CN116865866A - Carrier-suppressed zero-return alternating polarization/frequency shift keying quadrature modulation optical communication system - Google Patents
Carrier-suppressed zero-return alternating polarization/frequency shift keying quadrature modulation optical communication system Download PDFInfo
- Publication number
- CN116865866A CN116865866A CN202311127396.1A CN202311127396A CN116865866A CN 116865866 A CN116865866 A CN 116865866A CN 202311127396 A CN202311127396 A CN 202311127396A CN 116865866 A CN116865866 A CN 116865866A
- Authority
- CN
- China
- Prior art keywords
- signal
- optical
- csrz
- signals
- optical signal
- 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
- 230000003287 optical effect Effects 0.000 title claims abstract description 175
- 238000004891 communication Methods 0.000 title claims abstract description 44
- 230000010287 polarization Effects 0.000 title claims abstract description 32
- 101150097208 MZM1 gene Proteins 0.000 claims abstract description 37
- 230000001629 suppression Effects 0.000 claims abstract description 18
- 239000000969 carrier Substances 0.000 claims abstract description 14
- 238000005520 cutting process Methods 0.000 claims abstract description 14
- 230000008878 coupling Effects 0.000 claims abstract description 8
- 238000010168 coupling process Methods 0.000 claims abstract description 8
- 238000005859 coupling reaction Methods 0.000 claims abstract description 8
- 238000000034 method Methods 0.000 claims description 18
- 239000013307 optical fiber Substances 0.000 claims description 9
- 238000001514 detection method Methods 0.000 claims description 6
- 230000008569 process Effects 0.000 claims description 6
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 abstract description 15
- 238000001228 spectrum Methods 0.000 abstract description 4
- 238000004020 luminiscence type Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 19
- 230000008054 signal transmission Effects 0.000 description 9
- 238000004590 computer program Methods 0.000 description 7
- 230000009022 nonlinear effect Effects 0.000 description 6
- 230000008859 change Effects 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 4
- 230000006870 function Effects 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 238000011160 research Methods 0.000 description 3
- 230000003595 spectral effect Effects 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- 230000004075 alteration Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 230000006855 networking Effects 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 102100029469 WD repeat and HMG-box DNA-binding protein 1 Human genes 0.000 description 1
- 101710097421 WD repeat and HMG-box DNA-binding protein 1 Proteins 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
- H04B10/5165—Carrier suppressed; Single sideband; Double sideband or vestigial
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
- H04B10/5161—Combination of different modulation schemes
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
- H04B10/532—Polarisation modulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
- H04B10/54—Intensity modulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
- H04B10/548—Phase or frequency modulation
- H04B10/556—Digital modulation, e.g. differential phase shift keying [DPSK] or frequency shift keying [FSK]
- H04B10/5563—Digital frequency modulation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Optical Communication System (AREA)
Abstract
The invention relates to a carrier wave suppression zeroing alternating polarization/frequency shift keying quadrature modulation optical communication system, CW continuous luminescence generates a path of optical signal to enter MZM1; the MZM1 is used for carrying out intensity modulation on the optical signal and inputting the optical signal into the MZM2; the MZM2 performs pulse cutting on the optical signal, and generates a carrier suppression return-to-zero CSRZ signal to be input into the PBS after pi phase difference is added between carriers of each adjacent sign bit of the optical signal; the PBS divides the CSRZ signals into two paths of CSRZ signals with the same intensity and orthogonal polarization states, modulates one path of CSRZ signal optical carrier frequency by 1 and 0 alternate half-rate clock signals to realize phase modulation, inputs the two paths of CSRZ signals into the PBC for coupling, and outputs carrier suppression return-to-zero alternate polarization CSRZ-AP signals by the PBC; the system can improve the data transmission rate and the frequency spectrum efficiency, improve the error code performance and the channel throughput rate of signals, and realize the solution of high-speed optical interconnection in a low-cost mode with simple system realization.
Description
Technical Field
The invention relates to the field of optical signal modulation, in particular to a carrier suppression zeroing alternating polarization/frequency shift keying quadrature modulation optical communication system.
Background
The application of advanced modulation format in high-speed optical communication does not need system to change lines and equipment, and only needs to change corresponding single boards or optical modules on the sending and receiving equipment, thus being a very effective solution. Compared with other modulation formats, the traditional intensity modulation direct detection is simple to realize, has few devices and certain cost advantages, but as the signal rate is improved, the dispersion effect in the system is increased along with the square of the rate, when the service signal rate is improved to be more than 10Gbps, the intensity variation of the intensity modulation signal aggravates the nonlinear effect of the signal, causes pulse distortion, causes frequency offset, generates new frequency components, causes inter-channel inter-code interference, optical power transfer and the like, becomes a main factor for limiting the rate and the performance of the system, and the damage of the traditional intensity modulation signal caused by the nonlinear effect of an optical fiber, the spontaneous radiation noise of an amplifier, chromatic dispersion and the like is difficult to resist and eliminate, so that the traditional intensity modulation is easy to realize, but is generally suitable for a low-speed optical communication system, and cannot provide a solution with the cost, power consumption and capacity advantages under a high-speed interconnection scene of 40Gbps or more than 100Gbps due to the limitation of the signal rate, sensitivity and low nonlinear resistance; in addition, one optical fiber in the traditional 40Gbps or 100Gbps single-channel system can only provide one path of 40Gbps or 100Gbps signal transmission, multiple optical fibers are needed for multiplexing signal transmission, or a WDM (wavelength division multiplexing) system is used for transmission, and the cost is also increased sharply.
Disclosure of Invention
The invention provides a code modulation and demodulation method and a communication device of a CSRZ-AP (Carrier Suppressed Return-to-Zero-Alternately Polarized) which can be used in a high-speed optical communication system with the speed of more than 100Gbps and provides a carrier-suppression Zero-return alternate polarization/frequency shift keying orthogonal modulation and demodulation scheme on the basis of the defect that the signal transmission performance is rapidly deteriorated due to nonlinear effect when the conventional CSRZ technology is applied to the high-speed optical communication system.
According to a first aspect of the present invention, there is provided a carrier-suppressed zeroing alternating polarization modulation and demodulation method, comprising: a signal transmitting side and a signal receiving side, the signal transmitting side comprising: a laser CW, a Mach-Zehnder modulator MZM1, a Mach-Zehnder modulator MZM2, an optical polarizer PBS and a combiner PBC;
the CW continuously emits light to generate an optical signal which enters the MZM1;
the MZM1 carries out intensity modulation on the optical signal and then inputs the optical signal into the MZM2;
the MZM2 performs pulse cutting on the optical signal, generates carrier suppression return-to-zero CSRZ signals after pi phase differences are added between carriers of each adjacent symbol bit of the optical signal, and inputs the carrier suppression return-to-zero CSRZ signals into the PBS;
the PBS divides the CSRZ signals into two paths of CSRZ signals with the same intensity and orthogonal polarization states, one path of CSRZ signal optical carrier frequency is modulated by 1 and 0 alternate half-rate clock signals to realize phase modulation, the two paths of CSRZ signals are input into the PBC for coupling, and the PBC outputs carrier suppression return-to-zero alternate polarization CSRZ-AP signals.
On the basis of the technical scheme, the invention can also make the following improvements.
Optionally, during intensity modulation of the optical signal by the MZM1, an electrical signal is applied to the MZM1；
wherein ,for half-wave voltage of the optical signal, +.>。
Optionally, in the process of pulse cutting of the optical signal by the MZM2, two sinusoidal clock signals with a rate half of the NRZ code rate are respectively sent into two electrodes of the MZM2, that is, the amplitude and the frequency of the clock signals are respectively V pi/2 and half of the rate, the MZM2 is biased at V pi/2, and V pi is the half-wave voltage of the optical signal;
when the phase phi vbias generated by the direct current component is 0, a pi phase difference is added between the carriers of each adjacent sign bit of the optical signal to ensure that the duty ratio of the optical signal is 67 percent, and the width corresponding to the half maximum full width of the optical signal is the period of the optical signalAnd obtaining the CSRZ signal.
Optionally, the signal receiving side includes: a photodiode detector;
and the photodiode detector detects the signal intensity, demodulates the optical signal, and demodulates and recovers to obtain the CSRZ-AP signal.
According to a second aspect of the present invention there is provided a carrier suppressed return to zero alternating polarisation/frequency shift keying quadrature modulated optical communication system comprising: a signal transmitting side and a signal receiving side, the signal transmitting side comprising: laser CW1, laser CW2, mach-zehnder modulator MZM1, mach-zehnder delay interferometer MZDI, mach-zehnder modulator MZM2, mach-zehnder modulator MZM3, optical polarizer PBS and combiner PBC;
the CW1 and the CW2 respectively generate an optical signal with a frequency of 193.1THz and 193.0THz and then are coupled into the MZM1;
the MZM1 carries out DPSK modulation on the optical signals with two frequencies and then inputs the optical signals into the MZDI;
the MZDI demodulates the input optical signal to generate a 50Gbps FSK signal and inputs the signal into the MZDI 2;
the MZM2 carries out quadrature modulation on the input optical signal and then inputs the optical signal into the MZM3;
the MZM3 performs pulse cutting on the optical signal, adds pi phase difference between carriers of each adjacent symbol bit of the optical signal, and inputs the optical signal into the PBS;
the PBS divides the CSRZ signals into two paths of CSRZ signals with the same intensity and orthogonal polarization states, modulates one path of CSRZ signal optical carrier frequency by 1 and 0 alternate half-rate clock signals to realize phase modulation, inputs the two paths of CSRZ signals into the PBC for coupling, and the PBC outputs 100Gbps CSRZ-AP/50Gbps FSK signals.
Optionally, the optical signals output by the CW1 and the CW2 are combined into one optical fiber to enter the MZM1 after passing through the coupler.
Optionally, in the process that the MZM1 performs DPSK modulation on the optical signals with two frequencies, data loaded on the MZM1 is 100Gbps data.
Optionally, in the process of quadrature modulating the input optical signal by the MZM2, the data loaded on the MZM2 is 50Gbps signal data.
Optionally, during the process of pulse cutting of the optical signal by the MZM3, the MZM2 is biased at vpi/2, and the amplitude and frequency of the clock signal are vpi/2 and 25Gbps respectively;
when the phase phi vbias generated by the direct current component is 0, pi phase difference is added between carriers of each adjacent sign bit of the optical signal.
Optionally, the signal receiving side includes: a beam splitter, a photodiode detector A, a band-pass filter and a photodiode detector B;
the optical splitter divides the received optical signal into two paths of optical signals, wherein one path of optical signal demodulates the optical signal through the detection signal intensity of the photodiode detector A, and the 100Gbps CSRZ-AP signal is recovered by demodulation;
and the other path of optical signal is filtered out by the band-pass filter, and then the 50Gbps FSK signal is subjected to photoelectric conversion by the detection of the photodiode detector B, so that the demodulation of the 50Gbps FSK signal is realized.
The invention provides a carrier suppression zeroing alternating polarization/frequency shift keying quadrature modulation optical communication system, which has the beneficial effects that:
the traditional intensity modulation signal is easy to realize and low in cost, but when the traditional CSRZ modulation is used in a high-speed optical communication system based on intensity modulation, the variation of the signal intensity is easy to cause nonlinear effect in a channel along with the increase of the power of the channel, and becomes a main factor for limiting the signal transmission performance, so that high-speed and long-distance transmission cannot be realized. Therefore, the invention discloses an optimization scheme, which adds alternate polarization to generate a new modulation format on the basis of the traditional CSRZ signal, thereby further improving the nonlinear resistance of the modulation signal, improving the signal transmission performance, realizing the transmission of high-capacity and long-distance signals above 100Gbps and solving the problem of large nonlinear damage of intensity modulation in a high-speed long-distance transmission system with low cost;
with the advent of the universal intelligent networking era, the number of users and the traffic flow are greatly increased, and meanwhile, the number of servers of a data center for information interaction is also continuously increased, and the connection rate is continuously improved, so that the connection transmission expansibility of the data center is required to be higher. In the traditional WDM system, signals are required to be carried through different wavelengths, wavelength combining and splitting are required to be realized during the combining and splitting periods, the number of channels of an optical fiber channel in practical engineering is limited, the use of a multi-channel system will bring about the increase of the cost of devices and systems, and how to expand the capacity of an optical interconnection system of a data center network in a low-cost manner has become an important point and a difficulty of attention in the industry. The invention discloses a method for realizing orthogonal modulation and demodulation of 100Gbps CSRZ-AP signals and 50Gbps FSK signals, which can bear two paths of signals from different servers, and are orthogonally modulated on the same channel for transmission without adding wavelength channels or using wave combining and wave dividing devices as WDM systems, because the wave combining and wave dividing devices adopt different orthogonal modulation formats, the separation of the two paths of signals and the identification and updating of information are easier to realize at an intermediate node. The CSRZ-AP signal and the FSK signal have high nonlinear resistance, and the interconnection and the intercommunication of high-speed signals of different servers in the data center can be realized in a low-cost mode.
Drawings
Fig. 1 is a block diagram of a signal transmitting side of a first embodiment of a carrier-suppressed-return-to-zero alternate-polarization optical communication system provided by the present invention;
fig. 2 is a block diagram of a signal receiving side of a first embodiment of a carrier-suppressed return-to-zero alternate-polarization optical communication system according to an embodiment of the present invention;
fig. 3 is a block diagram of a second embodiment of a signal transmitting side of a carrier-suppressed-return-to-zero alternating polarization/frequency shift keying quadrature modulation optical communication system according to an embodiment of the present invention;
FIG. 4 is a spectrum diagram of an FSK signal according to an embodiment of the present invention;
FIG. 5 is a spectrum diagram of a 40Gbps CSRZ-AP/10Gbps FSK quadrature modulation signal provided by an embodiment of the invention;
FIG. 6 is an eye diagram of a 40Gbps CSRZ-AP/10Gbps FSK quadrature modulation signal provided by an embodiment of the present invention;
fig. 7 is a block diagram of an FSK signal receiving side in a second embodiment of a signal receiving side of a carrier-suppressed zero-resetting alternate polarization/frequency shift keying quadrature modulation optical communication system according to an embodiment of the present invention.
Detailed Description
The principles and features of the present invention are described below with reference to the drawings, the examples are illustrated for the purpose of illustrating the invention and are not to be construed as limiting the scope of the invention.
In order to solve the problems, the invention provides a low-cost solution, the invention discloses a novel modulation and demodulation method of a modulation format CSRZ-AP and a realization scheme of CSRZ-AP/FSK quadrature modulation and demodulation realized based on the modulation method, the invention can realize a solution that one path of 100Gbps CSRZ-AP signal and one path of 50Gbps FSK (Frequency Shift Keying) signal are subjected to quadrature modulation and then are synthesized into one path of 150Gbps signal to be loaded into light waves and transmitted to a receiving end through an optical fiber, the invention only needs to divide the signal into two paths at the receiving end, and the final information can be obtained by directly detecting the signals through a detector.
At present, no related research report of CSRZ-AP and CSRZ-AP/FSK quadrature modulation is found yet; researches show that compared with the traditional NRZ, RZ, CSRZ, CRZ, DQPSK, the CSRZ-AP and FSK modulation formats have higher nonlinear tolerance and high dispersion tolerance, can effectively overcome transmission damage caused by system rate improvement and channel interval narrowing, distinguish signals through different frequencies and different amplitudes by one CSRZ-AP and FSK modulation format, and can be applied to high-speed optical connection systems such as 50Gbps and 100Gbps after quadrature modulation, so that the cost is relatively low and the problem of high-speed optical interconnection is easy to solve. Fig. 1 is a block diagram of a signal transmitting side of a first embodiment of a carrier-suppressed-return-to-zero alternating-polarization optical communication system according to the present invention, and as can be seen from fig. 1, the signal transmitting side includes: a laser CW, a Mach-Zehnder modulator MZM1, a Mach-Zehnder modulator MZM2, an optical polarizer PBS and a combiner PBC;
CW continuous light emission generates an optical signal that enters MZM1.
MZM1 is input into MZM2 after intensity modulating the optical signal.
The MZM2 performs pulse cutting on the optical signal, and generates a carrier suppression return-to-zero CSRZ signal to be input into the PBS after pi phase difference is added between carriers of each adjacent sign bit of the optical signal.
The PBS divides the CSRZ signals into two paths of CSRZ signals with the same intensity and orthogonal polarization states, the carrier frequency of one path of CSRZ signals is modulated by a 1-0 alternate half-rate clock signal to realize phase modulation, the phase of the signal is changed between 0 and pi, the two paths of CSRZ signals are input into the PBC for coupling, and the PBC outputs a carrier suppression return-to-zero alternate polarization CSRZ-AP signal.
The invention provides a carrier suppression return-to-zero alternating polarization/frequency shift keying quadrature modulation optical communication system, which aims at the defect that the signal transmission performance is rapidly deteriorated due to nonlinear effect when the traditional CSRZ technology is applied to a high-speed optical communication system, and provides a code modulation and demodulation method and a communication device of CSRZ-AP which can be used in the high-speed optical communication system with the speed of more than 100 Gbps.
Example 1
Embodiment 1 provided by the present invention is an embodiment 1 of a carrier suppression return-to-zero alternating polarization/frequency shift keying quadrature modulation optical communication system provided by the present invention, as can be seen with reference to fig. 1, the embodiment of the optical communication system includes: the optical communication system includes a signal transmitting side and a signal receiving side, the signal transmitting side including: laser CW, mach-zehnder modulator MZM1, mach-zehnder modulator MZM2, optical polarizer PBS and combiner PBC.
CW continuous light emission generates an optical signal that enters MZM1.
MZM1 is input into MZM2 after intensity modulating the optical signal.
In one possible embodiment, the electrical signal applied to MZM1 during intensity modulation of the optical signal by MZM1。
wherein ,is half-wave voltage of optical signal, < >>When the signals are "1" and "0", -the signal is "1" and "0">Taking +1 and-1 respectively.
The MZM2 performs pulse cutting on the optical signal, and generates a carrier suppression return-to-zero CSRZ signal to be input into the PBS after pi phase difference is added between carriers of each adjacent sign bit of the optical signal.
In one possible embodiment, during the pulse cutting of the optical signal by the MZM2, two sinusoidal clock signals with a rate half the NRZ code rate are respectively fed into the two electrodes of the MZM2, i.e. the amplitude and frequency of the clock signals are respectively V pi/2 and half the rate, the MZM2 is biased at V pi/2, and V pi is the half-wave voltage of the optical signal.
When the phase phi vbias generated by the direct current component is 0, pi phase difference is added between the carriers of each adjacent sign bit of the optical signal to make the duty ratio of the optical signal 67%, and the width corresponding to the half maximum full width of the optical signal is exactly the period of the optical signalThe desired CSRZ signal is obtained such that the resulting signal has a narrower spectral width.
The PBS divides the CSRZ signals into two paths of CSRZ signals with the same intensity and orthogonal polarization states, modulates one path of CSRZ signal optical carrier frequency by 1 and 0 alternate half-rate clock signals to realize phase modulation, inputs the two paths of CSRZ signals into the PBC for coupling, and outputs carrier suppression return-to-zero alternate polarization CSRZ-AP signals by the PBC.
As shown in fig. 2, which is a block diagram of a signal receiving side of an embodiment one of a carrier-suppressed zero-resetting alternating polarization optical communication system according to an embodiment of the present invention, as can be seen from fig. 2, in a possible embodiment, the signal receiving side includes: a photodiode detector.
The photodiode detector detects the signal intensity, demodulates the optical signal, and demodulates and recovers to obtain the CSRZ-AP signal.
The conventional ASK/FSK quadrature modulation system is mainly used in the quadrature modulation system with the rate of 10Gbps ASK/622Mbps or less because of the weak nonlinear resistance of ASK signals, so that it is common to use 10Gbps or 2.5Gbps ASK signals to carry load signals. The traditional FSK signal generation is that a frequency modulator directly modulates the current of a laser, the output frequency of the laser can change along with the change of a driving current, so that FSK modulation is formed, different digital signals '0' and '1' can be carried through different frequencies, but the output power and the driving current curve of the laser are not absolutely flat in a saturation region, so that the output FSK signal is accompanied with ASK modulation to a certain extent, the quality of the signal is degraded, the signal is generally used in a low-speed optical communication system, the signal is used for carrying low-speed OAM (operation, management and maintenance) signals with hundred megabits per second level or less in the optical communication system, in such research, orthogonal modulation of two paths of high-speed optical signals is generally not realized, therefore, the application field is very limited, high-speed, large-capacity and long-distance transmission cannot be realized, and the signal cannot be used for high-speed interconnection of a data center server.
However, in this scheme, the invention discloses a modulation-demodulation method and implementation method for improving the nonlinear resistance of the intensity modulation format, through the 100Gbps CSRZ-AP signal and the 50Gbps FSK signal, the CSRZ-AP signal in this scheme has higher nonlinear resistance compared with the traditional ASK signal, so that the signal transmission of a high-speed optical communication system above 100Gbps can be realized with low cost, in addition, the generation method of the FSK signal does not adopt the current mode of the traditional direct modulation laser, but adopts MZDI demodulation after DPSK modulation is carried out through two paths of optical signals, therefore, compared with the FSK signal generated through the current mode of the traditional direct modulation laser, the FSK signal has higher nonlinear resistance, can realize higher-speed signal bearing, the orthogonal modulation scheme can bear two paths of high-speed signals from different servers, and can realize transmission on the same channel after orthogonal modulation, without adding a wavelength channel, and can realize the mutual identification of two paths of different information between two nodes and the two paths of different modulation devices because the two paths of signals are more easily identified by mutually different modulation formats. The CSRZ-AP signal and the FSK signal have high nonlinear resistance, and the interconnection and the intercommunication of high-speed signals of different servers in the data center can be realized in a low-cost mode.
Example 2
An embodiment 2 provided by the present invention is a second embodiment of a carrier-suppressed-zero-return-to-zero-alternating-polarization/frequency-shift-keying quadrature-modulation optical communication system provided by the present invention, and fig. 3 is a block diagram of a second embodiment of a signal transmitting side of a carrier-suppressed-zero-return-to-zero-alternating-polarization/frequency-shift-keying quadrature-modulation optical communication system provided by the embodiment of the present invention, which is known from fig. 2, where the embodiment of the optical communication system includes: a signal transmitting side and a signal receiving side, characterized in that the signal transmitting side includes: laser CW1, laser CW2, mach-zehnder modulator MZM1, mach-zehnder delay interferometer MZDI, mach-zehnder modulator MZM2, mach-zehnder modulator MZM3, optical polarizer PBS and combiner PBC.
CW1 and CW2 generate an optical signal having a frequency of 193.1THz and 193.0THz, respectively, and are coupled into MZM1.
In one possible embodiment, the optical signals output by CW1 and CW2 are coupled back through a coupler into an optical fiber that enters MZM1.
The MZM1 performs DPSK modulation on the optical signals of two frequencies and inputs the optical signals to the MZDI.
In one possible embodiment, the data loaded on MZM1 during DPSK modulation of the optical signal at two frequencies is 100Gbps data.
The MZDI demodulates the input optical signal to generate a 50Gbps FSK signal and inputs the signal into the MZM2.
FIG. 4 is a spectral diagram of an FSK signal according to an embodiment of the present invention.
The MZM2 quadrature-modulates the input optical signal, and then inputs the modulated optical signal to the MZM3.
In one possible embodiment, the data loaded on MZM2 during quadrature modulation of the input optical signal is 50Gbps signal data.
The MZM3 performs pulse cutting on the optical signal, and inputs the optical signal into the PBS after pi phase difference is added between carriers of each adjacent sign bit of the optical signal.
In one possible embodiment, MZM3 is biased at Vpi/2 during pulse cutting of the optical signal, with the clock signal having an amplitude and frequency of Vpi/2 and 25Gbps, respectively.
When the phase phi vbias generated by the direct current component is 0, pi phase difference is added between carriers of each adjacent sign bit of the optical signal, so that the generated signal has narrower frequency spectrum width, and dispersion resistance is improved.
The PBS divides the CSRZ signals into two paths of CSRZ signals with the same intensity and orthogonal polarization states, modulates one path of CSRZ signal optical carrier frequency through 1 and 0 alternate half-rate clock signals to realize phase modulation, and inputs the two paths of CSRZ signals into the PBC for coupling, and the PBC outputs 100Gbps CSRZ-AP/50Gbps FSK signals. Since the FSK signal carries frequency information and the CSRZ-AP signal carries intensity information and polarization state information, quadrature modulated signals are generated, and the generated signal spectral diagrams and eye diagrams are shown in fig. 5 and 6, respectively.
In one possible embodiment, the signal receiving side includes: a beam splitter, a photodiode detector A, a bandpass filter and a photodiode detector B.
The optical splitter divides the received optical signal into two paths of optical signals, one path of optical signal is demodulated by detecting the signal intensity through a photodiode detector A (shown in figure 2), and the 100Gbps CSRZ-AP signal is recovered by demodulation.
Demodulation of the other 50Gbps FSK signal is shown in FIG. 7, after the 50Gbps FSK signal is filtered out by the band-pass filter, photoelectric conversion is completed by detection of the photodiode detector B, and demodulation of the 50Gbps FSK signal is realized.
The carrier suppression zeroing alternating polarization/frequency shift keying quadrature modulation optical communication system provided by the embodiment of the invention has the beneficial effects that:
the traditional intensity modulation signal is easy to realize and low in cost, but when the traditional CSRZ modulation is used in a high-speed optical communication system based on intensity modulation, the variation of the signal intensity is easy to cause nonlinear effect in a channel along with the increase of the power of the channel, and becomes a main factor for limiting the signal transmission performance, so that high-speed and long-distance transmission cannot be realized. Therefore, the invention discloses an optimization scheme, which adds alternate polarization to generate a new modulation format on the basis of the traditional CSRZ signal, thereby further improving the nonlinear resistance of the modulation signal, improving the signal transmission performance, realizing the transmission of high-capacity and long-distance signals above 100Gbps and solving the problem of large nonlinear damage of intensity modulation in a high-speed long-distance transmission system with low cost.
With the advent of the universal intelligent networking era, the number of users and the traffic flow are greatly increased, and meanwhile, the number of servers of a data center for information interaction is also continuously increased, and the connection rate is continuously improved, so that the connection transmission expansibility of the data center is required to be higher. In the traditional WDM system, signals are required to be carried through different wavelengths, wavelength combining and splitting are required to be realized during the combining and splitting periods, the number of channels of an optical fiber channel in practical engineering is limited, the use of a multi-channel system will bring about the increase of the cost of devices and systems, and how to expand the capacity of an optical interconnection system of a data center network in a low-cost manner has become an important point and a difficulty of attention in the industry. The invention discloses a method for realizing orthogonal modulation and demodulation of 100Gbps CSRZ-AP signals and 50Gbps FSK signals, which can bear two paths of signals from different servers, and are orthogonally modulated on the same channel for transmission without adding wavelength channels or using wave combining and wave dividing devices as WDM systems, because the wave combining and wave dividing devices adopt different orthogonal modulation formats, the separation of the two paths of signals and the identification and updating of information are easier to realize at an intermediate node. The CSRZ-AP signal and the FSK signal have high nonlinear resistance, and the interconnection and the intercommunication of high-speed signals of different servers in the data center can be realized in a low-cost mode.
In the foregoing embodiments, the descriptions of the embodiments are focused on, and for those portions of one embodiment that are not described in detail, reference may be made to the related descriptions of other embodiments.
It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
Claims (10)
1. A carrier-suppressed-return-to-zero alternating polarization/frequency shift keying quadrature modulated optical communication system in which generation and reception of a carrier-suppressed-return-to-zero alternating polarization signal are respectively realized by a signal transmitting side and a signal receiving side, characterized in that the signal transmitting side comprises: a laser CW, a Mach-Zehnder modulator MZM1, a Mach-Zehnder modulator MZM2, an optical polarizer PBS and a combiner PBC;
the CW continuously emits light to generate an optical signal which enters the MZM1;
the MZM1 carries out intensity modulation on the optical signal and then inputs the optical signal into the MZM2;
the MZM2 performs pulse cutting on the optical signal, generates carrier suppression return-to-zero CSRZ signals after pi phase differences are added between carriers of each adjacent symbol bit of the optical signal, and inputs the carrier suppression return-to-zero CSRZ signals into the PBS;
the PBS divides the CSRZ signals into two paths of CSRZ signals with the same intensity and orthogonal polarization states, one path of CSRZ signal optical carrier frequency is modulated by 1 and 0 alternate half-rate clock signals to realize phase modulation, the two paths of CSRZ signals are input into the PBC for coupling, and the PBC outputs carrier suppression return-to-zero alternate polarization CSRZ-AP signals.
2. The optical communication system of claim 1, wherein the MZM1 modulates the intensity of the optical signal by an electrical signal applied to the MZM1；
wherein ,for half-wave voltage of the optical signal, +.>。
3. The optical communication system according to claim 1, wherein in the process of pulse cutting the optical signal by the MZM2, two sinusoidal clock signals with a rate half of the NRZ code rate are respectively sent into two electrodes of the MZM2, the amplitude and frequency of the clock signals are respectively V pi/2 and half of the rate, the MZM2 is biased at V pi/2, and V pi is half-wave voltage of the optical signal;
when the phase phi vbias generated by the direct current component is 0, a pi phase difference is added between the carriers of each adjacent sign bit of the optical signal to ensure that the duty ratio of the optical signal is 67 percent, and the width corresponding to the half maximum full width of the optical signal is the period of the optical signalAnd obtaining the CSRZ signal.
4. The optical communication system according to claim 1, wherein the signal receiving side includes: a photodiode detector;
and the photodiode detector detects the signal intensity, demodulates the optical signal, and demodulates and recovers to obtain the CSRZ-AP signal.
5. A carrier-suppressed-return-to-zero alternating polarization/frequency shift keying quadrature modulated optical communication system, the optical communication system comprising a signal transmitting side and a signal receiving side, the signal transmitting side comprising: laser CW1, laser CW2, mach-zehnder modulator MZM1, mach-zehnder delay interferometer MZDI, mach-zehnder modulator MZM2, mach-zehnder modulator MZM3, optical polarizer PBS and combiner PBC;
the CW1 and the CW2 respectively generate an optical signal with a frequency of 193.1THz and 193.0THz and then are coupled into the MZM1;
the MZM1 carries out DPSK modulation on the optical signals with two frequencies and then inputs the optical signals into the MZDI;
the MZDI demodulates the input optical signal to generate a 50Gbps FSK signal and inputs the signal into the MZDI 2;
the MZM2 carries out quadrature modulation on the input optical signal and then inputs the optical signal into the MZM3;
the MZM3 performs pulse cutting on the optical signal, adds pi phase difference between carriers of each adjacent symbol bit of the optical signal, and inputs the optical signal into the PBS;
the PBS divides the CSRZ signals into two paths of CSRZ signals with the same intensity and orthogonal polarization states, modulates one path of CSRZ signal optical carrier frequency by 1 and 0 alternate half-rate clock signals to realize phase modulation, inputs the two paths of CSRZ signals into the PBC for coupling, and the PBC outputs 100Gbps CSRZ-AP/50Gbps FSK signals.
6. The optical communication system of claim 5, wherein the optical signals output by CW1 and CW2 are coupled back into an optical fiber through a coupler into MZM1.
7. The optical communication system of claim 5, wherein the data loaded on the MZM1 during the DPSK modulation of the optical signal at two frequencies by the MZM1 is 100Gbps data.
8. The optical communication system of claim 5, wherein the MZM2 performs quadrature modulation on the input optical signal, and the data loaded on the MZM2 is 50Gbps signal data.
9. The optical communication system of claim 5, wherein during the pulse cutting of the optical signal by the MZM3, the MZM2 is biased at vpi/2, and the amplitude and frequency of the clock signal are vpi/2 and 25Gbps, respectively;
when the phase phi vbias generated by the direct current component is 0, pi phase difference is added between carriers of each adjacent sign bit of the optical signal.
10. The optical communication system according to claim 5, wherein the signal receiving side includes: a beam splitter, a photodiode detector A, a band-pass filter and a photodiode detector B;
the optical splitter divides the received optical signal into two paths of optical signals, wherein one path of optical signal demodulates the optical signal through the detection signal intensity of the photodiode detector A, and the 100Gbps CSRZ-AP signal is recovered by demodulation;
and the other path of optical signal is filtered out by the band-pass filter, and then the 50Gbps FSK signal is subjected to photoelectric conversion by the detection of the photodiode detector B, so that the demodulation of the 50Gbps FSK signal is realized.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311127396.1A CN116865866B (en) | 2023-09-04 | 2023-09-04 | Carrier-suppressed zero-return alternating polarization/frequency shift keying quadrature modulation optical communication system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311127396.1A CN116865866B (en) | 2023-09-04 | 2023-09-04 | Carrier-suppressed zero-return alternating polarization/frequency shift keying quadrature modulation optical communication system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116865866A true CN116865866A (en) | 2023-10-10 |
| CN116865866B CN116865866B (en) | 2023-12-05 |
Family
ID=88234470
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311127396.1A Active CN116865866B (en) | 2023-09-04 | 2023-09-04 | Carrier-suppressed zero-return alternating polarization/frequency shift keying quadrature modulation optical communication system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116865866B (en) |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005045415A (en) * | 2003-07-24 | 2005-02-17 | Kyocera Corp | Optical wavelength multiplex transmission device |
| US20050100346A1 (en) * | 2003-11-12 | 2005-05-12 | Hoon Kim | Optical transmitter for use in high-density wavelength division multiplexing (WDM) optical transmission system |
| US20060171723A1 (en) * | 2005-02-01 | 2006-08-03 | Alcatel | Method for modulating an optical signal and optical transmitter |
| JP2007057782A (en) * | 2005-08-24 | 2007-03-08 | National Institute Of Information & Communication Technology | Optical frequency shift keying/single slide-band modulator having intensity balancing function |
| US20090022498A1 (en) * | 2007-07-20 | 2009-01-22 | Makoto Shibutani | Optical transmission system |
| CN101494501A (en) * | 2008-01-25 | 2009-07-29 | 华为技术有限公司 | Multi-code type light transmitter and method for generating optical signal |
| CN101527601A (en) * | 2008-03-04 | 2009-09-09 | 华为技术有限公司 | Optical transmitter and optical signal generating method |
| JP2010118842A (en) * | 2008-11-12 | 2010-05-27 | Nippon Telegr & Teleph Corp <Ntt> | Optical transmission system, transmitter and receiver |
| JP2010166242A (en) * | 2009-01-14 | 2010-07-29 | Nippon Telegr & Teleph Corp <Ntt> | Optical transmitter and method |
| CN101902422A (en) * | 2010-08-05 | 2010-12-01 | 复旦大学 | System and method for modulating high-speed optical MSK signals |
| CN102064890A (en) * | 2010-11-08 | 2011-05-18 | 武汉邮电科学研究院 | Ultra-long single span optical transmission method based on polarization multiplexing push-pull modulation encoding |
| CN104243046A (en) * | 2014-08-29 | 2014-12-24 | 南京邮电大学 | PDM-MSK modulation and demodulation method for optical communication system |
| CN104467978A (en) * | 2014-12-01 | 2015-03-25 | 华中科技大学 | Optical transmitter supporting multiple modulation formats and control method |
| CN104717166A (en) * | 2015-03-12 | 2015-06-17 | 华中科技大学 | FSK modulating system based on smoothing modulator |
-
2023
- 2023-09-04 CN CN202311127396.1A patent/CN116865866B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005045415A (en) * | 2003-07-24 | 2005-02-17 | Kyocera Corp | Optical wavelength multiplex transmission device |
| US20050100346A1 (en) * | 2003-11-12 | 2005-05-12 | Hoon Kim | Optical transmitter for use in high-density wavelength division multiplexing (WDM) optical transmission system |
| US20060171723A1 (en) * | 2005-02-01 | 2006-08-03 | Alcatel | Method for modulating an optical signal and optical transmitter |
| JP2007057782A (en) * | 2005-08-24 | 2007-03-08 | National Institute Of Information & Communication Technology | Optical frequency shift keying/single slide-band modulator having intensity balancing function |
| US20090022498A1 (en) * | 2007-07-20 | 2009-01-22 | Makoto Shibutani | Optical transmission system |
| CN101494501A (en) * | 2008-01-25 | 2009-07-29 | 华为技术有限公司 | Multi-code type light transmitter and method for generating optical signal |
| CN101527601A (en) * | 2008-03-04 | 2009-09-09 | 华为技术有限公司 | Optical transmitter and optical signal generating method |
| JP2010118842A (en) * | 2008-11-12 | 2010-05-27 | Nippon Telegr & Teleph Corp <Ntt> | Optical transmission system, transmitter and receiver |
| JP2010166242A (en) * | 2009-01-14 | 2010-07-29 | Nippon Telegr & Teleph Corp <Ntt> | Optical transmitter and method |
| CN101902422A (en) * | 2010-08-05 | 2010-12-01 | 复旦大学 | System and method for modulating high-speed optical MSK signals |
| CN102064890A (en) * | 2010-11-08 | 2011-05-18 | 武汉邮电科学研究院 | Ultra-long single span optical transmission method based on polarization multiplexing push-pull modulation encoding |
| CN104243046A (en) * | 2014-08-29 | 2014-12-24 | 南京邮电大学 | PDM-MSK modulation and demodulation method for optical communication system |
| CN104467978A (en) * | 2014-12-01 | 2015-03-25 | 华中科技大学 | Optical transmitter supporting multiple modulation formats and control method |
| CN104717166A (en) * | 2015-03-12 | 2015-06-17 | 华中科技大学 | FSK modulating system based on smoothing modulator |
Non-Patent Citations (3)
| Title |
|---|
| HE ZHOU .ET AL: "Research on novel modulation format Apol-FSK for optical transport network of 5G", OPTICS COMMUNICATIONS * |
| 凌毓;李勇;何舟;: "新型APol-CSRZ-FSK调制格式的研究", 电视技术, no. 13 * |
| 李佳泯;刘继红;: "光纤通信系统中新型调制格式分析", 广东通信技术, no. 10 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116865866B (en) | 2023-12-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10243688B2 (en) | Reach extension of multi-carrier channels using unequal subcarrier spacing | |
| CN101895495B (en) | Method and system for transmitting and receiving by orthogonally dual-polarized differential quaternary phase shift keying | |
| CN108768540B (en) | Optical signal receiving device, method and coherent optical transmission system with the device | |
| EP2154796B1 (en) | Device and method for receiving a dopsk signal and method for obtaining a dopsk signal | |
| US20170005747A1 (en) | Methods and systems for periodic optical filtering to identify tone modulated optical signals | |
| WO2015176527A1 (en) | Orthogonal multicarrier light source and pdm-qpsk signal transmission device | |
| JP5460618B2 (en) | Phase control circuit and method for optical receiver | |
| EP1041783A2 (en) | Encoding, modulation and multiplexing for optical transmission | |
| CN103067091A (en) | Optical transmitter, optical transmission method, and optical transmission/reception system | |
| CN101515828B (en) | optical transmitter, optical transmission method and optical transmission system | |
| US8301034B2 (en) | Optical modulation device | |
| CN1808946A (en) | Offset quadrature phase-shift-keying method and optical transmitter using the same | |
| JP6658346B2 (en) | Method and system for superchannel subcarrier monitoring using amplitude modulated tones | |
| JP2007158600A (en) | Signal recovery apparatus, optical receiver, and signal processing method | |
| US20140044439A1 (en) | Method and apparatus for transmission of two modulated signals via an optical channel | |
| JP5068240B2 (en) | Optical transmission system, transmitter and receiver | |
| EP2204928B1 (en) | Method and device for receiving OPFDM-DQPSK signal | |
| CN104106229A (en) | System and method for coherent detection with digital signal procession | |
| US20110020003A1 (en) | Generating A 400-Gbit/s Single-Channel Optical Signal | |
| CN116865866B (en) | Carrier-suppressed zero-return alternating polarization/frequency shift keying quadrature modulation optical communication system | |
| JP2008211713A (en) | Optical transmission system, optical transmission method, and optical transmission apparatus | |
| Huszaník et al. | Performance Analysis of Optical Modulation Formats for 10 Gbit/s DWDM System | |
| JP6705307B2 (en) | Method and system for superchannel subcarrier monitoring using frequency modulated tones | |
| CN102065045A (en) | D8PSK/IRZ quadrature modulation-based optical label switching method and system | |
| WO2010026757A1 (en) | Transmitter, receiver, optical transmission system, and optical transmission method |
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 |