WO2022027866A1 - Synchronization method and apparatus for quantum key distribution system - Google Patents

Synchronization method and apparatus for quantum key distribution system Download PDF

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Publication number
WO2022027866A1
WO2022027866A1 PCT/CN2020/130225 CN2020130225W WO2022027866A1 WO 2022027866 A1 WO2022027866 A1 WO 2022027866A1 CN 2020130225 W CN2020130225 W CN 2020130225W WO 2022027866 A1 WO2022027866 A1 WO 2022027866A1
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signal
synchronization
pulse
synchronization signal
frame synchronization
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PCT/CN2020/130225
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French (fr)
Chinese (zh)
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徐建益
杨军
李镇
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北京中创为南京量子通信技术有限公司
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
    • H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
    • H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
    • H04L9/0852—Quantum cryptography
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/70—Photonic quantum communication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L7/00—Arrangements for synchronising receiver with transmitter
    • H04L7/0075—Arrangements for synchronising receiver with transmitter with photonic or optical means
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L7/00—Arrangements for synchronising receiver with transmitter
    • H04L7/0079—Receiver details
    • H04L7/0087—Preprocessing of received signal for synchronisation, e.g. by code conversion, pulse generation or edge detection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L7/00—Arrangements for synchronising receiver with transmitter
    • H04L7/0091—Transmitter details

Definitions

  • the present application relates to the technical field of quantum secure communication, in particular to a synchronization method and device for a quantum key distribution system.
  • Quantum secure communication technology is mainly based on quantum key distribution technology (QuantumKeyDistribution, QKD).
  • QKD uses quantum mechanical properties to ensure communication security, so that both parties in the communication can generate and share a random and secure key to encrypt and Decrypt the message.
  • the quantum key distribution technology based on entangled states has not yet been commercialized, so the existing commercial quantum Key distribution technology is basically based on single photon implementation.
  • the transmitter (Alice) and the receiver (Bob) need to compare the basis vectors, that is, compare the basis vectors and sums used by Alice to send photons at a certain position. Whether the measurement basis used by Bob to detect the photon at this location is consistent. In order to ensure that Alice and Bob perform the basis vector comparison at the same position, precise "position" synchronization is required between the sender and the receiver. Otherwise, the keys at both ends of Alice and Bob will be inconsistent. Therefore, the system The synchronization method is particularly important. In addition, only after the synchronization process is completed, the quantum key distribution system can perform the subsequent negotiation process to generate a secure key. Therefore, synchronization technology plays an extremely important role in the quantum key distribution system.
  • the existing synchronization scheme is shown in Figure 1.
  • Alice aligns the first signal pulse of the quantum signal with the first signal pulse of the frame synchronization signal, and the frequency of the frame synchronization signal is much lower than that of the quantum signal.
  • the frequency of the synchronization signal is hundreds to thousands of times lower than the frequency of the quantum signal.
  • the transmission frequency of the quantum signal is 100MHz
  • the transmission frequency of the frame synchronization signal is 100KHz. Due to the efficiency of the detector and the attenuation of the optical fiber path, Bob can only receive one or two signal pulses of the quantum signal in the period of each frame synchronization signal.
  • Bob uses the signal pulse of the received frame synchronization signal each time as a reference. , measuring the distance between the signal pulse of a detected quantum signal and the signal pulse of the frame synchronization signal, the position of the signal pulse of the quantum signal can be determined, thereby completing the synchronization between Alice and Bob.
  • the above-mentioned prior art is the synchronization between Alice and Bob which is done ideally, however, due to the efficiency of the detector and the attenuation of the fiber path, or the turbulence of free space causes the attenuation to vary, in practice,
  • the frame synchronization optical signal has the problem of signal loss in the process of detection or transmission. If a frame synchronization optical signal is lost, all the frame synchronization signal sequences following the lost frame synchronization signal at the Bob end will have errors, such as in the frame synchronization signal. If the fifth signal pulse is lost, Bob will mistake the sixth signal pulse in the detected original frame synchronization signal as the fifth signal pulse, resulting in the wrong sequence number of all subsequent signal pulses, which in turn leads to the relationship between Alice and Bob. Synchronization failed. Therefore, if the problem of how to avoid the loss of the frame synchronization signal can be solved, the risk of synchronization failure between Alice and Bob can be greatly reduced.
  • the present application provides a synchronization method and device for a quantum key distribution system to solve the problem of synchronization failure caused by the loss of frame synchronization signal pulses.
  • a synchronization method for a quantum key distribution system comprising:
  • the synchronization signal is generated according to the clock signal, the pulse width of the synchronization signal is W, and the synchronization period of the synchronization signal is ⁇ t; in the nth synchronization period ⁇ t, a start command is generated, and the first synchronization signal is obtained according to the start command, and the first synchronization signal is obtained according to the start command.
  • the pulse width of a synchronization signal in the n+1th synchronization period is greater than 2W, only one signal pulse of the first synchronization signal has a pulse width greater than 2W, and the signal pulses with the pulse width greater than 2W occupy The duration is less than the synchronization period ⁇ t;
  • a start code signal is obtained according to the start command, the start code signal only includes one signal pulse, the rising edge of the signal pulse of the start code signal and the rising edge of the signal pulse with a pulse width greater than 2W in the first synchronization signal Alignment, according to the start coding signal and the clock signal regulation and emission quantum signal;
  • the frame synchronization signal is temporally compensated.
  • the synchronization method includes: the Bob end: receiving the first synchronization signal, and recovering a reference clock signal according to the first synchronization signal; delaying the first synchronization signal to obtain a second synchronization signal , the delay duration is longer than the duration occupied by the synchronization signal pulse with the pulse width of W, and the delay duration is smaller than the duration occupied by the signal pulse with the pulse width greater than 2W;
  • a frame synchronization start signal is obtained by performing an AND operation on the second synchronization signal; a frame synchronization signal is generated according to the recovered reference clock signal and the frame synchronization start signal; and the frame synchronization signal is compensated according to the delay time.
  • the synchronization method includes: the Bob end: receiving the first synchronization signal, and recovering a reference clock signal according to the first synchronization signal; integrating the first synchronization signal to obtain a third synchronization signal synchronization signal; compare the integral size of the third synchronization signal, and obtain a frame synchronization start signal according to the largest integral signal; generate a frame synchronization signal according to the recovered reference clock signal and the frame synchronization start signal; time compensation the frame synchronization signal.
  • the synchronization method includes: the Bob end: receiving the first synchronization signal, and recovering a reference clock signal according to the first synchronization signal; sampling by clock according to the first synchronization signal Identify the signal pulse with the pulse width greater than 2W; generate the frame synchronization start signal according to the signal pulse with the pulse width greater than 2W; generate frame synchronization according to the recovered reference clock signal and the frame synchronization start signal signal; temporally compensate the frame synchronization signal.
  • the pulse width of the n+1th synchronization period in the synchronization signal is modulated by means of pulse width modulation, so that the pulse width of the first synchronization signal in the n+1th synchronization period is greater than 2W.
  • the start command is a pulse signal including only one signal pulse, and according to the start command, the start code is generated while generating a signal pulse with a pulse width greater than 2W in the first synchronization signal The signal pulse of the signal.
  • the time difference between the rising edges of adjacent signal pulses in the first synchronization signal is equal, and the time difference between the rising edges of the adjacent signal pulses is the synchronization period ⁇ t.
  • the frame synchronization start signal includes only one signal pulse.
  • a frame synchronization signal is generated according to the clock signal and the frame synchronization start signal, and the rising edge of the frame synchronization start signal pulse is used as a starting point, and the period is counted according to the clock signal.
  • the synchronization period ⁇ t generates a frame synchronization signal pulse to obtain the frame synchronization signal.
  • a synchronization device for a quantum key distribution system comprising:
  • the synchronization unit is used to generate a synchronization signal according to the clock signal, the pulse width of the synchronization signal is W, and the synchronization period of the synchronization signal is ⁇ t, and is used to obtain the first synchronization signal according to the start command, and the first synchronization signal is at the n+1th
  • the pulse width of each synchronization period is greater than 2W, only one signal pulse of the first synchronization signal has a pulse width greater than 2W, and the signal pulse with a pulse width greater than 2W occupies a period less than the synchronization period ⁇ t, and is used for Obtaining a start code signal according to the start command, the start code signal contains only one signal pulse, and the rising edge of the signal pulse of the start code signal is aligned with the rising edge of the signal pulse with a pulse width greater than 2W in the first synchronization signal;
  • control unit configured to generate a start command within the nth synchronization period ⁇ t;
  • the coding unit is used to regulate and emit quantum signals according to the start coding signal and the clock signal; Bob's side:
  • a synchronization signal detection unit for receiving the first synchronization signal
  • a clock recovery unit configured to recover a reference clock signal according to the first synchronization signal
  • a frame synchronization start signal extraction unit configured to generate a frame synchronization start signal according to the first synchronization signal
  • the frame synchronization signal generating unit is used for generating the frame synchronization signal according to the recovered reference clock signal and the frame synchronization start signal.
  • the frame synchronization start signal extraction unit is configured to: receive a first synchronization signal, delay the first synchronization signal, and combine the received first synchronization signal with the delayed first synchronization signal.
  • a synchronization signal is ANDed to generate a frame synchronization start signal, and the frame synchronization start signal is output.
  • the present application provides a synchronization method and device for a quantum key distribution system, which has the following characteristics compared with the prior art:
  • the Alice end in this application uses pulse width modulation to make the transmitted synchronization signal pulse contain a synchronization signal pulse with a pulse width greater than twice the normal value, and a synchronization signal pulse appears in the synchronization signal obtained by the Bob end through detection.
  • the width is greater than twice the normal width.
  • the Bob end obtains a frame synchronization start signal containing only one signal pulse through detection and processing, and the Bob end generates a frame synchronization signal according to the recovered reference clock signal and the obtained frame synchronization start signal. Then, the final frame synchronization signal after time compensation is obtained through the post-processing process of the Bob end, and the synchronization between the Alice end and the Bob end is completed according to the finally obtained frame synchronization signal.
  • the synchronization signal output from the Alice end to the Bob end includes a synchronization signal pulse with a pulse width greater than twice the normal value. Because the pulse width is wider, the probability of losing it is much smaller than that of other normal width synchronization signal pulses, so in some normal In the case where the pulse width of the synchronization signal is lost, the Bob end can basically still detect the synchronization signal pulse whose pulse width is greater than twice the normal value.
  • the final frame synchronization signal is obtained according to the frame synchronization start signal and the recovered clock signal, and then the synchronization between Alice and Bob is completed. At this time, the final frame synchronization signal mainly depends on the reference clock signal and the frame synchronization start signal, and no longer It directly depends on the original synchronization signal transmitted by Alice.
  • the clock recovery unit using the analog phase-locked loop mode at the Bob end in the present application can still recover the clock signal normally under the occasional loss or misidentification of the synchronization signal, which further improves the stability and reliability of the synchronization operation.
  • Fig. 1 is the time sequence schematic diagram of the quantum key distribution system synchronization scheme in the prior art
  • Fig. 2 is the time sequence schematic diagram of the quantum key distribution system synchronization method of the present application
  • FIG. 3 is a schematic structural diagram of a synchronization device of the quantum key distribution system of the application.
  • FIG. 4 is a schematic time sequence diagram of the synchronization method of the quantum key distribution system based on the delay phase sum of the application;
  • FIG. 5 is a schematic time sequence diagram of the synchronization method of the quantum key distribution system based on integral comparison of the present application.
  • a first aspect of the present application provides a method for synchronizing a quantum key distribution system, as shown in FIG. 2 , which is a schematic time sequence diagram of the method for synchronizing a quantum key distribution system of the present application.
  • the synchronization method includes: the Alice side: regulating and controlling according to a clock signal
  • the synchronizing unit enables the synchronizing unit to transmit a synchronizing signal, the pulse width of the synchronizing signal is W, the synchronizing period of the synchronizing signal is ⁇ t, for example ⁇ t is 10us, and the time between the rising edge of one signal pulse of the synchronization signal and the rising edge of the next signal pulse is The interval is a synchronization period ⁇ t, and the duration of the signal pulse with the pulse width W (for example, 2us) is less than the synchronization period ⁇ t; in the nth (n is a positive integer greater than or equal to 1) synchronization period ⁇ t, the control unit sends The synchronization unit outputs a start command, and
  • the pulse width of each synchronization period is greater than 2W, and only one signal pulse of all signal pulses of the first synchronization signal has a pulse width greater than 2W.
  • the first synchronization signal is transmitted through the synchronization unit, and the pulse width is greater than 2W.
  • the length of time occupied by the signal pulse (for example, 5us) is less than the synchronization period ⁇ t; according to the start command, the start code signal is obtained, and the start code signal is output to the code unit through the synchronization unit, and the start code signal contains only one signal pulse,
  • the rising edge of the signal pulse of the start coding signal is aligned with the rising edge of the signal pulse whose pulse width is greater than 2W in the first synchronization signal, and the coding unit is regulated to emit quantum signals according to the start coding signal and the clock signal. .
  • the synchronization unit is regulated to transmit the synchronization signal.
  • the normal pulse width of the synchronization signal is W
  • the synchronization period of the synchronization signal that is, the time difference between the rising edges of adjacent signal pulses is ⁇ t, for example, ⁇ t is 10us
  • the duration occupied by the signal pulse with the pulse width W is less than ⁇ t; within the nth synchronization period ⁇ t, that is, between the rising edges of two adjacent signal pulses in the nth synchronization period (it may also include the rising edges of the two signal pulses) edge), output a start command to the synchronization unit through the control unit, the start command is a pulse signal containing only one signal pulse, and the pulse rising edge of the start command is between the rise of the adjacent two signal pulses of the nth synchronization cycle Between edges (which may also include the rising edges of two signal pulses), the pulse width of the start command is not specifically limited in this application; according to the start command, the synchronization unit is made to transmit a pulse width greater than 2W in the n+1th synchronization cycle.
  • the first synchronization signal is obtained from the signal pulse of the first synchronization signal, that is, the signal pulse width in the n+1th synchronization period in the first synchronization signal is greater than 2W, and the signal pulse width in the remaining first synchronization signals is the normal pulse width W.
  • the signal pulse with a width greater than 2W occupies less than the synchronization period ⁇ t.
  • the time difference between the rising edges of adjacent signal pulses in the first synchronization signal is equal, that is, the time difference between the rising edges of adjacent signal pulses is the synchronization period ⁇ t; according to
  • the start command obtains a start code signal, and the start code signal is output to the code unit through the synchronization unit.
  • the synchronization unit According to the start command, the synchronization unit generates a signal pulse with a pulse width greater than 2W in the first synchronization signal.
  • the signal pulse of the start encoding signal is generated, that is, the rising edge of the signal pulse of the start encoding signal is aligned with the rising edge of the first synchronization signal pulse whose pulse width is greater than 2W in the first synchronization signal, so as to regulate the quantum signal.
  • the launch of the encoding signal only includes a signal pulse, and the pulse width of the encoding signal is not specifically limited in this application; according to the encoding signal and the local clock signal, the encoding unit is regulated to transmit a quantum signal, according to the pulse of the encoding signal.
  • the rising edge regulation and coding unit starts to emit the quantum signal, that is, the rising edge of the first signal pulse of the quantum signal and the rising edge of the signal pulse whose pulse width is greater than 2W in the first synchronization signal and the rising edge of the start coding signal pulse Align.
  • the Alice end sends the generated first synchronization signal and the quantum signal to the Bob end.
  • the Alice end modulates the pulse width of the n+1th synchronization period in the synchronization signal by means of pulse width modulation, so that the synchronization unit transmits a signal pulse with a pulse width greater than 2W in the n+1th synchronization period to obtain the first sync signal.
  • the Bob end Referring to FIG. 2, receiving the first synchronization signal, recovering a reference clock signal according to the first synchronization signal; generating a frame synchronization start signal according to the first synchronization signal; according to the recovered reference
  • the clock signal and the frame synchronization start signal generate a frame synchronization signal; the frame synchronization signal is compensated in time.
  • the Bob end receives the first synchronization signal transmitted by the Alice end through the synchronization signal detection unit, and according to the received first synchronization signal, the clock recovery unit restores the reference clock signal CLK synchronized with the Alice end, and the Bob end recovers
  • the reference clock signal and the clock signal of the Alice end are the same source clock, and the two are synchronized.
  • the reference clock signal recovered according to the first synchronization signal is configured to still be able to be used even in the case of occasional loss or misidentification of part of the signal pulse of the first synchronization signal.
  • the reference clock signal synchronized with the Alice end is recovered normally; the frame synchronization start signal is extracted according to the first synchronization signal by the frame synchronization start signal extraction unit, and the frame synchronization start signal is mainly based on the pulse width in the first synchronization signal. If the signal pulse is greater than 2W, the frame synchronization start signal contains only one signal pulse; according to the recovered reference clock signal and the obtained frame synchronization start signal, the frame synchronization signal is generated by the frame synchronization signal generating unit.
  • the frame synchronization signal is generated by the frame synchronization signal.
  • the rising edge of the start signal pulse is the starting point, and the cycle count is performed according to the recovered reference clock signal to keep the output frame synchronization period consistent with the synchronization signal of the Alice side, and a frame synchronization signal pulse is generated every synchronization period ⁇ t to obtain the frame synchronization signal, That is, the synchronization period of the frame synchronization signal is also ⁇ t; the frame synchronization signal is compensated in time so that the rising edge of the first signal pulse in the time-compensated frame synchronization signal is the same as the first synchronization signal whose pulse width is greater than 2W.
  • the rising edges of the signal pulses are aligned, and the frame synchronization signal after time compensation is the final frame synchronization signal used for the synchronization between the Alice end and the Bob end.
  • the signal pulse with the pulse width greater than twice the normal value in the first synchronization signal is also lost, Alice can obtain the frame synchronization status of Bob through classic communication interaction. If Bob cannot generate a frame synchronization start signal, Alice and Bob will It is determined that the synchronization is invalid this time, and the transmitted and received quantum signals are also invalid. The Alice side will resend the first synchronization signal until the frame synchronization is normal. In addition, since the pulse width of only one signal pulse in the first synchronization signal is greater than twice the normal value, the light intensity of the first synchronization signal will not affect the quantum signal during the signal transmission process. If the width of a plurality of signal pulses in the signal is relatively wide, the light intensity of the first synchronization signal is very strong, which will greatly interfere with the quantum signal.
  • a second aspect of the present application provides a synchronization device for a quantum key distribution system, which is used to implement the above synchronization method provided by the present application.
  • the device includes: an Alice end: a synchronization unit for outputting a first synchronization signal containing a signal pulse with a pulse width greater than twice the normal pulse width according to a clock signal and a start command, and for outputting a start encoding signal to the encoding unit; a control unit for sending the synchronization signal to the synchronization unit The unit outputs a start command; the coding unit is used to transmit a quantum signal according to the start code signal and the clock signal CLK; Bob end: a synchronization signal detection unit, used to receive a first synchronization signal pulse with a pulse width greater than twice the normal pulse width signal; a clock recovery unit, configured as a clock recovery unit based on an analog phase-locked loop, for recovering the reference clock signal CLK
  • the synchronization unit is configured to: receive a clock signal, receive a start command sent by the control unit, generate and output a first synchronization signal and a start encoding signal simultaneously according to the clock signal and the start command, and the first synchronization signal contains a pulse width greater than A signal pulse with twice the normal pulse width;
  • the control unit is configured to: output a start command to the synchronization unit through the control unit within a certain synchronization period ⁇ t such as the nth (n is a positive integer greater than or equal to 1);
  • encoding The unit is configured to: regulate and output the quantum signal according to the received rising edge of the start encoding signal pulse and the clock signal;
  • the synchronization signal detection unit is configured to: receive the first synchronization signal sent by the Alice end, and output the first synchronization signal;
  • the clock The recovery unit is configured as: a clock recovery unit based on an analog phase-locked loop mode, recovers the reference clock signal CLK according to the received first synchronization signal, and can still recover
  • the clock signal is recovered normally;
  • the frame synchronization start signal extraction unit is configured to: receive the first synchronization signal, extract the frame synchronization start signal according to the first synchronization signal, and output the frame synchronization start signal;
  • the frame synchronization signal generation unit is configured The steps include: receiving the recovered reference clock signal and the frame synchronization start signal, generating a frame synchronization signal according to the frame synchronization start signal and the reference clock signal, temporally compensating the frame synchronization signal, and outputting the compensated frame synchronization signal.
  • the synchronization signal and quantum signal can be transmitted between Alice and Bob through optical fiber quantum communication or free space quantum communication.
  • the synchronization signal is transmitted through the synchronization channel or the classical channel, and the quantum signal is transmitted through the quantum channel.
  • the Alice end sends the first synchronization signal containing a signal pulse with a relatively wide pulse width and the quantum signal generated by timely regulation to the Bob end, and the Bob end processes the detected first synchronization signal to obtain the final synchronization signal.
  • Frame synchronization signal and finally the Bob end can complete the synchronization between the Alice end and the Bob end according to the obtained frame synchronization signal and the received quantum signal according to the existing synchronization scheme as shown in FIG. 1 .
  • the clock recovery unit adopting the analog phase-locked loop method at the Bob end can still recover the reference clock signal normally even if the signal pulse of the first synchronization signal is occasionally lost or misidentified, which improves the stability and reliability of the synchronization operation.
  • the Bob end generates a frame synchronization start signal according to the first synchronization signal; the specific embodiment of generating the frame synchronization start signal is as follows.
  • Embodiment 1 as shown in FIG. 4 , referring to the above synchronization method, the synchronization method of the Alice side remains unchanged, and the Bob side: receives the first synchronization signal, and restores a reference clock signal according to the first synchronization signal; delays the The first synchronization signal obtains a second synchronization signal, and the delay duration is greater than the duration occupied by the synchronization signal pulse with the pulse width of W, and the delay duration is smaller than the duration occupied by the signal pulse with the pulse width greater than 2W;
  • the first synchronization signal and the second synchronization signal are ANDed to obtain a frame synchronization start signal; a frame synchronization signal is generated according to the recovered reference clock signal and the frame synchronization start signal; according to the delay time compensation the frame synchronization signal.
  • the Bob end receives the first synchronization signal transmitted by the Alice end through the synchronization signal detection unit, and according to the received first synchronization signal, the clock recovery unit restores the reference clock signal CLK synchronized with the Alice end, and according to the first synchronization signal
  • the recovery of the reference clock signal is configured to be able to recover the reference clock signal synchronized with the Alice end normally even when part of the signal pulse of the first synchronization signal is occasionally lost or misidentified;
  • the first synchronization signal obtains the second synchronization signal.
  • the above delay is only a time delay, and the pulse width and synchronization period remain unchanged.
  • the delay time is required to be longer than the pulse
  • the duration occupied by the synchronization signal pulse with a width of W, and the delay duration is required to be less than the duration occupied by the signal pulse with a pulse width greater than 2W, so that the pulse width is W when the first synchronization signal and the second synchronization signal are subsequently ANDed.
  • the signal pulses are eliminated; the frame synchronization start signal is obtained by AND operation of the first synchronization signal and the second synchronization signal through the frame synchronization start signal extraction unit, and most of the pulse signals are eliminated by the phase and operation, so that the frame synchronization starts.
  • the start signal contains only one signal pulse.
  • the frame synchronization start signal can only contain One signal pulse, and the rising edge of the frame synchronization start signal is aligned with the rising edge of the signal pulse whose pulse width is greater than 2W in the second synchronization signal.
  • the final frame synchronization signal can be obtained through two implementations.
  • Embodiment 1 Referring to FIG. 2 , first, the frame synchronization is performed according to the recovered reference clock signal and the obtained frame synchronization start signal.
  • the signal generating unit generates a frame synchronization signal.
  • the period count is performed according to the clock signal, and a frame synchronization signal pulse is generated every synchronization period ⁇ t to obtain a frame synchronization signal, that is, a frame synchronization signal.
  • the synchronization period of the synchronization signal is also ⁇ t, and then, time compensation is performed for the obtained frame synchronization signal, that is, the delay time of the second synchronization signal is compensated for the frame synchronization signal, so that the frame after delay compensation
  • the rising edge of the first signal pulse in the synchronization signal is aligned with the rising edge of the signal pulse whose pulse width is greater than 2W in the first synchronization signal, and the obtained frame synchronization signal after delay compensation is the final frame synchronization signal to be used
  • Embodiment 2 First, the obtained frame synchronization start signal is compensated for the delay duration, that is, the frame synchronization start signal obtained in the above process is first compensated in time, that is, the signal in the frame synchronization start signal after compensation is compensated.
  • the rising edge of the pulse is aligned with the rising edge of the signal pulse whose pulse width is greater than 2W in the first synchronization signal, and then passes the frame synchronization signal generation unit according to the recovered reference clock signal and the frame synchronization start signal obtained after time compensation.
  • the final frame synchronization signal is generated, and the specific method of generating the frame synchronization signal is the same as the generation method of generating the frame synchronization signal from the recovered reference clock signal and the obtained frame synchronization start signal in the first embodiment.
  • the final frame synchronization signal can be accurately obtained through the delay compensation of the above two methods.
  • the frame synchronization start signal extraction unit is configured to: receive the first synchronization signal, delay the first synchronization signal in time to obtain the second synchronization signal, and extract the received first synchronization signal The signal and the obtained second synchronization signal are ANDed to generate a frame synchronization start signal, and the frame synchronization start signal is output;
  • the frame synchronization signal generation unit is configured to: receive the recovered reference clock signal and the frame synchronization start signal, and according to the frame synchronization
  • the start signal and the reference clock signal generate a frame synchronization signal, compensate the frame synchronization signal in time, and output the compensated frame synchronization signal, or the frame synchronization signal generation unit is configured to: receive the recovered reference clock signal and start the frame synchronization.
  • the frame synchronization start signal is compensated in time, and the frame synchronization signal is generated according to the compensated frame synchronization start signal and the reference clock signal.
  • Embodiment 2 as shown in FIG. 5 , with reference to the above synchronization method, the synchronization method of the Alice end remains unchanged, and the Bob end: receives the first synchronization signal, and restores a reference clock signal according to the first synchronization signal; The first synchronization signal is integrated to obtain a third synchronization signal; the integral size of the third synchronization signal is compared, and a frame synchronization start signal is obtained according to the largest integrated signal; according to the recovered reference clock signal and the frame synchronization start The signal generates a frame synchronization signal; the frame synchronization signal is temporally compensated.
  • the first synchronization signal is integrated by the frame synchronization start signal extraction unit to obtain a third synchronization signal
  • the signal pulse integration of the narrower width is smaller than the signal pulse integration of the wider width
  • a comparison level is set
  • the comparison level is The size is between the signal pulse integral of the narrower width and the signal pulse integral of the wider width.
  • the pulse width in the first synchronization signal is greater than
  • the position of the 2W signal pulse can then generate the frame synchronization start signal at this position, that is, the frame synchronization start signal is obtained according to the largest integral signal, and then, the frame synchronization start signal is generated according to the recovered reference clock signal and the frame synchronization start signal.
  • the frame synchronization signal is finally compensated for the frame synchronization signal in time by the post-processing unit at the Bob end.
  • the frame synchronization start signal extraction unit is configured to: integrate the first synchronization signal to obtain a third synchronization signal, compare the integration size of the third synchronization signal, and obtain a third synchronization signal according to the largest integration The signal gets the frame sync start signal.
  • Embodiment 3 referring to the above synchronization method, the synchronization method of the Alice end remains unchanged, and the Bob end: receives the first synchronization signal, recovers a reference clock signal according to the first synchronization signal; passes the clock according to the first synchronization signal Identify the signal pulse with the pulse width greater than 2W by means of direct sampling; generate the frame synchronization start signal according to the signal pulse with the pulse width greater than 2W; start the frame synchronization according to the recovered reference clock signal and the frame synchronization start The signal generates a frame synchronization signal; the frame synchronization signal is temporally compensated.
  • the clock module in the frame synchronization start signal extraction unit uses digital clock sampling to identify the signal pulses in the first synchronization signal with a pulse width greater than 2W, that is, the signal pulses with a pulse width greater than 2W in the first synchronization signal.
  • the occupied duration is longer than the duration occupied by the signal pulses of other normal widths, and accordingly, the signal pulses with the pulse width greater than 2W in the first synchronization signal are identified, and the frame synchronization start signal is generated according to the signal pulses with the pulse width greater than 2W, and then, according to The recovered reference clock signal and the frame synchronization start signal generate a frame synchronization signal, and finally, the frame synchronization signal is temporally compensated by the post-processing unit at the Bob end.
  • the frame synchronization start signal extraction unit is configured to: identify a signal pulse with a pulse width greater than 2W according to the first synchronization signal by means of clock sampling, and according to the pulse width greater than 2W The signal pulse generates a frame sync start signal.

Abstract

The present application provides a synchronization method and apparatus for a quantum key distribution system, relating to the technical field of quantum secure communications. In said method, an Alice end causes, by means of pulse width modulation, transmitted synchronization signal pulses to contain a synchronization signal pulse having a pulse width greater than the value twice a normal value, a Bob end detects that in an obtained synchronization signal, there is a synchronization signal pulse having a pulse width greater than the value twice a normal value, the Bob end obtains, by means of detection and processing, a frame synchronization start signal only containing one signal pulse, then the Bob end generates a frame synchronization signal according to a restored reference clock signal and the obtained frame synchronization start signal, and finally a final frame synchronization signal having been subjected to time compensation is obtained by means of a post-processing process by the Bob end, and synchronization between the Alice end and Bob end is completed according to the finally obtained frame synchronization signal. The technical solution provided in the present application greatly reduces the risk of failure of synchronization between Alice and Bob, and has high reliability.

Description

一种量子密钥分发系统的同步方法及装置Synchronization method and device for quantum key distribution system 技术领域technical field
本申请涉及量子保密通信技术领域，具体涉及一种量子密钥分发系统的同步方法及装置。The present application relates to the technical field of quantum secure communication, in particular to a synchronization method and device for a quantum key distribution system.
背景技术Background technique
量子保密通信技术主要是基于量子密钥分发技术(QuantumKeyDistribution，QKD)，QKD是利用量子力学特性来保证通信安全性，使通信的双方能够产生并分享一个随机的、安全的密钥，来加密和解密消息。量子密钥分发通常有两种方式：一种是基于单光子方案实现，另一种基于纠缠态方案实现，然而基于纠缠态的量子密钥分发技术还未能实现商业化，所以现有商用量子密钥分发技术基本上是基于单光子实现的。Quantum secure communication technology is mainly based on quantum key distribution technology (QuantumKeyDistribution, QKD). QKD uses quantum mechanical properties to ensure communication security, so that both parties in the communication can generate and share a random and secure key to encrypt and Decrypt the message. There are usually two ways of quantum key distribution: one is based on a single-photon scheme, and the other is based on an entangled state scheme. However, the quantum key distribution technology based on entangled states has not yet been commercialized, so the existing commercial quantum Key distribution technology is basically based on single photon implementation.
现有的基于单光子实现的量子密钥分发过程中，发射端(Alice)和接收端(Bob)需要进行基矢比对，即比对Alice在某一个位置上发送光子所使用的基矢和Bob在探测这一位置的光子时所使用的测量基矢是否是一致的。为了保证Alice和Bob在同一个位置上进行基矢比对，发送方和接收方之间需要精确的“位置”同步，否则，最终Alice和Bob两端的密钥会出现不一致的现象，所以，系统的同步方法就显得尤其重要。此外，只有完成同步过程后，量子密钥分发系统才可以进行后续的协商处理过程产生安全密钥，因此，同步技术对于量子密钥分发系统来说具有极其重要的作用。In the existing single-photon-based quantum key distribution process, the transmitter (Alice) and the receiver (Bob) need to compare the basis vectors, that is, compare the basis vectors and sums used by Alice to send photons at a certain position. Whether the measurement basis used by Bob to detect the photon at this location is consistent. In order to ensure that Alice and Bob perform the basis vector comparison at the same position, precise "position" synchronization is required between the sender and the receiver. Otherwise, the keys at both ends of Alice and Bob will be inconsistent. Therefore, the system The synchronization method is particularly important. In addition, only after the synchronization process is completed, the quantum key distribution system can perform the subsequent negotiation process to generate a secure key. Therefore, synchronization technology plays an extremely important role in the quantum key distribution system.
现有的同步方案如图1所示，Alice将量子信号的第一个信号脉冲与帧同步信号的第一个信号脉冲对齐，且帧同步信号的频率比量子信号的频率低的多，一般帧同步信号的频率比量子信号的频率低数百倍至上千倍，例如量子信号的发射频率为100MHz，帧同步信号的发射频率为100KHz。由于探测器的效率和光纤路径衰减的原因，Bob在每个帧同 步信号的周期内只能接收到一两个量子信号的信号脉冲，Bob以每次接收到的帧同步信号的信号脉冲作为参考，测量某一探测到的量子信号的信号脉冲与该帧同步信号的信号脉冲之间的距离，即可确定出该量子信号的信号脉冲的位置，从而完成Alice与Bob之间的同步。The existing synchronization scheme is shown in Figure 1. Alice aligns the first signal pulse of the quantum signal with the first signal pulse of the frame synchronization signal, and the frequency of the frame synchronization signal is much lower than that of the quantum signal. The frequency of the synchronization signal is hundreds to thousands of times lower than the frequency of the quantum signal. For example, the transmission frequency of the quantum signal is 100MHz, and the transmission frequency of the frame synchronization signal is 100KHz. Due to the efficiency of the detector and the attenuation of the optical fiber path, Bob can only receive one or two signal pulses of the quantum signal in the period of each frame synchronization signal. Bob uses the signal pulse of the received frame synchronization signal each time as a reference. , measuring the distance between the signal pulse of a detected quantum signal and the signal pulse of the frame synchronization signal, the position of the signal pulse of the quantum signal can be determined, thereby completing the synchronization between Alice and Bob.
上述现有技术是在理想情况下完成的Alice与Bob之间的同步，然而，由于探测器的效率和光纤路径衰减的原因，或者，自由空间的湍流导致衰减变化的原因，在实际操作中，帧同步光信号在探测或者传输的过程中存在信号丢失的问题，倘若丢失一个帧同步光信号，则在Bob端所丢失帧同步信号后续的所有帧同步信号序列皆产生错误，例如帧同步信号中的第五个信号脉冲丢失，则Bob会把探测到的原帧同步信号中的第六个信号脉冲误当作第五个信号脉冲，导致后续的所有信号脉冲序号错误，进而导致Alice与Bob之间的同步失败。因此，若能解决如何避免帧同步信号丢失的问题，则能极大的降低Alice与Bob之间同步失败的风险。The above-mentioned prior art is the synchronization between Alice and Bob which is done ideally, however, due to the efficiency of the detector and the attenuation of the fiber path, or the turbulence of free space causes the attenuation to vary, in practice, The frame synchronization optical signal has the problem of signal loss in the process of detection or transmission. If a frame synchronization optical signal is lost, all the frame synchronization signal sequences following the lost frame synchronization signal at the Bob end will have errors, such as in the frame synchronization signal. If the fifth signal pulse is lost, Bob will mistake the sixth signal pulse in the detected original frame synchronization signal as the fifth signal pulse, resulting in the wrong sequence number of all subsequent signal pulses, which in turn leads to the relationship between Alice and Bob. Synchronization failed. Therefore, if the problem of how to avoid the loss of the frame synchronization signal can be solved, the risk of synchronization failure between Alice and Bob can be greatly reduced.
发明内容SUMMARY OF THE INVENTION
本申请提供一种量子密钥分发系统的同步方法及装置，以解决帧同步信号脉冲丢失导致同步失败的问题。The present application provides a synchronization method and device for a quantum key distribution system to solve the problem of synchronization failure caused by the loss of frame synchronization signal pulses.
一种量子密钥分发系统的同步方法，包括：A synchronization method for a quantum key distribution system, comprising:
Alice端：Alice side:
根据时钟信号生成同步信号，同步信号的脉冲宽度为W，同步信号的同步周期为Δt；在第n个同步周期Δt内，生成启动命令，根据所述启动命令得到第一同步信号，所述第一同步信号在第n+1个同步周期的脉冲宽度大于2W，所述第一同步信号的所有信号脉冲中仅有一个信号脉冲的脉冲宽度大于2W，所述脉冲宽度大于2W的信号脉冲所占用时长小于同步周期Δt；The synchronization signal is generated according to the clock signal, the pulse width of the synchronization signal is W, and the synchronization period of the synchronization signal is Δt; in the nth synchronization period Δt, a start command is generated, and the first synchronization signal is obtained according to the start command, and the first synchronization signal is obtained according to the start command. The pulse width of a synchronization signal in the n+1th synchronization period is greater than 2W, only one signal pulse of the first synchronization signal has a pulse width greater than 2W, and the signal pulses with the pulse width greater than 2W occupy The duration is less than the synchronization period Δt;
根据所述启动命令得到启动编码信号，所述启动编码信号仅包含一个信号脉冲，所述启动编码信号的信号脉冲的上升沿与所述第一同步信号中脉冲宽度大于2W的信号脉冲的上升沿对齐，根据所述启动编码信号和所述时钟信号调控发射量子信号；A start code signal is obtained according to the start command, the start code signal only includes one signal pulse, the rising edge of the signal pulse of the start code signal and the rising edge of the signal pulse with a pulse width greater than 2W in the first synchronization signal Alignment, according to the start coding signal and the clock signal regulation and emission quantum signal;
Bob端：Bob's side:
接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信号；receiving the first synchronization signal, and recovering a reference clock signal according to the first synchronization signal;
根据所述第一同步信号生成帧同步起始信号；generating a frame synchronization start signal according to the first synchronization signal;
根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号；generating a frame synchronization signal according to the recovered reference clock signal and the frame synchronization start signal;
时间上补偿所述帧同步信号。The frame synchronization signal is temporally compensated.
根据本申请的一些实施例，所述同步方法包括：Bob端：接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信号；延迟所述第一同步信号得到第二同步信号，所述延迟时长大于所述脉冲宽度为W的同步信号脉冲所占用的时长，所述延迟时长小于所述脉冲宽度大于2W的信号脉冲所占用的时长；将所述第一同步信号与所述第二同步信号做与运算得到帧同步起始信号；根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号；根据所述延迟时长补偿所述帧同步信号。According to some embodiments of the present application, the synchronization method includes: the Bob end: receiving the first synchronization signal, and recovering a reference clock signal according to the first synchronization signal; delaying the first synchronization signal to obtain a second synchronization signal , the delay duration is longer than the duration occupied by the synchronization signal pulse with the pulse width of W, and the delay duration is smaller than the duration occupied by the signal pulse with the pulse width greater than 2W; A frame synchronization start signal is obtained by performing an AND operation on the second synchronization signal; a frame synchronization signal is generated according to the recovered reference clock signal and the frame synchronization start signal; and the frame synchronization signal is compensated according to the delay time.
根据本申请的一些实施例，所述同步方法包括：Bob端：接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信号；将所述第一同步信号进行积分得到第三同步信号；比较所述第三同步信号的积分大小，根据最大的积分信号得到帧同步起始信号；根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号；时间上补偿所述帧同步信号。According to some embodiments of the present application, the synchronization method includes: the Bob end: receiving the first synchronization signal, and recovering a reference clock signal according to the first synchronization signal; integrating the first synchronization signal to obtain a third synchronization signal synchronization signal; compare the integral size of the third synchronization signal, and obtain a frame synchronization start signal according to the largest integral signal; generate a frame synchronization signal according to the recovered reference clock signal and the frame synchronization start signal; time compensation the frame synchronization signal.
根据本申请的一些实施例，所述同步方法包括：Bob端：接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信号；根据所述第一同步信号通过时钟采样的方式识别出所述脉冲宽度大于2W的信号脉冲；根据所述脉冲宽度大于2W的信号脉冲生成所述帧同步起始信号；根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号；时间上补偿所述帧同步信号。According to some embodiments of the present application, the synchronization method includes: the Bob end: receiving the first synchronization signal, and recovering a reference clock signal according to the first synchronization signal; sampling by clock according to the first synchronization signal Identify the signal pulse with the pulse width greater than 2W; generate the frame synchronization start signal according to the signal pulse with the pulse width greater than 2W; generate frame synchronization according to the recovered reference clock signal and the frame synchronization start signal signal; temporally compensate the frame synchronization signal.
根据本申请的一些实施例，通过脉冲宽度调制的方式调制同步信号中第n+1个同步周期的脉冲宽度，使所述第一同步信号在第n+1个同步周期的脉冲宽度大于2W。According to some embodiments of the present application, the pulse width of the n+1th synchronization period in the synchronization signal is modulated by means of pulse width modulation, so that the pulse width of the first synchronization signal in the n+1th synchronization period is greater than 2W.
根据本申请的一些实施例，所述启动命令为仅包含一个信号脉冲的脉冲信号，根据所述启动命令在产生所述第一同步信号中脉冲宽度大于2W的信号脉冲的同时产生所述启动编码信号的信号脉冲。According to some embodiments of the present application, the start command is a pulse signal including only one signal pulse, and according to the start command, the start code is generated while generating a signal pulse with a pulse width greater than 2W in the first synchronization signal The signal pulse of the signal.
根据本申请的一些实施例，所述第一同步信号中相邻信号脉冲上升沿之间的时间差相等，所述相邻信号脉冲上升沿之间的时间差为同步周期Δt。According to some embodiments of the present application, the time difference between the rising edges of adjacent signal pulses in the first synchronization signal is equal, and the time difference between the rising edges of the adjacent signal pulses is the synchronization period Δt.
根据本申请的一些实施例，所述帧同步起始信号仅包含一个信号脉冲。According to some embodiments of the present application, the frame synchronization start signal includes only one signal pulse.
根据本申请的一些实施例，根据所述时钟信号与所述帧同步起始信号生成帧同步信号，以所述帧同步起始信号脉冲的上升沿为起点，依据时钟信号进行周期计数，每隔同步周期Δt生成一个帧同步信号脉冲，得到帧同步信号。According to some embodiments of the present application, a frame synchronization signal is generated according to the clock signal and the frame synchronization start signal, and the rising edge of the frame synchronization start signal pulse is used as a starting point, and the period is counted according to the clock signal. The synchronization period Δt generates a frame synchronization signal pulse to obtain the frame synchronization signal.
一种量子密钥分发系统的同步装置，包括：A synchronization device for a quantum key distribution system, comprising:
Alice端：Alice side:
同步单元，用于根据时钟信号生成同步信号，同步信号的脉冲宽度为W，同步信号的同步周期为Δt，用于根据启动命令得到第一同步信号，所述第一同步信号在第n+1个同步周期的脉冲宽度大于2W，所述第一同步信号的所有信号脉冲中仅有一个信号脉冲的脉冲宽度大于2W，所述脉冲宽度大于2W的信号脉冲所占用时长小于同步周期Δt，并用于根据启动命令得到启动编码信号，所述启动编码信号仅包含一个信号脉冲，所述启动编码信号的信号脉冲的上升沿与所述第一同步信号中脉冲宽度大于2W的信号脉冲的上升沿对齐；The synchronization unit is used to generate a synchronization signal according to the clock signal, the pulse width of the synchronization signal is W, and the synchronization period of the synchronization signal is Δt, and is used to obtain the first synchronization signal according to the start command, and the first synchronization signal is at the n+1th The pulse width of each synchronization period is greater than 2W, only one signal pulse of the first synchronization signal has a pulse width greater than 2W, and the signal pulse with a pulse width greater than 2W occupies a period less than the synchronization period Δt, and is used for Obtaining a start code signal according to the start command, the start code signal contains only one signal pulse, and the rising edge of the signal pulse of the start code signal is aligned with the rising edge of the signal pulse with a pulse width greater than 2W in the first synchronization signal;
控制单元，用于在第n个同步周期Δt内，生成启动命令；a control unit, configured to generate a start command within the nth synchronization period Δt;
编码单元，用于根据启动编码信号和时钟信号调控发射量子信号；Bob端：The coding unit is used to regulate and emit quantum signals according to the start coding signal and the clock signal; Bob's side:
同步信号探测单元，用于接收第一同步信号；a synchronization signal detection unit for receiving the first synchronization signal;
时钟恢复单元，用于根据第一同步信号恢复出参考时钟信号；a clock recovery unit, configured to recover a reference clock signal according to the first synchronization signal;
帧同步起始信号提取单元，用于根据第一同步信号生成帧同步起始信号；a frame synchronization start signal extraction unit, configured to generate a frame synchronization start signal according to the first synchronization signal;
帧同步信号生成单元，用于根据恢复的参考时钟信号与帧同步起始 信号生成帧同步信号。The frame synchronization signal generating unit is used for generating the frame synchronization signal according to the recovered reference clock signal and the frame synchronization start signal.
根据本申请的一些实施例，所述帧同步起始信号提取单元被配置为：接收第一同步信号、延迟所述第一同步信号、将接收到的所述第一同步信号与延迟后的第一同步信号做与运算生成帧同步起始信号，输出所述帧同步起始信号。According to some embodiments of the present application, the frame synchronization start signal extraction unit is configured to: receive a first synchronization signal, delay the first synchronization signal, and combine the received first synchronization signal with the delayed first synchronization signal. A synchronization signal is ANDed to generate a frame synchronization start signal, and the frame synchronization start signal is output.
本申请提供一种量子密钥分发系统的同步方法及装置，与现有技术相比有以下特点：The present application provides a synchronization method and device for a quantum key distribution system, which has the following characteristics compared with the prior art:
1、本申请中的Alice端通过脉冲宽度调制的方式使得发射的同步信号脉冲中包含一个脉冲宽度大于正常值两倍的同步信号脉冲，Bob端通过探测得到的同步信号中出现一个同步信号脉冲其宽度大于正常宽度的两倍，Bob端通过探测与处理得到仅包含一个信号脉冲的帧同步起始信号，Bob端再根据恢复后的参考时钟信号和得到的帧同步起始信号生成帧同步信号，再通过Bob端的后处理过程得到时间补偿后的最终帧同步信号，根据最终得到的帧同步信号完成Alice端与Bob端之间的同步。因此，Alice端输出给Bob端的同步信号中包含一个脉冲宽度大于正常值两倍的同步信号脉冲，由于该脉冲宽度较宽其丢失的概率远小于其他正常宽度的同步信号脉冲，所以在某些正常宽度的同步信号脉冲丢失的情况下，Bob端基本仍能探测到脉冲宽度大于正常值两倍的同步信号脉冲，Bob端跟据上述脉冲宽度较宽的信号脉冲生成帧同步起始信号，然后，根据帧同步起始信号与恢复的时钟信号得到最终的帧同步信号，进而完成Alice与Bob之间的同步，此时，最终的帧同步信号主要依靠参考时钟信号和帧同步起始信号，不再直接依赖Alice端发射的原始同步信号，即使原始同步信号中任何正常宽度的同步信号脉冲丢失，只要脉冲宽度大于正常值两倍的同步信号脉冲可以被Bob端探测到，就能完成Alice与Bob之间的同步，极大的降低了Alice与Bob之间同步失败的风险，可靠性较高。1. The Alice end in this application uses pulse width modulation to make the transmitted synchronization signal pulse contain a synchronization signal pulse with a pulse width greater than twice the normal value, and a synchronization signal pulse appears in the synchronization signal obtained by the Bob end through detection. The width is greater than twice the normal width. The Bob end obtains a frame synchronization start signal containing only one signal pulse through detection and processing, and the Bob end generates a frame synchronization signal according to the recovered reference clock signal and the obtained frame synchronization start signal. Then, the final frame synchronization signal after time compensation is obtained through the post-processing process of the Bob end, and the synchronization between the Alice end and the Bob end is completed according to the finally obtained frame synchronization signal. Therefore, the synchronization signal output from the Alice end to the Bob end includes a synchronization signal pulse with a pulse width greater than twice the normal value. Because the pulse width is wider, the probability of losing it is much smaller than that of other normal width synchronization signal pulses, so in some normal In the case where the pulse width of the synchronization signal is lost, the Bob end can basically still detect the synchronization signal pulse whose pulse width is greater than twice the normal value. The final frame synchronization signal is obtained according to the frame synchronization start signal and the recovered clock signal, and then the synchronization between Alice and Bob is completed. At this time, the final frame synchronization signal mainly depends on the reference clock signal and the frame synchronization start signal, and no longer It directly depends on the original synchronization signal transmitted by Alice. Even if any normal-width synchronization signal pulse in the original synchronization signal is lost, as long as the synchronization signal pulse with a pulse width greater than twice the normal value can be detected by the Bob side, the communication between Alice and Bob can be completed. The synchronization between Alice and Bob greatly reduces the risk of synchronization failure between Alice and Bob, and the reliability is high.
2、本申请中的Bob端采用模拟锁相环方式的时钟恢复单元在同步信号偶发性的丢失或误甄别下仍可以正常恢复出时钟信号，进一步提高了同步工作的稳定性与可靠性。2. The clock recovery unit using the analog phase-locked loop mode at the Bob end in the present application can still recover the clock signal normally under the occasional loss or misidentification of the synchronization signal, which further improves the stability and reliability of the synchronization operation.
附图说明Description of drawings
为了更清楚地说明本申请的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，显而易见地，对于本领域普通技术人员而言，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。In order to illustrate the technical solutions of the present application more clearly, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, without creative work, the Additional drawings can be obtained from these drawings.
图1为现有技术中量子密钥分发系统同步方案的时序示意图；Fig. 1 is the time sequence schematic diagram of the quantum key distribution system synchronization scheme in the prior art;
图2为本申请的量子密钥分发系统同步方法的时序示意图；Fig. 2 is the time sequence schematic diagram of the quantum key distribution system synchronization method of the present application;
图3为本申请的量子密钥分发系统的同步装置结构示意图；3 is a schematic structural diagram of a synchronization device of the quantum key distribution system of the application;
图4为本申请基于延时相与的量子密钥分发系统同步方法时序示意图；FIG. 4 is a schematic time sequence diagram of the synchronization method of the quantum key distribution system based on the delay phase sum of the application;
图5为本申请基于积分比较的量子密钥分发系统同步方法时序示意图。FIG. 5 is a schematic time sequence diagram of the synchronization method of the quantum key distribution system based on integral comparison of the present application.
具体实施方式detailed description
为使本申请的上述目的、特征和优点能够更加明显易懂，下面结合附图和具体实施方式对本申请作进一步详细的说明。In order to make the above objects, features and advantages of the present application more clearly understood, the present application will be described in further detail below with reference to the accompanying drawings and specific embodiments.
本申请的第一方面提供一种量子密钥分发系统的同步方法，如图2所示的本申请的量子密钥分发系统同步方法的时序示意图，该同步方法包括：Alice端：根据时钟信号调控同步单元，使所述同步单元发射同步信号，同步信号的脉冲宽度为W，同步信号的同步周期为Δt，例如Δt为10us，同步信号的一个信号脉冲上升沿到下一个信号脉冲的上升沿之间是一个同步周期Δt，脉冲宽度为W的信号脉冲所占用时长(例如为2us)小于同步周期Δt；在第n个(n为大于等于1的正整数)同步周期Δt内，通过控制单元向所述同步单元输出启动命令，根据所述启动命令所述同步单元在第n+1个同步周期发射一个脉冲宽度大于2W的信号脉冲得到第一同步信号，即第一同步信号在第n+1个同步周期的脉冲宽度大于2W，所述第一同步信号的所有信号脉冲中仅有一个信号脉冲的脉冲宽度大于2W，通过所述同步单元发射所述第一同步信号，所述脉冲宽度大于2W的信号脉冲所占用时长(例如为5us)小于同步周期Δt；根据所述启动命令得到启动编码信号，通过所述同步单元向编码单元输出启动编码信号，所述启动编码信号仅包含一个信号脉冲， 所述启动编码信号的信号脉冲的上升沿与所述第一同步信号中脉冲宽度大于2W的信号脉冲的上升沿对齐，根据所述启动编码信号和所述时钟信号调控所述编码单元发射量子信号。具体地，根据Alice端的本地时钟信号CLK调控同步单元发射同步信号，同步信号的正常脉冲宽度为W，同步信号的同步周期即相邻信号脉冲上升沿之间的时间差为Δt，例如Δt为10us，脉冲宽度为W的信号脉冲所占用时长小于Δt；在第n个同步周期Δt内，即在第n个同步周期相邻两个信号脉冲的上升沿之间(也可以包括两个信号脉冲的上升沿)，通过控制单元向所述同步单元输出启动命令，所述启动命令为仅包含一个信号脉冲的脉冲信号，启动命令的脉冲上升沿介于第n个同步周期相邻两个信号脉冲的上升沿之间(也可以包括两个信号脉冲的上升沿)，启动命令的脉冲宽度本申请不作具体的限制；根据所述启动命令使得同步单元在第n+1个同步周期发射一个脉冲宽度大于2W的信号脉冲得到第一同步信号，即第一同步信号中的第n+1个同步周期内的信号脉冲宽度大于2W，其余第一同步信号中的信号脉冲宽度为正常脉冲宽度W，所述脉冲宽度大于2W的信号脉冲所占用时长小于同步周期Δt，此外，第一同步信号中相邻信号脉冲上升沿之间的时间差相等，即相邻信号脉冲上升沿之间的时间差为同步周期Δt；根据所述启动命令得到启动编码信号，通过所述同步单元向编码单元输出所述启动编码信号，根据所述启动命令所述同步单元在产生所述第一同步信号中脉冲宽度大于2W的信号脉冲的同时产生所述启动编码信号的信号脉冲，即所述启动编码信号的信号脉冲的上升沿与所述第一同步信号中脉冲宽度大于2W的第一同步信号脉冲的上升沿对齐，以便调控量子信号的发射，所述启动编码信号仅包含一个信号脉冲，启动编码信号的脉冲宽度本申请不作具体的限制；根据启动编码信号和本地时钟信号调控所述编码单元发射量子信号，根据启动编码信号脉冲的上升沿调控编码单元开始发射量子信号，即量子信号的第一个信号脉冲的上升沿与所述第一同步信号中脉冲宽度大于2W的信号脉冲的上升沿以及所述启动编码信号脉冲的上升沿对齐。Alice端将产生的第一同步信号以及量子信号发送给Bob端。A first aspect of the present application provides a method for synchronizing a quantum key distribution system, as shown in FIG. 2 , which is a schematic time sequence diagram of the method for synchronizing a quantum key distribution system of the present application. The synchronization method includes: the Alice side: regulating and controlling according to a clock signal The synchronizing unit enables the synchronizing unit to transmit a synchronizing signal, the pulse width of the synchronizing signal is W, the synchronizing period of the synchronizing signal is Δt, for example Δt is 10us, and the time between the rising edge of one signal pulse of the synchronization signal and the rising edge of the next signal pulse is The interval is a synchronization period Δt, and the duration of the signal pulse with the pulse width W (for example, 2us) is less than the synchronization period Δt; in the nth (n is a positive integer greater than or equal to 1) synchronization period Δt, the control unit sends The synchronization unit outputs a start command, and according to the start command, the synchronization unit transmits a signal pulse with a pulse width greater than 2W in the n+1th synchronization cycle to obtain the first synchronization signal, that is, the first synchronization signal is in the n+1th synchronization period. The pulse width of each synchronization period is greater than 2W, and only one signal pulse of all signal pulses of the first synchronization signal has a pulse width greater than 2W. The first synchronization signal is transmitted through the synchronization unit, and the pulse width is greater than 2W. The length of time occupied by the signal pulse (for example, 5us) is less than the synchronization period Δt; according to the start command, the start code signal is obtained, and the start code signal is output to the code unit through the synchronization unit, and the start code signal contains only one signal pulse, The rising edge of the signal pulse of the start coding signal is aligned with the rising edge of the signal pulse whose pulse width is greater than 2W in the first synchronization signal, and the coding unit is regulated to emit quantum signals according to the start coding signal and the clock signal. . Specifically, according to the local clock signal CLK at the Alice side, the synchronization unit is regulated to transmit the synchronization signal. The normal pulse width of the synchronization signal is W, and the synchronization period of the synchronization signal, that is, the time difference between the rising edges of adjacent signal pulses is Δt, for example, Δt is 10us, The duration occupied by the signal pulse with the pulse width W is less than Δt; within the nth synchronization period Δt, that is, between the rising edges of two adjacent signal pulses in the nth synchronization period (it may also include the rising edges of the two signal pulses) edge), output a start command to the synchronization unit through the control unit, the start command is a pulse signal containing only one signal pulse, and the pulse rising edge of the start command is between the rise of the adjacent two signal pulses of the nth synchronization cycle Between edges (which may also include the rising edges of two signal pulses), the pulse width of the start command is not specifically limited in this application; according to the start command, the synchronization unit is made to transmit a pulse width greater than 2W in the n+1th synchronization cycle. The first synchronization signal is obtained from the signal pulse of the first synchronization signal, that is, the signal pulse width in the n+1th synchronization period in the first synchronization signal is greater than 2W, and the signal pulse width in the remaining first synchronization signals is the normal pulse width W. The signal pulse with a width greater than 2W occupies less than the synchronization period Δt. In addition, the time difference between the rising edges of adjacent signal pulses in the first synchronization signal is equal, that is, the time difference between the rising edges of adjacent signal pulses is the synchronization period Δt; according to The start command obtains a start code signal, and the start code signal is output to the code unit through the synchronization unit. According to the start command, the synchronization unit generates a signal pulse with a pulse width greater than 2W in the first synchronization signal. At the same time, the signal pulse of the start encoding signal is generated, that is, the rising edge of the signal pulse of the start encoding signal is aligned with the rising edge of the first synchronization signal pulse whose pulse width is greater than 2W in the first synchronization signal, so as to regulate the quantum signal The launch of the encoding signal only includes a signal pulse, and the pulse width of the encoding signal is not specifically limited in this application; according to the encoding signal and the local clock signal, the encoding unit is regulated to transmit a quantum signal, according to the pulse of the encoding signal. The rising edge regulation and coding unit starts to emit the quantum signal, that is, the rising edge of the first signal pulse of the quantum signal and the rising edge of the signal pulse whose pulse width is greater than 2W in the first synchronization signal and the rising edge of the start coding signal pulse Align. The Alice end sends the generated first synchronization signal and the quantum signal to the Bob end.
此外，Alice端通过脉冲宽度调制的方式调制同步信号中第n+1个 同步周期的脉冲宽度，使所述同步单元在第n+1个同步周期发射一个脉冲宽度大于2W的信号脉冲得到第一同步信号。In addition, the Alice end modulates the pulse width of the n+1th synchronization period in the synchronization signal by means of pulse width modulation, so that the synchronization unit transmits a signal pulse with a pulse width greater than 2W in the n+1th synchronization period to obtain the first sync signal.
Bob端：参照图2所示，接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信号；根据所述第一同步信号生成帧同步起始信号；根据所述恢复的参考时钟信号与所述帧同步起始信号生成帧同步信号；时间上补偿所述帧同步信号。具体地，Bob端通过同步信号探测单元接收Alice端发射的第一同步信号，根据接收到的第一同步信号，通过时钟恢复单元恢复出与Alice端同步的参考时钟信号CLK，Bob端恢复出的参考时钟信号与Alice端的时钟信号为同源时钟，两者同步，根据第一同步信号恢复出参考时钟信号被配置为在第一同步信号的部分信号脉冲偶发性的丢失或者误甄别情况下仍能正常恢复出与Alice端同步的参考时钟信号；通过帧同步起始信号提取单元根据第一同步信号提取出帧同步起始信号，所述帧同步起始信号主要是根据第一同步信号中脉冲宽度大于2W的信号脉冲得到的，帧同步起始信号仅包含一个信号脉冲；根据恢复的参考时钟信号与得到的帧同步起始信号通过帧同步信号生成单元生成帧同步信号，具体地，以帧同步起始信号脉冲的上升沿为起点，依据恢复的参考时钟信号进行周期计数以保持输出的帧同步周期和Alice端同步信号一致，每隔同步周期Δt生成一个帧同步信号脉冲，得到帧同步信号，即帧同步信号的同步周期也为Δt；时间上补偿所述帧同步信号使得时间补偿后的帧同步信号中的第一个信号脉冲的上升沿与所述第一同步信号中脉冲宽度大于2W的信号脉冲的上升沿对齐，时间补偿后的帧同步信号即为最终的用于Alice端与Bob端同步的帧同步信号。Bob end: Referring to FIG. 2, receiving the first synchronization signal, recovering a reference clock signal according to the first synchronization signal; generating a frame synchronization start signal according to the first synchronization signal; according to the recovered reference The clock signal and the frame synchronization start signal generate a frame synchronization signal; the frame synchronization signal is compensated in time. Specifically, the Bob end receives the first synchronization signal transmitted by the Alice end through the synchronization signal detection unit, and according to the received first synchronization signal, the clock recovery unit restores the reference clock signal CLK synchronized with the Alice end, and the Bob end recovers The reference clock signal and the clock signal of the Alice end are the same source clock, and the two are synchronized. The reference clock signal recovered according to the first synchronization signal is configured to still be able to be used even in the case of occasional loss or misidentification of part of the signal pulse of the first synchronization signal. The reference clock signal synchronized with the Alice end is recovered normally; the frame synchronization start signal is extracted according to the first synchronization signal by the frame synchronization start signal extraction unit, and the frame synchronization start signal is mainly based on the pulse width in the first synchronization signal. If the signal pulse is greater than 2W, the frame synchronization start signal contains only one signal pulse; according to the recovered reference clock signal and the obtained frame synchronization start signal, the frame synchronization signal is generated by the frame synchronization signal generating unit. Specifically, the frame synchronization signal is generated by the frame synchronization signal. The rising edge of the start signal pulse is the starting point, and the cycle count is performed according to the recovered reference clock signal to keep the output frame synchronization period consistent with the synchronization signal of the Alice side, and a frame synchronization signal pulse is generated every synchronization period Δt to obtain the frame synchronization signal, That is, the synchronization period of the frame synchronization signal is also Δt; the frame synchronization signal is compensated in time so that the rising edge of the first signal pulse in the time-compensated frame synchronization signal is the same as the first synchronization signal whose pulse width is greater than 2W. The rising edges of the signal pulses are aligned, and the frame synchronization signal after time compensation is the final frame synchronization signal used for the synchronization between the Alice end and the Bob end.
通过上述同步方法，帧同步信号在探测或者传输的过程中部分正常宽度的信号脉冲丢失时，只要第一同步信号中脉冲宽度大于正常值两倍的信号脉冲可以被Bob端探测到，在Bob端就能实现并得到完整的帧同步信号，然后，根据如图1所示的现有的同步方案即可完成Alice端与Bob端之间的同步，该同步方法中最终的帧同步信号主要依靠参考时钟信号和帧同步起始信号，不再直接依赖Alice端发射的原始同步信号，极大的降低了Alice与Bob之间同步失败的风险，可靠性较高。假 如第一同步信号中脉冲宽度大于正常值两倍的信号脉冲也丢失了，Alice端可通过经典通信交互获取Bob端的帧同步状态，如果Bob端无法生成帧同步起始信号，Alice与Bob则会判定此次同步无效，发射和接收的量子信号也无效，Alice端会重新发送第一同步信号直到帧同步正常。此外，由于第一同步信号中有且仅有一个信号脉冲的脉冲宽度大于正常值的两倍，使得在信号传输的过程中第一同步信号的光强强度不至于影响量子信号，倘若第一同步信号中有多个信号脉冲的宽度较宽，则第一同步信号的光强很强，会极大地干扰量子信号。Through the above synchronization method, when part of the normal width of the frame synchronization signal is lost in the process of detection or transmission, as long as the first synchronization signal pulse width is greater than twice the normal value of the signal pulse can be detected by the Bob end, at the Bob end A complete frame synchronization signal can be realized and obtained, and then, according to the existing synchronization scheme shown in Figure 1, the synchronization between the Alice end and the Bob end can be completed. The final frame synchronization signal in this synchronization method mainly depends on the reference The clock signal and the frame synchronization start signal are no longer directly dependent on the original synchronization signal transmitted by Alice, which greatly reduces the risk of synchronization failure between Alice and Bob, and has high reliability. If the signal pulse with the pulse width greater than twice the normal value in the first synchronization signal is also lost, Alice can obtain the frame synchronization status of Bob through classic communication interaction. If Bob cannot generate a frame synchronization start signal, Alice and Bob will It is determined that the synchronization is invalid this time, and the transmitted and received quantum signals are also invalid. The Alice side will resend the first synchronization signal until the frame synchronization is normal. In addition, since the pulse width of only one signal pulse in the first synchronization signal is greater than twice the normal value, the light intensity of the first synchronization signal will not affect the quantum signal during the signal transmission process. If the width of a plurality of signal pulses in the signal is relatively wide, the light intensity of the first synchronization signal is very strong, which will greatly interfere with the quantum signal.
对应于上述同步方法，本申请的第二方面提供一种量子密钥分发系统的同步装置，用于实现本申请提供的上述同步方法，参照图3所示的示意图，该装置包括：Alice端：同步单元，用于根据时钟信号和启动命令输出含有一个脉冲宽度大于正常脉冲宽度两倍的信号脉冲的第一同步信号，并用于向编码单元输出启动编码信号；控制单元，用于向所述同步单元输出启动命令；编码单元，用于根据启动编码信号和时钟信号CLK发射量子信号；Bob端：同步信号探测单元，用于接收含有一个脉冲宽度大于正常脉冲宽度两倍的信号脉冲的第一同步信号；时钟恢复单元，被配置为基于模拟锁相环方式的时钟恢复单元，用于根据第一同步信号恢复出参考时钟信号CLK；帧同步起始信号提取单元，用于根据第一同步信号生成帧同步起始信号；帧同步信号生成单元，用于根据帧同步起始信号和恢复的参考时钟信号CLK输出帧同步信号。具体地，同步单元被配置为：接收时钟信号、接收控制单元发出的启动命令、根据时钟信号和启动命令同时生成并输出第一同步信号以及启动编码信号，第一同步信号中含有一个脉冲宽度大于正常脉冲宽度两倍的信号脉冲；控制单元被配置为：在某个例如第n(n为大于等于1的正整数)个同步周期Δt内，通过控制单元向所述同步单元输出启动命令；编码单元被配置为：根据接收到的启动编码信号脉冲的上升沿和时钟信号调控输出量子信号；同步信号探测单元被配置为：接收Alice端发出的第一同步信号、并输出第一同步信号；时钟恢复单元被配置为：基于模拟锁相环方式的时钟恢复单元，根据接收到的第一同步信号恢复出参考时钟信号CLK，在第一同步信号的信号脉冲偶发性的丢失或误甄别下仍 可以正常恢复出时钟信号；帧同步起始信号提取单元被配置为：接收第一同步信号、根据第一同步信号提取出帧同步起始信号，输出帧同步起始信号；帧同步信号生成单元被配置为：接收恢复的参考时钟信号以及帧同步起始信号、根据帧同步起始信号和参考时钟信号生成帧同步信号、时间上补偿所述帧同步信号、输出补偿后的帧同步信号。Corresponding to the above synchronization method, a second aspect of the present application provides a synchronization device for a quantum key distribution system, which is used to implement the above synchronization method provided by the present application. Referring to the schematic diagram shown in FIG. 3 , the device includes: an Alice end: a synchronization unit for outputting a first synchronization signal containing a signal pulse with a pulse width greater than twice the normal pulse width according to a clock signal and a start command, and for outputting a start encoding signal to the encoding unit; a control unit for sending the synchronization signal to the synchronization unit The unit outputs a start command; the coding unit is used to transmit a quantum signal according to the start code signal and the clock signal CLK; Bob end: a synchronization signal detection unit, used to receive a first synchronization signal pulse with a pulse width greater than twice the normal pulse width signal; a clock recovery unit, configured as a clock recovery unit based on an analog phase-locked loop, for recovering the reference clock signal CLK according to the first synchronization signal; a frame synchronization start signal extraction unit for generating according to the first synchronization signal A frame synchronization start signal; a frame synchronization signal generating unit, configured to output a frame synchronization signal according to the frame synchronization start signal and the recovered reference clock signal CLK. Specifically, the synchronization unit is configured to: receive a clock signal, receive a start command sent by the control unit, generate and output a first synchronization signal and a start encoding signal simultaneously according to the clock signal and the start command, and the first synchronization signal contains a pulse width greater than A signal pulse with twice the normal pulse width; the control unit is configured to: output a start command to the synchronization unit through the control unit within a certain synchronization period Δt such as the nth (n is a positive integer greater than or equal to 1); encoding The unit is configured to: regulate and output the quantum signal according to the received rising edge of the start encoding signal pulse and the clock signal; the synchronization signal detection unit is configured to: receive the first synchronization signal sent by the Alice end, and output the first synchronization signal; the clock The recovery unit is configured as: a clock recovery unit based on an analog phase-locked loop mode, recovers the reference clock signal CLK according to the received first synchronization signal, and can still recover under the occasional loss of signal pulses of the first synchronization signal or misidentification. The clock signal is recovered normally; the frame synchronization start signal extraction unit is configured to: receive the first synchronization signal, extract the frame synchronization start signal according to the first synchronization signal, and output the frame synchronization start signal; the frame synchronization signal generation unit is configured The steps include: receiving the recovered reference clock signal and the frame synchronization start signal, generating a frame synchronization signal according to the frame synchronization start signal and the reference clock signal, temporally compensating the frame synchronization signal, and outputting the compensated frame synchronization signal.
Alice端与Bob端之间可以通过光纤量子通信或者自由空间量子通信传输同步信号与量子信号，其中，同步信号通过同步信道或经典信道传输，量子信号通过量子信道传输。The synchronization signal and quantum signal can be transmitted between Alice and Bob through optical fiber quantum communication or free space quantum communication. The synchronization signal is transmitted through the synchronization channel or the classical channel, and the quantum signal is transmitted through the quantum channel.
通过上述同步装置，Alice端将含有一个脉冲宽度相对较宽的信号脉冲的第一同步信号以及适时调控生成的量子信号发送给Bob端，Bob端根据探测到的第一同步信号经过处理得到最终的帧同步信号，最后Bob端根据得到的帧同步信号以及接收到的量子信号按照如图1所示的现有的同步方案即可完成Alice端与Bob端之间的同步。此外，Bob端采用模拟锁相环方式的时钟恢复单元在第一同步信号的信号脉冲偶发性的丢失或误甄别下仍能正常恢复出参考时钟信号，提高了同步工作的稳定性与可靠性。Through the above synchronization device, the Alice end sends the first synchronization signal containing a signal pulse with a relatively wide pulse width and the quantum signal generated by timely regulation to the Bob end, and the Bob end processes the detected first synchronization signal to obtain the final synchronization signal. Frame synchronization signal, and finally the Bob end can complete the synchronization between the Alice end and the Bob end according to the obtained frame synchronization signal and the received quantum signal according to the existing synchronization scheme as shown in FIG. 1 . In addition, the clock recovery unit adopting the analog phase-locked loop method at the Bob end can still recover the reference clock signal normally even if the signal pulse of the first synchronization signal is occasionally lost or misidentified, which improves the stability and reliability of the synchronization operation.
上述同步方法中，Bob端：根据所述第一同步信号生成帧同步起始信号；生成帧同步起始信号的具体实施例如下。In the above synchronization method, the Bob end: generates a frame synchronization start signal according to the first synchronization signal; the specific embodiment of generating the frame synchronization start signal is as follows.
实施例1，参照图4所示，参照上述同步方法，Alice端的同步方法保持不变，Bob端：接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信号；延迟所述第一同步信号得到第二同步信号，所述延迟时长大于所述脉冲宽度为W的同步信号脉冲所占用的时长，所述延迟时长小于所述脉冲宽度大于2W的信号脉冲所占用的时长；将所述第一同步信号与所述第二同步信号做与运算得到帧同步起始信号；根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号；根据所述延迟时长补偿所述帧同步信号。具体地，Bob端通过同步信号探测单元接收Alice端发射的第一同步信号，根据接收到的第一同步信号，通过时钟恢复单元恢复出与Alice端同步的参考时钟信号CLK，根据第一同步信号恢复出参考时钟信号被配置为在第一同步信号的部分信号脉冲偶发性的丢失或者误甄别情况下仍能正常恢复出与Alice端同步的 参考时钟信号；通过帧同步起始信号提取单元延迟所述第一同步信号得到第二同步信号，上述延迟仅为时间上的延迟，脉冲宽度与同步周期等均保持不变，为了得到仅包含一个信号脉冲的帧同步起始信号，要求延迟时长大于脉冲宽度为W的同步信号脉冲所占用的时长，并且要求延迟时长小于脉冲宽度大于2W的信号脉冲所占用的时长，以便后续将第一同步信号与第二同步信号做与运算时将脉冲宽度为W的信号脉冲消掉；通过帧同步起始信号提取单元将第一同步信号与第二同步信号做与运算得到帧同步起始信号，通过相与运算消掉大部分的脉冲信号，使得帧同步起始信号仅包含一个信号脉冲，由于第二同步信号是由第一同步信号时间延迟得到的，并且延迟时长满足两种信号相与时部分脉冲消除的要求，则能使得帧同步起始信号仅仅包含一个信号脉冲，并且帧同步起始信号的上升沿与第二同步信号中脉冲宽度大于2W的信号脉冲的上升沿对齐。得到帧同步起始信号之后，可以通过两种实施方式得到最终的帧同步信号，实施方式一：参照图2所示，首先，根据恢复的参考时钟信号与得到的帧同步起始信号通过帧同步信号生成单元生成帧同步信号，具体地，以帧同步起始信号脉冲的上升沿为起点，依据时钟信号进行周期计数，每隔同步周期Δt生成一个帧同步信号脉冲，得到帧同步信号，即帧同步信号的同步周期也为Δt，然后，针对得到的所述帧同步信号进行时间上的补偿，即向所述帧同步信号补偿所述第二同步信号的延迟时长，使得经延迟补偿后的帧同步信号中第一个信号脉冲的上升沿与所述第一同步信号中脉冲宽度大于2W的信号脉冲的上升沿对齐，得到的经延迟补偿后的帧同步信号即为最终要使用的帧同步信号；实施方式二：首先，将得到的帧同步起始信号进行所述延迟时长的补偿，即先时间上补偿上述过程中得到的帧同步起始信号，即经补偿后帧同步起始信号中信号脉冲的上升沿与所述第一同步信号中脉冲宽度大于2W的信号脉冲的上升沿对齐，然后再根据恢复的参考时钟信号与时间上补偿后得到的帧同步起始信号通过帧同步信号生成单元生成最终的帧同步信号，具体生成帧同步信号的方式与实施方式一中由恢复的参考时钟信号与得到的帧同步起始信号生成帧同步信号的生成方式相同。通过上述两种方式的延时补偿均可以精准的得到最终的帧同步信 号。Embodiment 1, as shown in FIG. 4 , referring to the above synchronization method, the synchronization method of the Alice side remains unchanged, and the Bob side: receives the first synchronization signal, and restores a reference clock signal according to the first synchronization signal; delays the The first synchronization signal obtains a second synchronization signal, and the delay duration is greater than the duration occupied by the synchronization signal pulse with the pulse width of W, and the delay duration is smaller than the duration occupied by the signal pulse with the pulse width greater than 2W; The first synchronization signal and the second synchronization signal are ANDed to obtain a frame synchronization start signal; a frame synchronization signal is generated according to the recovered reference clock signal and the frame synchronization start signal; according to the delay time compensation the frame synchronization signal. Specifically, the Bob end receives the first synchronization signal transmitted by the Alice end through the synchronization signal detection unit, and according to the received first synchronization signal, the clock recovery unit restores the reference clock signal CLK synchronized with the Alice end, and according to the first synchronization signal The recovery of the reference clock signal is configured to be able to recover the reference clock signal synchronized with the Alice end normally even when part of the signal pulse of the first synchronization signal is occasionally lost or misidentified; The first synchronization signal obtains the second synchronization signal. The above delay is only a time delay, and the pulse width and synchronization period remain unchanged. In order to obtain a frame synchronization start signal containing only one signal pulse, the delay time is required to be longer than the pulse The duration occupied by the synchronization signal pulse with a width of W, and the delay duration is required to be less than the duration occupied by the signal pulse with a pulse width greater than 2W, so that the pulse width is W when the first synchronization signal and the second synchronization signal are subsequently ANDed. The signal pulses are eliminated; the frame synchronization start signal is obtained by AND operation of the first synchronization signal and the second synchronization signal through the frame synchronization start signal extraction unit, and most of the pulse signals are eliminated by the phase and operation, so that the frame synchronization starts. The start signal contains only one signal pulse. Since the second synchronization signal is obtained by the time delay of the first synchronization signal, and the delay time meets the requirements of the phase and time partial pulse elimination of the two signals, the frame synchronization start signal can only contain One signal pulse, and the rising edge of the frame synchronization start signal is aligned with the rising edge of the signal pulse whose pulse width is greater than 2W in the second synchronization signal. After the frame synchronization start signal is obtained, the final frame synchronization signal can be obtained through two implementations. Embodiment 1: Referring to FIG. 2 , first, the frame synchronization is performed according to the recovered reference clock signal and the obtained frame synchronization start signal. The signal generating unit generates a frame synchronization signal. Specifically, starting from the rising edge of the frame synchronization start signal pulse, the period count is performed according to the clock signal, and a frame synchronization signal pulse is generated every synchronization period Δt to obtain a frame synchronization signal, that is, a frame synchronization signal. The synchronization period of the synchronization signal is also Δt, and then, time compensation is performed for the obtained frame synchronization signal, that is, the delay time of the second synchronization signal is compensated for the frame synchronization signal, so that the frame after delay compensation The rising edge of the first signal pulse in the synchronization signal is aligned with the rising edge of the signal pulse whose pulse width is greater than 2W in the first synchronization signal, and the obtained frame synchronization signal after delay compensation is the final frame synchronization signal to be used Embodiment 2: First, the obtained frame synchronization start signal is compensated for the delay duration, that is, the frame synchronization start signal obtained in the above process is first compensated in time, that is, the signal in the frame synchronization start signal after compensation is compensated. The rising edge of the pulse is aligned with the rising edge of the signal pulse whose pulse width is greater than 2W in the first synchronization signal, and then passes the frame synchronization signal generation unit according to the recovered reference clock signal and the frame synchronization start signal obtained after time compensation. The final frame synchronization signal is generated, and the specific method of generating the frame synchronization signal is the same as the generation method of generating the frame synchronization signal from the recovered reference clock signal and the obtained frame synchronization start signal in the first embodiment. The final frame synchronization signal can be accurately obtained through the delay compensation of the above two methods.
参照上述同步装置，在该实施例中，帧同步起始信号提取单元被配置为：接收第一同步信号、时间上延迟所述第一同步信号得到第二同步信号、将接收到的第一同步信号与得到的第二同步信号做与运算生成帧同步起始信号，输出帧同步起始信号；帧同步信号生成单元被配置为：接收恢复的参考时钟信号以及帧同步起始信号、根据帧同步起始信号和参考时钟信号生成帧同步信号、时间上补偿所述帧同步信号、输出补偿后的帧同步信号，或者，帧同步信号生成单元被配置为：接收恢复的参考时钟信号以及帧同步起始信号、时间上补偿所述帧同步起始信号、根据补偿后的帧同步起始信号和参考时钟信号生成帧同步信号。Referring to the above synchronization device, in this embodiment, the frame synchronization start signal extraction unit is configured to: receive the first synchronization signal, delay the first synchronization signal in time to obtain the second synchronization signal, and extract the received first synchronization signal The signal and the obtained second synchronization signal are ANDed to generate a frame synchronization start signal, and the frame synchronization start signal is output; the frame synchronization signal generation unit is configured to: receive the recovered reference clock signal and the frame synchronization start signal, and according to the frame synchronization The start signal and the reference clock signal generate a frame synchronization signal, compensate the frame synchronization signal in time, and output the compensated frame synchronization signal, or the frame synchronization signal generation unit is configured to: receive the recovered reference clock signal and start the frame synchronization. The frame synchronization start signal is compensated in time, and the frame synchronization signal is generated according to the compensated frame synchronization start signal and the reference clock signal.
实施例2，参照图5所示，参照上述同步方法，Alice端的同步方法保持不变，Bob端：接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信号；将所述第一同步信号进行积分得到第三同步信号；比较所述第三同步信号的积分大小，根据最大的积分信号得到帧同步起始信号；根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号；时间上补偿所述帧同步信号。具体地，通过帧同步起始信号提取单元将第一同步信号进行积分得到第三同步信号，宽度较窄的信号脉冲积分小于宽度较宽的信号脉冲积分，设置一个比较电平，比较电平的大小介于宽度较窄的信号脉冲积分与宽度较宽的信号脉冲积分大小之间，比较第三同步信号中各信号脉冲积分与比较电平的大小，可以判断出第一同步信号中脉冲宽度大于2W的信号脉冲的位置进而可以在此位置生成帧同步起始信号，即根据最大的积分信号得到帧同步起始信号，然后，根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号，最后，通过Bob端的后处理单元时间上补偿所述帧同步信号。Embodiment 2, as shown in FIG. 5 , with reference to the above synchronization method, the synchronization method of the Alice end remains unchanged, and the Bob end: receives the first synchronization signal, and restores a reference clock signal according to the first synchronization signal; The first synchronization signal is integrated to obtain a third synchronization signal; the integral size of the third synchronization signal is compared, and a frame synchronization start signal is obtained according to the largest integrated signal; according to the recovered reference clock signal and the frame synchronization start The signal generates a frame synchronization signal; the frame synchronization signal is temporally compensated. Specifically, the first synchronization signal is integrated by the frame synchronization start signal extraction unit to obtain a third synchronization signal, the signal pulse integration of the narrower width is smaller than the signal pulse integration of the wider width, a comparison level is set, and the comparison level is The size is between the signal pulse integral of the narrower width and the signal pulse integral of the wider width. Comparing the integral of each signal pulse in the third synchronization signal and the comparison level, it can be judged that the pulse width in the first synchronization signal is greater than The position of the 2W signal pulse can then generate the frame synchronization start signal at this position, that is, the frame synchronization start signal is obtained according to the largest integral signal, and then, the frame synchronization start signal is generated according to the recovered reference clock signal and the frame synchronization start signal. The frame synchronization signal is finally compensated for the frame synchronization signal in time by the post-processing unit at the Bob end.
参照上述同步装置，在该实施例中，帧同步起始信号提取单元被配置为：将第一同步信号进行积分得到第三同步信号、比较所述第三同步信号的积分大小、根据最大的积分信号得到帧同步起始信号。Referring to the above synchronization device, in this embodiment, the frame synchronization start signal extraction unit is configured to: integrate the first synchronization signal to obtain a third synchronization signal, compare the integration size of the third synchronization signal, and obtain a third synchronization signal according to the largest integration The signal gets the frame sync start signal.
实施例3，参照上述同步方法，Alice端的同步方法保持不变，Bob端：接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信 号；根据所述第一同步信号通过时钟直接采样的方式识别出所述脉冲宽度大于2W的信号脉冲；根据所述脉冲宽度大于2W的信号脉冲生成所述帧同步起始信号；根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号；时间上补偿所述帧同步信号。具体地，通过帧同步起始信号提取单元中的时钟模块采用时钟数字采样的方式识别出第一同步信号中脉冲宽度大于2W的信号脉冲，即第一同步信号中脉冲宽度大于2W的信号脉冲所占用时长大于其他正常宽度的信号脉冲所占用时长，据此识别出第一同步信号中脉冲宽度大于2W的信号脉冲，根据所述脉冲宽度大于2W的信号脉冲生成帧同步起始信号，然后，根据恢复的参考时钟信号与所述帧同步起始信号生成帧同步信号，最后，通过Bob端的后处理单元时间上补偿所述帧同步信号。Embodiment 3, referring to the above synchronization method, the synchronization method of the Alice end remains unchanged, and the Bob end: receives the first synchronization signal, recovers a reference clock signal according to the first synchronization signal; passes the clock according to the first synchronization signal Identify the signal pulse with the pulse width greater than 2W by means of direct sampling; generate the frame synchronization start signal according to the signal pulse with the pulse width greater than 2W; start the frame synchronization according to the recovered reference clock signal and the frame synchronization start The signal generates a frame synchronization signal; the frame synchronization signal is temporally compensated. Specifically, the clock module in the frame synchronization start signal extraction unit uses digital clock sampling to identify the signal pulses in the first synchronization signal with a pulse width greater than 2W, that is, the signal pulses with a pulse width greater than 2W in the first synchronization signal. The occupied duration is longer than the duration occupied by the signal pulses of other normal widths, and accordingly, the signal pulses with the pulse width greater than 2W in the first synchronization signal are identified, and the frame synchronization start signal is generated according to the signal pulses with the pulse width greater than 2W, and then, according to The recovered reference clock signal and the frame synchronization start signal generate a frame synchronization signal, and finally, the frame synchronization signal is temporally compensated by the post-processing unit at the Bob end.
参照上述同步装置，在该实施例中，帧同步起始信号提取单元被配置为：根据第一同步信号通过时钟采样的方式识别出脉冲宽度大于2W的信号脉冲、根据所述脉冲宽度大于2W的信号脉冲生成帧同步起始信号。Referring to the above synchronization device, in this embodiment, the frame synchronization start signal extraction unit is configured to: identify a signal pulse with a pulse width greater than 2W according to the first synchronization signal by means of clock sampling, and according to the pulse width greater than 2W The signal pulse generates a frame sync start signal.
需要说明的是，在本申请的描述中，术语“第一”、“第二”等仅用于描述目的和区别类似的对象，两者之间并不存在先后顺序，也不能理解为指示或暗示相对重要性。此外，在本申请的描述中，除非另有说明，“多个”的含义是两个或两个以上。It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for the purpose of description and to distinguish similar objects, and there is no sequence between the two, nor can they be understood as indicating or imply relative importance. Also, in the description of this application, unless otherwise specified, "plurality" means two or more.
以上结合具体实施方式和范例性实例对本申请进行了详细说明，不过这些说明并不能理解为对本申请的限制。本领域技术人员理解，在不偏离本申请精神和范围的情况下，可以对本申请技术方案及其实施方式进行多种等价替换、修饰或改进，这些均落入本申请的范围内。本申请的保护范围以所附权利要求为准。The present application has been described in detail above with reference to specific embodiments and exemplary examples, but these descriptions should not be construed as a limitation on the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, various equivalent replacements, modifications or improvements can be made to the technical solutions of the present application and the embodiments thereof, which all fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.

Claims (10)

  1. 一种量子密钥分发系统的同步方法，其中，所述同步方法包括：A synchronization method for a quantum key distribution system, wherein the synchronization method comprises:
    Alice端：Alice side:
    根据时钟信号生成同步信号，所述同步信号的脉冲宽度为W，所述同步信号的同步周期为Δt；在第n个同步周期Δt内，生成启动命令，根据所述启动命令得到第一同步信号，所述第一同步信号在第n+1个同步周期的脉冲宽度大于2W，所述第一同步信号的所有信号脉冲中仅有一个信号脉冲的脉冲宽度大于2W，所述脉冲宽度大于2W的信号脉冲所占用时长小于同步周期Δt；A synchronization signal is generated according to the clock signal, the pulse width of the synchronization signal is W, and the synchronization period of the synchronization signal is Δt; in the nth synchronization period Δt, a start command is generated, and the first synchronization signal is obtained according to the start command , the pulse width of the first synchronization signal in the n+1th synchronization period is greater than 2W, only one signal pulse of the first synchronization signal has a pulse width greater than 2W, and the pulse width is greater than 2W The time occupied by the signal pulse is less than the synchronization period Δt;
    根据所述启动命令得到启动编码信号，所述启动编码信号仅包含一个信号脉冲，所述启动编码信号的信号脉冲的上升沿与所述第一同步信号中脉冲宽度大于2W的信号脉冲的上升沿对齐，根据所述启动编码信号和所述时钟信号调控发射量子信号；A start code signal is obtained according to the start command, the start code signal only includes one signal pulse, the rising edge of the signal pulse of the start code signal and the rising edge of the signal pulse with a pulse width greater than 2W in the first synchronization signal Alignment, according to the start coding signal and the clock signal regulation and emission quantum signal;
    Bob端：Bob's side:
    接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信号；receiving the first synchronization signal, and recovering a reference clock signal according to the first synchronization signal;
    根据所述第一同步信号生成帧同步起始信号；generating a frame synchronization start signal according to the first synchronization signal;
    根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号；generating a frame synchronization signal according to the recovered reference clock signal and the frame synchronization start signal;
    时间上补偿所述帧同步信号。The frame synchronization signal is temporally compensated.
  2. 根据权利要求1所述的量子密钥分发系统的同步方法，其中，所述同步方法包括：The synchronization method of a quantum key distribution system according to claim 1, wherein the synchronization method comprises:
    Bob端：Bob's side:
    接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信号；receiving the first synchronization signal, and recovering a reference clock signal according to the first synchronization signal;
    延迟所述第一同步信号得到第二同步信号，所述延迟时长大于所述脉冲宽度为W的同步信号脉冲所占用的时长，所述延迟时长小于所述脉冲宽度大于2W的信号脉冲所占用的时长；Delaying the first synchronization signal to obtain a second synchronization signal, the delay duration is greater than the duration occupied by the synchronization signal pulse with a pulse width of W, and the delay duration is smaller than the duration occupied by the signal pulse with a pulse width greater than 2W duration;
    将所述第一同步信号与所述第二同步信号做与运算得到帧同步起始信号；Perform an AND operation on the first synchronization signal and the second synchronization signal to obtain a frame synchronization start signal;
    根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号；generating a frame synchronization signal according to the recovered reference clock signal and the frame synchronization start signal;
    根据所述延迟时长补偿所述帧同步信号。The frame synchronization signal is compensated according to the delay duration.
  3. 根据权利要求1所述的量子密钥分发系统的同步方法，其中，所述同步方法包括：The synchronization method of a quantum key distribution system according to claim 1, wherein the synchronization method comprises:
    Bob端：Bob's side:
    接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信号；receiving the first synchronization signal, and recovering a reference clock signal according to the first synchronization signal;
    将所述第一同步信号进行积分得到第三同步信号；integrating the first synchronization signal to obtain a third synchronization signal;
    比较所述第三同步信号的积分大小，根据最大的积分信号得到帧同步起始信号；Comparing the integral size of the third synchronization signal, and obtaining a frame synchronization start signal according to the largest integral signal;
    根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号；generating a frame synchronization signal according to the recovered reference clock signal and the frame synchronization start signal;
    时间上补偿所述帧同步信号。The frame synchronization signal is temporally compensated.
  4. 根据权利要求1所述的量子密钥分发系统的同步方法，其中，所述同步方法包括：The synchronization method of a quantum key distribution system according to claim 1, wherein the synchronization method comprises:
    Bob端：Bob's side:
    接收所述第一同步信号，根据所述第一同步信号恢复出参考时钟信号；receiving the first synchronization signal, and recovering a reference clock signal according to the first synchronization signal;
    根据所述第一同步信号通过时钟采样的方式识别出所述脉冲宽度大于2W的信号脉冲；Identify the signal pulse with the pulse width greater than 2W by means of clock sampling according to the first synchronization signal;
    根据所述脉冲宽度大于2W的信号脉冲生成所述帧同步起始信号；generating the frame synchronization start signal according to the signal pulse with the pulse width greater than 2W;
    根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号；generating a frame synchronization signal according to the recovered reference clock signal and the frame synchronization start signal;
    时间上补偿所述帧同步信号。The frame synchronization signal is temporally compensated.
  5. 根据权利要求1所述的量子密钥分发系统的同步方法，其中，通过脉冲宽度调制的方式调制所述同步信号中第n+1个同步周期的脉冲宽度，使所述第一同步信号在第n+1个同步周期的脉冲宽度大于2W。The synchronization method of the quantum key distribution system according to claim 1, wherein the pulse width of the n+1th synchronization period in the synchronization signal is modulated by means of pulse width modulation, so that the first synchronization signal is in the first synchronization period. The pulse width of n+1 sync cycles is greater than 2W.
  6. 根据权利要求1所述的量子密钥分发系统的同步方法，其中，所述 启动命令为仅包含一个信号脉冲的脉冲信号，根据所述启动命令在产生所述第一同步信号中脉冲宽度大于2W的信号脉冲的同时产生所述启动编码信号的信号脉冲。The synchronization method of a quantum key distribution system according to claim 1, wherein the start command is a pulse signal containing only one signal pulse, and the pulse width is greater than 2W in generating the first synchronization signal according to the start command The signal pulse of the start coding signal is generated at the same time.
  7. 根据权利要求1所述的量子密钥分发系统的同步方法，其中，所述第一同步信号中相邻信号脉冲上升沿之间的时间差相等，所述相邻信号脉冲上升沿之间的时间差为同步周期Δt。The synchronization method of a quantum key distribution system according to claim 1, wherein the time difference between the rising edges of adjacent signal pulses in the first synchronization signal is equal, and the time difference between the rising edges of the adjacent signal pulses is Synchronization period Δt.
  8. 根据权利要求1所述的量子密钥分发系统的同步方法，其中，所述帧同步起始信号仅包含一个信号脉冲。The synchronization method of a quantum key distribution system according to claim 1, wherein the frame synchronization start signal contains only one signal pulse.
  9. 根据权利要求1所述的量子密钥分发系统的同步方法，其中，根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号，包括：The synchronization method of a quantum key distribution system according to claim 1, wherein generating a frame synchronization signal according to the recovered reference clock signal and the frame synchronization start signal, comprising:
    以所述帧同步起始信号脉冲的上升沿为起点，依据时钟信号进行周期计数，每隔同步周期Δt生成一个帧同步信号脉冲，得到帧同步信号。Taking the rising edge of the frame synchronization start signal pulse as a starting point, period counting is performed according to the clock signal, and a frame synchronization signal pulse is generated every synchronization period Δt to obtain a frame synchronization signal.
  10. 一种量子密钥分发系统的同步装置，其中，所述装置包括：A synchronization device for a quantum key distribution system, wherein the device comprises:
    Alice端：Alice side:
    同步单元，用于根据时钟信号生成同步信号，所述同步信号的脉冲宽度为W，所述同步信号的同步周期为Δt，用于根据启动命令得到第一同步信号，所述第一同步信号在第n+1个同步周期的脉冲宽度大于2W，所述第一同步信号的所有信号脉冲中仅有一个信号脉冲的脉冲宽度大于2W，所述脉冲宽度大于2W的信号脉冲所占用时长小于同步周期Δt，并用于根据启动命令得到启动编码信号，所述启动编码信号仅包含一个信号脉冲，所述启动编码信号的信号脉冲的上升沿与所述第一同步信号中脉冲宽度大于2W的信号脉冲的上升沿对齐；The synchronization unit is used to generate a synchronization signal according to a clock signal, the pulse width of the synchronization signal is W, and the synchronization period of the synchronization signal is Δt, and is used to obtain a first synchronization signal according to a start command, and the first synchronization signal is in The pulse width of the n+1th synchronization period is greater than 2W, only one of all signal pulses of the first synchronization signal has a pulse width greater than 2W, and the duration of the signal pulse with a pulse width greater than 2W is less than the synchronization period Δt, and is used to obtain a start code signal according to the start command, the start code signal contains only one signal pulse, and the rising edge of the signal pulse of the start code signal is the same as the first synchronization signal. The pulse width of the signal pulse is greater than 2W rising edge alignment;
    控制单元，用于在第n个同步周期Δt内，生成所述启动命令；a control unit, configured to generate the start command within the nth synchronization period Δt;
    编码单元，用于根据所述启动编码信号和所述时钟信号调控发射量子信号；an encoding unit for regulating and transmitting quantum signals according to the start encoding signal and the clock signal;
    Bob端：Bob's side:
    同步信号探测单元，用于接收所述第一同步信号；a synchronization signal detection unit, configured to receive the first synchronization signal;
    时钟恢复单元，用于根据所述第一同步信号恢复出参考时钟信号；a clock recovery unit, configured to recover a reference clock signal according to the first synchronization signal;
    帧同步起始信号提取单元，用于根据所述第一同步信号生成帧同步起始信号；a frame synchronization start signal extraction unit, configured to generate a frame synchronization start signal according to the first synchronization signal;
    帧同步信号生成单元，用于根据恢复的所述参考时钟信号与所述帧同步起始信号生成帧同步信号。A frame synchronization signal generating unit, configured to generate a frame synchronization signal according to the recovered reference clock signal and the frame synchronization start signal.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023187836A1 (en) * 2022-03-31 2023-10-05 Centre For Development Of Telematics (C-Dot) Methods and system for fast synchronization in long range quantum key distribution

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111740829B (en) * 2020-08-03 2020-12-04 北京中创为南京量子通信技术有限公司 Synchronization method and device of quantum key distribution system
CN113541819B (en) * 2020-12-30 2023-12-19 广东国腾量子科技有限公司 Time synchronization system for quantum key distribution
CN114422126B (en) * 2021-12-31 2023-11-28 广东国腾量子科技有限公司 Joint debugging test system and method for quantum key management software module

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007050285A2 (en) * 2005-10-24 2007-05-03 Magiq Technologies, Inc. Qkd system with synchronization channel verification
CN110519057A (en) * 2019-10-23 2019-11-29 北京中创为南京量子通信技术有限公司 Classical signals decoding method, synchronous method and the device of quantum key distribution system
CN110830247A (en) * 2019-10-31 2020-02-21 中国人民解放军国防科技大学 Blind vulnerability detection method and device for gated detector in quantum key distribution system
CN111180998A (en) * 2020-01-03 2020-05-19 国开启科量子技术(北京)有限公司 Method and device for realizing narrow pulse laser driving circuit without delay chip
CN111740829A (en) * 2020-08-03 2020-10-02 北京中创为南京量子通信技术有限公司 Synchronization method and device of quantum key distribution system

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103516455B (en) * 2012-06-21 2017-02-22 天津中兴智联科技有限公司 Data synchronism method and device
JP5786976B2 (en) * 2013-06-11 2015-09-30 オンキヨー株式会社 Signal modulation circuit

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007050285A2 (en) * 2005-10-24 2007-05-03 Magiq Technologies, Inc. Qkd system with synchronization channel verification
CN110519057A (en) * 2019-10-23 2019-11-29 北京中创为南京量子通信技术有限公司 Classical signals decoding method, synchronous method and the device of quantum key distribution system
CN110830247A (en) * 2019-10-31 2020-02-21 中国人民解放军国防科技大学 Blind vulnerability detection method and device for gated detector in quantum key distribution system
CN111180998A (en) * 2020-01-03 2020-05-19 国开启科量子技术(北京)有限公司 Method and device for realizing narrow pulse laser driving circuit without delay chip
CN111740829A (en) * 2020-08-03 2020-10-02 北京中创为南京量子通信技术有限公司 Synchronization method and device of quantum key distribution system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023187836A1 (en) * 2022-03-31 2023-10-05 Centre For Development Of Telematics (C-Dot) Methods and system for fast synchronization in long range quantum key distribution

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