CN113612611B - Asynchronous sampling method and system for continuous variable quantum key distribution - Google Patents
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Abstract
The invention provides a continuous variable quantum key distribution asynchronous sampling method and a system, which relate to the technical field of computer information, and the method comprises the following steps: step S1: constructing a quantum light pulse signal conforming to Gaussian distribution, constructing a strong light pulse signal with constant amplitude, and then inserting the strong light pulse signal into the quantum light pulse signal for transmission; step S2: and oversampling the received optical pulse signal, searching index bits of peak sampling points of the strong optical pulse signal, and extracting peak sampling values of the quantum optical pulse signal based on the index bits. The invention can judge the optimal sampling point by using the strong light pulse signal with constant amplitude, and extract the optimal sampling value of the quantum light pulse signal based on the optimal sampling point, thereby not only reducing the hardware complexity without transmitting synchronous clock signals, but also eliminating sampling deviation caused by non-homologous clock jitter, and being beneficial to the realization of an integrated continuous variable quantum key distribution system.
Description
Technical Field
The invention relates to the technical field of computer information, in particular to a continuous variable quantum key distribution asynchronous sampling method and a system, and especially relates to a continuous variable quantum key distribution asynchronous sampling method.
Background
With the rapid development of information society, important fields such as finance and energy in human society have stronger dependence on information technology, and accordingly high demands on information security are brought. Quantum secret communication is a communication mode with higher security known at present, and the communication information is protected from being acquired by an eavesdropper by means of quantum mechanical characteristics. Quantum secret communication is mainly divided into two parts: firstly, quantum Key Distribution (QKD) is carried out, and a key with extremely high confidentiality is distributed on a quantum channel by utilizing the quantum mechanical characteristics such as the uncertainty principle; the obtained secret key is then used for carrying out one-time pad encryption scheme on the communication information, and the classical channel is used for completing information transmission. In the whole process, quantum key distribution is a very critical step, and the safety of the step determines the safety of the whole communication process, so that the method is widely researched and is a mature development item in the current quantum information technology.
Quantum key distribution is largely divided into two types, discrete variable quantum key distribution and continuous variable quantum key distribution. The main difference between discrete variable quantum key distribution and continuous variable quantum key distribution is the different carriers that transport information. Discrete variable quantum key distribution represented by the BB84 protocol proposed in 1984 uses discrete variables such as single photon polarization for key distribution; whereas continuous variable quantum key distribution represented by GG02 protocol proposed in 2002 uses continuous variables such as optical field regularization component for key distribution. Compared with discrete variable quantum key distribution, continuous variable quantum key distribution starts later, but has the advantages of easy signal detection, easy integration with a classical optical network and the like, and has better practical application prospect, so that the method and the device are valued and researched in the industry. The continuous variable quantum key distribution protocol with the most complete and mature safety certification is a Gaussian modulation coherent state continuous variable quantum key distribution protocol, and the protocol uses Gaussian modulation coherent state signals to finish key distribution.
The invention patent with publication number of CN106130943A discloses a data acquisition method and system of a continuous variable quantum key distribution system, wherein the system comprises a transmitting end and a receiving end which adopt homologous clocks, and the clock of the transmitting end is divided into one path which is transmitted to the receiving end through a classical channel and is used as a system clock source of the receiving end; the receiving end adopts the same clock frequency as the modulation information of the transmitting end to sample the received signal, and sends the sampled data to the data processing and control module to be processed, the phase difference between the rising edge of the sampling clock and the peak position point of the signal is determined according to the information provided by the sampled data, and the delay value of the delay module is adjusted through feedback, so that the rising edge of the sampling clock and the peak position point are strictly aligned to realize accurate peak sampling.
The invention patent with publication number CN109039606A discloses a common-frequency sampling method and circuit in a continuous variable quantum key distribution system, comprising the following steps: sampling data on an optical path to obtain a section of sampling data; calculating the average value of the sampling data, and storing the obtained average value and the corresponding sampling point; adjusting the sampling phase when the data is sampled; repeating as such, number of repetitions = single data period/DPS minimum adjustment granularity; comparing the stored average values of all the sampling points, taking the sampling point corresponding to the maximum average value as a final sampling point, and adjusting the sampling phase to be the sampling phase corresponding to the final sampling point.
In order to ensure that the continuous variable quantum key distribution system works normally in practical implementation, it is necessary for the receiving end to accurately acquire signals. The traditional continuous variable quantum key distribution system uses local oscillation light emitted by a transmitting end as a clock signal or adopts another wavelength to independently transmit the clock signal, thereby guaranteeing the clock synchronization of a receiving end and realizing synchronous sampling of signals. However, the scheme increases the complexity of hardware equipment, and is not beneficial to the realization of an integrated continuous variable quantum key distribution system. The local clock signal is used for sampling directly, and sampling errors can be caused by inherent clock offset at the receiving end and the transmitting end. And because the light quantum signal is very weak, the traditional clock recovery scheme is not applicable. Therefore, an asynchronous sampling method is required to be provided for a continuous variable quantum key distribution system, so that accurate transmission of key information of two communication parties is ensured.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a continuous variable quantum key distribution asynchronous sampling method and a system.
The invention provides a continuous variable quantum key distribution asynchronous sampling method and a system, wherein the scheme is as follows:
in a first aspect, there is provided a continuous variable quantum key distribution asynchronous sampling method, the method comprising:
step S1: constructing a quantum light pulse signal conforming to Gaussian distribution, constructing a strong light pulse signal with constant amplitude, and then inserting the strong light pulse signal into the quantum light pulse signal for transmission;
step S2: and oversampling the received optical pulse signal, searching index bits of peak sampling points of the strong optical pulse signal, and extracting peak sampling values of the quantum optical pulse signal based on the index bits.
Preferably, the step S1 includes:
step S1.1: constructing a quantum optical pulse signal obeying Gaussian distribution, wherein the quantum optical pulse signal is generated by a random number generator and a photoelectric modulator;
step S1.2: constructing a strong light pulse signal with constant amplitude, wherein the strong light pulse signal is generated by a photoelectric modulator;
step S1.3: the strong light pulse signal is inserted into the quantum light pulse signal to form an emitting light pulse sequence, and the operation is completed by the light time delay line and the light beam combiner.
Preferably, the step S2 includes:
step S2.1: detecting the received light pulse signal by using a coherent detector, and oversampling the output electric signal;
step S2.2: in one period, obtaining an index bit of a peak sampling point of the strong light pulse signal based on an optimal index bit searching scheme;
step S2.3: and obtaining the peak value sampling point index bit of the quantum optical pulse signal based on the peak value sampling point index bit of the strong optical pulse signal and the optimal sampling value extraction scheme, and extracting the peak value sampling value of the quantum optical pulse signal.
Preferably, the electrical signal oversampling scheme is as followsIs sampling the electrical signal at a sampling rate of +.>For the transmission frequency of the pulse signal, < >>For the oversampling rate, the resulting sample points can be expressed as:
；
wherein,representing the collectionSample value (I)>Representing sample point index, +.>Representing the sample length.
Preferably, the optimal index bit searching scheme is that all sampling points are divided by taking a double oversampling rate as a unit, and a sampling point array in one period is obtained as follows:
searching the maximum value in the array to obtain the index bit corresponding to the maximum value as，/>Is the oversampling rate.
Preferably, the optimal sampling value extraction scheme is that according to the following stepsSearching the index bit of the peak value of the quantum light pulse, namely
Wherein,index bit for the optimal quantum light pulse peak value;
is a modulo operator; />The peak value of the quantum light pulse signal is obtained.
Preferably, the quantum light pulse signal subjected to gaussian distribution can be expressed as:
wherein,and->Regular positions and regular momentums, respectively representing continuous variables, all subject to gaussian distribution, i.e，/>Modulating variance for the signal;
complex amplitude values that are continuous variables;
index for the position of a gaussian data sequence, +.>；
The length of the quantum optical pulse signal is;
in imaginary units.
Preferably, the strong light pulse signal may be expressed as:
wherein,is of constant amplitude;
indicating the position index of strong light pulse signal as +.>Specific numerical value of>。
Preferably, strong light pulse signals are interleaved between quantum light pulse signals, and the emitted light pulse sequence can be expressed as:
。
in a second aspect, there is provided a continuous variable quantum key distribution asynchronous sampling system, the system comprising:
and the transmitting end: constructing a quantum light pulse signal conforming to Gaussian distribution, constructing a strong light pulse signal with constant amplitude, and inserting the strong light pulse signal into the quantum light pulse signal for transmission;
the receiving end: receiving a quantum light pulse signal, oversampling the received light pulse signal, searching an index bit of a peak sampling point of the strong light pulse signal, and extracting a peak sampling value of the quantum light pulse signal based on the index bit;
the transmitting end comprises:
module M1.1: constructing a quantum optical pulse signal obeying Gaussian distribution, wherein the quantum optical pulse signal is generated by a random number generator and a photoelectric modulator;
module M1.2: constructing a strong light pulse signal with constant amplitude, wherein the strong light pulse signal is generated by a photoelectric modulator;
module M1.3: the strong light pulse signal is inserted into the quantum light pulse signal to form an emission light pulse sequence, and the operation is completed by a light time delay line and a light beam combiner;
the receiving end comprises:
module M2.1: detecting the received light pulse signal by using a coherent detector, and oversampling the output electric signal;
module M2.2: in one period, obtaining an index bit of a peak sampling point of the strong light pulse signal based on an optimal index bit searching scheme;
module M2.3: and obtaining the peak value sampling point index bit of the quantum optical pulse signal based on the peak value sampling point index bit of the strong optical pulse signal and the optimal sampling value extraction scheme, and extracting the peak value sampling value of the quantum optical pulse signal.
Compared with the prior art, the invention has the following beneficial effects:
1. according to the invention, the optimal sampling point is judged by using the strong light pulse signal with constant amplitude, and the optimal sampling value of the quantum light pulse signal is extracted based on the optimal sampling point, so that a synchronous clock signal is not required to be transmitted, the hardware complexity is reduced, and the integration of a continuous variable quantum key distribution system is facilitated;
2. the invention can also eliminate sampling deviation caused by non-homologous clock jitter, and the sampling deviation caused by clock signal jitter can be eliminated because the quantum optical pulse signals in each period are subjected to optimal index bit searching and optimal sampling value extraction;
3. the strong light pulse signal adopted in the invention can also be used for realizing polarization compensation and phase recovery, and improving the channel damage resistance of the system.
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Other features, objects and advantages of the present invention will become more apparent upon reading of the detailed description of non-limiting embodiments, given with reference to the accompanying drawings in which:
FIG. 1 is a schematic diagram of a continuous variable quantum key distribution asynchronous sampling method;
fig. 2 is a schematic diagram of a continuous variable quantum key distribution asynchronous sampling system.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications could be made by those skilled in the art without departing from the inventive concept. These are all within the scope of the present invention.
The embodiment of the invention provides a continuous variable quantum key distribution asynchronous sampling method, which is shown by referring to FIG. 1 and comprises the following specific steps:
step S1: the sending end firstly constructs a quantum light pulse signal which is subjected to Gaussian distribution, then constructs a strong light pulse signal with constant amplitude, and finally inserts the strong light pulse signal into the quantum light pulse signal.
Specifically, in the step S1, firstly, a quantum optical pulse signal which obeys Gaussian distribution is constructed, and the signal is generated by a random number generator and a photoelectric modulator; reconstructing a strong light pulse signal with constant amplitude, generating the signal by a photoelectric modulator, and inserting the strong light pulse signal into a quantum light pulse signal to form an emission light pulse sequence, wherein the operation is completed by a light delay line and a beam combiner.
Step S2: the receiving end firstly carries out oversampling on the received signal, then searches index bits of the peak sampling points of the strong light pulse signals, and finally extracts the peak sampling values of the quantum light pulse signals based on the index bits.
Specifically, in the step S2, a coherent detector is used to detect the received optical pulse signal, and the output electrical signal is oversampled; in one period (comprising a strong light pulse signal and a quantum light pulse signal), obtaining a peak sampling point index bit of the strong light pulse signal based on an optimal index bit searching scheme; and obtaining the peak value sampling point index bit of the quantum optical pulse signal based on the peak value sampling point index bit of the strong optical pulse signal and the optimal sampling value extraction scheme, and extracting the peak value sampling value of the quantum optical pulse signal.
A quantum light pulse signal that follows a gaussian distribution can be expressed as:
wherein,and->Regular positions and regular momentums, respectively representing continuous variables, all subject to gaussian distribution, i.e，/>Modulating variance for the signal;
is the complex amplitude of the continuous variable, +.>Index for the position of a gaussian data sequence, +.>Wherein->The length of the quantum optical pulse signal is; />In imaginary units.
The intense light pulse signal can be expressed as:
wherein,is of constant amplitude +.>Indicating the position index of strong light pulse signal as +.>Is used in the field of electronic devices,。
the sequence of emitted light pulses can be expressed as:
the electrical signal oversampling scheme is thatIs sampling the electrical signal at a sampling rate of +.>For the transmission frequency of the pulse signal, < >>Is the oversampling rate. The resulting sample points can be expressed as:
wherein the method comprises the steps ofIndicating the sampled value +.>Representing sample point index, +.>Representing the sample length.
The optimal index bit searching scheme is that all sampling points are divided by taking the double oversampling rate as a unit, and the sampling point array in one period is obtained as follows:
finding the maximum in the arrayObtain the corresponding index bit as。
The optimal sampling value extraction scheme is that according toSearching the index bit of the peak value of the quantum light pulse, namely
Wherein,index bit for optimal peak value of quantum light pulse, < >>Is a modulo operator. />The peak value of the quantum light pulse signal is obtained.
The principle of the asynchronous sampling method for continuous variable quantum key distribution of the invention is as follows:
in a continuous variable quantum key distribution system, a legal sender firstly prepares a quantum light pulse signal which is subjected to Gaussian distribution, then prepares a strong light pulse signal with constant amplitude, and then forms a transmitting light pulse sequence by passing the strong light pulse signal through a light delay line and a light beam combiner, wherein the sequence can be expressed asTotal length of transmitting sequence->The sender is +.>Pulse transmission is performed at the system frequency of (a).
After the optical signal passes through the channel, the legal receiver receives the optical signal and carries out coherent detectionObtaining an output electrical signal, and oversampling the electrical signal at a sampling rate ofI.e. oversampling rate +.>The method comprises the steps of carrying out a first treatment on the surface of the Then dividing all sampling points by taking double over-sampling rate as a unit to obtain a sampling point array in one period as +.>Searching the array for the maximum value to obtain the index bit corresponding to the maximum value>The method comprises the steps of carrying out a first treatment on the surface of the According to->Searching the peak index bit of the quantum light pulse, namely +.>The method comprises the steps of carrying out a first treatment on the surface of the At this time->Namely, a peak sampling value of the quantum light pulse signal; and (3) carrying out the operation on each dividing unit, extracting a peak sampling value of the quantum optical pulse signal in each period, and completing asynchronous sampling of the quantum optical signal in continuous variable quantum key distribution.
The invention also provides a continuous variable quantum key distribution asynchronous sampling system, which comprises the following modules:
and the transmitting end: firstly, constructing a quantum light pulse signal which is subjected to Gaussian distribution, then constructing a strong light pulse signal with constant amplitude, and finally, inserting the strong light pulse signal into the quantum light pulse signal.
The transmitting end specifically comprises: firstly, constructing a quantum optical pulse signal obeying Gaussian distribution, wherein the signal is generated by a random number generator and a photoelectric modulator; reconstructing a strong light pulse signal with constant amplitude, wherein the signal is generated by a photoelectric modulator; and finally, the module inserts the strong light pulse signal into the quantum light pulse signal to form an emission light pulse sequence, and the operation is completed by the light delay line and the light beam combiner.
The receiving end: and finally, extracting the peak sampling value of the quantum optical pulse signal based on the index bit.
The transmitting end specifically comprises: firstly, detecting a received optical pulse signal by using a coherent detector, and oversampling an output electric signal; in one period (comprising a strong light pulse signal and a quantum light pulse signal), obtaining a peak sampling point index bit of the strong light pulse signal based on an optimal index bit searching scheme; and finally, obtaining the peak value sampling point index bit of the quantum optical pulse signal based on the peak value sampling point index bit of the strong optical pulse signal and an optimal sampling value extraction scheme, and extracting the peak value sampling value of the quantum optical pulse signal.
The embodiment of the invention provides a continuous variable quantum key distribution asynchronous sampling method and a system, which utilize strong light pulse signals with constant amplitude to judge optimal sampling points, extract optimal sampling values of quantum light pulse signals based on the optimal sampling points, avoid the transmission of synchronous clock signals and reduce hardware complexity; sampling deviation caused by non-homologous clock jitter can be eliminated, and the sampling deviation caused by clock signal jitter can be eliminated because the quantum optical pulse signals in each period are subjected to optimal index bit searching and optimal sampling value extraction; the adopted strong light pulse signal can also be used for realizing polarization compensation and phase recovery, and improving the channel damage resistance of the system.
Those skilled in the art will appreciate that the invention provides a system and its individual devices, modules, units, etc. that can be implemented entirely by logic programming of method steps, in addition to being implemented as pure computer readable program code, in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. Therefore, the system and various devices, modules and units thereof provided by the invention can be regarded as a hardware component, and the devices, modules and units for realizing various functions included in the system can also be regarded as structures in the hardware component; means, modules, and units for implementing the various functions may also be considered as either software modules for implementing the methods or structures within hardware components.
The foregoing describes specific embodiments of the present invention. It is to be understood that the invention is not limited to the particular embodiments described above, and that various changes or modifications may be made by those skilled in the art within the scope of the appended claims without affecting the spirit of the invention. The embodiments of the present application and features in the embodiments may be combined with each other arbitrarily without conflict.
Claims (10)
1. A continuous variable quantum key distribution asynchronous sampling method, comprising:
step S1: constructing a quantum light pulse signal conforming to Gaussian distribution, constructing a strong light pulse signal with constant amplitude, and then inserting the strong light pulse signal into the quantum light pulse signal for transmission;
step S2: oversampling is carried out on the received optical pulse signal, index bits of peak sampling points of the strong optical pulse signal are searched, and peak sampling values of the quantum optical pulse signal are extracted based on the index bits;
specifically, a quantum optical pulse signal g [ obeying Gaussian distribution ] is firstly prepared through a legal transmitting end]Then preparing strong light pulse signal with constant amplitude, and then adding strong light pulse signal p [/head-on ]>],/>The method comprises the steps of carrying out a first treatment on the surface of the The light pulse sequence is formed by light delay line and light beam combiner, and is expressed as [ p 1]]，g[1]，p[2]，g[2]，…，p[N]，g[N]]The method comprises the steps of carrying out a first treatment on the surface of the N is the total length of the transmitting sequence, the transmitting end carries out pulse transmission at the frep system frequency, and legal connection is carried outThe receiving party receives the optical signal, obtains an output electric signal through coherent detection, and oversamples the electric signal;
then dividing all sampling points with twice over sampling rate as unit to obtain sampling point array in one period as [ A1, A2 ],. A [ i ], … A2 r ] ], r is over sampling rate; searching the maximum value in the array to obtain the index bit imax corresponding to the maximum value; looking up the quantum light pulse peak index bit from imax, i.e., iopt=mod ((imax+r-1), 2r) +1;
at this time, A [ iopt ] is the peak sampling value of the quantum light pulse signal; and (3) carrying out the operation on each dividing unit, extracting a peak sampling value of the quantum optical pulse signal in each period, and completing asynchronous sampling of the quantum optical signal in continuous variable quantum key distribution.
2. The asynchronous sampling method for continuous variable quantum key distribution according to claim 1, wherein the step S1 comprises:
step S1.1: constructing a quantum optical pulse signal obeying Gaussian distribution, wherein the quantum optical pulse signal is generated by a random number generator and a photoelectric modulator;
step S1.2: constructing a strong light pulse signal with constant amplitude, wherein the strong light pulse signal is generated by a photoelectric modulator;
step S1.3: the strong light pulse signal is inserted into the quantum light pulse signal to form an emitting light pulse sequence, and the operation is completed by the light time delay line and the light beam combiner.
3. The asynchronous sampling method for continuous variable quantum key distribution according to claim 1, wherein the step S2 comprises:
step S2.1: detecting the received light pulse signal by using a coherent detector, and oversampling the output electric signal;
step S2.2: in one period, obtaining an index bit of a peak sampling point of the strong light pulse signal based on an optimal index bit searching scheme;
step S2.3: and obtaining the peak value sampling point index bit of the quantum optical pulse signal based on the peak value sampling point index bit of the strong optical pulse signal and the optimal sampling value extraction scheme, and extracting the peak value sampling value of the quantum optical pulse signal.
4. The method of claim 3, wherein the electrical signal oversampling scheme is performed byIs sampling the electrical signal at a sampling rate of +.>For the transmission frequency of the pulse signal, < >>For the oversampling rate, the resulting sample points can be expressed as:
；
wherein,indicating the sampled value +.>Representing sample point index, +.>Representing the sample length.
5. The asynchronous sampling method for continuous variable quantum key distribution according to claim 3, wherein the optimal index bit search scheme is to divide all sampling points with a unit of twice the oversampling rate, and obtain an array of sampling points in one period as follows:
searching the maximum value in the array to obtain the index bit corresponding to the maximum value as，/>Is the oversampling rate.
6. The asynchronous sampling method for continuous variable quantum key distribution according to claim 3, wherein the optimal sampling value extraction scheme is as followsSearching the index bit of the peak value of the quantum light pulse, namely
Wherein,index bit for the optimal quantum light pulse peak value;
is a modulo operator; />The peak value of the quantum light pulse signal is obtained.
7. The continuous variable quantum key distribution asynchronous sampling method of claim 1, wherein the gaussian distribution compliant quantum light pulse signal is representable as:
wherein,and->Regular positions and regular momentums, respectively representing continuous variables, all subject to gaussian distribution, i.e，/>Modulating variance for the signal;
complex amplitude values that are continuous variables;
index for the position of a gaussian data sequence, +.>；
The length of the quantum optical pulse signal is;
in imaginary units.
8. The continuous variable quantum key distribution asynchronous sampling method of claim 1, wherein the strong light pulse signal is representable as:
wherein,is of constant amplitude;
indicating the position index of strong light pulse signal as +.>Specific numerical value of>。
9. The asynchronous sampling method for continuous variable quantum key distribution according to claim 2, wherein strong light pulse signals are interleaved between quantum light pulse signals, and the emitted light pulse sequence can be expressed as:
。
10. a continuous variable quantum key distribution asynchronous sampling system, comprising:
and the transmitting end: constructing a quantum light pulse signal conforming to Gaussian distribution, constructing a strong light pulse signal with constant amplitude, and inserting the strong light pulse signal into the quantum light pulse signal for transmission;
the receiving end: receiving a quantum light pulse signal, oversampling the received light pulse signal, searching an index bit of a peak sampling point of the strong light pulse signal, and extracting a peak sampling value of the quantum light pulse signal based on the index bit;
the transmitting end comprises:
module M1.1: constructing a quantum optical pulse signal obeying Gaussian distribution, wherein the quantum optical pulse signal is generated by a random number generator and a photoelectric modulator;
module M1.2: constructing a strong light pulse signal with constant amplitude, wherein the strong light pulse signal is generated by a photoelectric modulator;
module M1.3: the strong light pulse signal is inserted into the quantum light pulse signal to form an emission light pulse sequence, and the operation is completed by a light time delay line and a light beam combiner;
the receiving end comprises:
module M2.1: detecting the received light pulse signal by using a coherent detector, and oversampling the output electric signal;
module M2.2: in one period, obtaining an index bit of a peak sampling point of the strong light pulse signal based on an optimal index bit searching scheme;
module M2.3: based on the strong light pulse signal peak sampling point index bit and an optimal sampling value extraction scheme, obtaining a quantum light pulse signal peak sampling point index bit and extracting a peak sampling value of a quantum light pulse signal;
specifically, a quantum optical pulse signal g [ obeying Gaussian distribution ] is firstly prepared through a legal transmitting end]Then preparing strong light pulse signal with constant amplitude, and then adding strong light pulse signal p [/head-on ]>],/>The method comprises the steps of carrying out a first treatment on the surface of the The light pulse sequence is formed by light delay line and light beam combiner, and is expressed as [ p 1]]，g[1]，p[2]， g[2]，…，p[N]，g[N]]The method comprises the steps of carrying out a first treatment on the surface of the N is the total length of a transmitting sequence, a transmitting end transmits pulses at the frep system frequency, a legal receiver receives optical signals, and outputs electric signals through coherent detection, and the electric signals are oversampled;
then dividing all sampling points with twice over sampling rate as unit to obtain sampling point array in one period as [ A1, A2 ],. A [ i ], … A2 r ] ], r is over sampling rate; searching the maximum value in the array to obtain the index bit imax corresponding to the maximum value; looking up the quantum light pulse peak index bit from imax, i.e., iopt=mod ((imax+r-1), 2r) +1;
at this time, A [ iopt ] is the peak sampling value of the quantum light pulse signal; and (3) carrying out the operation on each dividing unit, extracting a peak sampling value of the quantum optical pulse signal in each period, and completing asynchronous sampling of the quantum optical signal in continuous variable quantum key distribution.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102868520A (en) * | 2012-08-28 | 2013-01-09 | 上海交通大学 | Continuous variable quantum key distribution system and phase compensation method thereof |
| CN107302430A (en) * | 2017-07-06 | 2017-10-27 | 上海交通大学 | A kind of continuous variable quantum key distribution system Gaussian modulation implementation method and device |
| CN111314071A (en) * | 2020-02-14 | 2020-06-19 | 上海循态信息科技有限公司 | Continuous variable quantum key distribution method and system |
| CN111740778A (en) * | 2020-08-25 | 2020-10-02 | 北京中创为南京量子通信技术有限公司 | Light source phase difference testing system and method |
| KR102238186B1 (en) * | 2019-12-27 | 2021-04-09 | 한국과학기술원 | CV QKD system using optical interferometer phase lock scheme for optical homodyne detection |
-
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102868520A (en) * | 2012-08-28 | 2013-01-09 | 上海交通大学 | Continuous variable quantum key distribution system and phase compensation method thereof |
| CN107302430A (en) * | 2017-07-06 | 2017-10-27 | 上海交通大学 | A kind of continuous variable quantum key distribution system Gaussian modulation implementation method and device |
| KR102238186B1 (en) * | 2019-12-27 | 2021-04-09 | 한국과학기술원 | CV QKD system using optical interferometer phase lock scheme for optical homodyne detection |
| CN111314071A (en) * | 2020-02-14 | 2020-06-19 | 上海循态信息科技有限公司 | Continuous variable quantum key distribution method and system |
| CN111740778A (en) * | 2020-08-25 | 2020-10-02 | 北京中创为南京量子通信技术有限公司 | Light source phase difference testing system and method |
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