CN109004984A - Communication means, system and method for signal multiplexing, device between time-frequency domain - Google Patents
Communication means, system and method for signal multiplexing, device between time-frequency domain Download PDFInfo
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- CN109004984A CN109004984A CN201810788411.XA CN201810788411A CN109004984A CN 109004984 A CN109004984 A CN 109004984A CN 201810788411 A CN201810788411 A CN 201810788411A CN 109004984 A CN109004984 A CN 109004984A
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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
- H04B10/25—Arrangements specific to fibre transmission
- H04B10/2589—Bidirectional transmission
- H04B10/25891—Transmission components
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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
- H04B10/25—Arrangements specific to fibre transmission
- H04B10/2507—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
- H04B10/2513—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion
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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
- H04B10/25—Arrangements specific to fibre transmission
- H04B10/2575—Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/02—Selecting arrangements for multiplex systems for frequency-division multiplexing
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
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Abstract
The invention discloses a kind of communication means, system and method for signal multiplexing, devices between time-frequency domain, wherein between time-frequency domain the method for fiber optic communication the following steps are included: in transmitting terminal, the serial binary electric signal of input is converted into the parallel electric signal in the road N, and it is converted into the multiplexed electrical signal on the domain between time-frequency domain, it is modulated on light carrier and forms multiplexing optical signal, input optical fibre link is transmitted；In receiving end, the multiplexing optical signal received from optical fiber link is converted into multiplexed electrical signal, and the multiplexed electrical signal is demultiplexed, reverts to serial binary electric signal.The present invention, traditional frequency domain multiplex techniques have been generalized on the domain between T/F, multiplexing and demultiplexing are realized into domain of the signal between T/F, to inhibit the non-linear and effect of dispersion bring Signal Degrade that light transmits in a fiber, the band efficiency in ofdm system is improved, PAPR is reduced.
Description
Technical field
The present invention relates to technical field of optical fiber communication, and in particular to a kind of optical fibre communication method, system and between time domain-frequency
The method, apparatus that signal is multiplexed between domain.
Background technique
With the progress of human society, the communication technology is able to fast development.Wherein, fiber optic communication has signal steady
Determine, various advantages such as small, transmission range is long, capacity height are lost, has become the most important communication technology in countries in the world
One of.
Nowadays, the research hotspot of Fibre Optical Communication Technology is: ultrahigh speed Transmission system, vast capacity wdm system and full light connection
Net.Wherein, fiber optic communication is developed so far, in order to improve message capacity, numerous advanced technologies, such as coherent light communication, high contrast
Format processed, dense wave division multipurpose (dense wavelength multiplexing, DWDM) etc. occur in succession.In general, phase
Compared with other technologies, multiplexing technology be most can direct lifting system message capacity, be equivalent to existing fiber optic communication directly
The capacity boost of system several times.
With the sharp increase of society's communication total amount, the traffic capacity demands of optical fiber telecommunications system also rapid growth.Currently, being directed to
Most of signal multiplexing in optical fiber telecommunications system is realized in frequency domain, on the one hand, spectrum utilization efficiency will receive bottleneck
Influence can not be improved unlimitedly；On the other hand, the non-linear and effect of dispersion that light transmits in a fiber is not can be well solved
The problem of bring Signal Degrade.
For this purpose, 105812060 A of Chinese invention patent CN discloses adaptive equalization filter in a kind of fiber optic communication
And method, received time-domain signal is indexed according to sampling point and is grouped, grouping time-domain signal is obtained；The grouping time-domain signal is turned
It is changed to grouping frequency-region signal；According to frequency domain equalization filter factor, equalization filtering is carried out to the grouping frequency-region signal；Equilibrium is filtered
Grouping frequency-region signal after wave carries out inverse Fourier transform, is equalized filtered grouping time-domain signal；By the balanced filter
Grouping time-domain signal after wave merges, and obtains time-domain signal after complete equalization filtering.Pass through the time-domain signal that will be inputted
According to the grouping of sampling point index, segmentation, multiple segments are divided the signal into, and filter coefficient is also divided into two parts by index odd even,
Frequency domain filtering mode is reused later, and the points of required Fourier transform are few, lesser Fourier transform of counting, and realize letter
Single, circuit scale is smaller, small power consumption, postpones also small.
104639254 A of Chinese invention patent CN discloses a kind of three-dimensional orthogonal frequency division multiplexed data modulator approach and number
According to demodulation method, three-dimensional data constellation point is carried out to sent bit sequence, obtains the orthogonal frequency based on three-dimensional mapping
Divide multiplexing OFDM symbol；When by plural number of the obtained three-dimensional OFDM symbol after three-dimensional inverse Fourier transform (3D-IDFT)
The real and imaginary parts of domain signal pass through three-dimensional CAP orthogonal filter respectively, final to carry out three tunnel superpositions, and are combined into final
Send time domain data；Data to be transmitted is obtained by the time-domain signal of 3D-CAP-OFDM system and sends data to be transmitted, is reached
In the case where not influencing communication system other performance, it is effectively reduced the technical effect of signal PAPR.
Both the above scheme, although reducing non-linear and effect of dispersion bring Signal Degrade ask to a certain extent
Topic, but there is no spectrum utilization efficiency is significantly improved, transmission capacity can not be increased substantially.
In view of this, needing to there is wavelength-division multiplex technique to improve existing, held with greatly improving the transmission of fiber optic communication
Amount, while reducing non-linear and effect of dispersion bring Signal Degrade.
Summary of the invention
The technical problem to be solved by the present invention is to existing optical fiber telecommunications systems in use of wavelength division multiplexing can not be into one
Step improves the problem of transmission capacity.
In order to solve the above-mentioned technical problem, the technical scheme adopted by the invention is that provide it is a kind of between time-frequency domain it
Between method of signal multiplexing, comprising the following steps:
Serial binary input electrical signal is converted into the road N parallel electric signal, N is positive integer；
The road N parallel electric signal is encoded, is mapped, the parallel high order modulation signal in the road N is formed；
By the parallel high order modulation signal in the road N, it is modulated to corresponding sub- load on the domain between time-frequency domain respectively
On wave, and it is multiplexed and obtains multiplexed electrical signal.
In above-mentioned method of signal multiplexing, the method that multiplexing obtains the multiplexed electrical signal is as follows:
Generate the subcarrier on N number of domain between time-frequency domain；
It by the parallel high order modulation signal in the road N, is multiplied, adjusts with the subcarrier on N number of domain between time-frequency domain
The road N time-frequency domain modulated signal is made；
The road the N time-frequency domain modulated signal is added, multiplexing obtains the multiplexed electrical signal.
In above-mentioned method of signal multiplexing, the method that multiplexing obtains the multiplexed electrical signal is as follows:
Carrying out order to the parallel high order modulation signal in the road N is p Fourier Transform of Fractional Order, and output is the multiplexing
Electric signal, and the parallel high order modulation signal in the road N is modulated to the corresponding subcarrier in domain between time-frequency domain respectively
On, wherein p is the real number between -1 to 1.
The signal multiplexing device that the present invention also provides a kind of between time-frequency domain, comprising:
Serioparallel exchange module, for serial binary input electrical signal sequence to be divided into N group, and it is electric parallel to be converted to the road N
Signal, N are positive integer；
Coding mapping module forms the parallel high order modulation in the road N for being encoded, being mapped by the road N parallel electric signal
Signal；
Multiplex data processing module, for being modulated to the parallel high order modulation signal in the road N between time domain-frequency respectively
On the corresponding subcarrier in domain between domain, and it is multiplexed and obtains multiplexed electrical signal；
D/A converter module can be directly modulated to for the multiplexed electrical signal to be carried out digital-to-analogue conversion so as to subsequent
On light carrier.
In above-mentioned signal multiplexing device, the multiplex data processing module includes:
Time-frequency domain subcarrier generation module, for generating the subcarrier on N number of domain between time-frequency domain；
N number of multiplier is used for the son in the parallel high order modulation signal in the road N, with the domain between time-frequency domain
Carrier multiplication, modulation obtain the road N time-frequency domain modulated signal；
One adder is multiplexed with the multiplexed electrical signal for the road the N time-frequency domain modulated signal to be added.
In above-mentioned signal multiplexing device, the multiplex data processing module to the parallel high order modulation signal in the road N into
Row order time is the Fourier Transform of Fractional Order of p, is modulated on the corresponding subcarrier in domain between time-frequency domain respectively, multiple
With for the multiplexed electrical signal, wherein p is the real number between -1 to 1.
The signal Deplexing method that the present invention also provides a kind of between time-frequency domain, comprising the following steps:
It is detected using photodetector and samples the multiplexing optical signal received from optical fiber link, and be quantized into number
Sampled signal；
The digital sampled signal is divided into the road N parallel subcarrier signals, the road N parallel subcarrier signals are demodulated
System, recovers the parallel high order modulation signal in the road N；
The parallel high order modulation signal in the road N that demodulation recovers is carried out reflection to penetrate, obtains the road N parallel binary electricity
Signal；
The road the N parallel binary electric signal that reflection is penetrated carries out parallel-serial conversion, and recovery obtains serial binary telecommunications
Number.
In above-mentioned signal Deplexing method, the method for recovering the parallel high order modulation signal in the road N is as follows:
N subcarriers are generated, and carry out conjugation reason, N is positive integer；
By the road N parallel subcarrier signals, it is filtered respectively with corresponding bandpass filter；
By the filtered road N parallel subcarrier signals, respectively with the conjugate multiplication of the corresponding subcarrier, restore
The parallel high order modulation signal in the road N out.
In above-mentioned signal Deplexing method, carrying out order to the road N parallel subcarrier signals is in-p fractional order Fu
Leaf transformation, output are the parallel high order modulation signal in the road N, and wherein p is the real number between -1 to 1.
The signal Deplexing apparatus that the present invention also provides a kind of between time-frequency domain, comprising:
Analog-to-digital conversion module, the multiplexing optical signal for detecting the photodetector samples, and is quantized into
Digital sampled signal；
Demultiplexed data processing module is divided into the parallel subcarrier letter in the road N for demultiplexing the digital sampled signal
Number, and demodulate and recover the parallel high order modulation signal in the road N；
Anti- mapping block is penetrated for the parallel high order modulation signal in the road N that recovers of demodulation to be carried out reflection, is obtained
The binary electrical signal parallel to the road N；
Parallel serial conversion module restores for that will reflect that the parallel binary electrical signal in the road N penetrated carries out parallel-serial conversion
At serial binary electrical signal.
In above-mentioned signal Deplexing apparatus, the demultiplexed data processing module includes:
One sub- carrier generator, for generating N subcarriers；
One conjugate module, for the N subcarriers to be carried out conjugation processing；
One filter module is filtered out for the digital sampled signal with corresponding bandpass filter respectively, generates the road N simultaneously
Capable sub-carrier signal；
N number of multiplier restores for the parallel sub-carrier signal in the road N to be multiplied by the conjugation of corresponding subcarrier respectively
The road N high order modulation signal out.
In above-mentioned signal Deplexing apparatus, the demultiplexed data processing module is to the road N parallel subcarrier signals
Progress order is-p Fourier Transform of Fractional Order, and output is the parallel high order modulation signal in the road N, and wherein p is between -1 to 1
Real number.
The method for fiber optic communication that the present invention also provides a kind of between time-frequency domain, comprising the following steps:
In transmitting terminal, using above-mentioned method of signal multiplexing, multiplexed electrical signal is converted by input signal, and be modulated to light
Multiplexing optical signal is formed on carrier wave, input optical fibre link is transmitted；
In receiving end, the multiplexing optical signal received from optical fiber link is converted into multiplexed electrical signal, and utilize upper
The method of signal multiplexing stated demultiplexes the multiplexed electrical signal, reverts to serial binary electric signal.
The optical fiber telecommunications system that the present invention also provides a kind of between time-frequency domain, including transmitting terminal and receiving end,
The two is communicated by optical fiber link,
The transmitting terminal, including modulation module and above-mentioned signal multiplexing device, the signal multiplexing device is used for will be defeated
The serial binary electric signal entered is converted to the multiplexed electrical signal on the domain between time-frequency domain, and the modulation module is used
Multiplexing optical signal is formed in the multiplexed electrical signal to be modulated on light carrier, input optical fibre link is transmitted；
The receiving end, including photodetector and above-mentioned signal Deplexing apparatus, the photodetector is used for will
The multiplexing optical signal received from optical fiber link is converted to multiplexed electrical signal, and the signal Deplexing apparatus is used for will be described
Multiplexed electrical signal demultiplexing, reverts to serial binary electric signal.
In the present invention, the selection of fraction order Fourier transform order p is chosen using gradient descent method, comprising the following steps:
S1: an initial p0 value is chosen；
S2: signal is multiplexed according to the initial p0 value of selection, transmitted, is demultiplexed；
S3: judge signal quality；
S4: one step-length u of initial p0 value increase is obtained into p1, p1=p0+u, u are the decimal less than 1, and guarantee that p1 is situated between
Between -1 and 1；Repeat S2 and S3；
S5: comparing after multiplexing, transmission, demultiplexing, twice the quality of signal, according to the signal quality of order p0
Preferably, then p1=p0-u is taken；It is preferable according to the signal quality of order p1, then take p0=p1, p1=p1+u；
S6: repeating S2~S5, until the quality of signal reaches best, obtains the p value.
Compared with prior art, traditional frequency domain multiplex techniques have been generalized to T/F by scheme provided by the invention
Between domain on, multiplexing and demultiplexing are realized into domain of the signal between T/F, so that light be inhibited to transmit in a fiber
Non-linear and effect of dispersion bring Signal Degrade, improve OFDM (Orthogonal Frequency Division
Multiplexing, orthogonal frequency division multiplexing) band efficiency in system, reduce PAPR (Peak to Average Power
Ratio, papr).
Detailed description of the invention
Fig. 1 is the optical fiber telecommunications system schematic diagram provided by the invention between time-frequency domain；
Fig. 2 is traditional frequency-region signal multiplexing schematic diagram；
Fig. 3 is the schematic diagram of time-frequency domain signal multiplexing in the present invention；
Fig. 4 is a kind of implementation schematic diagram of multiplex data processing module in the present invention；
Fig. 5 is a kind of implementation schematic diagram of demultiplexed data processing module in the present invention；
Fig. 6 is the flow chart that best score rank Fourier transformation order p is found in the present invention.
Specific embodiment
The present invention provides a kind of optical fibre communication method, system and between time-frequency domain to signal carry out multiplexing and
Traditional frequency domain multiplex techniques have been generalized on the domain between T/F by the method, apparatus of demultiplexing, by signal when
It is multiplexed and is demultiplexed in domain between m- frequency, thus the non-linear and dispersion for inhibiting optical signal to transmit in a fiber
Effect bring Signal Degrade, improves the band efficiency in ofdm system, reduces PAPR.With reference to the accompanying drawings of the specification
The present invention is described in detail with specific embodiment.
Realization principle of the invention is:
It is multiplexed again behind specific signal area when by transforming to transmission signal between m- frequency domain, so as to
With the non-linear and effect of dispersion bring Signal Degrade for inhibiting light to transmit in a fiber, can also be improved in an ofdm system
Band efficiency and reduction PAPR etc. can also be used in combination with other multiplex modes and provide the utilization rate of channel.
Technical solution of the present invention, main includes the content of six aspects:
Method of signal multiplexing between time-frequency domain；
Signal multiplexing device between time-frequency domain；
Signal Deplexing method between time-frequency domain；
Signal Deplexing apparatus between time-frequency domain；
The method of fiber optic communication between time-frequency domain；
Optical fiber telecommunications system between time-frequency domain.
Wherein, the optical fibre communication method between time-frequency domain, the realization of basic technical scheme mainly include following
Step:
In transmitting terminal, the serial binary electric signal of input is converted into the parallel electric signal in the road N, then disposable conversion
For the multiplexed electrical signal on the domain between time-frequency domain, multiplexing optical signal, input optical fibre are formed in re-modulation to light carrier
Link is transmitted；
In receiving end, the multiplexing optical signal received from optical fiber link is converted into multiplexed electrical signal, and the multiplexing is electric
Signal demultiplexing, recovery obtain serial binary electric signal.
Optical fiber telecommunications system between time-frequency domain, including transmitting terminal and receiving end, the two by optical fiber link into
Row information communication.
Transmitting terminal is then converted to be situated between for the serial binary electric signal of input to be converted to the parallel electric signal in the road N
The multiplexed electrical signal on domain between time-frequency domain forms multiplexing optical signal, input optical fibre link in re-modulation to light carrier
It is transmitted；
Receiving end for the multiplexing optical signal received from optical fiber link to be converted to multiplexed electrical signal, and demultiplexes, extensive
Regain serial binary electric signal.
The present invention program, due to being multiplexed on the domain between time-frequency domain to transmission signal, compared to tradition
Frequency domain multiplex techniques, have better adjustment space, can by adjusting fractional order convert order, better adapt to each germline
System channel, to improve band efficiency.At the same time it can also the non-linear and effect of dispersion band for inhibiting light to transmit in a fiber
The Signal Degrade come.
In introduction below, what is mainly introduced is the optical fiber telecommunications system and method between time-frequency domain.The present invention
The method of signal multiplexing and device between time-frequency domain in scheme, and signal between time-frequency domain demultiplex
With method and apparatus, introduction explanation together will be interspersed in the optical fiber telecommunications system between time-frequency domain and method.
In order to make more clearly explanation and illustration to technical solution of the present invention and implementation, realization introduced below is originally
Several preferred specific embodiments of inventive technique scheme.Obviously, specific embodiment discussed below is only of the invention one
Section Example, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art are not doing
Every other embodiment obtained under the premise of creative work out, shall fall within the protection scope of the present invention.
Specific embodiment 1.
As shown in Figure 1, the optical fiber telecommunications system between time-frequency domain that the specific embodiment of the invention 1 provides includes
Transmitting terminal 100 and receiving end 200, the two are communicated by optical fiber link 300.
Transmitting terminal 100 includes Multiplexing module 110 and modulation module 120, and Multiplexing module 110 is electric by the serial binary of input
Signal is converted to the parallel electric signal in the road N, the multiplexed electrical signal being then converted on the domain between time-frequency domain, modulation
Multiplexed electrical signal is modulated on light carrier by module 120 forms multiplexing optical signal, and input optical fibre link 300 is transmitted.N is positive
Integer can need self-setting according to system.
Receiving end 200 includes photodetector 210 and demultiplexing module 220, and photodetector 110 will be from optical fiber link
300 multiplexing optical signals received are converted to multiplexed electrical signal, and multiplexed electrical signal is demultiplexed, restored by demultiplexing module 220
To serial binary electric signal, that is, recover the serial binary electric signal of input.
It is as follows in the method that transmitting terminal carries out signal multiplexing in above system:
Serial binary input electrical signal is converted into the road N parallel electric signal first, N is positive integer, then simultaneously by this road N
Horizontal electrical signal is encoded, is mapped, and the parallel high order modulation signal in the road N is formed, and finally by this parallel high order modulation signal in road N, is divided
It is not modulated on the domain between time-frequency domain on corresponding subcarrier, multiplexing obtains multiplexed electrical signal.
In above system, the method demultiplexed to above-mentioned multiplexed signals is as follows:
The multiplexing optical signal received from optical fiber link 300 is sampled first with photodetector detection 210, and
It is quantized into digital sampled signal, obtained digital sampled signal is then divided into the road N parallel subcarrier signals, and simultaneously to the road N
Row sub-carrier signal demodulation, recovery obtain the parallel high order modulation signal in the road N；Finally, the road N that demodulation is recovered is high parallel
Rank modulated signal carries out reflection and penetrates, and obtains the road N parallel binary electric signal；The road the N parallel binary electricity that reflection is penetrated again
Signal carries out parallel-serial conversion, and recovery obtains serial binary electric signal, that is, recovers the serial binary electric signal of input.
Fig. 2 and Fig. 3 illustrates the signal multiplexing in traditional frequency domain signal multiplexing and the present invention between time-frequency domain
Difference.In figure, abscissa indicates that time shaft, ordinate indicate frequency axis.By Fig. 2, it can be seen that, frequency axis is divided into one
Bar frequency band, every frequency band indicate a subcarrier, carry signal all the way above；By Fig. 3, it can be seen that, entire T/F is flat
Face is divided into a rule time-frequency band, the corresponding subcarrier of every time-frequency band.It is multiplexed compared to traditional frequency-region signal, this hair
Signal multiplexing in bright has higher multiplexing efficiency.And since in time frequency space, the division of time-frequency band is can be adaptive
Adjustment, therefore different channel situations can be better adapted to, such as to the dispersion of optical fiber, non-linear have better resistance.
Specific embodiment 2.
The specific embodiment of the invention 2 is the structure refinement to signal multiplexing device, and referring to Fig. 1, signal multiplexing device includes
Serioparallel exchange module 111, coding mapping module 112, multiplex data processing module 113 and D/A converter module 114.
Serioparallel exchange module 111 is used to the serial electric signal sequence of input being divided into N group, and is converted to the parallel electricity in the road N
Signal；
Coding mapping module 112 is mapped as the parallel height in the road N for encoding the parallel electric signal in the above-mentioned road N
Rank modulated signal, such as quadrature amplitude modulation.
Multiplex data processing module 113 be used for the high order modulation signal that the above-mentioned road N is parallel, be modulated to respectively between when
On the corresponding subcarrier in domain between domain-frequency domain, it is then multiplexed with multiplexed electrical signal all the way；
D/A converter module 114 is used to above-mentioned multiplexed electrical signal carrying out digital-to-analogue conversion, can directly modulate so as to subsequent
Optical fiber transmission is carried out on to light carrier.
Specific embodiment 3.
The specific embodiment of the invention 3 is the first implementation of multiplex data processing module, using traditional son
The mode of carrier multiplexing is realized, as shown in figure 4, its composed structure includes time-frequency domain subcarrier generation module 1131, a N
A multiplier 1132 and an adder 1133.
The son that time-frequency domain subcarrier generation module 1131 is used to generate on N number of domain between time-frequency domain carries
Wave；
N number of multiplier 1132 is by the son in the parallel high order modulation signal in the road N, with the above-mentioned domain between time-frequency domain
Carrier multiplication, so that modulation obtains the road N time-frequency domain modulated signal；
The above-mentioned road N time-frequency domain modulated signal is added by adder 1133, is multiplexed with multiplexed electrical signal.Multiplexed electrical signal
It is modulated on light carrier by modulation module 120 again and forms multiplexing optical signal, input optical fibre link is transmitted.
Specific embodiment 4.
The specific embodiment of the invention 4 provides another multiplex data processing mode, becomes using fractional order Fourier
Mode is changed, the parallel high order modulation signal in the road N is modulated to respectively on the corresponding subcarrier in domain between time-frequency domain, it is multiple
With for the multiplexed electrical signal.
The specific practice is: carrying out the Fourier Transform of Fractional Order that an order is p to the road N parallel subcarrier signals, respectively
It is modulated on the corresponding subcarrier in domain between time-frequency domain, is multiplexed with multiplexed electrical signal.
Specific embodiment 5.
The specific embodiment of the invention 5 is the realization to the demultiplexing of the multiplexed signals carried out using above scheme, such as Fig. 1 institute
Show, demultiplexing module includes analog-to-digital conversion module 221, demultiplexed data processing module 222, anti-mapping block 223 and and string turn
Change the mold block 224.
Analog-to-digital conversion module 221 samples the multiplexing optical signal that photodetector 210 detects, and is quantized into number
Sampled signal；
Demultiplexed data processing module 222 demultiplexes above-mentioned digital sampled signal, is divided into the parallel subcarrier letter in the road N
Number, and demodulate and recover the parallel high order modulation signal in the road N；
The parallel high order modulation signal in the above-mentioned road N that recovers of demodulation is carried out reflection and penetrated by anti-mapping block 223, is obtained
The parallel binary electrical signal in the road N；
The parallel binary electrical signal in the road N that parallel serial conversion module 224 penetrates reflection carries out parallel-serial conversion, reverts to
Serial binary electrical signal restores to obtain serial binary electric signal.
Specific embodiment 6.
The specific embodiment of the invention 6 is the first implementation of demultiplexed data processing module, using traditional son
The mode of carrier multiplexing is realized, as shown in figure 5, its composed structure includes 2221, conjugate modules of a sub- carrier generator
2222, a filter module 2223 and N number of multiplier 2224.
Subcarrier generator 2221 is for generating N subcarriers；
The N subcarriers that conjugate module 2222 generates subcarrier generator 2221 carry out conjugation processing；
Filter module 2223 filters the digital sampled signal after being digitized by analog-to-digital conversion module 221 with corresponding band logical
Wave device filters out respectively, generates the parallel sub-carrier signal in the road N；
N number of multiplier, the parallel sub-carrier signal in the road N for exporting filter module 2223 are multiplied by corresponding son respectively and carry
The conjugation of wave eliminates carrier information, reverts to the road N high order modulation signal.
Specific embodiment 7.
The specific embodiment of the invention 7 is second of implementation of demultiplexed data processing module, using fractional order
Fourier transformation mode carries out Fourier Transform of Fractional Order to the road N parallel subcarrier signals, and output is the road N high contrast parallel
Signal processed.
The specific practice is: the road the N parallel subcarrier signals (photodetection that photodetector 210 is sampled and is converted to
Device 210 samples the multiplexing optical signal detected, and is quantized into digital sampled signal, the digital sampled signal be the road N simultaneously
Row sub-carrier signal), the discrete fractional Brownian random field that an order is-p is carried out, output is the parallel high-order in the road N
Modulated signal.
When realizing multiplexing and the demultiplexing of signal using Fourier Transform of Fractional Order, the order of Fourier Transform of Fractional Order
P is the real number between -1 to 1, and gradient descent method can be used and choose optimal order p value, the specific steps are as follows:
S1: one initial p value p0, such as p0=0.5 of selection first；
S2: signal is multiplexed according to the initial p value p0 of selection, transmitted, is demultiplexed；
S3: the parameter (such as PAR peak to average ratio, Q value etc.) of signal is calculated, and judges signal quality accordingly；
S4: increasing a step-length u for initial p value p0, and taking p1=p0+u, u is the decimal less than 1, and guarantees p1 between -1
And between 1, S2 and S3 is repeated；Under normal conditions, u takes a lesser value, and such as 0.1；
S5: comparing after multiplexing, transmission, demultiplexing, twice using the matter of the signals that order p is finally exported different out
Amount, it is preferable according to the signal quality of order p0, then take p1=p0-u；Conversely, it is preferable according to the signal quality of order p1, then
Take p0=p1, p1=p1+u；
S6: repeating S2~S5, until the quality of signal reaches best, corresponding p value is best p value.
Based on the above optical fiber telecommunications system between time-frequency domain, the present invention also provides one kind between time domain-
Optical fibre communication method between frequency domain, specifically includes the following steps:
Step S1: in transmitting terminal, the serial binary electric signal of input is converted into the parallel electric signal in the road N；
The parallel electric signal in the road step S2:N is converted into the multiplexed electrical signal on the domain between time-frequency domain；
Step S3: being modulated on light carrier and form multiplexing optical signal, and input optical fibre link is transmitted；
Step S5: in receiving end, the multiplexing optical signal received from optical fiber link is converted into multiplexed electrical signal；
Step S6: the multiplexed electrical signal is demultiplexed, and reverts to serial binary electric signal.
In this method, by the way of Fourier Transform of Fractional Order, the parallel high order modulation signal in the road N is modulated respectively
Onto the corresponding subcarrier in domain between time-frequency domain, then multiplexing forms multiplexed electrical signal all the way.Retouching in front
Sufficient introduction explanation is carried out in stating, details are not described herein again.
In order to which realization process of the invention is explained further, following present signals to be entirely multiplexed reconciliation multiplex process.
Assuming that initial serial binary signal is S "k, wherein k=1,2, L, are carried out serioparallel exchange, become the road N simultaneously
Capable binary signal is expressed as S "m,n, wherein m=ceil (k/N), n=k mod N+1, ceil expression round up, mod
Expression takes the remainder.
Then the parallel binary signal in the road N is subjected to coding mapping, is mapped as the parallel high order modulation signal in the road N, table
It is shown as S 'l,n, wherein l=ceil (m/M), M are the selected corresponding bit number of each symbol of higher order modulation formats, such as when
When selecting QPSK modulation, M=2, when selecting 16QAM modulation, M=4.
Next N subcarriers C is generatedn(t, f), every subcarriers are all a time-frequency domain signals, and are met just
The property handed over:
Wherein i, j=1,2, L N, δ (i, j) are Dirac function.
Then it is added after the parallel high order modulation signal in the road N being multiplied with corresponding subcarrier, so that it may obtain by multiple
Signal after, is expressed as
Parameter t indicates the time, and parameter f indicates frequency, so multiplexed signal SlIt is the domain between time-frequency domain
On signal.
Particularly, when the form of subcarrier uses linear FM signal, i.e.,
Cn(t,fn, k) and=exp (i2 π fnt+iπkt2) (3)
Wherein fnFor the initial frequency of n-th of subcarrier, k is chirp rate.It should be noted that the i inside this is
Imaginary unit, it is different from the i for being used to count in front formula (1).In this case, formula (2) can use Discrete Fractional Fu
In leaf transformation realize:
Sl=FRFTp[S′l,n] (4)
Wherein FRFTp[] indicates that order is the discrete fractional Brownian random field of p, and p is the real number between -1 to 1, and
And it is related with chirp rate k:
Wherein arccot is arc cotangent function, and dt and df are respectively the temporal resolution and frequency resolution of signal.
The process of demultiplexing and the process of above-mentioned multiplexing are exactly the opposite.It in receiving end, is received by receiver, ADC sampling
Afterwards, multiplexed signal S is obtainedl, the parallel signal containing carrier information in the road N after filtering, can obtained:
Sl,n=S 'l,n·Cn(t,f) (6)
With after the conjugate multiplication of corresponding carrier wave, carrier information is removed, the parallel high order modulation signal S ' in the road N is obtainedl,n:
S′l,n=Sl,n·C* n(t,f) (7)
Then the high order modulation signal S ' that the road N is parallell,nIt carries out reflection to penetrate, obtains the parallel binary signal S in the road N
″m,n.Parallel-serial conversion is finally carried out, obtaining original serial binary signal is S "k。
Similarly, when the form of subcarrier uses linear FM signal, during demodulation from the road N it is parallel contain carrier wave
The signal S of informationl,nThe high order modulation signal S ' parallel to the road Nl,nThis process can also be become using Discrete Fractional Fourier
Bring realization:
S′l,n=FRFT-p[Sl] (8)
The present invention program has following apparent advantage:
(1) signal is multiplexed on the domain between time-frequency domain, the order of adjustable fractional order transformation, because
This has better adjustment space, can better adapt to various system channels, can also distribute for greater flexibility time domain, frequency domain can
With resource, higher frequency efficiency is realized.
(2) by converting the signal into it is multiplexed, can be inhibited again behind specific signal area when between m- frequency domain
The non-linear and effect of dispersion bring Signal Degrade that light transmits in a fiber.
(3) band efficiency in an ofdm system can be improved and reduce PAPR.
The invention is not limited to above-mentioned preferred forms, and anyone should learn that is made under the inspiration of the present invention
Structure change, the technical schemes that are same or similar to the present invention are fallen within the scope of protection of the present invention.
Claims (15)
1. a kind of method of signal multiplexing between time-frequency domain, which comprises the following steps:
Serial binary input electrical signal is converted into the road N parallel electric signal, N is positive integer；
The road N parallel electric signal is encoded, is mapped, the parallel high order modulation signal in the road N is formed；
By the parallel high order modulation signal in the road N, it is modulated to corresponding subcarrier on the domain between time-frequency domain respectively
On, and be multiplexed and obtain multiplexed electrical signal.
2. method of signal multiplexing according to claim 1, which is characterized in that the method that multiplexing obtains the multiplexed electrical signal
It is as follows:
Generate the subcarrier on N number of domain between time-frequency domain；
By the parallel high order modulation signal in the road N, it is multiplied, modulates with the subcarrier on N number of domain between time-frequency domain
To the road N time-frequency domain modulated signal；
The road the N time-frequency domain modulated signal is added, multiplexing obtains the multiplexed electrical signal.
3. method of signal multiplexing according to claim 1, which is characterized in that the method that multiplexing obtains the multiplexed electrical signal
It is as follows:
Using linear frequency modulation sub-carrier signal, order is carried out for the change of p fractional order Fourier to the parallel high order modulation signal in the road N
Change, output be the multiplexed electrical signal, and the parallel high order modulation signal in the road N be modulated to respectively between time-frequency domain it
Between the corresponding linear frequency modulation subcarrier in domain on, wherein p be -1 to 1 between real number.
4. a kind of signal multiplexing device between time-frequency domain characterized by comprising
Serioparallel exchange module for serial binary input electrical signal sequence to be divided into N group, and is converted to the road N parallel electric signal,
N is positive integer；
Coding mapping module forms the parallel high order modulation letter in the road N for being encoded, being mapped by the road N parallel electric signal
Number；
Multiplex data processing module, for by the parallel high order modulation signal in the road N, be modulated to respectively between time-frequency domain it
Between the corresponding subcarrier in domain on, and be multiplexed obtain multiplexed electrical signal；
D/A converter module, for the multiplexed electrical signal to be carried out digital-to-analogue conversion, so that the subsequent light that can directly be modulated to carries
On wave.
5. signal multiplexing device according to claim 4, which is characterized in that the multiplex data processing module includes:
Time-frequency domain subcarrier generation module, for generating the subcarrier on N number of domain between time-frequency domain；
N number of multiplier is used for the subcarrier in the parallel high order modulation signal in the road N, with the domain between time-frequency domain
It is multiplied, modulation obtains the road N time-frequency domain modulated signal；
One adder is multiplexed with the multiplexed electrical signal for the road the N time-frequency domain modulated signal to be added.
6. signal multiplexing device according to claim 4, which is characterized in that the multiplex data processing module is to the N
The parallel high order modulation signal in road carries out the Fourier Transform of Fractional Order that order is p, is modulated between time-frequency domain respectively
On the corresponding subcarrier in domain, it is multiplexed with the multiplexed electrical signal, wherein p is the real number between -1 to 1.
7. a kind of signal Deplexing method between time-frequency domain, which comprises the following steps:
It is detected using photodetector and samples the multiplexing optical signal received from optical fiber link, and be quantized into digital sample
Signal；
The digital sampled signal is divided into the road N parallel subcarrier signals, the road N parallel subcarrier signals are demodulated, it is extensive
It appears again the parallel high order modulation signal in the road N；
The parallel high order modulation signal in the road N that demodulation recovers is carried out reflection to penetrate, obtains the road N parallel binary telecommunications
Number；
The road the N parallel binary electric signal that reflection is penetrated carries out parallel-serial conversion, and recovery obtains serial binary electric signal.
8. signal Deplexing method according to claim 7, which is characterized in that recover the parallel high order modulation signal in the road N
Method it is as follows:
N subcarriers are generated, and carry out conjugation reason, N is positive integer；
By the road N parallel subcarrier signals, it is filtered respectively with corresponding bandpass filter；
By the filtered road N parallel subcarrier signals, respectively with the conjugate multiplication of the corresponding subcarrier, institute is recovered
State the parallel high order modulation signal in the road N.
9. signal Deplexing method according to claim 7, which is characterized in that the road N parallel subcarrier signals into
Row order time is-p Fourier Transform of Fractional Order, and output is the parallel high order modulation signal in the road N, and wherein p is between -1 to 1
Real number.
10. a kind of signal Deplexing apparatus between time-frequency domain characterized by comprising
Analog-to-digital conversion module, the multiplexing optical signal for detecting the photodetector samples, and is quantized into number
Sampled signal；
Demultiplexed data processing module is divided into the parallel sub-carrier signal in the road N for demultiplexing the digital sampled signal,
And it demodulates and recovers the parallel high order modulation signal in the road N；
Anti- mapping block is penetrated for the parallel high order modulation signal in the road N that recovers of demodulation to be carried out reflection, obtains N
The parallel binary electrical signal in road；
Parallel serial conversion module restores bunchiness for that will reflect that the parallel binary electrical signal in the road N penetrated carries out parallel-serial conversion
Capable binary electrical signal.
11. signal Deplexing apparatus according to claim 10, which is characterized in that the demultiplexed data processing module packet
It includes:
One sub- carrier generator, for generating N subcarriers；
One conjugate module, for the N subcarriers to be carried out conjugation processing；
One filter module is filtered out for the digital sampled signal with corresponding bandpass filter respectively, and it is parallel to generate the road N
Sub-carrier signal；
N number of multiplier recovers the road N for the parallel sub-carrier signal in the road N to be multiplied by the conjugation of corresponding subcarrier respectively
High order modulation signal.
12. signal Deplexing apparatus according to claim 10, which is characterized in that the demultiplexed data processing module pair
It is-p Fourier Transform of Fractional Order that the road N parallel subcarrier signals, which carry out order, and output is the parallel high order modulation in the road N
Signal, wherein p is the real number between -1 to 1.
13. a kind of method of the fiber optic communication between time-frequency domain, which comprises the following steps:
Multiplexed electrical signal is converted by input signal using 3 described in any item methods of claims 1 to 3 in transmitting terminal, and
It is modulated on light carrier and forms multiplexing optical signal, input optical fibre link is transmitted；
In receiving end, the multiplexing optical signal received from optical fiber link is converted into multiplexed electrical signal, and want using right
It asks the described in any item methods of 7-9 to demultiplex the multiplexed electrical signal, reverts to serial binary electric signal.
14. a kind of optical fiber telecommunications system between time-frequency domain, including transmitting terminal and receiving end, the two passes through optical fiber chain
Road communicates, which is characterized in that
The transmitting terminal, including modulation module and such as described in any item signal multiplexing devices of claim 4 to 6, the letter
Number multiplexer is used to being converted to the serial binary electric signal of input into the multiplex telecommunication on the domain between time-frequency domain
Number, the modulation module forms multiplexing optical signal for the multiplexed electrical signal to be modulated on light carrier, input optical fibre link
It is transmitted；
The receiving end, including photodetector and such as described in any item signal Deplexing apparatus of claim 10 to 12,
The photodetector is used to the multiplexing optical signal received from optical fiber link being converted to multiplexed electrical signal, the signal
Deplexing apparatus reverts to serial binary electric signal for demultiplexing the multiplexed electrical signal.
15. the selection method of the fraction order Fourier transform order p as described in claim 3,6,9 or 12, it is characterised in that: p
Value is chosen using gradient descent method, comprising the following steps:
S1: an initial p0 value is chosen；
S2: signal is multiplexed according to the initial p0 value of selection, transmitted, is demultiplexed；
S3: judge signal quality；
S4: obtaining p1 for one step-length u of initial p0 value increase, and p1=p0+u, u are the decimal less than 1, and guarantee p1 between -1 and
Between 1；Repeat S2 and S3；
S5: comparing after multiplexing, transmission, demultiplexing, twice the quality of signal, according to order p0 signal quality compared with
It is good, then take p1=p0-u；It is preferable according to the signal quality of order p1, then take p0=p1, p1=p1+u；
S6: repeating S2~S5, until the quality of signal reaches best, obtains the p value.
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