CN113490083B - All-optical fast mode matching method and system for QPSK signal and application thereof - Google Patents

All-optical fast mode matching method and system for QPSK signal and application thereof Download PDF

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CN113490083B
CN113490083B CN202110766201.2A CN202110766201A CN113490083B CN 113490083 B CN113490083 B CN 113490083B CN 202110766201 A CN202110766201 A CN 202110766201A CN 113490083 B CN113490083 B CN 113490083B
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CN113490083A (en
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李新
黄善国
唐颖
石子成
张路
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Beijing University of Posts and Telecommunications
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Abstract

The invention discloses an all-optical fast mode matching method and system for QPSK signals and application thereof, wherein the matching system or method divides sequences to be matched into two paths containing different types of phase symbols, and performs different compression on optical data sequences composed of input QPSK signals by utilizing phase compression processing to convert the optical data sequences into two paths of data sequences only containing two phase symbols and a null symbol, in an all-optical mode matching unit, each path only needs to identify two of four phase symbols, so that the symbol processing process is simplified, the limitation of an original binary all-optical mode matching system is broken through, not only is the all-optical mode matching extended to a higher-order modulation format, but also the processing efficiency and throughput of the all-optical mode matching system can be greatly improved, and the mode identification is quickly and effectively completed.

Description

All-optical fast mode matching method and system for QPSK signal and application thereof
Technical Field
The invention relates to the technical field of optical network security.
Background
At present, the vigorous development of digital economy becomes an important engine for promoting the economic growth of the world, a network is a cornerstone for constructing the digital world, and the construction of a high-speed, reliable and safe network is always the strategic planning of China. The optical network is used as the basic physical facility of various types of networks, has the characteristics of large transmission capacity, multiple bearing services, wide coverage area and the like, is rapidly developed, and effectively supports the information and communication industries such as 5G, a data center, the Internet of things, integration of space, space and ground and the like. Especially for 5G, the development of 5G will greatly stimulate the construction and deployment of optical communication networks due to the massive optical fiber cable requirements caused by interconnection between base stations and the increase of data traffic.
An optical network is used as a physical link layer in the whole communication system, and has the characteristics of closed and insulated transmission medium, high signal rate and reliability and the like, so that the optical network is considered to have higher security in the traditional sense, and therefore security defense measures for service transmission are usually realized on an electrical layer, so that the security of the optical network is always ignored, but the destructive behavior for the security of the optical network is not rare.
As the research and design of the optical network in the aspects of transmission, exchange, management and control, etc. mainly consider transparent opening and interconnection, the protection of the optical network is weak, and the existing security measures mainly focus on the security protection for the optical transmission channel. Specifically, for the problem of optical network security, a series of security measures proposed in the prior art mainly include: optical Code Division Multiple Access (O-CDMA), quantum encryption communication, chaotic encryption, node security reinforcement, intrusion detection, Optical network security management, photonic firewall, and the like.
The firewall is a relatively mature security protection measure against network attack and intrusion, because photoelectric conversion in a high-speed electronic signal processing system has the defects of high cost, low processing speed, small processing bandwidth and the like, meanwhile, with the continuous development of an optical fiber communication technology, the processing of the ultra-100 Gbps all-optical information becomes the inevitable trend of a future optical network, the intrusion detection and security defense of transmission data only on an electrical layer cannot adapt to the transmission characteristics of the optical network such as high speed, high capacity and low time delay, the optical layer needs to be extended when the firewall function is applied in the optical network, and the implementation of intrusion detection and defense means on the optical layer is needed, namely, an optical sub-firewall supporting the processing of the all-optical information needs to be designed. For example, in the "optical signal line speed safety monitoring" project sponsored by the european union in the prior art, the photon fire wall directly identifies information carried by an optical signal in the optical domain by using all-optical matching, and selects a corresponding defense means according to a set safety strategy to realize intrusion detection and safety protection in the optical domain. The project has been tested to realize the intrusion detection of the optical burst data packet with the rate of 42.6Gbps, and the project is compatible with two optical signal formats of non-return-to-zero code and return-to-zero code, and an optical signal matching system supports the target mode length of 256 bits.
Similarly, in the photon firewall in the prior art, information carried by an optical signal is directly identified by using an all-optical matching mechanism, and photoelectric conversion is not required, so that the photon firewall has the advantages of high processing speed, low energy consumption and large capacity, but the application performance is limited due to the defects that the current all-optical matching is low in matching rate and cannot be applied to a high-order modulation format, and the like, and specifically includes:
(1) matching model processing speed based on semiconductor optical amplifier is low
The core component of the photon firewall is an all-optical mode matching system, the all-optical mode matching system mainly performs logic operation on an input optical data sequence and a sequence to be matched, and judges whether the input optical data sequence comprises the sequence to be matched according to an output pulse. The all-optical mode matching system mainly comprises all-optical logic gates, including an exclusive-OR gate, an AND gate, a NOT gate, a regenerator and the like. The all-Optical logic gate can be implemented by various Optical devices, including a silicon waveguide, periodically poled lithium niobate, and a Semiconductor Optical Amplifier (SOA), etc., wherein the SOA-based all-Optical logic gate is widely studied. As a nonlinear device, the SOA has a small size, low power consumption, a high nonlinear coefficient, and has advantages of various nonlinear effects including Cross Phase Modulation (XPM), Cross Gain Modulation (XGM), Cross Polarization Modulation (XPoM), Four-Wave Mixing (FWM), and easy integration. However, limited by the long carrier recovery time of SOAs (about 100ps), which causes broadening of the output pulses, the operating speed of a single SOA cannot typically exceed 10 Gbps. The item of Optical signal line speed safety monitoring adopts a matching model of a push-pull Mach-Zehnder Interferometer (SOA-MZI) structure, can realize the matching of Optical signals of 42.6Gbps in binary amplitude keying (OOK) modulation format at the highest level, but cannot process the Optical signals with higher speed.
(2) Lack of matching models suitable for higher order modulation formats
The currently widely studied all-optical matching model is mainly oriented to optical signals adopting amplitude modulation, and mainly utilizes the XPM effect in SOA. For an optical signal adopting amplitude modulation, the all-optical matching model changes the carrier concentration passing through the SOA by using the power of an input optical signal, when probe light passes through the SOA, the phase of the probe light changes, then the two paths of probe light are coupled and output, and the amplitude of an output optical signal can reflect some logic relations of the two paths of input optical signals, namely the logical relations of OR, AND and the like. Optical signals using amplitude modulation have the disadvantages of short transmission distance, weak noise immunity, low rate, etc., so that optical signals using Quadrature Phase Shift Keying (QPSK) modulation format, which is the main format of high-order Phase modulation, have been widely used in commercial optical communication devices. For the optical signal adopting the phase modulation, the amplitude of the input optical signal does not carry any information, and the XPM effect is no longer applicable at this time, so that the matching model facing the optical signal adopting the amplitude modulation cannot be applied to the optical signal adopting the phase modulation format. Meanwhile, for an optical signal adopting a QPSK modulation format, each symbol no longer contains only information of one bit of "0" or "1", and logic gates such as an exclusive nor, and gate can only perform logic operation on variables of "0" and "1", and cannot implement a matching structure by using existing logic gates.
Disclosure of Invention
In view of the above drawbacks of the prior art, the present invention aims to provide an efficient, fast and all-optical mode matching system and matching and application method for QPSK modulation format signals, where the matching method can accurately match high-order phase modulation signals and has fast nonlinear effect response.
The invention firstly discloses the following technical scheme:
an all-optical fast mode matching system facing QPSK signals comprises an input unit, a matching unit and an output unit; the input unit comprises an input data sequence channel for inputting a QPSK signal sequence, a first target sequence channel for inputting a first target sequence in a signal sequence to be matched and a second target sequence channel for inputting a second target sequence in the signal sequence to be matched; the matching unit comprises a first matching subunit and a second matching subunit which are connected in parallel, wherein each matching subunit comprises a phase compression device connected with the input data sequence channel, a frequency conversion device and a first multiplexing device which are connected with the other end of the phase compression device and are mutually connected in parallel, a first AND gate device connected with the frequency conversion device and the other end of the first multiplexing device, a second AND gate connected to the first AND gate and the first or second target sequence input channel, and a second multiplexing device connected to both the second AND gates of the two matching subunits, and the first target sequence input channel is connected with the first multiplexing device of the first matching subunit, the second target sequence input channel is connected with the first multiplexing device of the second matching subunit; the output unit comprises a third AND gate device connected with the other end of the second multiplexing device and a regeneration device forming a circulation loop with the third AND gate device;
wherein one or more of the and gate arrangement, the frequency conversion arrangement, the phase compression arrangement and the regeneration arrangement is selected from a highly nonlinear fiber (HNLF) based structure or component or combination of components.
In the above scheme, the QPSK signal is a Quadrature Phase Shift Keying (QPSK) signal.
According to some preferred embodiments of the invention, the phase compression means is a phase sensitive amplifier based on a highly nonlinear optical fiber.
According to some preferred embodiments of the present invention, the input unit further comprises a circulation subunit which enters the matching unit after being connected to the input data sequence channel, and the circulation subunit can continuously and repeatedly input the input signal sequence into the matching unit with periodic delay.
According to some preferred embodiments of the present invention, the output unit further includes a delay subunit connected to the third and gate and the regenerating means, and the delay subunit enables each matching result to be combined with the next matching result with a periodic delay.
According to some preferred embodiments of the present invention, the matching system further comprises a power adjusting device for adaptively adjusting the signal power in different units in the system.
In the actual matching process, if different units have different requirements on the power of the signal or other parameters that can be changed by power adjustment, the adaptive adjustment may be implemented by adding a power adjustment device, such as a signal amplifier, an attenuator, etc., to meet the corresponding requirements.
The invention further provides an all-optical fast mode matching method for QPSK signals, which comprises the following steps:
obtaining an optical data sequence consisting of a plurality of equal periodic, out-of-phase QPSK signals;
obtaining a first target sequence and a second target sequence which are obtained by separation in a signal sequence to be matched and composed of QPSK signals, wherein the signal sequence to be matched and the optical data sequence have the same amplitude, and the first target sequence and the second target sequence comprise two different types of signal phases, namely a first type phase and a second type phase;
separating the optical data sequence into two identical sequences, namely an upper sequence and a lower sequence, respectively performing phase compression processing based on a four-wave mixing effect (FWM) in a high-nonlinearity optical fiber on the upper sequence or the lower sequence, until each compressed sequence only contains the first type phase or the second type phase, and correspondingly obtaining an upper compressed sequence or a lower compressed sequence;
separating the upper compressed sequence or the lower compressed sequence to enable each compressed sequence to form two identical subsequences, namely a first subsequence or a second subsequence;
performing frequency conversion processing based on a four-wave mixing effect (FWM) in a high nonlinear optical fiber on signals in the first subsequence of the upper compressed sequence or the lower compressed sequence to correspondingly obtain an up-converted sequence or a down-converted sequence;
carrying out coherent superposition on the signal of the second subsequence of the upper compressed sequence or the lower compressed sequence and the signal of the first target sequence or the second target sequence to correspondingly obtain an upper coherent sequence or a lower coherent sequence;
performing first logic and processing on the up-conversion sequence and the up-correlation sequence or the down-conversion sequence and the down-correlation sequence based on a four-wave mixing effect (FWM) in a high nonlinear optical fiber to obtain an upper phase and a lower phase and a sequence correspondingly;
performing second logic and processing on the upper phase and sequence and the first target sequence or the lower phase and sequence and the second target sequence based on a four-wave mixing effect (FWM) in a high-nonlinearity optical fiber, and correspondingly obtaining an upper unit matching result or a lower unit matching result after interference cancellation;
coupling the upper unit matching result with the lower unit matching result to obtain a matching result of the signal in the optical data sequence and the current signal in the target sequence;
and sequentially carrying out the matching process on all signals of the optical data sequence and the target sequence to obtain the matching result of all signals.
According to some preferred embodiments of the present invention, in matching of all signals in sequence, regenerated data generated by delaying the result of the last matching and based on the high-nonlinearity fiber regeneration is added to each matching, and in the first matching, the data is set as an initial pulse sequence of all signals having a symbol of 1.
According to some preferred embodiments of the present invention, the delay is (M +1) T, where M denotes the number of signals of the optical data sequence and T denotes the duration of each signal in the optical data sequence.
According to some preferred embodiments of the present invention, the first type of phase comprises any two of the four discrete phases of the QPSK signal out of phase by pi, and the second type of phase comprises the remaining two phases of the QPSK signal.
This preferred embodiment may be as follows: when the QPSK signal includes four phases of (0, pi/2, pi, 3 pi/2), the first type phase includes 0 and pi, and the second type phase includes pi/2 and 3 pi/2, or the first type phase includes pi/2 and 3 pi/2, and the second type phase includes 0 and pi; or when the QPSK signal includes four phases (pi/4, 3 pi/4, 5 pi/4, 7 pi/4), the first type phase includes pi/4 and 5 pi/4, and the second type phase includes 3 pi/4 and 7 pi/4, etc.
According to some preferred embodiments of the present invention, the phase compression process is implemented by the following compression model:
Figure BDA0003151663300000061
Figure BDA0003151663300000062
Figure BDA0003151663300000063
Figure BDA0003151663300000064
Figure BDA0003151663300000065
wherein E isoutAn optical field representing the output signal, AoutRepresenting the amplitude of the output signal after phase sensitive amplification,
Figure BDA0003151663300000066
representing the phase of the output signal after phase sensitive amplification,
Figure BDA0003151663300000067
representing the phase of the input signal, M representing the amplitude ratio between the (M-1) subharmonic and the input signal, M representing the number of symbols contained in the input signal, P1、P2Two initial phases are 0 and frequencies are omega respectively0Omega and is omega0+ omega continuous optical pumping signal, P1’、P2' means that the sum of two initial phases is pi and the frequency is omega respectively0Omega and is omega0+ omega continuous optical pumping signal, omega0Representing the frequency of the input signal, omega representing the difference in frequency between the pump signal and the input signal, Eidler1An optical field representing the signal generated by the FWM effect in the phase compression process on the upper sequence,
Figure BDA0003151663300000068
representing the pump signal P1Of the light field of (a) and (b),
Figure BDA0003151663300000069
representing the pump signal P2The light field of (a) is,
Figure BDA00031516633000000610
representing the conjugate of the optical field of the input signal, Eidler2An optical field representing a signal generated by the FWM effect in the phase compression process on the lower sequence,
Figure BDA00031516633000000611
representing the pumping signal P1' of the optical field of the optical sensor,
Figure BDA00031516633000000612
representing the pump signal P2' of the optical field of the optical sensor,
Figure BDA00031516633000000613
representing the phase of the signal generated by the FWM effect in the phase compression process on the upper sequence,
Figure BDA00031516633000000614
representing the pump signal P1The phase of (a) is determined,
Figure BDA00031516633000000615
representing the pump signal P2The phase of (a) is determined,
Figure BDA00031516633000000616
which represents the phase of a signal generated by the FWM effect in the phase compression process on the lower sequence,
Figure BDA0003151663300000071
representing the pump signal P1The phase of the phase-locked loop,
Figure BDA0003151663300000072
representing the pump signal P2The phase of.
The invention further discloses application methods of the matching system and/or the matching method, such as application of the matching system and/or the matching method in a photon firewall.
The invention has the following beneficial effects:
the matching system of the invention uses the high nonlinear fiber, has short nonlinear effect response time compared with the traditional SOA, can realize the optical signal processing with the speed of more than 1Tbps, is easy to be coupled with a transmission link, reduces the coupling loss, and is a passive device, so that additional noise can not be introduced during the signal processing.
Compared with the existing all-optical matching method which mostly aims at binary modulation formats, especially OOK modulation format systems, the matching method or system of the invention aims at QPSK signals which have stable amplitude, stronger anti-noise capability and higher speed and are more suitable for long-distance large-capacity transmission of signals.
The matching method or system of the invention can directly arrange the firewall in the optical domain, realize the direct analysis and processing of the information in the optical layer, avoid the optical/electrical/optical conversion which is needed because of using the traditional electronic firewall, and reduce the equipment cost.
The matching system or method of the invention can reflect the phase information of the input optical signal to the amplitude of the output optical signal, and has the advantages of quick response of nonlinear effect and suitability for high-order modulation formats.
In some embodiments of the present invention, the regenerator in the loop may perform frequency conversion and waveform shaping functions, convert the output sequence obtained in the previous loop into the same frequency as the initial pulse frequency, and shape the signal that may be deteriorated in the actual process, and the and gate device or the logic and process may sufficiently eliminate the interference information to obtain a more accurate matching result.
The matching system or method divides the sequence to be matched into two paths containing completely different phase symbols, performs different compression on the input optical data sequence by utilizing phase compression processing, converts the input QPSK signal into two paths of data sequences only containing two phase symbols and one null symbol, ensures that in an all-optical mode matching unit, only two of the four phase symbols need to be identified in each path, simplifies the symbol processing process, breaks through the limitation of the original binary all-optical mode matching system, not only extends the all-optical mode matching to a higher-order modulation format, but also can greatly improve the processing efficiency and throughput of the all-optical mode matching system, and quickly and effectively completes the mode identification.
Drawings
Fig. 1 is a block diagram of an all-optical fast mode matching system for QPSK signals according to the present invention;
FIG. 2 is a sequence of input optical data and a sequence to be matched according to an embodiment;
FIG. 3 is a diagram illustrating a process of implementing phase compression by FWM in an embodiment;
FIG. 4 is a signal representation of the various elements during the first cycle described in the examples;
FIG. 5 is a signal representation of the elements during the second cycle described in the examples;
FIG. 6 is a signal representation of the units during the third cycle described in the examples;
FIG. 7 is a signal representation of the units during the fourth cycle described in the examples;
FIG. 8 is a graph showing the waveform change in the example.
Detailed Description
The present invention is described in detail below with reference to the following embodiments and the attached drawings, but it should be understood that the embodiments and the attached drawings are only used for the illustrative description of the present invention and do not limit the protection scope of the present invention in any way. All reasonable variations and combinations that fall within the spirit of the invention are intended to be within the scope of the invention.
According to the technical scheme of the invention, a specific all-optical fast pattern matching system comprises a structure as shown in the attached figure 1, and specifically comprises the following steps:
the system comprises an input unit, a matching unit and an output unit; the input unit comprises an input data sequence channel for inputting a QPSK signal sequence, a first sequence input channel for inputting a first target sequence (namely, a diagram target sequence 1) in a signal sequence to be matched, and a second sequence input channel for inputting a second target sequence (namely, a diagram target sequence 2); the matching unit comprises two matching subunits which are connected in parallel, namely a first matching subunit and a second matching subunit; each matching subunit comprises a phase compression device connected with an input data sequence channel, a frequency converter and a first multiplexer which are connected with the other end of the phase compression device and are connected with each other in parallel, a first AND gate connected with the other end of the frequency converter and the other end of the first multiplexer, a second AND gate connected with the first AND gate and a target sequence input channel, and a second multiplexer connected with the second AND gates of the two matching subunits, wherein the first target sequence input channel is connected with the first multiplexer of the first matching subunit, and the second target sequence input channel is connected with the first multiplexer of the second matching subunit; and the output unit comprises a third AND gate connected with the other end of the second multiplexer and a regenerator forming a circulation loop with the third AND gate.
Further, in this system, the and gate is preferably based on the structure of the four-wave mixing (FWM) effect of the highly nonlinear fiber (HNLF), with the two inputs at different frequencies. The phase compression means is preferably based on a phase sensitive amplifier of the Four Wave Mixing (FWM) effect of a highly nonlinear fiber (HNLF). The frequency converter and/or regenerator is preferably based on the structure of the four-wave mixing (FWM) effect of highly nonlinear fibers (HNLF).
Furthermore, in the system, the input unit further comprises a circulation subunit which is connected with the input data sequence channel and then enters the matching unit, and the circulation subunit can repeatedly input the input signal sequence into the matching unit according to the periodic delay to realize the circulation matching of the signals; further, the delay is periodically performed according to the number of signals of the input signal sequence.
Furthermore, in the system, the output unit further comprises a delay subunit connected with the third and gate and the regenerator, and the delay subunit can combine each matching result with the next matching result continuously according to periodic delay to realize complete output of the matching result; further, the delay is performed periodically by adding 1 to the number of signals of the input signal sequence.
In a specific implementation, the circulation subunit may be implemented by a circulation component, a module, and/or a loop, and the delay subunit may be implemented by a delay component, a module, and/or a loop.
Furthermore, some signal amplifiers and/or attenuators may be further disposed in the system, so as to adjust the signal power according to different matching requirements, and implement the matching of the signal power, for example, the amplitude of the signal in the compressed sequence obtained according to the phase compression apparatus is the same as the amplitude of the input optical data sequence/target sequence signal through the amplifiers or attenuators.
Under the system, the quick matching of the signals can be realized by the following methods:
s1 inputting an optical data sequence composed of a plurality of QPSK signals with equal periods and different phases from the input data sequence channel;
more specifically, it may be as follows:
input optical data sequence a ═ { a ═ a1,…ai,…aMAt an initial frequency ω, with a number of signals M0A sequence of QPSK signals comprising four phases {0, pi/2, pi, 3 pi/2 }, wherein each QPSK signal has a duration T.
S2, dividing the sequence to be matched into two paths of input systems from the first sequence input channel and the second sequence input channel, wherein the two obtained target sequences have different phase types; wherein the sequence to be matched and the input optical data sequence have the same amplitude and consist of QPSK signals;
more specifically, it may be as follows:
sequence to be matched B ═ B1,…bj,…bN-a sequence of QPSK signals of the same amplitude as said optical data sequence a, comprising four phases {0, pi/2, pi, 3 pi/2 } with a signal number N, wherein each QPSK signal has a duration M x T;
the different phase types can be a first type phase composed of phases 0 and pi and a second type phase composed of phases pi/2 and 3 pi/2, and further, after the input is separated, a first target sequence only containing the first type phase and a second target sequence only containing the second type phase can be obtained;
furthermore, in the first target sequence only containing the first type of phase, the corresponding symbols of the signals with the phases pi/2 and 3 pi/2 in the original sequence to be matched are set to be in a no-signal state, that is, the corresponding state of the origin of the signal amplitude 0 in the QPSK signal constellation diagram, and in the second target sequence only containing the second type of phase, the corresponding symbols of the signals with the phases 0 and pi in the original sequence to be matched are set to be in a no-signal state;
more specifically, the sequence to be matched may be a set of symbol sequences pre-configured by a network administrator according to a network condition.
S3, dividing the optical data sequence entering the system into two identical sequences, namely an upper sequence and a lower sequence, respectively entering the phase compression devices of the two sub-matching units, and performing different phase compression processing to obtain an upper compressed sequence and a lower compressed sequence;
more specifically, the phase compression process may be as follows:
after being processed by the phase compression device of the first sub-matching unit, the symbols of the signals with the first type of phase in the upper sequence are kept unchanged, the symbols of the signals with the second type of phase are compressed into symbols with the amplitude of 0, the symbols of the signals with the second type of phase in the lower sequence are kept unchanged, and the symbols of the signals with the first type of phase are compressed into symbols with the amplitude of 0;
more specifically, the phase compression process may be as follows:
after being processed by the phase compression device of the first sub-matching unit, the signs of the signals with the phases of 0 and pi in the upper sequence are kept unchanged, and the signs of the signals with the phases of pi/2 and 3 pi/2 are compressed into the sign with the amplitude of 0; after processing by the phase compression means of the second sub-matching unit, the signs of the signals with phases pi/2 and 3 pi/2 in the lower sequence remain unchanged, while the signs of the signals with phases 0 and pi will be compressed into signs with amplitude 0.
S4, converting frequency of a part of the sequence after the up-down compression based on the frequency converter in the sub-matching unit to obtain a sequence after the up-down conversion; based on the first multiplexer, obtaining an upper coherent sequence and a lower coherent sequence through coherent superposition of the other part of the upper compressed sequence and the lower compressed sequence with the first target sequence and the second target sequence;
more specifically, taking frequency conversion and unit matching performed in the first sub-matching unit as an example, the method includes:
dividing the upper compressed sequence into two identical parts, namely a first upper compressed sequence and a second upper compressed sequence, wherein the first upper compressed sequence is subjected to frequency conversion by the frequency converter from the original omega0Conversion to omega1Obtaining the up-converted sequence with the frequency still being omega0The second upper compressed sequence and the first target sequence enter the first multiplexer at the same time, and coherent superposition occurs, so that only when the amplitude of an output signal after passing through the multiplexer is equal toWhen the amplitude of the signal in the compressed sequence or the target sequence is twice as large as the amplitude of the signal in the compressed sequence or the target sequence, the phase of the signal in the corresponding original optical data sequence is the same as the phase of the signal in the target sequence, and the two phases are matched; otherwise, no match is made.
Wherein, ω is0And omega1The difference of (A) is preferably controlled within 10-1000 GHz.
More specifically, coherent matching of signals having phases of 0 and pi is realized in the first multiplexer of the first sub-matching unit, and coherent matching of signals having phases of pi/2 and 3 pi/2 is realized in the first multiplexer of the second sub-matching unit.
S5, processing the upper and lower coherent sequences through the first AND gate and the second AND gate to obtain a matching result after eliminating output interference caused by the compressed sequence and a signal with zero amplitude in the target sequence;
more specifically, the above process is based on the following findings:
after step S4, when the output signal amplitude after passing through the multiplexer is not twice the signal amplitude in the optical data sequence or the target sequence, the following two cases may occur: (1) the amplitude of the output signal after passing through the multiplexer is zero, which indicates that the phase difference between the signal in the input optical data sequence and the signal in the target sequence is pi, and the two signals are coherently cancelled; (2) the amplitude of the output signal after passing through the multiplexer is the same as that of the signal in the original optical data sequence or the signal in the target sequence, and only one of the signals in the optical data sequence signal after being subjected to the phase compression and the signal in the target sequence is a signal with zero amplitude. If the amplitude of the output signal is zero, it indicates that the two signals are not matched, and no further processing is needed, and if the amplitude of the output signal is the same as the amplitude of the original optical data sequence signal or the target sequence signal, the subsequent processing will be affected.
Therefore, the invention further connects two groups of AND gates after the frequency converter and the first multiplexer, wherein two inputs of the first group of AND gates are respectively the outputs of the frequency converter and the multiplexer; and two inputs of the second group of AND gates are respectively the output of the first group of AND gates and the target sequence used by the way, if the compressed sequence and the target sequence have signals with zero amplitude, the output result is always zero after passing through the two groups of AND gates, thereby eliminating the interference.
S6, performing coupling multiplexing on the unit matching result after the interference cancellation by using the second multiplexer, to obtain a matching result between a signal in the input optical data sequence and a current signal in the target sequence;
more specifically, the matching result is represented by: after the upper and lower unit matching results are combined into one path through a second multiplexer, if a pulse appears in the output of the multiplexer, the signal of the optical data sequence is matched with the signal of the target sequence at the signal position; if no pulse is present, the two do not match.
More specifically, the matching of the signals of 0 and pi phases in the optical data sequence with the signals of 0 and pi phases in the first target sequence is performed by the first sub-matching unit, and the matching of the signals of pi/2 and 3 pi/2 phases with the signals of pi/2 and 3 pi/2 phases of the second target sequence is performed by the second sub-matching unit;
s7 continuously matches the optical data sequence repeatedly input into the input data sequence channel N times through the third and gate and the regenerator of the output unit until a matching result of each signal in the optical data sequence and the last signal in the target sequence is obtained, where N represents the number of signals of the sequence to be matched;
wherein the continuous matching is as follows: in each frame or cycle, since the duration of each target sequence is consistent with the duration of the M-bit optical data sequence, each matching is the matching of the M-bit optical data sequence and the 1-bit target sequence, and the matching result of each signal in the optical data sequence and the last signal in the target sequence can be obtained by repeating the input or preferably by performing N times of matching through the cyclic subunit.
More specifically, in the output unit, each matching preferably delays the input signal by (M +1) T, and then the input signal enters the regenerator for regeneration, and in the first matching or cycle period, an initial pulse sequence is added to the third and gate, and in the remaining cycle periods, data after the delay and regeneration of the matching result of the previous cycle period is input to the third and gate each time.
Then, during the time of [0, M × T ], one input of the third and gate is the output of the matching unit, and the other input is the initial pulse sequence, which is composed of a series of pulse sequences with all "1" symbols, so that the output result of the and gate in the cycle loop during the time of [0, M × T ] is the matching result of the optical data sequence and the first signal in the sequence to be matched.
And the other input of the AND gate in the circulation loop is the matching result of the optical data sequence after the (M +1) T time delay and the regenerator and the first signal in the sequence to be matched in the time of [ M, 2M, T ], so that the output result of the AND gate in the circulation loop in the time of [ M, T, 2M, T ] is the matching result of the optical data sequence and the first two signals in the sequence to be matched.
And circulating the steps until finally obtaining a matching result of the optical data sequence and the sequence to be matched of the N signals.
In the cyclic output, if there is a sequence to be matched in the input optical data sequence, several pulses are output, which means that several sequences to be matched are included in the optical data sequence, and the position of the pulse indicates the position of the last symbol of the sequence to be matched in the input optical data sequence; if the input optical data sequence does not have the sequence to be matched, no pulse is output.
Example 1
By performing a simulation experiment on the all-optical fast pattern matching system and method of the above specific embodiment, wherein:
the QPSK signal used includes four selectable phases {0, pi/2, pi, 3 pi/2 }, which are correspondingly encoded as {00, 01, 10, 11}, and the corresponding decimal numbers are {0, 1, 2, 3}, respectively.
The input optical data sequence and the data to be matched are shown in fig. 2, and specifically include:
the input optical data sequence a is {1, 0, 2, 3, 0, 1, 0, 2, 3, 1}, the length M thereof is 10, and the amplitude Am thereof.
The sequence to be matched B is {1, 0, 2, 3}, the length N is 4, and the amplitude Am is also.
Dividing a sequence to be matched into a target sequence 1 and a target sequence 2 according to included symbols, so that the target sequence 1 and the target sequence 2 only include two symbols with a phase difference of pi, specifically, the target sequence 1 only includes two symbols with phases of 0 and pi, which are { ×, 0, 2, and x (× represents that there is no signal at the symbol position, namely the amplitude is 0, corresponding to a signal state at the origin on a QPSK constellation diagram); the target sequence 2 contains only two symbols with phases of pi/2 and 3 pi/2, which are {1, x, 3 }.
The phase compression is achieved by a phase sensitive amplifier based on the FWM effect and by a process as shown in fig. 3, using the following phase compression model:
Figure BDA0003151663300000131
Figure BDA0003151663300000132
Figure BDA0003151663300000133
Figure BDA0003151663300000134
Figure BDA0003151663300000135
under the above phase compression model, the input frequency is ω0QPSK signal and continuous optical pumping signal P1And P2Simultaneously input into HNLF at frequency omega due to FWM effect in HNLF0Will produce a phase of
Figure BDA0003151663300000141
The idler of (2) to (3), the phase is
Figure BDA0003151663300000142
The idle frequency optical signal can be in coherent superposition with the input QPSK signal, and second-order phase compression of the QPSK signal is realized.
Under the above phase compression model, when the phase of the input signal is changed
Figure BDA0003151663300000143
While having an initial phase
Figure BDA0003151663300000144
Will be amplified when the phase of the input signal is changed
Figure BDA0003151663300000145
Figure BDA0003151663300000146
Has an initial phase
Figure BDA0003151663300000147
Will be attenuated by appropriately adjusting the two pump signals P1And P2Can theoretically have an initial phase
Figure BDA0003151663300000148
The power attenuation of the symbol of (a) is 0. Similarly, if there is P1' and P2' the initial phase is pi/2, then has the initial phase
Figure BDA0003151663300000149
Figure BDA00031516633000001410
Will be amplified to have an initial phase
Figure BDA00031516633000001411
Will be attenuated and theoretically can be attenuated to a power of 0.
Under the above conditions, the signal representation of each unit in the first cycle of the matching system is as shown in fig. 4, which specifically includes:
the input optical data sequence a ═ {1, 0, 2, 3, 0, 1, 0, 2, 3, 1} is divided into two paths, wherein the add sequence is obtained by splitting two pump lights P1And P2The initial phase of (a) is set to 0, and symbols with phases of 0 and pi can be filtered out, resulting in a phase-compressed sequence of { ×, 0, 2, ×, 0, ×, 0, 2, ×, × }; the down sequence is formed by combining two pump lights P1' and P2' the initial phase is set to pi/2, and the symbols with phases pi/2 and 3 pi/2 can be filtered out to obtain the sequence {1, x, 3, x, 1, x, 3, 1} after phase compression; during the first cycle, the sequence to be matched B is {1} and has a symbol duration of 10T, so that there is no symbol in the generated target sequence 1, while the generated target sequence 2 is {1} and has a symbol duration of 10T. For synchronization with the symbols in a, the generated target sequence 2 is denoted as {1, 1, 1, 1, 1, 1}, where the duration of each symbol is the same as in a, and is T.
Each sequence of the upper sequence and the lower sequence after the phase compression is divided into two paths again, wherein one path is subjected to frequency conversion, and the other path and the corresponding target sequence enter a multiplexer; the information carried in the sequence subjected to frequency conversion is not changed, only the frequency is from ω0Become omega1Based on the foregoing analysis, the output result of the all-optical mode matching unit is essentially an OOK signal, and then as shown in the figure, the subsequent signals are all represented by amplitudes in the time domain, which is specifically represented as: the signal amplitude of the sequence passing through the frequency converter is Am only at the position with the symbol and 0 at the position without the symbol; then for the upper sequence of the two sequences, the amplitude of the sequence after passing through the frequency converter is {0, Am, 0, Am, 0, 0} in the time domain, and for the lower sequence, the amplitude of the sequence after passing through the frequency converter is { Am, 0, 0, Am }.
The input optical data sequence and the sequence to be matched are positioned at the same frequency, and as shown in fig. 3, the frequency of the signal filtered out after the phase compression is consistent with that of the input signal, so that the frequency of the sequence after the phase compression is consistent with that of the target sequence, after the multiplexer is passed, due to coherent superposition, if the sequence symbol after the phase compression is the same as that of the target sequence, the output pulse amplitude is 2 Am; if the phase difference between the sequence symbol after the phase compression and the target sequence symbol is pi, the amplitude of the output pulse is 0; otherwise, the output pulse amplitude is Am. Then, for the upper and lower sequences, the output signal sequence is as shown in fig. 4: in the upper sequence, the amplitude of the sequence after passing through the multiplexer is {0, Am, 0, Am, 0, 0}, and in the lower sequence, the amplitude of the sequence after passing through the multiplexer is {2 Am, 0, Am, 2 Am, 0, 2 Am }.
And simultaneously entering the symbol sequence after the frequency conversion and the multiplexer into a next first AND gate, wherein the AND gate can eliminate the influence of the symbol in the sequence after the phase compression on an output result, and the amplitude of the sequence after the first AND gate in the time domain is {0, Am, 0, Am, 0, 0} for the upper sequence, and the amplitude of the sequence after the first AND gate in the time domain is {2 Am, 0, 0, 0, 0, 0, 2 Am } for the lower sequence.
And simultaneously inputting the obtained output result and the corresponding target sequence into a second AND gate, wherein the AND gate can eliminate the influence of the symbol X in the target sequence on the output result, the amplitude of the sequence passing through the second AND gate in the time domain is {0, 0, 0, 0, 0, 0, 0, 0} for the upper sequence, and the amplitude of the sequence passing through the second AND gate in the time domain is {2 Am, 0, 0, 0, 0, 0, 2 Am }, for the lower sequence.
And simultaneously inputting the output results of the second AND gate in the upper and lower sequences into a multiplexer to obtain the output result of the final all-optical mode matching unit, wherein the amplitude of the output result is {2 Am, 0, 0, 0, 0, 2 Am } in the time domain, and the result shows the position of the first sequence symbol "1" to be matched in the input optical data sequence, and the sequence symbol can be regarded as an OOK signal because the output result has only two states of high and low in amplitude.
During the first cycle, the output of the all-optical pattern matching unit is taken as one input of the and gate in the cycle, and simultaneously enters the and gate in the next cycle with an initial pulse sequence with the amplitude of 2 Am and the duration of 10T. Because a part of the output of the AND gate enters the regenerator and the delay module in the circulation loop at the same time to generate an input sequence of the AND gate entering the circulation loop in the second circulation, the amplitude attenuation of the pulse in the output result of the AND gate is set to be the same as the amplitude of the initial pulse, namely 2 Am, and the final output result is {2 Am, 0, 0, 0, 0, 0, 2 Am }. The result shows the position of the first symbol "1" of the sequence to be matched in the input optical data sequence, and accurate matching is realized.
Example 2
Under the conditions and processes of example 1, the signal representation of each unit of the matching system in the second cycle process is shown in fig. 5, which specifically comprises:
dividing an input optical data sequence A into two paths, wherein the two paths are divided into {1, 0, 2, 3, 0, 1, 0, 2, 3, 1}, and filtering out symbols with phases of 0 and pi on the upper path to obtain a phase-compressed sequence { x, 0, 2, x, 0, 2, ×, }; the symbols with phases π/2 and 3 π/2 are filtered out in the next pass to obtain a phase-compressed sequence {1, ×, ×, 3, ×, 1, ×, ×, 3, 1 }.
The sequence B to be matched during the second cycle is chosen to be {0} with a symbol duration of 10 × T, so that the generated target sequence 1 is {0, 0, 0, 0, 0, 0, 0, 0, 0, 0} and the generated target sequence 2 has no symbol.
And dividing the sequence subjected to the phase compression into two paths, wherein one path passes through a frequency converter, and the other path enters a multiplexer together with a corresponding target sequence. For the upper path, the amplitude of the sequence after passing through the frequency converter in the time domain is {0, Am, 0, Am, 0, 0}, and the amplitude of the sequence after passing through the multiplexer in the time domain is { Am, 2 Am, 0, Am, 2 Am, 2 Am, 0, Am }; for the down-path, the amplitude of the sequence after the frequency converter is { Am, 0, 0, Am, 0, 0, 0, Am } in the time domain, and the amplitude of the sequence after the multiplexer is { Am, 0, 0, Am, 0, 0, Am }.
The symbol sequence after the frequency conversion and the multiplexer simultaneously enters a first AND gate, and for the upper path, the amplitude of the sequence after the first AND gate in the time domain is {0, 2 Am, 0, 0 }; for the down-path, the magnitude of the sequence after the first AND gate in the time domain is { Am, 0, 0, Am, 0, 0, Am }.
Inputting the output result and the corresponding target sequence into a second AND gate at the same time, wherein for the upper path, the amplitude of the sequence after passing through the second AND gate in the time domain is {0, 2 Am, 0, 0 }; for the down-path, the magnitude of the sequence after the second AND gate is {0, 0, 0, 0, 0, 0, 0} in the time domain.
And simultaneously inputting the output results of the second AND gate in the upper path and the lower path into a multiplexer to obtain the output result of the final all-optical mode matching unit, wherein the amplitude of the output result in the time domain is {0, 2 Am, 0, 0, 0}, and the result shows the position of the symbol '0' of the second sequence to be matched in the input optical data sequence.
In the second circulation process, the output of the all-optical mode matching unit is taken as one input of the AND gates in the circulation loop, and enters the AND gates in the next circulation loop simultaneously with the result of the first circulation output after (M +1) × T delay and regeneration operation. Since the delay is (M +1) × T, in the second cycle, the input of another and gate is {0, 2 × Am, 0, 0, 0, 0, 2 × Am, 0, 0, 0}, after amplitude attenuation, the output of the and gate is {0, 2 × Am, 0, 0, 0, 0, 2 × Am, 0, 0, 0}, and there are two pulses in the result, indicating that there are two "10" in the input optical data sequence, i.e., the first two symbols of the sequence to be matched, and the position where the pulse appears is aligned with the last symbol "0" of "10" in the optical data sequence. Similarly, a portion of the output is simultaneously fed into the regenerator and delay elements of the recycle loop to generate the required input sequence for the third cycle.
Example 3
After the second cycle of example 2, a third cycle was performed under the same system and conditions, and the signal representation of each unit is shown in fig. 6, which specifically includes:
dividing an input optical data sequence A into two paths, wherein the two paths are divided into {1, 0, 2, 3, 0, 1, 0, 2, 3, 1}, and filtering out symbols with phases of 0 and pi on the upper path to obtain a phase-compressed sequence { x, 0, 2, x, 0, 2, ×, }; the symbols with phases π/2 and 3 π/2 are filtered out in the next pass to obtain a phase-compressed sequence {1, ×, ×, 3, ×, 1, ×, ×, 3, 1 }. During the third cycle, the sequence to be matched B is {2} and has a symbol duration of 10 × T, so that the generated target sequence 1 is {2, 2, 2, 2, 2, 2} and the generated target sequence 2 has no symbol.
And dividing the sequence subjected to the phase compression into two paths, wherein one path passes through a frequency converter, and the other path enters a multiplexer together with a corresponding target sequence. For the upper path, the amplitude of the sequence after passing through the frequency converter in the time domain is {0, Am, 0, Am, 0, 0}, and the amplitude of the sequence after passing through the multiplexer in the time domain is { Am, 0, 2 Am, 0, 2 Am, Am }; for the down-path, the amplitude of the sequence after the frequency converter is { Am, 0, 0, Am, 0, 0, 0, Am } in the time domain, and the amplitude of the sequence after the multiplexer is { Am, 0, 0, Am, 0, 0, Am }.
The symbol sequence after the frequency conversion and the multiplexer simultaneously enters a first AND gate, and for the upper path, the amplitude of the sequence after the first AND gate in the time domain is {0, 0, 2 Am, 0, 0, 0, 0, 2 Am, 0, 0 }; for the down-path, the magnitude of the sequence after the first AND gate in the time domain is { Am, 0, 0, Am, 0, 0, Am }.
Inputting the output result and the corresponding target sequence into a second AND gate at the same time, wherein for the upper path, the amplitude of the sequence after passing through the second AND gate in the time domain is {0, 0, 2 Am, 0, 0, 0, 0, 2 Am, 0, 0 }; for the down-path, the magnitude of the sequence after the second AND gate is {0, 0, 0, 0, 0, 0, 0} in the time domain.
And simultaneously inputting the output results of the second AND gate in the upper path and the lower path into a multiplexer to obtain the final output result of the all-optical mode matching unit, wherein the amplitude of the final output result in the time domain is {0, 0, 2 Am, 0, 0, 0, 0, 2 Am, 0, 0}, and the result shows the position of a third sequence symbol "2" to be matched in the input optical data sequence.
During the third cycle, the output of the all-optical pattern matching unit is taken as one input of the and gate in the cycle, and is taken as the result of the second cycle output after the (M +1) T delay and regeneration operation, {2 Am, 0, 0, 0, 0, 0, 2 Am, 0, 0} and simultaneously enters the and gate in the next cycle. After amplitude adjustment, the output result of the and gate is {0, 0, 2 Am, 0, 0, 0, 0, 2 Am, 0, 0}, and there are two pulses in the result, indicating that there are two "102" in the input optical data sequence, i.e., the first three symbols of the sequence to be matched, and the position where the pulse appears is aligned with the last symbol "2" of "102" in the optical data sequence. Similarly, a portion of the output is simultaneously fed to the regenerator and delay blocks in the loop to generate the required input sequence for the fourth cycle.
Example 4
After the third cycle of example 3, a fourth cycle was performed under the same system and conditions, and the signal representation of each unit is shown in fig. 7, which specifically includes:
dividing an input optical data sequence A into two paths, wherein the two paths are divided into {1, 0, 2, 3, 0, 1, 0, 2, 3, 1}, and filtering out symbols with phases of 0 and pi on the upper path to obtain a phase-compressed sequence { x, 0, 2, x, 0, 2, ×, }; the symbols with phases π/2 and 3 π/2 are filtered out in the downstream path, resulting in a phase-compressed sequence {1, xxx, 3, xx, 1, xxx, 3, 1 }. During the fourth cycle, the sequence to be matched B is {3} with a symbol duration of 10 × T, so that the target sequence 1 is generated without any symbols, and the target sequence 2 is {3, 3, 3, 3, 3, 3, 3 }.
Dividing the sequence after phase compression into two paths, wherein one path passes through a frequency converter, the other path enters a multiplexer together with a corresponding target sequence, for the upper path, the amplitude of the sequence after the frequency converter in the time domain is {0, Am, 0, Am, 0, 0}, and the amplitude of the sequence after the frequency converter in the time domain is {0, Am, 0, 0 }; for the downstream, the amplitude of the sequence after passing through the frequency converter is { Am, 0, 0, Am, 0, 0, Am } in the time domain, and the amplitude of the sequence after passing through the multiplexer is {0, Am, 2 Am, 0, Am, 2 Am, 0} in the time domain.
The symbol sequence after frequency conversion and multiplexer enters a first AND gate at the same time, and for the uplink, the amplitude of the sequence after the first AND gate in the time domain is {0, Am, 0, Am, 0, 0 }; for the down-pass, the amplitude of the sequence after the first and-gate in time domain is {0, 0, 0, 2 Am, 0, 0, 0, 0, 2 Am, 0 }.
Inputting the output result and the corresponding target sequence into a second AND gate at the same time, wherein for the upper path, the amplitude of the sequence after passing through the second AND gate on the time domain is {0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; for the down-pass, the amplitude of the sequence after the second and-gate in time domain is {0, 0, 0, 2 Am, 0, 0, 0, 0, 2 Am, 0 }.
And simultaneously inputting the output results of the second AND gate in the upper path and the lower path into a multiplexer to obtain the final output result of the all-optical mode matching unit, wherein the amplitude of the final output result on the time domain is {0, 0, 0, 2 Am, 0}, and the result shows the position of the fourth sequence symbol to be matched '3' in the input optical data sequence.
During the fourth cycle, the output of the all-optical pattern matching unit is taken as one input of the and gate in the circulation loop, and is output as a result of the third cycle after the (M +1) × T delay and regeneration operation, {0, 0, 0, 2 × Am, 0}, and simultaneously enters the and gate in the next circulation loop. After the amplitude adjustment, the output result of the and gate is {0, 0, 0, 2 Am, 0, 0, 0, 0, 2 Am, 0}, and two pulses exist in the result, which indicates that two "1023" exist in the input optical data sequence, i.e., the sequence to be matched, and the position of the pulse occurrence is aligned with the last symbol "3" of "1023" in the optical data sequence. Since the sequence to be matched only contains 4 symbols, after the fourth cycle is finished, the system takes out the output result, restores the initial state and waits for the next instruction.
In the above embodiments, the change of the waveform diagram of the all-optical fast pattern matching system for QPSK signals is as shown in fig. 8, and it can be seen that after four cycles, the system can successfully find the number and position of sequences to be matched in an input optical data sequence, extend the original all-optical fast binary pattern matching system to a higher-order modulation format, and use HNLF with faster response time, thereby greatly increasing the data amount that can be processed in a unit time, enabling the all-optical fast pattern matching system for QPSK signals to be more suitable for the existing network, contributing to increasing the network throughput and reducing the network blocking rate.
The above examples are merely preferred embodiments of the present invention, and the scope of the present invention is not limited to the above examples. All technical schemes belonging to the idea of the invention belong to the protection scope of the invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention, and such modifications and embellishments should also be considered as within the scope of the invention.

Claims (9)

1. All-optical fast mode matching system for QPSK signals is characterized in that: the device comprises an input unit, a matching unit and an output unit; the input unit comprises an input data sequence channel for inputting a QPSK signal sequence, a first target sequence channel for inputting a first target sequence in a signal sequence to be matched and a second target sequence channel for inputting a second target sequence in the signal sequence to be matched; the matching unit comprises a first matching subunit and a second matching subunit which are connected in parallel, wherein each matching subunit comprises a phase compression device connected with the input data sequence channel, a frequency converter and a first multiplexer which are connected with the other end of the phase compression device and are connected in parallel with each other, a first AND gate device connected with the frequency converter and the other end of the first multiplexer, a second AND gate device connected with the first AND gate device and the first or second target sequence input channel, and a second multiplexer connected with the second AND gate devices of the two matching subunits, the first target sequence input channel is connected with the first multiplexer of the first matching subunit, and the second target sequence input channel is connected with the first multiplexer of the second matching subunit; the output unit comprises a third AND gate device connected with the other end of the second multiplexer and a regenerator forming a circulation loop with the third AND gate device;
wherein the AND gate device, the frequency converter and the regenerator are all selected from a structure based on a four-wave mixing effect of a high-nonlinearity optical fiber; the phase compression device is selected from phase sensitive amplifiers based on four-wave mixing effect of high nonlinear optical fibers.
2. The matching system of claim 1, wherein: the input unit also comprises a circulation subunit which is connected with the input data sequence channel and then enters the matching unit, and the circulation subunit can continuously and repeatedly input the input signal sequence into the matching unit according to periodic delay; and/or, the output unit further comprises a delay subunit connected with the third and gate device and the regeneration device, and the delay subunit can enable each matching result to be continuously combined with the next matching result according to periodic delay.
3. The matching system of claim 1, wherein: it also includes a power adjusting device for adaptively adjusting the signal power in different units in the system.
4. All-optical fast mode matching method for QPSK signals based on the matching system of any of claims 1-3, characterized in that: it includes:
inputting an optical data sequence composed of a plurality of QPSK signals with equal periods and different phases from the input data sequence channel;
separating a signal sequence to be matched, which is composed of a QPSK signal, into a first target sequence and a second target sequence from the first sequence input channel and the second sequence input channel, wherein the signal sequence to be matched and the optical data sequence have the same amplitude, and the first target sequence and the second target sequence comprise two different types of signal phases, namely a first type of phase and a second type of phase;
separating the optical data sequence into two identical sequences, namely an upper sequence and a lower sequence, respectively entering a first matching subunit and a second matching subunit, performing phase compression processing based on a four-wave mixing effect in a high-nonlinearity optical fiber on the upper sequence or the lower sequence through the phase compression device until each compressed sequence only contains the first type phase or the second type phase, and correspondingly obtaining an upper compressed sequence or a lower compressed sequence;
separating the upper compressed sequence or the lower compressed sequence to enable each compressed sequence to form two identical subsequences, namely a first subsequence or a second subsequence;
carrying out frequency conversion processing based on a four-wave mixing effect in a high-nonlinearity optical fiber on signals in the first subsequence of the upper compressed sequence or the lower compressed sequence through the frequency converter to correspondingly obtain an up-conversion sequence or a down-conversion sequence;
carrying out coherent superposition on the signal of the second subsequence of the upper compressed sequence or the lower compressed sequence and the signal of the first target sequence or the second target sequence through the first multiplexer to correspondingly obtain an upper coherent sequence or a lower coherent sequence;
carrying out first logic and processing on the up-converted sequence and the upper coherent sequence or the down-converted sequence and the lower coherent sequence through a first AND gate device based on a four-wave mixing effect in a high nonlinear optical fiber to correspondingly obtain the upper coherent sequence or the lower coherent sequence;
performing second logic and processing based on a four-wave mixing effect in a high-nonlinearity optical fiber on the upper phase and sequence and the first target sequence or the lower phase and sequence and the second target sequence through a second AND gate device, and correspondingly obtaining an upper unit matching result or a lower unit matching result after interference elimination;
coupling the upper unit matching result and the lower unit matching result through a second multiplexer to obtain a matching result of a signal in the optical data sequence and a current signal in the target sequence;
sequentially carrying out the matching process on all signals of the optical data sequence and the target sequence until the matching result of all signals is obtained;
wherein the matching result is represented as: after the upper and lower unit matching results are combined into one path through the second multiplexer, if a pulse appears in the output of the multiplexer, the signal of the optical data sequence is matched with the signal of the target sequence at the signal position; if no pulse is present, the two do not match.
5. Matching method according to claim 4, characterized in that: in the matching of all signals in sequence, regenerated data generated by delaying the last matching result and regenerating based on a high-nonlinearity optical fiber is added in each matching, and in the first matching, the data is set as an initial pulse sequence with the symbol of 1 of all signals.
6. The matching method according to claim 5, wherein: the delay time is (M +1) T, where M represents the number of signals in the optical data sequence and T represents the duration of each signal in the optical data sequence.
7. Matching method according to claim 4, characterized in that: of the different types of phases, the first type of phase includes a phase in which any two of four discrete phases of the QPSK signal have a phase difference of pi, and the second type of phase includes the remaining two phases of the QPSK signal.
8. Matching method according to any of claims 4-7, characterized in that: the phase compression process is realized by the following compression model:
Figure FDA0003596187120000031
Figure FDA0003596187120000032
Figure FDA0003596187120000033
Figure FDA0003596187120000034
Figure FDA0003596187120000035
wherein E isoutOptical field representing the output signal, AoutRepresenting the amplitude of the output signal after phase sensitive amplification,
Figure FDA0003596187120000036
representing the phase of the output signal after phase sensitive amplification,
Figure FDA0003596187120000037
representing the phase of the input signal, M representing the amplitude ratio between the (M-1) subharmonic and the input signal, M representing the number of symbols contained in the input signal, P1、P2Two initial phases are 0 and frequencies are omega respectively0Omega and is omega0+ omega continuous optical pumping signal, omega0Representing the frequency of the input signal, omega representing the difference in frequency between the pump signal and the input signal, P1’、P2' means that the sum of two initial phases is pi and the frequency is omega respectively0Omega and omega are0+ omega continuous optical pumping signal, Eidler1An optical field representing a signal generated by the FWM effect in the phase compression process on the upper sequence,
Figure FDA0003596187120000038
representing the pump signal P1Of the light field of (a) and (b),
Figure FDA0003596187120000039
representing the pump signal P2The light field of (a) is,
Figure FDA00035961871200000310
representing the conjugate of the optical field of the input signal, Eidler2An optical field representing a signal generated by the FWM effect in the phase compression process on the lower sequence,
Figure FDA00035961871200000311
representing the pump signal P1' of the optical field of the optical sensor,
Figure FDA00035961871200000312
representing the pump signal P2' of the optical field of the optical sensor,
Figure FDA00035961871200000313
representing the phase of the signal generated by the FWM effect in the phase compression process on the upper sequence,
Figure FDA0003596187120000041
representing the pump signal P1The phase of (a) is determined,
Figure FDA0003596187120000042
representing the pump signal P2The phase of (a) is determined,
Figure FDA0003596187120000043
which represents the phase of a signal generated by the FWM effect in the phase compression process on the lower sequence,
Figure FDA0003596187120000044
representing the pump signal P1The phase of the phase-locked loop,
Figure FDA0003596187120000045
representing the pump signal P2The phase of'.
9. Use of the matching system of any one of claims 1-3 and/or the matching method of any one of claims 4-8 in a photonic firewall.
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