream of modulation symbols
For corresponding bit stream；
Caching and interface module, for cache information bit stream and are sent to external object application；
Based on above-mentioned visible light communication system, the present invention also provides a kind of filter bank multi-carriers based on direct current biasing
Visible light communication method (please refers to Fig.2), specifically includes：
S1, message bit stream to be transmitted is received from applications；
S2, by message bit stream to be transmitted carry out numeral pretreatment, including 4 system pulse amplitude modulations and go here and there and turn
It changes, generates the parallel stream of modulation symbols in the roads M=16；
S3, stream of modulation symbols is subjected to synthesis filter group processing, generates filter bank multi-carrier digital signal；It is described comprehensive
Filter group is closed using the synthesis filter group in the 16 channel cosine modulated filters groups with Perfect Reconstruction property, filter
Length is 128；
S4, digital signal is subjected to digital-to-analog conversion, generates analog electrical signal；
S5, direct current biasing is added to analog electrical signal and drives light source luminescent；Additional direct current biasing size is letter before biasing
K times of number standard deviation, k values are 3.5；
S6, the optical signal received is converted into analog electrical signal with photoelectric converter；
S7, analog electrical signal is amplified and is filtered, filter out DC component；
S8, analog/digital conversion is carried out to analog electrical signal, generates digital signal；
S9, analysis filter group processing is carried out to digital signal, generates multidiameter delay symbol stream；The analysis filter group
Using the analysis filter group in the 16 channel cosine modulated filters groups with Perfect Reconstruction property, filter length 128；
S10, multidiameter delay symbol stream is influenced per equilibrium treatment, elimination channel distortions are carried out all the way；Equalizer coefficients
Using single tap equalizers based on Zero Forcing, coefficient is the inverse of each subband center point respective channels frequency domain response；
S11, to carrying out digital post-processing by balanced multidiameter delay symbol stream, including parallel-serial conversion, symbol judgement and
Demodulation, recovers original information bits stream；
S12, the message bit stream recovered is sent to intended application.
In the above embodiment of the present invention, by the way that pulse amplitude modulation and cosine modulated filters group is used in combination so that
Send the requirement that signal meets real number value；By using direct current biasing so that transmission signal, which further meets positive, to be asked,
To which successfully filter bank multi-carrier technology is applied in the visible light communication system of IM/DD modes；Compared to existing
Based on the visible light communication system of OFDM multicarriers, the filter bank multi-carrier visible light communication based on direct current biasing that is proposed
System and method has the advantages that without additional CP, intersubband asynchronous transmission, the specific comparison result that quantifies is supported to please refer to Fig.1 0-
Figure 13.
Figure 10 is compared in the above-described embodiments, under Gaussian white noise channel and synchronous transfer module, the base that is proposed
Filter bank multi-carrier visible light communication system in direct current biasing and existing DCO-OFDM multi-carrier visible light communication systems
The simulation curve that bit error rate changes with bit signal-to-noise ratio (Eb/No).Wherein, for the fairness compared, DCO-OFDM's is straight
Stream biasing value is also k=3.5 times of biasing front signal standard deviation, and modulation system is 42=16 ary quadrature amplitudes
(16-QAM, 16-Quadrature Amplitude Modulation), number of sub carrier wave N=2M=32 (selected modulation modes
It ensure that with number of sub carrier wave：DCO-OFDM occupies same frequency band, using same bit transmission rate with carried system),
CP length is G=8.Figure 10 the result shows that, put forward the mistake of the filter bank multi-carrier visible light communication system based on direct current biasing
Bit-rate performance is better than DCO-OFDM systems, which is since carried filter bank multi-carrier visible light communication system is without attached
CP, the transmission power of saving is added to can be used for enhancing the reliability of effective information transmission.
Figure 11 is compared in the above-described embodiments, under multipath channel and synchronous transfer module, proposed based on direct current
The errored bit of the filter bank multi-carrier visible light communication system of biasing and existing DCO-OFDM multi-carrier visible light communication systems
The simulation curve that rate changes with bit signal-to-noise ratio (Eb/No).Wherein, for the fairness compared, the direct current biasing of DCO-OFDM
Value is also k=3.5 times of biasing front signal standard deviation, and modulation system is 42=16 ary quadrature amplitudes (16-QAM,
16-Quadrature Amplitude Modulation), number of sub carrier wave N=2M=32 (selected modulation mode and subcarrier
Number ensure that：DCO-OFDM occupies same frequency band, using same bit transmission rate with carried system), CP length is G
=8.Normalized channel impulse response coefficient is：[0.8945,0.3902,0.1859,0.0951,0.0516,0.0294,
0.0174,0.0107].Figure 11 the result shows that, carry the filter bank multi-carrier visible light communication system based on direct current biasing
Performance of BER is better than DCO-OFDM systems, which is since carried filter bank multi-carrier visible light communication system is not necessarily to
Additional CP, the transmission power of saving can be used for enhancing the reliability of effective information transmission.
Figure 12 is compared in the above-described embodiments, under Gaussian white noise channel and asynchronous transfer mode, the base that is proposed
Filter bank multi-carrier visible light communication system in direct current biasing and existing DCO-OFDM multi-carrier visible light communication systems
The simulation curve that bit error rate changes with bit signal-to-noise ratio (Eb/No).Wherein, for the fairness compared, DCO-OFDM's is straight
Stream biasing value is also k=3.5 times of biasing front signal standard deviation, and modulation system is 42=16 ary quadrature amplitudes
(16-QAM, 16-Quadrature Amplitude Modulation), number of sub carrier wave N=2M=32 (selected modulation modes
It ensure that with number of sub carrier wave：DCO-OFDM occupies same frequency band, using same bit transmission rate with carried system),
CP length is G=8.Under asynchronous mode, it is assumed that there are two users, occupy the subband (for carried system) or son of the first half respectively
The subband or subcarrier of carrier wave (for DCO-OFDM) and later half are isolated using a null subcarrier between two sections of frequency bands
Protection (the present embodiment is using the 1st subband of second user as insulation blocking subband), in addition, what the two users sent
Allow the timing offset for having within 1 sample value symbol between data block, and assumes the timing offset with identical probability random value
It is -1,0 (i.e. zero deflection is equivalent to synchronous transfer module) and 1 sample value symbol period.Figure 12 the result shows that, carry based on straight
The performance of BER for flowing the filter bank multi-carrier visible light communication system of biasing is better than DCO-OFDM systems, one side of the advantage
Face is since carried filter bank multi-carrier visible light communication system is not necessarily to additional CP, and the transmission power of saving can be used for enhancing
The reliability of effective information transmission, prior one side are since carried system supports asynchronous transfer mode, and DCO-OFDM
Asynchronous mode cannot be supported well.
Figure 13 is compared in the above-described embodiments, under multipath channel and asynchronous transfer mode, proposed based on direct current
The errored bit of the filter bank multi-carrier visible light communication system of biasing and existing DCO-OFDM multi-carrier visible light communication systems
The simulation curve that rate changes with bit signal-to-noise ratio (Eb/No).Wherein, for the fairness compared, the direct current biasing of DCO-OFDM
Value is also k=3.5 times of biasing front signal standard deviation, and modulation system is 42=16 ary quadrature amplitudes (16-QAM,
16-Quadrature Amplitude Modulation), number of sub carrier wave N=2M=32 (selected modulation mode and subcarrier
Number ensure that：DCO-OFDM occupies same frequency band, using same bit transmission rate with carried system), CP length is G
=8.Normalized channel impulse response coefficient is：[0.8945,0.3902,0.1859,0.0951,0.0516,0.0294,
0.0174,0.0107].Under asynchronous mode, it is assumed that there are two user, occupy respectively the first half subband (for carried system) or
The subband or subcarrier of subcarrier (for DCO-OFDM) and later half, between two sections of frequency bands using a null subcarrier carry out every
From protection (the present embodiment is using the 1st subband of second user as insulation blocking subband), in addition, the two users send
Data block between allow the timing offset for having within 1 sample value symbol, and assume that the timing offset is taken at random with identical probability
Value is -1,0 (i.e. zero deflection is equivalent to synchronous transfer module) and 1 sample value symbol period.Figure 13 the result shows that, carry and being based on
The performance of BER of the filter bank multi-carrier visible light communication system of direct current biasing is better than DCO-OFDM systems, the advantage one
Aspect is since carried filter bank multi-carrier visible light communication system is not necessarily to additional CP, and the transmission power of saving can be used for increasing
The reliability of strong effective information transmission, prior one side are and the DCO- since carried system supports asynchronous transfer mode
OFDM cannot support asynchronous mode well.
As preferred embodiment, the present invention adds coding before the modulation module of digital baseband preprocessing module
Module and interleaving block, coding module increase the reliability of transmission for carrying out channel coding to message bit stream；Intertexture mould
Block increases for being interleaved processing to the message bit stream after coding and resists continuous burst error ability.Meanwhile in digital base
After demodulation module with post-processing module, de-interleaving block and decoder module, de-interleaving block, for by solving are added
The bit stream of tune is deinterleaved operation；Decoder module, for being decoded to the bit stream after deinterleaving, to restore
Go out original information bits stream.Coding module and interleaving block are used in combination with de-interleaving block and decoder module needs, to increase
The reliability of transmission.
Claims (10)
1. a kind of filter bank multi-carrier visible light communication system based on direct current biasing, which is characterized in that including transmitting terminal and
Receiving terminal；
The transmitting terminal, including：
Interface and cache module, for being received from applications and caching the message bit stream to be transmitted；
Digital baseband preprocessing module generates multiplexing symbol stream for being pre-processed to message bit stream；
Synthesis filter group processing module, for carrying out synthesis filter group processing to the multiplexing symbol stream to be transmitted,
So that a son for being loaded into filter group respectively per stream of modulation symbols all the way takes, and it is superimposed generation multi-carrier digital letter all the way
Number stream；
Numeral/analog conversion module generates simulation letter for carrying out digital-to-analog conversion to the digital signal streams to be transmitted
Number；
Biasing and drive circuit module, for being amplified to analog signal, while additional direct current biasing so that by amplification
Match with the normal work section of analog signal and light source after biasing；
Light source turns for shining under the driving of the simulation electrical domain signal by amplification and biasing to simulate electrical domain signal
It is changed to light intensity signal, and is sent in visible light communication channel；
The receiving terminal includes：
Photoelectric converter and its drive circuit module, for the light intensity signal received to be converted to electricity by photoelectric converter
Signal；
Amplification filter module makes for the electrical domain signal after opto-electronic conversion to be amplified and filtered at its signal amplitude
In being followed by the operation interval of analog-to-digital converting module, while filtering out DC component and out-of-band noise；
Analog-to-digital converting module carries out analog/digital conversion for that will amplify filtered analog electrical signal, generates number
Electrical domain signal；
Analysis filter group processing module will multicarrier all the way for carrying out analysis filter group processing to digital electrical domain signal
Signal is decomposed into the symbol stream of multidiameter delay transmission again；
Balance module, the every of multidiameter delay symbol stream for being exported to analysis filter group carry out equalization operation, eliminate all the way
The influence that channel distortions generate signal；
Digital baseband post-processing module, for being post-processed by balanced multidiameter delay symbol stream, recovering original
Message bit stream all the way；
Caching and interface module, for cache information bit stream and are sent to external object application；
The synthesis filter group processing module uses the channels the M cosine modulated filters group with Perfect Reconstruction property, specifically
Including：The parallel P times of up-sampler in the roads M is up-sampled for carrying out P times to stream of modulation symbols, to generate P group image spectras；The roads M
Parallel subband synthesis filter, the frequency per the frequency response of road sub-band synthesis filter only with front and back adjacent two-way sub-band synthesis filter
It rings and overlaps, for carrying out sub-band filter to the stream of modulation symbols after up-sampling, take out corresponding one group of image spectra；Adder,
For being added to the multiple signals stream after sub-band filter, single channel digital signal streams are generated, which contains the roads M
Subband signal, to constitute filter bank multi-carrier signal.
2. a kind of filter bank multi-carrier visible light communication system based on direct current biasing according to claim 1, special
Sign is that the digital baseband preprocessing module specifically includes：
Modulation module generates stream of modulation symbols for carrying out pulse amplitude modulation to bit stream；
Serioparallel exchange module high speed symbol stream will be converted into multidiameter delay all the way for carrying out serioparallel exchange to stream of modulation symbols
Low-rate modulation symbol stream；
The digital baseband post-processing module specifically includes：
Parallel serial conversion module, the multidiameter delay low speed symbol stream for exporting analysis filter group carry out parallel-serial conversion, are formed
The symbol stream of high speed all the way；
Symbol judgement module carries out symbol judgement, impulse amplitude tune of the output by judgement for the high speed symbol stream to input
Symbol stream processed；
Demodulation module solves planisphere mapping for being demodulated to the pulse amplitude modulation symbol stream after judgement, thus will
Stream of modulation symbols is demodulated into corresponding bit stream.
3. a kind of filter bank multi-carrier visible light communication system based on direct current biasing according to claim 2, special
Sign is, before the modulation module of digital baseband preprocessing module, coding module and interleaving block is added；
Coding module, for carrying out channel coding to message bit stream；
Interleaving block, for being interleaved processing to the message bit stream after coding；
After the demodulation module of digital baseband post-processing module, de-interleaving block and decoder module is added；
De-interleaving block, for being deinterleaved operation to demodulated bit stream；
Decoder module, for being decoded to the bit stream after deinterleaving, to recover original information bits stream.
4. a kind of filter bank multi-carrier visible light communication system based on direct current biasing according to claim 1, special
Sign is that the analysis filter group processing module uses the channels the M cosine modulated filters group with Perfect Reconstruction property, tool
Body includes：The roads M parallel subband analysis filter, per the corresponding sub-band synthesis filter of the frequency band of road Subband Analysis Filter
It is identical, for carrying out sub-band filter to the digital electrical domain multi-carrier signal received, takes out and correspond to Substrip analysis filter in signal
Certain section of frequency band of wave device, to generate the roads M parallel subband signal；The parallel P times of down-sampler in the roads M, for passing through Substrip analysis
The multichannel subband signal of filtering carries out P times of down-sampling, reduces sampling rate, raw to which subband spectrum is expanded to entire frequency band
At the parallel low speed symbol stream in the roads M.
5. a kind of filter bank multi-carrier visible light communication system based on direct current biasing according to claim 4, special
Sign is that in the multi-user mode, a part of phase in M branch in the synthesis filter group is used alone in each user
Adjacent branch, is used alone a part of adjacent branch in M branch in the analysis filter group, and the user is made
Synthesis filter group branch and the serial number of analysis filter group branch correspond.
6. a kind of filter bank multi-carrier visible light communication system based on direct current biasing according to claim 4, special
Sign is, the Subband Analysis Filter in sub-band synthesis filter and the analysis filter group in the synthesis filter group
It is all made of real-valued coefficients.
7. a kind of filter bank multi-carrier visible light communication system based on direct current biasing according to claim 1, special
Sign is that the light source is light emitting diode (LED) or laser diode (LD)；The photoelectric converter is photodiode
(PD)。
8. a kind of filter bank multi-carrier visible light communication system based on direct current biasing according to claim 1, special
Sign is that the size of the additional direct current biasing is taken as k times that is attached the standard deviation of the signal of direct current biasing, the value of k
Section is [1,4].
9. utilizing a kind of filter bank multi-carrier visible light based on direct current biasing described in claim 1-8 any claims
A kind of filter bank multi-carrier visible light communication method based on direct current biasing that communication system is realized, which is characterized in that specific
Steps are as follows：
S1, message bit stream to be transmitted is received from applications；
S2, message bit stream to be transmitted is subjected to numeral pretreatment, including pulse amplitude modulation and serioparallel exchange, generates the roads M
Parallel stream of modulation symbols；
S3, stream of modulation symbols is subjected to synthesis filter group processing, generates filter bank multi-carrier digital signal；
S4, digital signal is subjected to digital-to-analog conversion, generates analog electrical signal；
S5, direct current biasing is added to analog electrical signal and drives light source luminescent；
S6, the optical signal received is converted into analog electrical signal with photoelectric converter；
S7, analog electrical signal is amplified and is filtered, filter out DC component；
S8, analog/digital conversion is carried out to analog electrical signal, generates digital signal；
S9, analysis filter group processing is carried out to digital signal, generates multidiameter delay symbol stream；
S10, multidiameter delay symbol stream is influenced per equilibrium treatment, elimination channel distortions are carried out all the way；
S11, digital post-processing, including parallel-serial conversion, symbol judgement, demodulation are carried out to the multidiameter delay symbol stream by equilibrium,
Recover original information bits stream；
S12, the message bit stream recovered is sent to intended application.
10. a kind of filter bank multi-carrier visible light communication system based on direct current biasing according to claim 9, special
Sign is, between step S2 pulse amplitude modulations and serioparallel exchange, coding is added and interweaves, for being carried out to message bit stream
Channel coding, and processing is interleaved to the message bit stream after coding；After step S11 demodulation, be added deinterleave and
Decoding for being deinterleaved operation to demodulated bit stream, and is decoded the bit stream after deinterleaving,
And recover original information bits stream.
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| CN111970585B (en) * | 2020-07-08 | 2022-07-15 | 武汉光迅科技股份有限公司 | Signal demodulation method, signal demodulation device, computer storage medium and equipment |
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| CN112039497A (en) * | 2020-08-21 | 2020-12-04 | 安徽蓝讯电子科技有限公司 | Multi-carrier sub-band filter of filter bank |
| CN112636831B (en) * | 2020-12-03 | 2022-02-22 | 哈尔滨工业大学（深圳） | Time synchronization method, system and storage medium based on DCO-OFDM visible light communication system |
| CN113726445B (en) * | 2021-07-12 | 2022-11-18 | 网络通信与安全紫金山实验室 | Modulation signal generation method and terahertz wireless transmission method and system |
| CN113644898A (en) * | 2021-08-11 | 2021-11-12 | 杭州维纳安可医疗科技有限责任公司 | Drive circuit, drive method and pulse generation system |
| EP4364679A1 (en) * | 2021-08-11 | 2024-05-08 | Hangzhou Wknife Medical Technology Co., Ltd. | Cooperative pulse generation apparatus, device and generation method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103346834A (en) * | 2013-06-26 | 2013-10-09 | 上海无线通信研究中心 | Visible-light energy-carrying communication system and method |
| CN104935383A (en) * | 2015-06-08 | 2015-09-23 | 上海交通大学 | Uplink system of subcarrier multiplexing optical network of filter based multicarrier modulation |
| CN104936047A (en) * | 2015-06-08 | 2015-09-23 | 上海交通大学 | Uplink system of PON (Passive Optical Network) of filter based multicarrier modulation technology |
-
2015
- 2015-12-03 CN CN201510882159.5A patent/CN105450577B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103346834A (en) * | 2013-06-26 | 2013-10-09 | 上海无线通信研究中心 | Visible-light energy-carrying communication system and method |
| CN104935383A (en) * | 2015-06-08 | 2015-09-23 | 上海交通大学 | Uplink system of subcarrier multiplexing optical network of filter based multicarrier modulation |
| CN104936047A (en) * | 2015-06-08 | 2015-09-23 | 上海交通大学 | Uplink system of PON (Passive Optical Network) of filter based multicarrier modulation technology |
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