CN107634814A - The removing method of carrier path crosstalk in a kind of mode division multiplexing system from homodyne detection - Google Patents
The removing method of carrier path crosstalk in a kind of mode division multiplexing system from homodyne detection Download PDFInfo
- Publication number
- CN107634814A CN107634814A CN201710821373.9A CN201710821373A CN107634814A CN 107634814 A CN107634814 A CN 107634814A CN 201710821373 A CN201710821373 A CN 201710821373A CN 107634814 A CN107634814 A CN 107634814A
- Authority
- CN
- China
- Prior art keywords
- mrow
- msub
- carrier path
- msup
- msqrt
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Optical Communication System (AREA)
Abstract
The invention discloses a kind of removing method of carrier path crosstalk in mode division multiplexing system from homodyne detection, belong to communication technical field, the present invention using carrier path pilot tone light transmitting terminal double sideband modulation and the method that receiving terminal down coversion is recovered effectively eliminated due in less fundamental mode optical fibre transmitting procedure carrier path by the crosstalk on signal road caused by be concerned with the influenceing of beat frequency noise.This method is not in the case where changing existing less fundamental mode optical fibre (FMF) parameter, improve the transmission range from homodyne detection mode division multiplexing (MDM SHD) system, reduce the requirement of model selection sensitivity of the MDM SHD systems to pattern multiplexer/demultiplexer (MUX/DEMUX), preferable error performance can be ensured simultaneously, there is the higher impact of performance.
Description
Technical field
The invention belongs to communication technical field, and in particular to one kind is based on logical from homodyne detection mode division multiplexing (MDM-SHD)
The removing method of carrier wave crosstalk in letter system.
Background technology
In recent years as mobile Internet, cloud computing, the application of technology of Internet of things and development, data service increase in explosion type
Long trend.Wherein, net is improved for the short-distance and medium-distance optic communication active demand of representative with optical access network and the interconnection of data center light
Network bandwidth capacities.At present generally using intensity modulated-direct detection (IM/DD) mode in short distance optic communication, which is only
Intensity information can be utilized, cause the loss of phase information, cause the waste of frequency spectrum resource, and IM/DD is by dispersion and non-
The influence of line noise is serious so that its high capacity transmission difficult to realize.Coherent light communication (ID) has high sensitivity, high spectrum
The advantages that efficiency, it has been widely used at present in the bone optical fiber network of long range Large Copacity.With reference to dense wave division multipurpose
(DWDM) technology, coherent light communication can even realize simple optical fiber number Tb/s high transfer rate.But coherent light communication system
The equipment that system has complexity, high cost, these prevent coherent light communication from meeting short haul connection for transmission cost
Requirement.In order to effectively improve the capacity of Transmission system and keep relatively low cost, based on from homodyne detection
Mode division multiplexing (MDM-SHD) communication technology arise at the historic moment.
In MDM-SHD systems, pilot tone (PT) light of carrier path will be with signal road quadrature amplitude modulation (mQAM) signal one
Rise to enter in less fundamental mode optical fibre (FMF) by pattern multiplexer (MUX) and transmit.In receiving terminal, pattern demultiplexer (DEMUX) will be believed
Number road and carrier path separation.The carrier path pilot tone light of separation will carry out relevant detection as this oscillation light (LO) and signal road, from
And obtain transmission signal.This detection mode can save the local oscillator lasing light emitter of receiving terminal, reduce wanting for transmitting terminal Light source line width
Ask, and because carrier path light and signal road light come from same lasing light emitter and experienced identical noisy channel environment, institute
Be not in frequency shift (FS) damage with the signal received, phase noise is also inhibited elimination, greatly reduced at DSP signals
The complexity and operation times of reason.But the pattern crosstalk in actual less fundamental mode optical fibre will make the pilot tone light of carrier path by from
The crosstalk on signal road, these crosstalks can produce beat frequency noise after relevant detection, reduce the transmission performance of whole system.Therefore disappear
Except the influence of the carrier path crosstalk in MDM-SHD systems, the further transmission performance for improving MDM-SHD systems is one and urgently solved
Certainly the problem of.
The content of the invention
For the problem of carrier path crosstalk, the present invention proposes a kind of bilateral based on carrier path in existing MDM-SHD systems
With modulation from homodyne detection mode division multiplexing (DSB-MDM-SHD) system schema.This method can not change existing few mould light
Under fine parameter, reduce due in transmitting procedure carrier path by the pattern crosstalk on signal road caused by be concerned with beat frequency noise shadow
Ring.This method has preferable effect, and the bit error rate of system can be reduced under identical traffic parameter.
What the present invention was achieved through the following technical solutions：
The removing method of carrier path crosstalk, is comprised the following steps that in a kind of mode division multiplexing system from homodyne detection：
The first step, modulation produce the double-side band pilot tone light of carrier path and the mQAM optical signals on signal road, specifically included as follows
Step：
Step S101：The symbol rates of the mQAM signals transmitted as needed and modulation format calculate the bandwidth f of signals,
With the frequencies omega of first spectral null of mQAM signals0The frequency for the sine wave that carrier path needs to use is determined, so as to keep
Carrier path and signal road are orthogonal on frequency spectrum；
Step S102：It is ω by frequency0Sine wave by Mach increase Dare intensity modulator (MZ) be modulated to carrier path
On light, so as to produce the double-side band pilot tone light of carrier path；
Step S103：The mQAM signals for needing to transmit are modulated on the light of signal road by orthogonal I/Q modulator, so as to
To the mQAM optical signals on signal road；
Wherein, in transmitting terminal, signal road ESAnd carrier path E (t)P(t) be expressed as：
Wherein, PSAnd PPThe respectively average light power of signal road and carrier path,Expression centre frequency is WCLight carry
Ripple；
Carrier path EPAnd signal road E (t)S(t) it is represented by respectively after step S102 and step S103：
Wherein, s (t) is the mQAM signals of energy normalized；
Second step, carrier path and signal road are sent into less fundamental mode optical fibre together and are transmitted, is specifically comprised the following steps：
Step S104：Carrier path and signal road are carried to different linear polarization mould (LP moulds) respectively by mode coupler
On, it is transmitted into less fundamental mode optical fibre；
Step S105：Carrier path and signal road are carried out by mode conversion and separation by pattern demultiplexer in receiving terminal,
And existed using length-adjustable optical fiber (ODLs) to eliminate the differential mode time delay (DMGD) in less fundamental mode optical fibre between different mode
Time difference caused by receiving terminal；
Because the signal in each LP patterns can be damaged in less fundamental mode optical fibre transmitting procedure by pattern crosstalk, differential mode time delay etc.
Hinder, and the time difference caused by differential mode group delay can be eliminated by ODLs, will not be to carrier path and the frequency spectrum on signal road
Orthogonality damages.Therefore for simple and clear analysis, in formula expression, we only consider pattern string in less fundamental mode optical fibre
The influence disturbed.
Wherein, after step S104 and step S105, carrier path EPAnd signal road E (t)S(t) can be expressed as：
Wherein, α and β is respectively the coefficient of coup of carrier path and signal road after less fundamental mode optical fibre transmits；
3rd step, down coversion, filtering, amplification are carried out to carrier path in receiving terminal, then as relevant local oscillator light (LO)
Relevant detection is carried out with signal road.
Step S106：The carrier path of pattern demultiplexer separation is sent into Mach and increases Dare intensity modulator, to carrier path
Carry out down coversion；
After step S106, carrier path can be expressed as：
Wherein,, can be as relevant local oscillator light source for required pilot tone light； For 2 frequencys multiplication of double-side band pilot tone light in original carrier path；WithThe right band and left side band respectively after carrier path crosstalk signal down coversion；Can according to formula (7)
To find out, the signal of carrier path crosstalk entered after down coversion, still kept spectrum orthogonal with required pilot tone light.
Step S107：The carrier path Jing Guo down coversion is filtered using optical band pass filter；
After step S107, carrier path can be expressed as carrier path：
Step S108：Filtered carrier path pilot tone light is close to preferable local oscillator light, yet with double sideband modulation depth
And the reason such as loss of optical fiber in transmitting procedure so that filtered carrier path pilot tone luminous power is relatively low, it is therefore desirable to which light is put
Big device is amplified to filtered carrier path, makes light power stabilising in mw levels；
Step S109：Local oscillator light source using the carrier path pilot tone light after amplification as coherent light communication, with signal road
Carry out relevant detection；
Step S110：It will be carried out in relevant electric signal feeding Digital Signal Processing (DSP) module for detecting and obtaining at signal
Reason；Wherein, signal transacting includes sampling, normalization, clock is synchronous, dispersion (CD) compensates, MIMO is balanced and the judgement bit error rate
(BER) calculate.
Compared with prior art, the invention has the advantages that：
The present invention has using carrier path pilot tone light in transmitting terminal double sideband modulation and in the method that receiving terminal down coversion is recovered
Effect eliminate due in less fundamental mode optical fibre transmitting procedure carrier path by the crosstalk on signal road caused by be concerned with beat frequency noise
Influence.This method is improved from homodyne detection mode division multiplexing (MDM-SHD) in the case where not changing existing less fundamental mode optical fibre (FMF) parameter
The transmission range of system, reduce model selection spirit of the MDM-SHD systems to pattern multiplexer/demultiplexer (MUX/DEMUX)
The requirement of sensitivity, while preferable error performance can be ensured, there is the higher impact of performance.
Brief description of the drawings
Fig. 1 is 4 × 4 based on carrier path double sideband modulation of the present invention from homodyne detection mode division multiplexing (DSB-MDM-
SHD) system structure diagram；
Fig. 2 is 4 × 4 based on carrier path double sideband modulation of the present invention from homodyne detection mode division multiplexing (DSB-MDM-
SHD) system transmitter structural representation；
Fig. 3 is 4 × 4 based on carrier path double sideband modulation of the present invention from homodyne detection mode division multiplexing (DSB-MDM-
SHD) system receiver structural representation；
Fig. 4 is of the invention when 60km is transmitted, and uses each portion of carrier path of 4 × 4DSB-MDM-SHD system architecture schemes
Frequency dividing spectrum change schematic diagram.Wherein, Fig. 4-1, the carrier path spectrogram difference knot of corresponding diagram 1 represented by 4-2,4-3,4-4,4-5
1,2,3,4,5 positions marked in structure.Fig. 4-1 is the frequency spectrum of transmitting terminal light source carrier path after beam splitter；Fig. 4-2 transmitting terminals
The spectrogram after double sideband modulation is carried out for carrier path；Fig. 4-3 is spectrogram of the receiving terminal carrier path after delay compensation；Figure
4-4 is spectrogram of the receiving terminal carrier path after down coversion；Fig. 4-5 is receiving terminal carrier path after light filtering and light amplification
Spectrogram.
Fig. 5 is of the invention after 60km is transmitted, and under different OSNRs (OSNR), uses 4 × 4DSB-MDM-
Error rate of system (BER) the performance figure on each mode signal road of SHD system architecture schemes；
Fig. 6 is 4 × 4DSB-MDM-SHD systems and 4 × 4MDM-SHD systems in the case that the OSNR of the present invention is 20dB
In error rate of system (BER) performance and contrast of pattern multiplexer/demultiplexer (MUX/DEMUX) using different stiffness of couplings
Figure；
Fig. 7 is 4 × 4DSB-MDM-SHD systems and 4 × 4MDM-SHD systems in the case that the OSNR of the present invention is 20dB
In error rate of system (BER) performance of different transmission ranges and comparison diagram；
Embodiment
In order to which the above method of the present invention, step is more clearly understood, below in conjunction with the accompanying drawings and specific embodiment party
The present invention is further described in detail method.
Embodiment 1
Emulation is carried out using 4 × 4 to method proposed by the present invention from homodyne detection mode division multiplexing (MDM-SHD) system to test
Card.Fig. 1 is 4 × 4 based on carrier path double sideband modulation of the use of the present invention from homodyne detection mode division multiplexing (DSB-MDM-
SHD) system structure diagram, its composition include：The DFB that 1 centre frequency is 193.1THz (centre wavelength 1552.5nm)
Laser light source module, its line width are 1MHz, and output mean power is 3mw；2 56Gb/s PDM-QPSK signal transmitter modules；One
Individual 1:3 and one 1:2 power splitter modules；Two 14GHz sine signal sources and two Mach increase Dare intensity modulator
(MZ) module, its driving current are 0.8A, bias current 0A；A pair of pattern multiplexers/demultiplexer module, its model selection
Sensitivity can be controlled according to Mode Coupling matrix, and the stiffness of coupling for giving tacit consent to introducing is respectively -25dB；Two segment length are adjustable
Single-mode fiber (ODLs)；One second order Gauss type optical band pass filter (OBPF) module, it is with a width of 10GHz；Two PDM-
QPSK signal receiver modules；One DSP data-signal processing module.Wherein, the simulation parameter of less fundamental mode optical fibre (FMF) is：
LP01 and LP11 mode-coupling resonats intensity is -34dB/km, and the merger Mode Coupling between LP11a and LP11b is -28dB/km；It is few
Mode fiber loss is 0.2dB/km；The chromatic dispersion of LP01 moulds is 20ps/nm/km, and the chromatic dispersion of LP11 moulds is 21ps/km/
nm；Differential mode time delay (MDGD) is 4ns/km between LP01 and LP11 patterns.The present invention is to from homodyne detection mode division multiplexing
(MDM-SHD) improvement on system carrier road, to realize more preferable transmission performance.
The removing method of carrier path crosstalk, is comprised the following steps that in a kind of mode division multiplexing system from homodyne detection：
Step S101：Present example uses 4 × 4DSB-MDM-SHD system architectures, and transmission signal uses two-way 56Gb/s
PDM-QPSK signals, its transmission spectrum band a width of 28GHz, wanted carrier road sinusoidal signal ω0=B/2 is 14GHz.
Step S102：The laser beam that the DFB lasing light emitters transmitting mean power that centre wavelength is 1552.5nm is 3mw, light beam
By 1:3 power splitters are equally divided into three beams.Fig. 4-1 is the frequency spectrum of transmitting terminal light source carrier path after beam splitter.Its
Middle light beam increases Dare intensity modulator to produce the double of carrier path as carrier path by the Mach driven by sine signal source
Sideband pilot tone light.Fig. 4-2 is the spectrogram after carrier path DSB modulation.
Step S103：The other two-beam of power splitter passes through 2 56Gbit/s orthogonal IQ respectively as signal road
Modulator produces two-way PDM-QPSK signals.Fig. 2 is the structural representation of PDM-IQ emitters.It has a PRBS random signal
Source, two polarization beam apparatus (PBS), two I/Q modulator compositions.Wherein, I/Q modulator increases Dare intensity modulated by two Mach
Device (MZ) and a pi/2 phase shift device composition.Length caused by PRBS is 2 by emitter15- 1 random signal carries out QPSK mappings, it
Afterwards by two polarization states of X and Y of QPSK signal modulations to each signal road laser beam, two-way PDM-QPSK signals are produced.
Step S104：3 patterns that carrier path and two signal roads are entered in less fundamental mode optical fibre via mode coupler
(LP01, LP11a and LP11b) and its corresponding polarization mode.Wherein LP01 moulds bearing carrier wave road, LP11a and LP11b are carried respectively
Two signal roads.
Step S105：After the transmission of 60km less fundamental mode optical fibres, in receiving terminal use pattern demultiplexer (DEMUX) to each pattern
Separated.LP11a and LP11b signals road after separation is eliminated into LP11 and LP01 in transmitting procedure by two sections of ODLs optical fiber
(according to less fundamental mode optical fibre parameter, the DMGD after 60km is transmitted between LP01 and LP11 moulds is differential mode time delay between pattern
240ns).Fig. 4-3 is the spectrogram of carrier path after demultiplexing, is believed including double-side band pilot tone light and the PDM-QPSK of crosstalk
Number.
Step S106：After delay compensation, carrier path is sent into a Mach and increases Dare intensity modulator (MZ) module, via
14GHz sinusoidal signals carry out down coversion.Fig. 4-4 is the spectrogram after carrier path down coversion.Carrier path double-side band pilot tone light passes through
Required pilot tone light can be regenerated in central wavelength by crossing down coversion, and keep pilot tone light and crosstalk signal frequency content just
Hand over.
Step S107：After down coversion, carrier path passes through a second order Gauss type optical band pass filter with a width of 10GHz
(OBPF) module filter out carrier path it is miscellaneous in frequency content and with outer ASE noises, retain the preferable pilot tone light (PT) of carrier path.
Step S108：Filtered carrier path pilot tone light (PT) one erbium-doped fiber amplifier (EDFA) of feeding is amplified,
The loss of power is compensated, makes its power stability in mw levels.Fig. 4-5 is the spectrogram of carrier path pilot tone light (PT) after filtering, amplification.
Step S109：Carrier path pilot tone light (PT) after EDFA amplifies is sent into one 1:2 beam splitters are divided
Beam, enter two PDM-QPSK coherent receivers respectively as local oscillator light (LO) and LP11a and LP11b signals road after beam splitting and carry out
Relevant detection.Fig. 3 is the structural representation of PDM coherent receivers.It is by two polarization beam apparatus (PBS), two 90 degree of mixing
Device, four balanced detectors and four low pass filter (LPF) compositions.Receiver is by LP11a the and LP11b patterns received
Light is sent into 90 ° of frequency mixers together with the pilot tone light (PT) Jing Guo beam splitting, and the optical signal after mixing passes through balanced detector
(BPD) electric signal is converted into, then electric signal is sent into low pass filter, output signal is finally obtained and is sent into DSP module.
Step S110：After relevant detection, the road signal of LP11ax, LP11ay, LP11bx and LP11by tetra- respectively enters
DSP signal processing modules, signal is sampled, normalized, clock synchronization, and optical fiber is transmitted using dispersion compensation algorithm
Chromatic dispersion (CD) compensates.Adaptive equalization is done to signal using 4 × 4MIMO-CMA algorithms, eliminates the string in LP11 moulds
Disturb.Hard decision, QPSK demappings and the bit error rate (BER) is carried out to data afterwards to calculate.
Fig. 5 is under different OSNR, and the change of the road signal error rate (BER) of LP11ax, LP11ay, LP11bx and LP11by tetra- is bent
Line chart.Four channels reach the FEC limit after 60km transmission, in 17dB and (realize that the highest system of inerrancy transmission is missed
Code check, 7%FEC thresholdings are 3.8e-3).
Fig. 6 is that the pattern multiplexer demultiplexing (MUX/DEMUX) of different degree of coupling is right in the case of OSNR is 20dB
The influence curve figure of the tunnel signal transmission performance of LP11ax, LP11ay, LP11bx and LP11by tetra-；Fig. 6 also provide a comparison the same terms
Under, the change of MDM-SHD systems and DSB-MDM-SHD error rate of systems.From fig. 6 it can be seen that DSB- proposed by the present invention
MDM-SHD system schemas can effectively reduce the bit error rate of system, reduce the influence of multiplexer/demultiplexer pattern crosstalk.
Fig. 7 is that different transmission ranges are to the tunnel of LP11ax, LP11ay, LP11bx and LP11by tetra- in the case of OSNR is 20dB
The influence of signal error rate；Fig. 7 also compared under different transmission ranges, MDM-SHD systems and DSB-MDM-SHD error rate of systems
Change.It can be seen from figure 7 that MDM-SHD systems error rate of system when transmitting 60km is higher than the FEC limit, and DSB-
MDM-SHD systems just reach the FEC limit when transmitting 90km.As a result show, DSB-MDM-SHD systems have more preferable transporting
Energy.
Base 4 × 4 described in examples detailed above is it is known in the art, by known approach from homodyne detection mode division multiplexing system
Obtain.
It is used in the present invention to be conciliate from terms such as homodyne detection, double sideband modulation, down coversions just to more convenient description
The present invention is released, its additional limitation can not be used as.
Claims (6)
1. the removing method of carrier path crosstalk in a kind of mode division multiplexing system from homodyne detection, it is characterised in that specific steps are such as
Under：
The first step, modulation produce the double-side band pilot tone light of carrier path and the mQAM optical signals on signal road；Specifically comprise the following steps：
Step S101：The symbol rates of the mQAM signals transmitted as needed and modulation format calculate the bandwidth f of signals, with mQAM
The frequencies omega of first spectral null of signal0The frequency for the sine wave that carrier path needs to use is determined, so as to keep carrier path
With signal road on frequency spectrum it is orthogonal；
Step S102：It is ω by frequency0Sine wave by Mach increase Dare intensity modulator (MZ) be modulated on carrier path light,
So as to produce the double-side band pilot tone light of carrier path；
Step S103：The mQAM signals for needing to transmit are modulated on the light of signal road by orthogonal I/Q modulator, so as to obtain letter
The mQAM optical signals on number road；
Second step, carrier path and signal road are sent into less fundamental mode optical fibre together and are transmitted；Specifically comprise the following steps：
Step S104：Carrier path and signal road are carried on different linear polarization mould (LP moulds) respectively by mode coupler,
It is transmitted into less fundamental mode optical fibre；
Step S105：Carrier path and signal road are carried out by mode conversion and separation by pattern demultiplexer in receiving terminal, and
Received using length-adjustable optical fiber (ODLs) to eliminate the differential mode time delay (DMGD) in less fundamental mode optical fibre between different mode
Time difference caused by end；
3rd step, down coversion, filtering, amplification are carried out to carrier path in receiving terminal, then as relevant local oscillator light (LO) and letter
Number road carries out relevant detection.
Step S106：The carrier path of pattern demultiplexer separation is sent into Mach and increases Dare intensity modulator, carrier path is carried out
Down coversion；
Step S107：The carrier path Jing Guo down coversion is filtered using optical band pass filter；
Step S108：Filtered carrier path is amplified using image intensifer, makes light power stabilising in mw levels；
Step S109：Local oscillator light source using the carrier path pilot tone light after amplification as coherent light communication, carried out with signal road
Relevant detection；
Step S110：Signal transacting will be carried out in relevant electric signal feeding Digital Signal Processing (DSP) module for detecting and obtaining.
2. the removing method of carrier path crosstalk in a kind of mode division multiplexing system from homodyne detection as claimed in claim 1, it is special
Sign is, in the described first step, in transmitting terminal, signal road ESAnd carrier path E (t)P(t) be expressed as：
<mrow>
<msub>
<mi>E</mi>
<mi>s</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<msqrt>
<msub>
<mi>P</mi>
<mi>s</mi>
</msub>
</msqrt>
<msup>
<mi>e</mi>
<mrow>
<msub>
<mi>jw</mi>
<mi>c</mi>
</msub>
<mi>t</mi>
</mrow>
</msup>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>1</mn>
<mo>)</mo>
</mrow>
</mrow>
<mrow>
<msub>
<mi>E</mi>
<mi>P</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<msqrt>
<msub>
<mi>P</mi>
<mi>P</mi>
</msub>
</msqrt>
<msup>
<mi>e</mi>
<mrow>
<msub>
<mi>jw</mi>
<mi>c</mi>
</msub>
<mi>t</mi>
</mrow>
</msup>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>2</mn>
<mo>)</mo>
</mrow>
</mrow>
Wherein, PSAnd PPThe respectively average light power of signal road and carrier path,Expression centre frequency is WCLight carrier；
Carrier path EPAnd signal road E (t)S(t) it is represented by respectively after step S102 and step S103：
<mrow>
<msub>
<mi>E</mi>
<mi>s</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<msqrt>
<msub>
<mi>P</mi>
<mi>s</mi>
</msub>
</msqrt>
<mi>s</mi>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<msup>
<mi>e</mi>
<mrow>
<msub>
<mi>jw</mi>
<mi>c</mi>
</msub>
<mi>t</mi>
</mrow>
</msup>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>3</mn>
<mo>)</mo>
</mrow>
</mrow>
<mrow>
<msub>
<mi>F</mi>
<mi>P</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
<msqrt>
<msub>
<mi>P</mi>
<mi>P</mi>
</msub>
</msqrt>
<msup>
<mi>e</mi>
<mrow>
<mi>j</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>&omega;</mi>
<mi>c</mi>
</msub>
<mo>+</mo>
<msub>
<mi>&omega;</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
<mi>t</mi>
</mrow>
</msup>
<mo>+</mo>
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
<msqrt>
<msub>
<mi>P</mi>
<mi>P</mi>
</msub>
</msqrt>
<msup>
<mi>e</mi>
<mrow>
<mi>j</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>&omega;</mi>
<mi>c</mi>
</msub>
<mo>-</mo>
<msub>
<mi>&omega;</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
<mi>t</mi>
</mrow>
</msup>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>4</mn>
<mo>)</mo>
</mrow>
</mrow>
Wherein, s (t) is the mQAM signals of energy normalized.
3. the removing method of carrier path crosstalk in a kind of mode division multiplexing system from homodyne detection as claimed in claim 1, it is special
Sign is, in described step two, after step S104 and step S105, and carrier path EPAnd signal road E (t)S(t) can be with table
It is shown as：
<mrow>
<msub>
<mi>F</mi>
<mi>P</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
<msqrt>
<msub>
<mi>P</mi>
<mi>P</mi>
</msub>
</msqrt>
<mrow>
<mo>(</mo>
<mn>1</mn>
<mo>-</mo>
<mi>&alpha;</mi>
<mo>)</mo>
</mrow>
<mo>&lsqb;</mo>
<msup>
<mi>e</mi>
<mrow>
<mi>j</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>&omega;</mi>
<mi>c</mi>
</msub>
<mo>+</mo>
<msub>
<mi>&omega;</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
<mi>t</mi>
</mrow>
</msup>
<mo>+</mo>
<msup>
<mi>e</mi>
<mrow>
<mi>j</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>&omega;</mi>
<mi>c</mi>
</msub>
<mo>-</mo>
<msub>
<mi>&omega;</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
<mi>t</mi>
</mrow>
</msup>
<mo>&rsqb;</mo>
<mo>+</mo>
<msqrt>
<msub>
<mi>P</mi>
<mi>S</mi>
</msub>
</msqrt>
<mi>&beta;</mi>
<mi>s</mi>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<msup>
<mi>e</mi>
<mrow>
<msub>
<mi>jw</mi>
<mi>c</mi>
</msub>
<mi>t</mi>
</mrow>
</msup>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>5</mn>
<mo>)</mo>
</mrow>
</mrow>
<mrow>
<msub>
<mi>aF</mi>
<mi>S</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<msqrt>
<msub>
<mi>P</mi>
<mi>S</mi>
</msub>
</msqrt>
<mrow>
<mo>(</mo>
<mn>1</mn>
<mo>-</mo>
<mi>&beta;</mi>
<mo>)</mo>
</mrow>
<mi>s</mi>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<msup>
<mi>e</mi>
<mrow>
<msub>
<mi>jw</mi>
<mi>c</mi>
</msub>
<mi>t</mi>
</mrow>
</msup>
<mo>+</mo>
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
<msqrt>
<msub>
<mi>P</mi>
<mi>P</mi>
</msub>
</msqrt>
<mi>&alpha;</mi>
<mo>&lsqb;</mo>
<msup>
<mi>e</mi>
<mrow>
<mi>j</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>&omega;</mi>
<mi>c</mi>
</msub>
<mo>+</mo>
<msub>
<mi>&omega;</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
<mi>t</mi>
</mrow>
</msup>
<mo>+</mo>
<msup>
<mi>e</mi>
<mrow>
<mi>j</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>&omega;</mi>
<mi>c</mi>
</msub>
<mo>-</mo>
<msub>
<mi>&omega;</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
<mi>t</mi>
</mrow>
</msup>
<mo>&rsqb;</mo>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>6</mn>
<mo>)</mo>
</mrow>
</mrow>
Wherein, α and β is respectively the coefficient of coup of carrier path and signal road after less fundamental mode optical fibre transmits.
4. the removing method of carrier path crosstalk in a kind of mode division multiplexing system from homodyne detection as claimed in claim 1, it is special
Sign is that described carrier path can be expressed as after step S106：
<mrow>
<mtable>
<mtr>
<mtd>
<mrow>
<msub>
<mi>E</mi>
<mi>P</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
<msqrt>
<msub>
<mi>P</mi>
<mi>P</mi>
</msub>
</msqrt>
<mrow>
<mo>(</mo>
<mn>1</mn>
<mo>-</mo>
<mi>&alpha;</mi>
<mo>)</mo>
</mrow>
<msup>
<mi>e</mi>
<mrow>
<msub>
<mi>j&omega;</mi>
<mi>c</mi>
</msub>
<mi>t</mi>
</mrow>
</msup>
<mo>+</mo>
<mfrac>
<mn>1</mn>
<mn>4</mn>
</mfrac>
<msqrt>
<msub>
<mi>P</mi>
<mi>P</mi>
</msub>
</msqrt>
<mrow>
<mo>(</mo>
<mn>1</mn>
<mo>-</mo>
<mi>&alpha;</mi>
<mo>)</mo>
</mrow>
<mo>&lsqb;</mo>
<msup>
<mi>e</mi>
<mrow>
<mi>j</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>&omega;</mi>
<mi>c</mi>
</msub>
<mo>+</mo>
<mn>2</mn>
<msub>
<mi>&omega;</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
<mi>t</mi>
</mrow>
</msup>
<mo>+</mo>
<msup>
<mi>e</mi>
<mrow>
<mi>j</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>&omega;</mi>
<mi>c</mi>
</msub>
<mo>-</mo>
<mn>2</mn>
<msub>
<mi>&omega;</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
<mi>t</mi>
</mrow>
</msup>
<mo>&rsqb;</mo>
</mrow>
</mtd>
</mtr>
<mtr>
<mtd>
<mrow>
<mo>+</mo>
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
<msqrt>
<msub>
<mi>P</mi>
<mi>S</mi>
</msub>
</msqrt>
<mi>&beta;</mi>
<mi>s</mi>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<msup>
<mi>e</mi>
<mrow>
<mi>j</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>w</mi>
<mi>c</mi>
</msub>
<mo>+</mo>
<msub>
<mi>w</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
<mi>t</mi>
</mrow>
</msup>
<mo>+</mo>
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
<msqrt>
<msub>
<mi>P</mi>
<mi>S</mi>
</msub>
</msqrt>
<mi>&beta;</mi>
<mi>s</mi>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<msup>
<mi>e</mi>
<mrow>
<mi>j</mi>
<mrow>
<mo>(</mo>
<msub>
<mi>w</mi>
<mi>c</mi>
</msub>
<mo>-</mo>
<msub>
<mi>w</mi>
<mn>0</mn>
</msub>
<mo>)</mo>
</mrow>
<mi>t</mi>
</mrow>
</msup>
</mrow>
</mtd>
</mtr>
</mtable>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>7</mn>
<mo>)</mo>
</mrow>
</mrow>
Wherein,, can be as relevant local oscillator light source for required pilot tone light； For 2 frequencys multiplication of double-side band pilot tone light in original carrier path；WithThe right band and left side band respectively after carrier path crosstalk signal down coversion.
5. the removing method of carrier path crosstalk in a kind of mode division multiplexing system from homodyne detection as claimed in claim 1, it is special
Sign is that described carrier path can be expressed as after step S107：
<mrow>
<msub>
<mi>E</mi>
<mi>P</mi>
</msub>
<mrow>
<mo>(</mo>
<mi>t</mi>
<mo>)</mo>
</mrow>
<mo>=</mo>
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
<msqrt>
<msub>
<mi>P</mi>
<mi>P</mi>
</msub>
</msqrt>
<mrow>
<mo>(</mo>
<mn>1</mn>
<mo>-</mo>
<mi>&alpha;</mi>
<mo>)</mo>
</mrow>
<msup>
<mi>e</mi>
<mrow>
<msub>
<mi>j&omega;</mi>
<mi>c</mi>
</msub>
<mi>t</mi>
</mrow>
</msup>
<mo>-</mo>
<mo>-</mo>
<mo>-</mo>
<mrow>
<mo>(</mo>
<mn>8</mn>
<mo>)</mo>
</mrow>
</mrow>
6. the removing method of carrier path crosstalk in a kind of mode division multiplexing system from homodyne detection as claimed in claim 1, it is special
Sign is, the signal transacting described in the step S110, which includes signal transacting, includes that sampling, normalization, clock be synchronous, dispersion
(CD) compensation, MIMO equilibriums and the judgement bit error rate (BER) calculate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710821373.9A CN107634814B (en) | 2017-09-13 | 2017-09-13 | A kind of removing method of the carrier path crosstalk from homodyne detection mode division multiplexing system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710821373.9A CN107634814B (en) | 2017-09-13 | 2017-09-13 | A kind of removing method of the carrier path crosstalk from homodyne detection mode division multiplexing system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107634814A true CN107634814A (en) | 2018-01-26 |
| CN107634814B CN107634814B (en) | 2019-03-01 |
Family
ID=61101302
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710821373.9A Active CN107634814B (en) | 2017-09-13 | 2017-09-13 | A kind of removing method of the carrier path crosstalk from homodyne detection mode division multiplexing system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107634814B (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110324140A (en) * | 2018-03-30 | 2019-10-11 | 上海国盾量子信息技术有限公司 | A kind of decoding apparatus, method and dissemination system for continuous variable quantum key distribution |
| CN110429988A (en) * | 2019-09-19 | 2019-11-08 | 上海大学 | It is a kind of based on fiber mode conversion all -fiber outside difference detector part |
| CN112702119A (en) * | 2021-03-25 | 2021-04-23 | 南京信息工程大学 | Differential mode group delay compensation method and system based on photoelectric fusion |
| CN113098595A (en) * | 2021-03-12 | 2021-07-09 | 华中科技大学 | Method, system and device for measuring group delay of few-mode optical fiber differential mode |
| CN113726433A (en) * | 2021-06-16 | 2021-11-30 | 暨南大学 | Multi-rate subcarrier modulation signal receiving and transmitting method and system |
| CN114448518A (en) * | 2020-11-04 | 2022-05-06 | 西安电子科技大学 | Method for detecting optical carrier radio frequency link with low complexity coherence |
| CN114598391A (en) * | 2020-12-03 | 2022-06-07 | 北京大学 | Far-end true delay beamforming implementation method based on few-mode optical fiber |
| CN114785418A (en) * | 2022-04-21 | 2022-07-22 | 南京信息工程大学 | Low-mode crosstalk few-mode optical fiber transmission system |
| CN115361068A (en) * | 2022-06-30 | 2022-11-18 | 北京邮电大学 | Self-adaptive damage equalization method and device for multi-core few-mode optical fiber signals |
| CN115865113A (en) * | 2022-11-04 | 2023-03-28 | 华南理工大学 | Millimeter wave self-homodyne receiver |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130071114A1 (en) * | 2011-08-15 | 2013-03-21 | Scott Robertson Bickham | Few mode optical fibers for mode division multiplexing |
| CN103095373A (en) * | 2013-01-31 | 2013-05-08 | 华中科技大学 | Self-correlation optical fiber communication system based on mode division multiplexing |
| CN103149640A (en) * | 2013-03-06 | 2013-06-12 | 上海理工大学 | Device and method for generating axisymmetric polarized light |
| US20170082796A1 (en) * | 2014-12-24 | 2017-03-23 | Jiangsu University | Mode filtering optical fibre |
-
2017
- 2017-09-13 CN CN201710821373.9A patent/CN107634814B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130071114A1 (en) * | 2011-08-15 | 2013-03-21 | Scott Robertson Bickham | Few mode optical fibers for mode division multiplexing |
| CN103095373A (en) * | 2013-01-31 | 2013-05-08 | 华中科技大学 | Self-correlation optical fiber communication system based on mode division multiplexing |
| CN103149640A (en) * | 2013-03-06 | 2013-06-12 | 上海理工大学 | Device and method for generating axisymmetric polarized light |
| US20170082796A1 (en) * | 2014-12-24 | 2017-03-23 | Jiangsu University | Mode filtering optical fibre |
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110324140A (en) * | 2018-03-30 | 2019-10-11 | 上海国盾量子信息技术有限公司 | A kind of decoding apparatus, method and dissemination system for continuous variable quantum key distribution |
| CN110429988A (en) * | 2019-09-19 | 2019-11-08 | 上海大学 | It is a kind of based on fiber mode conversion all -fiber outside difference detector part |
| CN114448518A (en) * | 2020-11-04 | 2022-05-06 | 西安电子科技大学 | Method for detecting optical carrier radio frequency link with low complexity coherence |
| CN114448518B (en) * | 2020-11-04 | 2024-01-30 | 西安电子科技大学 | Method for coherently detecting optical carrier radio frequency link with low complexity |
| CN114598391B (en) * | 2020-12-03 | 2023-11-07 | 北京大学 | Far-end true time delay beam forming realization method based on few-mode optical fiber |
| CN114598391A (en) * | 2020-12-03 | 2022-06-07 | 北京大学 | Far-end true delay beamforming implementation method based on few-mode optical fiber |
| CN113098595A (en) * | 2021-03-12 | 2021-07-09 | 华中科技大学 | Method, system and device for measuring group delay of few-mode optical fiber differential mode |
| CN112702119A (en) * | 2021-03-25 | 2021-04-23 | 南京信息工程大学 | Differential mode group delay compensation method and system based on photoelectric fusion |
| CN112702119B (en) * | 2021-03-25 | 2021-06-01 | 南京信息工程大学 | Differential mode group delay compensation method and system based on photoelectric fusion |
| CN113726433A (en) * | 2021-06-16 | 2021-11-30 | 暨南大学 | Multi-rate subcarrier modulation signal receiving and transmitting method and system |
| CN113726433B (en) * | 2021-06-16 | 2022-09-06 | 暨南大学 | Multi-rate subcarrier modulation signal receiving and transmitting method and system |
| CN114785418A (en) * | 2022-04-21 | 2022-07-22 | 南京信息工程大学 | Low-mode crosstalk few-mode optical fiber transmission system |
| CN114785418B (en) * | 2022-04-21 | 2023-09-19 | 南京信息工程大学 | Few-mode optical fiber transmission system with low-mode crosstalk |
| CN115361068B (en) * | 2022-06-30 | 2023-09-05 | 北京邮电大学 | Self-adaptive damage equalization method and device for multi-core few-mode optical fiber signals |
| CN115361068A (en) * | 2022-06-30 | 2022-11-18 | 北京邮电大学 | Self-adaptive damage equalization method and device for multi-core few-mode optical fiber signals |
| CN115865113B (en) * | 2022-11-04 | 2023-07-18 | 华南理工大学 | Millimeter wave self-homodyne receiver |
| CN115865113A (en) * | 2022-11-04 | 2023-03-28 | 华南理工大学 | Millimeter wave self-homodyne receiver |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107634814B (en) | 2019-03-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107634814B (en) | A kind of removing method of the carrier path crosstalk from homodyne detection mode division multiplexing system | |
| EP2175574B1 (en) | Transmission system comprising a CS-RZ DPSK optical transmitter | |
| US9197320B2 (en) | System and method for monitoring polarization-dependent loss | |
| CN103095373A (en) | Self-correlation optical fiber communication system based on mode division multiplexing | |
| US20120301146A1 (en) | Equivalent-Link Backward Propagation Method for Nonlinearity Compensation in Fiber Transmission Systems | |
| CN105612701A (en) | System and method using spectral shaping and expanded channel spacing | |
| CN110830249B (en) | Space division multiplexing continuous variable quantum communication encryption system and implementation method | |
| CN105680949A (en) | In-band full-duplex radio over fiber communication system based on wavelength division multiplexing | |
| Senthamizhselvan et al. | Performance analysis of DWDM based fiber optic communication with different modulation schemes and dispersion compensation fiber | |
| Maharana et al. | channel WDM based hybrid optical Fiber/FSO communication system using DP QPSK modulation for bit rate of 100/112 Gb/s | |
| CN105790846A (en) | Wired-and-wireless-optical-transmission-based double-polarization differential quadrature phase shift keying access apparatus | |
| Patnaik et al. | Optimized hybrid optical communication system for first mile and last mile problem solution of today's optical network | |
| Aboagye et al. | Performance analysis of 112 Gb/s× 4-channel WDM PDM-DQPSK optical label switching system with spectral amplitude code labels | |
| CN114142933B (en) | Secret communication device based on multi-core optical fiber and communication method thereof | |
| Yu et al. | Modified low CSPR Kramer–Kronig receivers based on a signal–signal beat interference estimation | |
| Reznikov et al. | Development to High-Rate Fiber Optic Communication Line with Orthogonal Frequency-Division Multiplexing | |
| Cherutoi et al. | Performance of DQPSK, NRZ and RZ modulation formats in different optical fibres | |
| Galili et al. | All-optical combination of DPSK and OOK to 160 Gbit/s DQPSK data signals | |
| Ismail et al. | ROF Communication System Performance Enhancement Using Both Modified Differential Phase Shift Keying (DPSK) and Sub-Carrier Multiplexing Technique. | |
| Abdul-Rahaim et al. | Performance of coherent optical OFDM in WDM system based on QPSK and 16-QAM modulation through super channels | |
| Ehsan et al. | Design and Implementation of Hybrid Medium DP-DQPSK DWDM ROF Transmission System for Different Weather Conditions. | |
| Shao et al. | A novel dual polarization multiplexing RoF system integrating optical fiber and FSO channel with AMI downlink signals | |
| Chen | Study on 4PAM radio over fiber system using self-mixing technique | |
| Horvath et al. | Coherent data system and slow data transmission in a single fiber with ITU grid spacing | |
| Kaszubowska-Anandarajah et al. | A multifunctional demultiplexer for optical frequency combs in broadband access networks |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |