Signal communication and encryption integrated processing method, sending device, receiving device and system

Abstract

The invention provides a signal communication and encryption integrated processing method, a sending device, a receiving device and a system, and relates to the technical field of quantum communication. The method comprises the following steps: a synchronizing signal generation module generates a synchronizing signal, a synchronizing signal modulation module receives a communication signal and performs pulse modulation on the synchronizing signal according to the communication signal so as to encode classical communication information carried by the communication signal into the synchronizing signal to obtain a modulated synchronizing signal, the quantum signal generation module generates a quantum signal according to the signal parameter of the modulated synchronizing signal, the combiner performs wave combination processing on the quantum signal and the modulated synchronizing signal to obtain a mixed signal, and the mixed signal is sent to a receiving device through a single transmission medium. The classical communication information is encoded into the synchronizing signal, and the classical communication information and the quantum signal are transmitted on the single optical fiber in a common-fiber manner, so that the problem that the optical fiber resource is insufficient and the security of the communication and encryption integrated system is difficult to consider is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of quantum communication, in particular to a signal transmission and encryption integrated processing method, a sending device, a receiving device and a system. BACKGROUND

[0002] A quantum key distribution (QKD) system generally includes quantum signal transmission, synchronization signal transmission, key negotiation and post-processing modules. Among them, the synchronization signal is used to accurately mark the receiving time sequence of the quantum signal, and ensures that the sender and the receiver are consistent in time, which is the key to ensuring the normal operation of the QKD system.

[0003] At present, the QKD system usually uses independent optical fibers to transmit quantum signals and classical communication signals respectively. Although this deployment method can effectively avoid signal interference, it leads to low utilization of optical fiber resources, high deployment cost and complex maintenance, which is difficult to meet the needs of large-scale quantum network construction. In order to realize resource conservation and system integration, the existing technology generally uses wavelength division multiplexing (WDM) technology, that is, different wavelength channels are used to transmit quantum state signals and classical communication signals. Since the synchronization signal, the classical communication signal and the quantum signal in the QKD system are transmitted through wavelength division multiplexing in different wavelengths, the new classical communication signal will cause crosstalk problem to the quantum signal, resulting in significant increase of quantum error rate, and the information transmission security cannot be guaranteed. If independent optical fibers are used to deploy the transmission link of quantum signals and classical communication signals, optical fiber resources will be wasted. Therefore, how to save optical fiber resources while ensuring the security of the transmission of signals and encryption integration is an urgent problem to be solved. SUMMARY

[0004] The purpose of the present application is to solve the problem of how to save optical fiber resources while ensuring the security of the transmission of signals and encryption integration in the prior art.

[0005] To achieve the above purpose, the technical solutions adopted by the embodiments of the present application are as follows: In a first aspect, the embodiments of the present application provide a signal transmission and encryption integrated processing method applied to a sending device, the sending device comprising a synchronization signal generation module, a synchronization signal modulation module, a quantum signal generation module and a wavelength division multiplexer, and the method comprising: The synchronization signal generation module generates a synchronization signal and sends the synchronization signal to the synchronization signal modulation module; The synchronization signal modulation module receives a communication signal, and performs pulse modulation on the synchronization signal according to the communication signal, so as to encode classical communication information carried by the communication signal into the synchronization signal, to obtain a modulated synchronization signal, and the synchronization signal modulation module sends the modulated synchronization signal to the combiner; The quantum signal generation module generates a quantum signal according to a signal parameter of the modulated synchronization signal, and sends the quantum signal to the combiner; The combiner performs combing processing on the quantum signal and the modulated synchronization signal, to obtain a mixed signal, and sends the mixed signal to a receiving device through a single transmission medium.

[0006] As a possible implementation manner, the sending device further comprises a communication signal generation module; The communication signal generation module generates the communication signal, and sends the communication signal to the synchronization signal modulation module; The synchronization signal modulation module receives a communication signal, and performs pulse modulation on the synchronization signal according to the communication signal, so as to encode classical communication information carried by the communication signal into the synchronization signal, to obtain a modulated synchronization signal, and the synchronization signal modulation module sends the modulated synchronization signal to the combiner; The synchronization signal modulation module receives the communication signal sent by the communication signal generation module, and performs binary encoding on classical communication information carried by the communication signal, to obtain a binary sequence corresponding to the classical communication information; According to the binary sequence, pulse modulation information is determined, the pulse modulation information comprises pulse width modulation information or pulse amplitude modulation information, the pulse width modulation information is used for indicating pulse width levels corresponding to each group of the binary sequence, and the pulse amplitude modulation information is used for indicating pulse amplitude levels corresponding to each group of the binary sequence; The synchronization signal is pulse-modulated according to the pulse modulation information, to obtain the modulated synchronization signal.

[0007] As a possible implementation manner, the determination of the pulse modulation information according to the binary sequence comprises: The binary sequence is divided to obtain a plurality of groups; According to a first mapping relationship, pulse width levels corresponding to each group are determined, and the first mapping relationship is used for indicating a corresponding relationship between the group and the pulse width level; The synchronization signal is pulse-modulated according to the pulse modulation information, to obtain the modulated synchronization signal, comprising: According to the pulse width levels corresponding to each group, pulse modulation widths of each synchronization pulse in the synchronization signal are determined; According to pulse modulation widths of the synchronization pulses, the synchronization signal is pulse width modulated to obtain the modulated synchronization signal.

[0008] As a possible implementation, the determining, according to the binary sequence, of pulse modulation information comprises: The binary sequence is divided to obtain a plurality of arrays; According to a second mapping relationship, a pulse amplitude level corresponding to each array is determined, the second mapping relationship being used to indicate a corresponding relationship between an array and a pulse amplitude level; The pulse modulating, according to the pulse modulation information, of the synchronization signal to obtain the modulated synchronization signal comprises: According to the pulse amplitude level corresponding to each array, a pulse modulation amplitude of each synchronization pulse in the synchronization signal is determined; According to the pulse modulation amplitude of each synchronization pulse, the synchronization signal is pulse amplitude modulated to obtain the modulated synchronization signal.

[0009] As a possible implementation, the quantum signal generation module generates a quantum signal according to a signal parameter of the modulated synchronization signal, comprising: The quantum signal generation module determines a transmission time slot of the modulated synchronization signal; The quantum signal generation module generates the quantum signal in the transmission time slot.

[0010] In a second aspect, an embodiment of the present application provides a signal processing method integrating encryption and decryption, applied to a receiving device, the receiving device comprising a wave divider, a quantum signal recovery module and a signal demodulation module, and the method comprising: The wave divider performs wave division processing on a mixed signal in a transmission medium to obtain a quantum signal and a modulated synchronization signal, and sends the quantum signal to the quantum signal recovery module and the modulated synchronization signal to the signal demodulation module; The signal demodulation module determines pulse modulation information of the modulated synchronization signal, and demodulates the modulated synchronization signal according to the pulse modulation information to extract classical communication information carried by a communication signal from the modulated synchronization signal; The quantum signal recovery module demodulates the quantum signal to obtain quantum information.

[0011] As a possible implementation, the signal demodulation module comprises a first rising edge detector, a pulse width timer, a first threshold comparator and a first information decoder. The signal demodulation module determines pulse modulation information of the modulated synchronization signal, and demodulates the modulated synchronization signal according to the pulse modulation information to extract classical communication information carried by a communication signal from the modulated synchronization signal, including: The first rising edge detector detects rising edges of each synchronization pulse in the modulated synchronization signal, and for each synchronization pulse, triggers the pulse width timer to start timing when the rising edge of the synchronization pulse is detected, to determine a pulse width of the synchronization pulse, the pulse width representing a time interval from a rising edge time to a falling edge time of the synchronization pulse, the modulated synchronization signal including a plurality of synchronization pulses; The first threshold comparator compares, for each synchronization pulse, the pulse width of the synchronization pulse with a preset pulse width level, to determine a pulse width level to which the pulse width of the synchronization pulse belongs; The first information decoder demodulates each synchronization pulse according to the pulse width level to which the pulse width of each synchronization pulse belongs, to extract classical communication information carried by a communication signal from the modulated synchronization signal.

[0012] As a possible implementation, the signal demodulation module includes a second rising edge detector, an amplitude sampler, a gain compensation unit, a second threshold comparator, and a second information decoder; The signal demodulation module determines pulse modulation information of the modulated synchronization signal, and demodulates the modulated synchronization signal according to the pulse modulation information to extract classical communication information carried by a communication signal from the modulated synchronization signal, including: The second rising edge detector detects rising edges of each synchronization pulse in the modulated synchronization signal, and for each synchronization pulse, triggers the amplitude sampler to start sampling when the rising edge of the synchronization pulse is detected, to obtain a sampling amplitude of the synchronization pulse; The gain compensation unit normalizes the sampling amplitude of each synchronization pulse to obtain a compensated pulse amplitude of each synchronization pulse; The second threshold comparator compares, for each synchronization pulse, the compensated pulse amplitude of the synchronization pulse with a preset pulse amplitude level, to determine a pulse amplitude level to which the compensated pulse amplitude of the synchronization pulse belongs; The second information decoder demodulates each synchronization pulse according to the pulse amplitude level to which the compensated pulse amplitude of each synchronization pulse belongs, to extract classical communication information carried by a communication signal from the modulated synchronization signal.

[0013] As a possible implementation, the quantum signal recovery module demodulates the quantum signal to obtain quantum information, including: The quantum signal recovery module demodulates the quantum signal according to a transmission time slot of the modulated synchronization signal to obtain the quantum information.

[0014] In a third aspect, an embodiment of the present application provides a sending device, comprising a synchronization signal generation module, a synchronization signal modulation module, a quantum signal generation module and a combiner. The sending device is configured to perform the steps in the signal communication and encryption integrated processing method of any one of the first aspect to send signals.

[0015] In a fourth aspect, an embodiment of the present application provides a receiving device, comprising a splitter, a quantum signal recovery module and a signal demodulation module. The receiving device is configured to perform the steps in the signal communication and encryption integrated processing method of any one of the second aspect to receive signals.

[0016] In a fifth aspect, an embodiment of the present application provides a signal communication and encryption integrated processing system, comprising the sending device of the third aspect and the receiving device of the fourth aspect.

[0017] In a sixth aspect, an embodiment of the present application provides a computer readable storage medium, and the computer readable storage medium stores a computer program. When the computer program is run by a processor, the steps of the signal communication and encryption integrated processing method of any one of the first aspect and the second aspect are executed.

[0018] According to the signal communication and encryption integrated processing method, the sending device, the receiving device and the system of the embodiment of the present application, at the sending end, the synchronization signal is used as a bearing carrier of the classical communication information, the synchronization signal is pulse-modulated by using a pulse modulation mode, including pulse width modulation and pulse amplitude modulation, so that the classical communication information is embedded in the synchronization pulse, the modulated synchronization signal is obtained, and the laying of the optical fiber for the classical channel is avoided. Meanwhile, the quantum signal and the modulated synchronization signal are combined and transmitted by using the wavelength division multiplexing mode, one-fiber dual use is realized, and the optical fiber resources are significantly saved. At the receiving end, the classical information is recovered by accurately demodulating the modulated synchronization signal, and the quantum information is obtained by independently demodulating the quantum signal. The quantum information demodulation and the modulated synchronization signal demodulation are kept isolated in the physical layer and the logical layer, the classical signal interference with the quantum state is prevented, the security of the quantum communication is ensured, and the synchronization precision and the anti-interference ability of the signal communication and encryption integrated processing system are further improved due to the time sequence reference function of the modulated synchronization signal. In this way, the classical communication information is encoded into the synchronization signal, and the quantum signal is co-fiber transmitted on a single optical fiber, so that the problem that the optical fiber resources are tight and the security of the communication and encryption integrated system is difficult to be considered is effectively solved. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor under the guidance of the content of the present application.

[0020] Figure 1 The architecture schematic diagram of a signal traffic and secret integrated processing system provided by an embodiment of the present application is shown; Figure 2 The architecture schematic diagram of another signal traffic and secret integrated processing system provided by an embodiment of the present application is shown; Figure 3 The architecture schematic diagram of still another signal traffic and secret integrated processing system provided by an embodiment of the present application is shown; Figure 4 The flow schematic diagram of a signal traffic and secret integrated processing method provided by an embodiment of the present application is shown; Figure 5 The schematic diagram of a synchronization signal provided by an embodiment of the present application is shown; Figure 6 The flow schematic diagram of a synchronization signal modulation method provided by an embodiment of the present application is shown; Figure 7 The schematic diagram of a modulated synchronization signal provided by an embodiment of the present application is shown; Figure 8 The schematic diagram of another modulated synchronization signal provided by an embodiment of the present application is shown; Figure 9 The flow schematic diagram of a signal demodulation method provided by an embodiment of the present application is shown; Figure 10 The flow schematic diagram of another signal demodulation method provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. It should be understood that the drawings in the present application only play the purpose of illustration and description, and should not be used to limit the protection scope of the present application. In addition, it should be understood that the schematic drawings are not drawn according to the actual proportion. The flowchart shows the operations realized according to some embodiments of the present application. It should be understood that the operations of the flowchart can not be realized in sequence, and the steps without logical context relationship can be reversed in sequence or implemented simultaneously. In addition, one or more other operations can be added to the flowchart or removed from the flowchart by those skilled in the art under the guidance of the content of the present application.

[0022] In addition, the described embodiments are only some embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0023] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0024] Figure 1 An architecture schematic diagram of a signal transmission and encryption integrated processing system provided by an embodiment of the present application is shown. Referring to Figure 1 The signal transmission and encryption integrated processing system includes a sending device and a receiving device. The sending device includes a synchronization signal generation module, a synchronization signal modulation module, a quantum signal generation module, and a combiner, and the receiving device includes a splitter, a quantum signal recovery module, and a signal demodulation module.

[0025] Optionally, in the sending device, the synchronization signal generation module generates a synchronization signal and delivers the synchronization signal to the synchronization signal modulation module, the synchronization signal modulation module receives an external communication signal, encodes classical communication information carried by the communication signal into the synchronization signal through pulse modulation to form a modulated synchronization signal, and sends the modulated synchronization signal to the combiner. At the same time, the quantum signal generation module generates a corresponding quantum signal according to the signal parameters of the modulated synchronization signal and sends the quantum signal to the combiner. Subsequently, the combiner performs combining processing on the modulated synchronization signal and the quantum signal to generate a mixed signal, and sends the mixed signal to the receiving device through a single transmission medium, such as a single optical fiber, specifically to the splitter in the receiving device.

[0026] Optionally, in the receiving device, the splitter performs splitting processing on the mixed signal in the transmission medium to separate out the quantum signal and the modulated synchronization signal, and sends the quantum signal to the quantum signal recovery module and the modulated synchronization signal to the signal demodulation module, respectively. The signal demodulation module analyzes the pulse modulation information of the modulated synchronization signal to demodulate and extract the classical communication information carried by the communication signal, ensuring accurate recovery of the classical communication information. At the same time, the quantum signal recovery module demodulates the quantum signal to recover the quantum information, ensuring the security and confidentiality of the communication.

[0027] Optionally, the sending device further comprises a communication signal generating module, configured to generate a communication signal and deliver the communication signal to the synchronization signal modulating module. The communication signal generating module, as an information source, is responsible for generating the communication signal carrying the classical communication information, ensuring the accuracy and integrity of the classical communication information. After receiving the communication signal delivered by the communication signal generating module, the synchronization signal modulating module encodes the classical communication information in the communication signal into the synchronization signal through pulse modulation technology, forming the modulated synchronization signal. In this way, the effective combination of the classical communication information and the synchronization signal is realized.

[0028] Since two pulse modulation methods are provided in the present application, including pulse width modulation and pulse amplitude modulation, correspondingly, two different signal demodulating modules are designed for different pulse modulation methods, to demodulate the modulated synchronization signal modulated by different pulse modulation methods. The signal demodulating modules in the two cases are described in detail below.

[0029] Optionally, as shown in Figure 2 , the signal demodulating module comprises a first rising edge detector, a pulse width timer, a first threshold comparator and a first information decoder, each component is used to jointly complete the demodulation work of the modulated synchronization signal, which is specifically pulse width demodulation work. Specifically, the first rising edge detector first detects the rising edge of each synchronization pulse in the modulated synchronization signal, and triggers the pulse width timer to start timing, to determine the pulse width of each synchronization pulse. The first threshold comparator compares the pulse width of each synchronization pulse with the preset pulse width level to determine its belonging level. The first information decoder demodulates the modulated synchronization signal according to the pulse width level of each synchronization pulse, thereby accurately extracting the classical communication information carried by the communication signal.

[0030] Optionally, as shown in Figure 3 , the signal demodulating module comprises a second rising edge detector, an amplitude sampler, a gain compensation unit, a second threshold comparator and a second information decoder, each component is used to jointly complete the demodulation work of the modulated synchronization signal, which is specifically pulse amplitude demodulation work. Specifically, the second rising edge detector detects the rising edge of each synchronization pulse in the modulated synchronization signal, and triggers the amplitude sampler to start sampling when the rising edge is detected, to obtain the sampling amplitude of each synchronization pulse. Then, the gain compensation unit normalizes these sampling amplitudes to obtain the compensated pulse amplitudes, to eliminate the amplitude distortion possibly introduced in the transmission process. The second threshold comparator compares the compensated pulse amplitudes with the preset pulse amplitude level to determine its belonging amplitude level. The second information decoder demodulates according to the compensated pulse amplitude level of each synchronization pulse, thereby accurately recovering the classical communication information carried by the communication signal.

[0031] It is worth noting that based on the above two different signal demodulation module composition structure, the application can realize two demodulation methods based on pulse width modulation and pulse amplitude modulation, not only improve the accuracy and reliability of signal demodulation, but also enhance the anti-interference ability of signal processing system, and ensure the high fidelity recovery of classical communication information in complex transmission environment. In addition, the signal demodulation module can effectively deal with various interference and attenuation in signal transmission process, and ensure the accuracy and integrity of classical communication information, which provides a solid technical support for the whole signal processing system.

[0032] Therefore, according to the signal processing system provided by the embodiment of the application, the sending device encodes the classical communication information into the synchronization signal by pulse width or pulse amplitude modulation mode using the synchronization signal as the carrier. The modulated synchronization signal is obtained, and the combiner combines the modulated synchronization signal with the quantum signal and transmits it to the receiving device. The receiving device realizes high-precision demodulation of the classical communication information through accurate rising edge detection, pulse width / amplitude sampling, gain compensation and threshold comparison mechanism, and independently recovers the quantum information, which guarantees the real-time and security of communication. In this way, the signal processing system of the application cooperates the classical communication signal and the quantum signal in the same transmission medium, not only realizes efficient and secure fusion communication of classical information and quantum information, but also saves the optical fiber transmission resource in the signal processing process, and improves the anti-interference ability and signal recovery precision through the optimization of modulation and demodulation mechanism, solves the problems of resource waste, synchronization difficulty and transmission security caused by the separation of classical and quantum signal transmission in traditional system.

[0033] The signal processing method provided by the embodiment of the application will be described in detail in combination with the above Figures 1 to 3 The signal processing method provided by the embodiment of the application will be described in detail in combination with the above

[0034] Figure 4 The signal processing method provided by the embodiment of the application will be described in detail in combination with the above Figure 4 The signal processing method provided by the embodiment of the application will be described in detail in combination with the above S401, the synchronization signal generation module generates a synchronization signal.

[0035] Optionally, the synchronization signal is used to provide a time reference to ensure that the sending device and the receiving device are consistent in time, and the signal processing system is shown in Figure 5As shown, the synchronization signal is a pulse sequence containing multiple synchronization pulses. The synchronization signal generation module is usually driven by a high-precision master clock to generate the synchronization signal. Specifically, the master clock signal generates synchronization pulses of the required frequency through a digital frequency divider, and generates a periodic pulse sequence with fixed period, frequency stability, and consistent phase as the synchronization signal through programmable logic. The signal parameters of the synchronization signal, such as duty cycle, rise / fall time, frequency, etc., need to meet the timing matching requirements of subsequent synchronization signal modulation and quantum signal generation to ensure that each module in the signal transmission system is in step in time, and high reliability and high precision are achieved.

[0036] S402, the synchronization signal generation module sends the synchronization signal to the synchronization signal modulation module.

[0037] Optionally, the synchronization signal generation module can transmit the generated synchronization signal to the synchronization signal modulation module through the electrical connection between the synchronization signal generation module and the synchronization signal modulation module. It is worth noting that the transmission path of the synchronization signal needs to be shielded from interference to ensure the integrity of the synchronization signal and avoid jitter introduction.

[0038] S403, the communication signal generation module generates a communication signal.

[0039] Optionally, the communication signal is a signal carrying classical communication information, usually in the form of electrical or optical signals, used for protocol interaction and information transmission between the sending end and the receiving end. The communication signal generation module usually realizes the generation of the communication signal by a field-programmable gate array (FPGA), a microcontroller or an embedded processor, so as to obtain a communication signal carrying the classical communication information to be transmitted.

[0040] S404, the communication signal generation module sends the communication signal to the synchronization signal modulation module.

[0041] Optionally, the communication signal generation module can transmit the generated communication signal to the synchronization signal modulation module through the electrical connection between the communication signal generation module and the synchronization signal modulation module. It is worth noting that, similarly, the transmission path of the communication signal needs to be shielded from interference to ensure the integrity of the communication signal and avoid jitter introduction.

[0042] S405, the synchronization signal modulation module modulates the synchronization signal according to the communication signal to encode the classical communication information carried by the communication signal into the synchronization signal, and obtains the modulated synchronization signal.

[0043] Optionally, the synchronization signal modulation module pulse-modulates the synchronization signal according to the communication signal, that is, encodes the classical communication information carried by the communication signal into the synchronization signal by pulse modulation. In the embodiment of the present application, the synchronization signal modulation module supports two pulse modulation modes, including pulse width modulation (PWM) and pulse amplitude modulation (PAM), wherein the pulse width modulation indicates that different pulse widths represent different data, and the pulse amplitude modulation indicates that different amplitudes represent different data.

[0044] Optionally, after receiving the communication signal generated and sent by the communication signal generation module, the synchronization signal modulation module pulse-modulates the synchronization signal by mapping the classical communication information carried by the communication signal into a modulation parameter, thereby obtaining a modulated synchronization signal. Specifically, mapping the classical communication information into a modulation parameter includes: if it is pulse width modulation, mapping each bit or data segment into a specific pulse width, and if it is pulse amplitude modulation, mapping the classical communication information into different voltage levels.

[0045] S406, the synchronization signal modulation module sends the modulated synchronization signal to the combiner.

[0046] Optionally, the combiner is a device that can combine multiple signals of different wavelengths or types into the same transmission medium. After the synchronization signal modulation module generates the modulated synchronization signal, the modulated synchronization signal can be sent to the input port of the combiner through the electrical connection between the synchronization signal modulation module and the combiner, and impedance matching and signal fidelity need to be ensured during the transmission of the modulated synchronization signal.

[0047] S407, the quantum signal generation module generates a quantum signal according to the signal parameter of the modulated synchronization signal.

[0048] Optionally, the quantum signal generation module uses the key signal parameters (such as pulse rising edge time, period, phase, etc.) of the modulated synchronization signal as a time reference to generate a quantum signal in the corresponding time slot. For example, under the trigger of the rising edge of each synchronization pulse, the quantum signal generation module generates a photon encoding quantum information, ensuring that the quantum signal and the classical signal are strictly aligned in time, facilitating synchronization recovery at the receiving end. It should be noted that the generation of the quantum signal by the quantum signal generation module, the generation of the synchronization signal by the synchronization signal generation module, and the generation of the communication signal by the communication signal generation module are independent steps, and the execution order is not limited.

[0049] S408, the quantum signal generation module sends the quantum signal to the combiner.

[0050] Optionally, the quantum signal generation module sends the quantum signal to the combiner through an independent optical path, so that the combiner combines the quantum signal and the modulated synchronization signal on different wavelength channels to form a mixed signal that can be transmitted in a single optical fiber.

[0051] S409, the combiner combines the quantum signal and the modulated synchronization signal to obtain a mixed signal.

[0052] Optionally, the combiner integrates signals from different paths, receives the modulated synchronization signal on one hand and the quantum signal on the other hand, and combines the two signals of different wavelengths and different types into the same output port to form a mixed signal containing quantum information and classical information, realizing multi-signal co-fiber transmission.

[0053] S410, the combiner sends the mixed signal to the demultiplexer through a single transmission medium.

[0054] Optionally, the transmission medium is, for example, an optical fiber. After the combination of the combiner, the quantum signal and the modulated synchronization signal are combined into a mixed signal, and the combiner can send the mixed signal to the demultiplexer in the receiving device using a single optical fiber. In this way, this integrated transmission method saves optical fiber resources and improves system integration, and can be widely used in quantum key distribution systems and classical communication co-fiber systems.

[0055] S411, the demultiplexer performs demultiplexing processing on the mixed signal in the transmission medium to obtain the quantum signal and the modulated synchronization signal.

[0056] Optionally, at the receiving end, the demultiplexer separates the mixed signal in the transmission medium according to the wavelength, separates the quantum signal to a quantum channel, and separates the modulated synchronization signal to a classical channel. During the demultiplexing processing of the mixed signal, the demultiplexer can ensure that the two types of signals do not interfere with each other and enter their respective processing paths based on wavelength selectivity.

[0057] S412, the demultiplexer sends the quantum signal to the quantum signal recovery module.

[0058] Optionally, the demultiplexer sends the separated quantum signal to the quantum signal recovery module for subsequent quantum state measurement and decoding.

[0059] S413, the demultiplexer sends the modulated synchronization signal to the signal demodulation module.

[0060] Optionally, the demultiplexer sends the separated modulated synchronization signal to the signal demodulation module, so that the signal demodulation module analyzes the time structure and signal characteristics of the modulated synchronization signal to provide raw data for subsequent classical communication information demodulation.

[0061] S414, the signal demodulation module determines the pulse modulation information of the modulated synchronization signal, and demodulates the modulated synchronization signal according to the pulse modulation information to extract the classical communication information carried by the communication signal from the modulated synchronization signal.

[0062] Optionally, based on the above explanation and description of the signal demodulation module in the signal processing and encryption integrated system, two pulse modulation methods are provided in the present application, and correspondingly, two signal demodulation modules with different structures are provided to process the two pulse modulation methods respectively. One is that the signal demodulation module includes a first rising edge detector, a pulse width timer, a first threshold comparator and a first information decoder. In this case, the first rising edge detector in the signal demodulation module can detect the rising edge of each synchronization pulse, and in combination with the pulse width timer, the first threshold comparator and the first information decoder, the pulse width of each synchronization pulse is determined, and the pulse width is compared with the preset pulse width level by the first threshold comparator to determine the pulse width level and convert it into the original bit stream to recover the communication signal and obtain the classical communication information carried by the communication signal. Figure 5 As shown, the pulse width timer starts timing from the rising edge start time and stops at the falling edge end time to determine the pulse width, and then the first threshold comparator compares the obtained pulse width with the preset pulse width level to determine the pulse width level and convert it into the original bit stream to recover the communication signal and obtain the classical communication information carried by the communication signal. The other is that the signal demodulation module includes a second rising edge detector, an amplitude sampler, a gain compensation unit, a second threshold comparator and a second information decoder. In this case, the second rising edge detector in the signal demodulation module can detect the rising edge of each synchronization pulse, and when the rising edge is detected, the amplitude sampler is triggered to sample, the gain compensation unit normalizes the sampling value to obtain the normalized amplitude, and then the second threshold comparator compares the obtained normalized amplitude with the preset amplitude level to determine the amplitude level and convert it into the original bit stream to recover the communication signal and obtain the classical communication information carried by the communication signal.

[0063] S415, the quantum signal recovery module demodulates the quantum signal to obtain quantum information.

[0064] Optionally, the quantum signal recovery module detects and measures the quantum signal in a correct time window according to the time reference such as the transmission time slot obtained from the modulated synchronization signal. For example, the quantum signal recovery module selects a correct base for polarization or phase measurement according to the rising edge of each synchronization pulse in the modulated synchronization signal, and finally decodes the quantum information. In this way, the rising edge of the modulated synchronization signal is used as the reference to realize high-precision time synchronization, which ensures the accuracy of quantum state measurement.

[0065] Based on this, the signal-communication-security integrated processing method according to the embodiments of this application utilizes a synchronization signal as the carrier of classical communication information at the transmitting end. Pulse modulation is employed to modulate the synchronization signal, including pulse width modulation and pulse amplitude modulation, thereby embedding classical communication information into the synchronization pulse to obtain a modulated synchronization signal, avoiding the need to lay separate optical fibers for the classical channel. Simultaneously, the quantum signal and the modulated synchronization signal are combined and transmitted via wavelength division multiplexing (WDM), achieving dual-use on a single fiber and significantly saving optical fiber resources. At the receiving end, classical information is recovered by accurately demodulating the modulated synchronization signal, and quantum information is obtained by independently demodulating the quantum signal. Furthermore, the demodulation of quantum information and the demodulation of the modulated synchronization signal are isolated at both the physical and logical layers, preventing classical signals from interfering with the quantum state and ensuring the security of quantum communication. Since the modulated synchronization signal itself also functions as a timing reference, the synchronization accuracy and anti-interference capability of the signal-communication-security integrated processing system are further improved. Thus, by encoding classical communication information into the synchronization signal and transmitting it along with the quantum signal on a single optical fiber, this application effectively solves the problem of balancing the scarcity of optical fiber resources with the security of the integrated communication-security system.

[0066] Figure 6 A schematic flowchart of a synchronization signal modulation method provided in an embodiment of this application is shown. (Refer to...) Figure 6 As shown, in step S405 above, the synchronization signal modulation module receives the communication signal and performs pulse modulation on the synchronization signal according to the communication signal to encode the classical communication information carried by the communication signal into the synchronization signal, thereby obtaining the modulated synchronization signal. Specifically, this includes the following steps: S601, the synchronization signal modulation module receives the communication signal sent by the communication signal generation module, performs binary encoding on the classic communication information carried by the communication signal, and obtains the binary sequence corresponding to the classic communication information.

[0067] Optionally, the communication signal sent from the communication signal generation module to the synchronization signal modulation module is generally a modulated original communication signal, such as amplitude modulation, phase modulation, or frequency modulation. Therefore, after receiving the communication signal, the synchronization signal modulation module needs to rely on a corresponding demodulation method to extract the classical communication information. This demodulation method depends on whether the communication signal generation module used amplitude modulation to modulate the original communication signal. Specifically, if the original communication signal uses amplitude modulation, the synchronization signal modulation module can recover the classical communication information by detecting changes in the amplitude of the communication signal. If the original communication signal uses frequency modulation, the synchronization signal modulation module can recover the classical communication information by detecting changes in the frequency of the communication signal. If the original communication signal uses phase modulation, the synchronization signal modulation module can recover the classical communication information by detecting changes in the phase of the communication signal.

[0068] Optionally, if the extracted classical communication information is an analog signal, it is necessary to perform quantization, i.e., to map continuous signal values to a set of discrete values, and then to map the quantized result to a binary sequence according to a predetermined mapping rule, e.g., a certain voltage range corresponds to 0 or 1, so as to obtain the binary sequence corresponding to the classical communication information, for example, 10110001. In addition, in order to improve the data transmission efficiency or enhance the anti-interference ability, the received data can also be subjected to additional encoding operations, such as differential encoding, Manchester encoding, etc.

[0069] S602, determining pulse modulation information according to the binary sequence.

[0070] Optionally, the pulse modulation information is an encoding rule for mapping the binary sequence to physical pulse characteristics (width or amplitude), which determines which pulse width level or pulse amplitude level should be used to represent each data unit (such as an array), so as to realize reliable transmission of digital information on an analog pulse signal. The pulse modulation information includes pulse width modulation information or pulse amplitude modulation information, the pulse width modulation information is used to indicate the pulse width level corresponding to each array in the binary sequence, and the pulse amplitude modulation information is used to indicate the pulse amplitude level corresponding to each array in the binary sequence.

[0071] Optionally, in the case where the pulse modulation information is pulse width modulation information, the step S602 of determining the pulse modulation information according to the binary sequence includes: dividing the binary sequence to obtain a plurality of arrays, and determining the pulse width level corresponding to each array according to a first mapping relationship.

[0072] Exemplarily, in the embodiments of the present application, the binary sequence can be divided into arrays of 2 bits each. Taking the above binary sequence 10110001 as an example, the entire binary sequence is divided into four arrays of 10, 11, 00 and 01 according to every 2 bits. On this basis, the pulse width level corresponding to each array can be further determined according to the first mapping relationship.

[0073] Exemplarily, the first mapping relationship is used to indicate the correspondence between the array and the pulse width level, and the first mapping relationship can be specifically shown in Table 1 as follows: Table 1: First mapping relationship

[0074] It is worth mentioning that, since the period of the quantum signal is 10 μs, it is necessary to ensure that the pulse width modulation signal matches the basic order of the quantum signal, that is, one or more pulses can be placed in each 10 μs period, and the total width does not exceed 10 μs. For example, in the first 10 μs period, a 6 μs pulse can be placed, in the second 10 μs period, an 8 μs pulse can be placed, and so on.

[0075] Further, according to the first mapping relationship shown in Table 1, a corresponding pulse width modulation signal can be generated, which is a series of pulses with different widths, that is, a form of modulated synchronization signal. Based on this, by dividing the binary sequence and applying the first mapping relationship, the classical communication information can be efficiently encoded into the pulse width, realizing the synchronous transmission with the quantum signal, so as to not only improve the data transmission efficiency, but also guarantee the independence and integrity of the classical information and the quantum information.

[0076] Optionally, in the case where the pulse modulation information is pulse amplitude modulation information, the step S602 of determining the pulse modulation information according to the binary sequence comprises: dividing the binary sequence to obtain a plurality of arrays, and determining the pulse amplitude level corresponding to each array according to a second mapping relationship.

[0077] Exemplarily, in the embodiment of the present application, the binary sequence can be divided into 2 bits per array. Continuing the above example of the binary sequence 10110001, the entire binary sequence is divided into 10, 11, 00, and 01 according to every 2 bits. On this basis, the pulse amplitude level corresponding to each array can be further determined according to the second mapping relationship.

[0078] Exemplarily, the second mapping relationship is used to indicate the correspondence between the array and the pulse amplitude level, and the second mapping relationship can be shown in Table 2 as follows: Table 2 Second mapping relationship table

[0079] It is worth mentioning that the range of pulse amplitude level should be controlled within the threshold value that does not cause crosstalk to the quantum signal, while ensuring that it is in the linear working interval of the classical channel, so as to guarantee the demodulation stability.

[0080] Further, according to the second mapping relationship shown in Table 2, a corresponding pulse amplitude modulation signal can be generated, which is a series of pulses with different widths, that is, another form of the modulated synchronization signal. Based on this, by dividing the binary sequence and applying the second mapping relationship, the classical communication information can be efficiently encoded into the pulse amplitude, realizing the synchronous transmission with the quantum signal, so as to not only improve the data transmission efficiency, but also ensure the independence and integrity of the classical information and the quantum information.

[0081] S603, pulse modulating the synchronization signal according to the pulse modulation information to obtain a modulated synchronization signal.

[0082] Optionally, in the case where the pulse modulation information is pulse amplitude modulation information, the step S603 of pulse modulating the synchronization signal according to the pulse modulation information to obtain a modulated synchronization signal comprises: determining pulse modulation amplitudes of each synchronization pulse in the synchronization signal according to the pulse amplitude levels corresponding to each group, and pulse amplitude modulating the synchronization signal according to the pulse modulation amplitudes of each synchronization pulse to obtain the modulated synchronization signal.

[0083] For example, as shown in Table 2, the original synchronization signal is a series of rectangular pulses with equal width and equal period. After pulse amplitude modulation, the pulse amplitude changes, while the width and period of the pulse remain unchanged. In this way, the classical communication information can be encoded by changing the pulse amplitude of the synchronization signal. Figure 7

[0084] For example, based on the second mapping relationship shown in Table 2, the pulse amplitude levels corresponding to each group can be determined, that is, each binary group will be converted into a specific pulse amplitude value. For example, the group 00 corresponds to the minimum amplitude level of 50mV, while the group 11 corresponds to the maximum amplitude level of 200mV. Further, according to the determined pulse amplitude level, each synchronization pulse in the synchronization signal is assigned a corresponding pulse modulation amplitude, that is, the amplitude of each synchronization pulse is set to the value specified by its corresponding pulse amplitude level, so as to ensure that each synchronization pulse carries specific information. Finally, according to the pulse modulation amplitudes of each synchronization pulse, the pulse amplitude modulation is performed on the synchronization signal, that is, the information is encoded by changing the amplitude of each pulse in the synchronization signal, so as to obtain the modulated synchronization signal, which not only contains the original synchronization function, but also carries additional information encoding.

[0085] ​Optionally, in the case that the pulse modulation information is pulse width modulation information, the step S603 of pulse-modulating the synchronization signal according to the pulse modulation information to obtain the modulated synchronization signal comprises: determining pulse modulation widths of the synchronization pulses in the synchronization signal according to the pulse width levels corresponding to the groups, and pulse width-modulating the synchronization signal according to the pulse modulation widths of the synchronization pulses to obtain the modulated synchronization signal.

[0086] For example, referring to FIG. 3, the original synchronization signal is also a series of rectangular pulses with equal width and equal period. However, after pulse amplitude modulation, the pulse width changes, while the pulse amplitude and period remain unchanged. In this way, the classical communication information can be encoded by changing the pulse width of the synchronization signal. Figure 8 For example, referring to FIG. 3, the original synchronization signal is also a series of rectangular pulses with equal width and equal period. However, after pulse amplitude modulation, the pulse width changes, while the pulse amplitude and period remain unchanged. In this way, the classical communication information can be encoded by changing the pulse width of the synchronization signal.

[0087] For example, based on the first mapping relationship shown in Table 1, the pulse width levels corresponding to the groups can be determined, that is, each binary group will be converted to a specific pulse width value. For example, the group 00 corresponds to the minimum width level of 2 μs, and the group 11 corresponds to the maximum width level of 8 μs. Further, according to the determined pulse width levels, each synchronization pulse in the synchronization signal is assigned a corresponding pulse modulation width, that is, the width of each synchronization pulse is set to the value specified by its corresponding pulse width level, so as to ensure that each synchronization pulse carries specific information. Finally, pulse width modulation is performed on the synchronization signal according to the pulse modulation widths of the synchronization pulses, that is, the information is encoded by changing the width of each pulse in the synchronization signal, so as to obtain the modulated synchronization signal, which contains the original synchronization function and carries additional information encoding.

[0088] It should be noted that in the above process, in view of the pulse width drift caused by channel noise, a method allowing a certain amount of error is used to enhance the robustness of the system. For example, if the preset pulse width is 6 μs and an error of ± 0.5 μs is allowed, then the actual received pulse width between 5.5 μs and 6.5 μs is still considered to belong to the same pulse width level, thereby effectively reducing the influence of noise on signal decoding. It should be understood that the above error processing method can also be applied to pulse amplitude, which will not be described here.

[0089] Based on this, by dividing the binary sequence into an array and converting it into a corresponding pulse level according to a preset mapping relationship, the synchronous signal is then pulse-modulated, realizing efficient and reliable encoding and transmission of classical communication information on the synchronous signal. Correspondingly, when demodulating, the measured pulse amplitude can be compared with the preset level, and an allowed error tolerance can be introduced, effectively improving the tolerance to channel noise, signal attenuation and timing jitter, avoiding misjudgment due to slight fluctuations, thereby significantly enhancing the stability and demodulation accuracy of signal recognition.

[0090] As a possible implementation manner, the step S407 of generating a quantum signal according to the signal parameter of the modulated synchronous signal includes: determining a sending time slot of the modulated synchronous signal, and generating a quantum signal in the sending time slot.

[0091] Exemplarily, the quantum signal generation module can detect the rising edge of each synchronous pulse in the modulated synchronous signal through a high-speed comparator to determine the accurate time position of the sending time slot. For example, if the modulated synchronous signal sends a pulse every 1 ms, the rising edge of each pulse is a sending time slot, and the quantum signal will be triggered to be generated at the rising edge.

[0092] Exemplarily, the quantum signal is usually a photon that encodes quantum information, that is, quantum state encoding needs to be performed while generating the photon. Common encoding methods include polarization encoding, phase encoding, time encoding, etc. The quantum signal generation module can include a time controller inside, which can generate a controllable trigger signal according to the rising edge of the synchronous pulse in the modulated synchronous signal to ensure that the quantum signal is generated in the correct time window.

[0093] Based on this, the modulated synchronous signal includes multiple synchronous pulses, and the rising edge start time corresponding to the rising edge of each synchronous pulse can be used as a sending time slot. The sending time slot indicates when the quantum signal should be generated as a time marker, and the quantum signal generation module accurately generates a quantum state at the corresponding time by recognizing the sending time slot, thereby ensuring that the quantum signal and the synchronous signal are strictly aligned in time.

[0094] Figure 9 A flowchart of a signal demodulation method provided by an embodiment of the application is shown. Referring to Figure 9 As shown in the figure, the step S414 of determining the pulse modulation information of the modulated synchronous signal and demodulating the modulated synchronous signal according to the pulse modulation information to extract the classical communication information carried by the communication signal from the modulated synchronous signal includes the following steps: S901, the first rising edge detector detects the rising edge of each synchronization pulse in the modulated synchronization signal, and for each synchronization pulse, when the rising edge of the synchronization pulse is detected, the pulse width timer is triggered to start timing to determine the pulse width of the synchronization pulse.

[0095] Exemplarily, referring to FIG. 1, Figure 5 As shown, the pulse width specifically represents the time interval from the rising edge starting time to the falling edge starting time of the synchronization pulse, that is, the high level duration, and the modulated synchronization signal includes a plurality of synchronization pulses.

[0096] Exemplarily, the first rising edge detector is responsible for accurately identifying the starting time of each synchronization pulse in the modulated synchronization signal. When the rising edge of a certain pulse signal is detected, the pulse width timer is triggered to start timing. The pulse width timer continues to run until the pulse falls to the low level, thereby accurately measuring the pulse width of the pulse. Since the modulated synchronization signal contains a plurality of pulses arranged in cycles, the width of each pulse has been encoded by the sending end according to the classical communication information, such as different widths representing different bit combinations, and the cooperation of the first rising edge detector and the pulse width timer realizes the key modulation feature of extracting the pulse width parameter from the physical signal, laying a foundation for the subsequent restoration of the classical communication information.

[0097] S902, the first threshold comparator compares the pulse width of each synchronization pulse with a preset pulse width level to determine the pulse width level to which the pulse width of the synchronization pulse belongs.

[0098] Exemplarily, the first threshold comparator receives the actual pulse width of each synchronization pulse measured by the pulse width timer, and compares it with the preset pulse width level. The preset width level is a discretization standard value agreed upon by the sending device and the receiving device in advance, and the first threshold comparator classifies the measured pulse width into the closest pulse width level by setting a reasonable judgment interval, such as allowing a tolerance of ±0.5 μs, to determine the logic symbol represented by the pulse. In this way, not only is the conversion from continuous physical quantity to discrete digital state realized, but also the slight drift of pulse width caused by jitter, attenuation or interference in the channel transmission process is effectively suppressed, improving the robustness and decision accuracy of the signal processing system.

[0099] S903, the first information decoder demodulates each synchronization pulse according to the pulse width level to which the pulse width of each synchronization pulse belongs, to extract the classical communication information carried by the communication signal from the modulated synchronization signal.

[0100] Exemplarily, the first information decoder decodes in reverse according to the first mapping relationship in light of the pulse width level to which each pulse belongs determined as aforementioned. For example, if the pulse width level to which a pulse belongs is determined as 6μs, the first information decoder outputs the corresponding binary number 10, if the pulse width level to which a pulse belongs is determined as 8μs, the first information decoder outputs the corresponding binary number 11, and so on. By decoding all the pulses one by one and splicing in time sequence, the complete original binary sequence, i.e. the classical communication information carried by the communication signal, is finally restored.

[0101] Based on this, the application utilizes the rising edge trigger timing to guarantee the accuracy of time measurement, and combines the threshold comparison with tolerance to effectively resist channel noise and timing jitter, and through the decoding of the preset mapping relationship, the unambiguous restoration of the classical communication information is ensured. In this way, not only the transmission stability of the classical communication information in complex environment is improved, but also the resource efficient multiplexing and time accurate synchronization when co-fiber transmission with quantum signals are realized.

[0102] Figure 10 A flowchart of another signal demodulation method provided by an embodiment of the application is shown. Referring to FIG. 13, the signal demodulation method comprises the following steps: Figure 10 As shown in FIG. 13, the step S414 of the signal demodulation module determines the pulse modulation information of the modulated synchronization signal, and demodulates the modulated synchronization signal according to the pulse modulation information to extract the classical communication information carried by the communication signal from the modulated synchronization signal, which specifically comprises the following steps: S1001, the second rising edge detector detects the rising edge of each synchronization pulse in the modulated synchronization signal, and for each synchronization pulse, the amplitude sampler is triggered to start sampling when the rising edge of the synchronization pulse is detected, to obtain the sampling amplitude of the synchronization pulse.

[0103] Exemplarily, the second rising edge detector is responsible for accurately identifying the starting time of each synchronization pulse in the modulated synchronization signal, and once the rising edge is detected, the amplitude sampler is triggered to sample the amplitude of the current pulse immediately, to ensure that the most stable amplitude value is obtained. It is worth noting that since the modulated synchronization signal is pulse amplitude modulated, the amplitude of each pulse has been encoded into different levels to represent specific binary information, so accurate detection of the rising edge and timely sampling are prerequisites for correct information restoration.

[0104] S1002, the gain compensation unit normalizes the sampling amplitudes of the synchronization pulses to obtain the compensated pulse amplitudes of the synchronization pulses.

[0105] Exemplarily, the gain compensation unit normalizes the sampling amplitudes of the received synchronization pulses to eliminate overall amplitude variations caused by channel attenuation, temperature drift, or light source fluctuation, etc. during transmission. Specifically, the gain compensation unit can scale the measured amplitudes by introducing a reference signal, such as a pilot pulse in the modulated synchronization signal or a historical average value, to restore the compensated pulse amplitudes within a standard range, thereby realizing the normalization of the sampling amplitudes. It is worth noting that the normalization process not only ensures that the signal amplitudes in different time periods and different environments can still accurately correspond to the preset levels, but also significantly improves the stability and demodulation reliability of the system under dynamic channel conditions.

[0106] S1003, the second threshold comparator compares the compensated pulse amplitude of each synchronization pulse with the preset pulse amplitude level to determine the pulse amplitude level to which the compensated pulse amplitude of the synchronization pulse belongs.

[0107] Exemplarily, the second threshold comparator compares the compensated pulse amplitudes with the preset pulse amplitude levels to determine the pulse amplitude level to which each pulse amplitude belongs. Further, the second threshold comparator determines the symbol represented by the pulse according to the pulse amplitude level to which the compensated amplitude value belongs. This process allows a certain tolerance range to prevent false judgments caused by minor fluctuations.

[0108] S1004, the second information decoder demodulates each synchronization pulse according to the pulse amplitude level to which the compensated pulse amplitude of each synchronization pulse belongs, to extract the classical communication information carried by the communication signal from the modulated synchronization signal.

[0109] Exemplarily, the second information decoder decodes in reverse according to the predetermined second mapping relationship according to the pulse amplitude level to which each pulse belongs. For example, if the pulse amplitude level to which a pulse belongs is determined to be 50 mA, the first information decoder outputs the corresponding binary sequence 00, if the pulse amplitude level to which a pulse belongs is determined to be 150 mA, the first information decoder outputs the corresponding binary sequence 10, and so on. By decoding all pulses in time sequence and splicing them into a complete binary sequence, i.e. the classical communication information carried by the original communication signal.

[0110] Based on this, the present application uses rising edge detection to ensure accurate sampling timing, and effectively eliminates amplitude drift caused by channel attenuation through gain compensation, and improves noise immunity through threshold comparison combined with a tolerance mechanism, and finally maps and decodes to restore the classical communication information. In this way, not only does it support multi-level modulation to improve data transmission efficiency, but it also significantly enhances the adaptability and stability of the system in long-distance, variable-loss environments.

[0111] As a possible implementation, the step S415 of recovering the quantum signal by the quantum signal recovery module to obtain quantum information comprises: the quantum signal recovery module demodulates the quantum signal according to the sending time slot of the modulated synchronization signal to obtain the quantum information.

[0112] Exemplarily, the modulated synchronization signal is a pulse sequence containing multiple synchronization pulses, and the sending time slot of the modulated synchronization signal refers to the time point corresponding to the rising edge of the synchronization pulse, in combination with Figure 7 and Figure 8 As shown in FIGS. 1, 2 and 3, each synchronization pulse in the pulse sequence has a distinct rising edge, and the time point corresponding to the rising edge start time can be used as a time reference point to represent the sending time slot. In the embodiment of the present application, the quantum signal recovery module demodulates the quantum signal according to the sending time slot of the modulated synchronization signal, that is, the rising edge start time of the synchronization pulse is used as the time reference point, and the rising edge is distinguished to ensure that the rising edge of the synchronization pulse in the modulated synchronization signal is used as the quantum state marking reference, thereby ensuring the synchronization reference of the quantum signal.

[0113] Exemplarily, the first rising edge detector detects the rising edge of each synchronization pulse in the modulated synchronization signal and sends the rising edge start time corresponding to the rising edge of the synchronization pulse to the quantum signal recovery module as the sending time slot. After receiving the quantum signal, the quantum signal recovery module performs time alignment using the rising edge of each synchronization pulse in the pulse sequence of the modulated synchronization signal. For example, when detecting a rising edge, the quantum signal recovery module aligns the internal clock with the rising edge, ensuring that the subsequent quantum signal demodulation operation can be performed in the correct time window, thereby effectively eliminating the influence of clock drift and transmission delay.

[0114] Further, after completing the time alignment, the quantum signal recovery module starts to demodulate the quantum signal, captures the quantum signal in a predetermined time window after the rising edge of each synchronization pulse and performs corresponding decoding operations. For example, if the quantum signal uses phase encoding, the quantum signal recovery module detects the phase state of the photon at a specific time point after each rising edge to recover the carried quantum information. If the quantum signal uses polarization encoding, the quantum signal recovery module detects the polarization direction of the photon at the time point corresponding to each rising edge to decode the quantum information.

[0115] Based on this, the embodiment of the present application provides a method for assisting quantum signal demodulation by modulating the rising edge of the post-synchronization signal. The quantum signal recovery module uses the rising edge of each synchronization pulse in the modulated post-synchronization signal as a time reference to ensure that the quantum signal is demodulated and read at the correct time point. Wherein, the modulated post-synchronization signal is composed of multiple synchronization pulses, and the rising edge of each synchronization pulse marks a specific time point, which is used to mark the quantum state, thereby ensuring that the demodulation process of the quantum signal is strictly synchronized with the sending end. In this way, the demodulation error caused by clock drift or transmission delay is avoided, the accurate recovery of quantum information is ensured, the reliability of quantum communication is improved, and effective technical support is provided for quantum information transmission in complex environments.

[0116] The embodiment of the present application also provides a computer readable storage medium, and the computer readable storage medium stores a computer program. When the computer program is run by a processor, the method steps in the signal processing method are executed.

[0117] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described system and device can refer to the corresponding process in the method embodiment, and will not be repeated in the present application. In the several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. The above-described device embodiments are only schematic, for example, the division of the modules is only a logical function division, and in actual implementation, there can be another division manner, for example, a plurality of modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed mutual elements can be indirect coupling or communication connection through some communication interface, device or module, which can be electrical, mechanical or other forms.

[0118] In addition, each function unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. When the functions are realized in the form of software function units and sold or used as an independent product, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0119] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application.

Claims

1. A signal transmission and encryption integrated processing method, characterized in that, The method is applied to a transmitting device, the transmitting device comprising: a synchronization signal generation module, a synchronization signal modulation module, a quantum signal generation module, and a combiner, the method comprising: The synchronization signal generation module generates a synchronization signal and sends the synchronization signal to the synchronization signal modulation module; The synchronization signal modulation module receives the communication signal and performs pulse modulation on the synchronization signal according to the communication signal to encode the classical communication information carried by the communication signal into the synchronization signal to obtain the modulated synchronization signal. The synchronization signal modulation module sends the modulated synchronization signal to the multiplexer. The quantum signal generation module generates a quantum signal based on the signal parameters of the modulated synchronization signal, and sends the quantum signal to the multiplexer; The multiplexer performs multiplexing on the quantum signal and the modulated synchronization signal to obtain a mixed signal, and then transmits the mixed signal to the receiving device through a single transmission medium.

2. The method according to claim 1, characterized in that, The transmitting device further includes: a communication signal generation module; The communication signal generation module generates the communication signal and sends the communication signal to the synchronization signal modulation module; The synchronization signal modulation module receives a communication signal and performs pulse modulation on the synchronization signal according to the communication signal to encode the classical communication information carried by the communication signal into the synchronization signal, thereby obtaining a modulated synchronization signal, including: The synchronization signal modulation module receives the communication signal sent by the communication signal generation module, performs binary encoding on the classic communication information carried by the communication signal, and obtains the binary sequence corresponding to the classic communication information; Based on the binary sequence, pulse modulation information is determined, which includes pulse width modulation information or pulse amplitude modulation information. The pulse width modulation information is used to indicate the pulse width level corresponding to each array in the binary sequence, and the pulse amplitude modulation information is used to indicate the pulse amplitude level corresponding to each array in the binary sequence. The synchronization signal is pulse-modulated according to the pulse modulation information to obtain the modulated synchronization signal.

3. The method according to claim 2, characterized in that, Determining the pulse modulation information based on the binary sequence includes: The binary sequence is divided into multiple arrays; The pulse width level corresponding to each array is determined according to the first mapping relationship, which is used to indicate the correspondence between the array and the pulse width level; The step of pulse modulating the synchronization signal according to the pulse modulation information to obtain the modulated synchronization signal includes: The pulse modulation width of each synchronization pulse in the synchronization signal is determined based on the pulse width level corresponding to each array. The synchronization signal is pulse-width modulated according to the pulse modulation width of each synchronization pulse to obtain the modulated synchronization signal.

4. The method according to claim 2, characterized in that, Determining the pulse modulation information based on the binary sequence includes: The binary sequence is divided into multiple arrays; The pulse amplitude level corresponding to each array is determined according to the second mapping relationship, which is used to indicate the correspondence between the array and the pulse amplitude level; The step of pulse modulating the synchronization signal according to the pulse modulation information to obtain the modulated synchronization signal includes: The pulse modulation amplitude of each synchronization pulse in the synchronization signal is determined based on the pulse amplitude level corresponding to each array. The synchronization signal is pulse amplitude modulated according to the pulse modulation amplitude of each synchronization pulse to obtain the modulated synchronization signal.

5. The method according to claim 1, characterized in that, The quantum signal generation module generates a quantum signal based on the signal parameters of the modulated synchronization signal, including: The quantum signal generation module determines the transmission time slot of the modulated synchronization signal; The quantum signal generation module generates the quantum signal during the transmission time slot.

6. A signal transmission and encryption integrated processing method, characterized in that, The method is applied to a receiving device, which includes a wavelength division multiplexer (WDM), a quantum signal recovery module, and a signal demodulation module. The wavelength divider performs wavelength division processing on the mixed signal in the transmission medium to obtain a quantum signal and a modulated synchronization signal, and sends the quantum signal to the quantum signal recovery module and the modulated synchronization signal to the signal demodulation module. The signal demodulation module determines the pulse modulation information of the modulated synchronization signal and demodulates the modulated synchronization signal according to the pulse modulation information to extract the classical communication information carried by the communication signal from the modulated synchronization signal. The quantum signal recovery module demodulates the quantum signal to obtain quantum information.

7. The method according to claim 6, characterized in that, The signal demodulation module includes: a first rising edge detector, a pulse width timer, a first threshold comparator, and a first information decoder; The signal demodulation module determines the pulse modulation information of the modulated synchronization signal and demodulates the modulated synchronization signal according to the pulse modulation information to extract the classical communication information carried by the communication signal from the modulated synchronization signal, including: The first rising edge detector detects the rising edge of each synchronization pulse in the modulated synchronization signal, and for each synchronization pulse, when the rising edge of the synchronization pulse is detected, the pulse width timer is triggered to start timing to determine the pulse width of the synchronization pulse. The pulse width represents the time interval from the rising edge to the falling edge of the synchronization pulse. The modulated synchronization signal includes multiple synchronization pulses. The first threshold comparator compares the pulse width of each synchronization pulse with a preset pulse width level to determine the pulse width level to which the pulse width of the synchronization pulse belongs. The first information decoder demodulates each synchronization pulse according to the pulse width level to which the pulse width of each synchronization pulse belongs, so as to extract the classic communication information carried by the communication signal from the modulated synchronization signal.

8. The method according to claim 6, characterized in that, The signal demodulation module includes: a second rising edge detector, an amplitude sampler, a gain compensation unit, a second threshold comparator, and a second information decoder; The signal demodulation module determines the pulse modulation information of the modulated synchronization signal and demodulates the modulated synchronization signal according to the pulse modulation information to extract the classical communication information carried by the communication signal from the modulated synchronization signal, including: The second rising edge detector detects the rising edge of each synchronization pulse in the modulated synchronization signal, and for each synchronization pulse, when the rising edge of the synchronization pulse is detected, the amplitude sampler is triggered to start sampling to obtain the sampling amplitude of the synchronization pulse; The gain compensation unit normalizes the sampling amplitude of each synchronization pulse to obtain the compensated pulse amplitude of each synchronization pulse. The second threshold comparator compares the compensated pulse amplitude of each synchronization pulse with a preset pulse amplitude level to determine the pulse amplitude level to which the compensated pulse amplitude of the synchronization pulse belongs. The second information decoder demodulates each synchronization pulse according to the pulse amplitude level to which the compensated pulse amplitude of each synchronization pulse belongs, so as to extract the classic communication information carried by the communication signal from the modulated synchronization signal.

9. The method according to claim 6, characterized in that, The quantum signal recovery module demodulates the quantum signal to obtain quantum information, including: The quantum signal recovery module demodulates the quantum signal according to the transmission time slot of the modulated synchronization signal to obtain the quantum information.

10. A transmitting device, characterized in that, include: Synchronization signal generation module, synchronization signal modulation module, quantum signal generation module, and combiner; The transmitting device is used to perform the steps in the integrated signal transmission and confidentiality processing method according to any one of claims 1-5 to transmit signals.

11. A receiving device, characterized in that, include: Wavelength divider, quantum signal recovery module, and signal demodulation module; The receiving device is used to perform the steps of the integrated signal transmission and confidentiality processing method according to any one of claims 6-9 to receive signals.

12. A signal transmission and encryption integrated processing system, characterized in that, include: The transmitting device of claim 10 and the receiving device of claim 11.

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