Chaotic module link delay test system and method

Abstract

The present application relates to information technology. The present application aims to solve the problem that the time delay mismatch cannot be accurately measured in the current chaotic module link system, and provides a chaotic module link time delay test system and method. The technical scheme can be summarized as follows: a continuous laser is used as a test carrier, and the test carrier is split into two parts, one of which is output to the chaotic module link system to be tested; the other test carrier is mixed with the output of the chaotic decryption device of the chaotic module link system to be tested to realize self-heterodyne detection, obtain mixed light field, and output Q component signal after photoelectric conversion of the mixed light field; the input Q component signal is high-speed sampled, and Q component digital signal is calculated, and autocorrelation operation is performed on the Q component digital signal to obtain a correlation curve, and then the time delay corresponding to the second peak is calculated according to the correlation curve to obtain the measured time delay mismatch Δt. The present application has the beneficial effect that the measured time delay mismatch Δt can be quickly and accurately calculated, and is suitable for chaotic module link systems.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of information technology, in particular to a chaotic module link delay test system and method. BACKGROUND

[0002] In a chaotic module link system, generally includes a service carrier input end, an encryption link, a decryption link and a chaotic decryption device, the service carrier input end is connected with the output end of the encryption link and the input end of the decryption link respectively, and the output end of the encryption link and the output end of the decryption link are connected with the input end of the chaotic decryption device respectively. When in use, the time delay of chaotic phase scrambling and descrambling operation applied to the service carrier needs to be strictly controlled, so that the chaotic scrambled service carrier is transmitted to the chaotic decryption device, and the synchronous chaotic descrambling signal is also transmitted to the chaotic decryption device at the same time. The transmission time delay of the two needs to be accurately aligned, and the time delay error should be less than ~ 10 ps. After a new chaotic module system is built, in order to realize accurate time delay matching of chaotic phase scrambling and descrambling operation applied to the service carrier, it is necessary to accurately measure the time delay mismatch Δt of the two. In the prior art, when calculating the time delay mismatch Δt, the delay of each optical device or electrical device is measured separately, and then the accumulated delay of the corresponding optical path is calculated, and finally the time delay mismatch Δt is estimated by comparing the accumulated delay of the two optical paths. However, since the delay of the optical-electrical conversion device involved cannot be accurately measured, and the error of the delay of each device is also accumulated, the existing scheme for estimating the time delay mismatch Δt is time-consuming and has low measurement accuracy (about 1-10 ns).

[0003] Therefore, the time delay mismatch Δt in the chaotic module link system cannot be accurately and quickly measured in the prior art. SUMMARY

[0004] The purpose of the present application is to solve the problem that the time delay mismatch Δt in the chaotic module link system cannot be accurately measured at present, and a chaotic module link delay test system and method are provided.

[0005] The technical scheme adopted by the present application to solve the above technical problem provides a chaotic module link delay test system in the first aspect, which comprises a laser beam splitting module, a balanced coherent receiving module and a sampling analysis module. The first output end of the laser beam splitting module is used to connect with the service carrier input end of the chaotic module link system to be measured. The second output end of the laser beam splitting module is connected with the second input end of the balanced coherent receiving module. The first input end of the balanced coherent receiving module is connected with the output end of the chaotic decryption device of the chaotic module link system to be measured. The Q component output end of the balanced coherent receiving module is connected with the input end of the sampling analysis module.

[0006] The laser beam splitting module has an input end for inputting a continuous laser as a test carrier and splitting the test carrier and outputting the test carrier through the first output end and the second output end respectively after splitting;

[0007] The balanced coherent receiving module is configured to perform 90° mixing of the test carrier and an output of a chaotic decryption device of a chaotic module link system under test to realize self-zero difference coherent detection, obtain mixed light field, and output a Q component signal after photoelectric conversion of the mixed light field.

[0008] The sampling and analyzing module is configured to perform high-speed sampling on the input Q component signal, calculate a Q component digital signal, perform autocorrelation operation on the Q component digital signal, obtain a correlation curve, calculate a time delay corresponding to a secondary peak according to the correlation curve, and obtain a measured time delay mismatch Δt.

[0009] Specifically, the sampling and analyzing module includes a high-speed sampling unit and a digital processing unit, an input end of the high-speed sampling unit is connected with a Q component output end of the balanced coherent receiving module, and an output end of the high-speed sampling unit is connected with the digital processing unit.

[0010] The high-speed sampling unit is configured to perform high-speed sampling on the Q component signal output by the Q component output end of the balanced coherent receiving module to obtain a Q component sampling signal.

[0011] The digital processing unit is configured to calculate a Q component digital signal according to the Q component sampling signal obtained by the high-speed sampling, perform autocorrelation operation on the Q component digital signal, obtain a correlation curve, calculate a time delay corresponding to a secondary peak according to the correlation curve, and obtain a measured time delay mismatch Δt.

[0012] Further, the Q component output end of the balanced coherent receiving module includes a Q p output end and a Q n output end, the Q p output end is configured to output an electrical signal corresponding to the Q p light field, denoted as Q p (t), and the Q n output end is configured to output an electrical signal corresponding to the Q n light field, denoted as Q n (t).

[0013] Specifically, the first input end of the balanced coherent receiving module is a signal light port, and the second input end of the balanced coherent receiving module is a local oscillator light port; or, the first input end of the balanced coherent receiving module is a local oscillator light port, and the second input end of the balanced coherent receiving module is a signal light port.

[0014] Further,

[0015] The calculation method of the Q-component digital signal is:

[0016] Q(t) = Q p (t) - Q n (t)

[0017] Q(t) represents the Q-component digital signal.

[0018] The technical solution adopted by the present application to solve the above technical problems comprises the following steps:

[0019] A continuous laser is selected as a test carrier, and the test carrier is split into two paths, one of which is output to the measured chaotic module link system;

[0020] The other path of the test carrier is mixed with the output of the chaotic decryption device of the measured chaotic module link system by 90° to realize self-heterodyne detection, and a mixed light field is obtained, and a Q-component signal is output after photoelectric conversion of the mixed light field;

[0021] The input Q-component signal is high-speed sampled, and a Q-component digital signal is calculated, and autocorrelation operation is performed on the Q-component digital signal to obtain a correlation curve, and the time delay corresponding to the secondary peak is calculated according to the correlation curve to obtain the measured time delay mismatch Δt.

[0022] Specifically, the 90° mixing comprises:

[0023] The output of the chaotic decryption device of the measured chaotic module link system is phase-shifted by kπ+π / 2, and then mixed with the test carrier for self-heterodyne mixing, wherein k is an integer.

[0024] Further, the calculation method of the Q-component digital signal is:

[0025] Q(t) = Q p (t) - Q n (t)

[0026] Here, Q(t) represents the Q-component digital signal, Q p (t) refers to the electrical signal corresponding to the Q p light field in the Q-component signal, and Q n (t) represents the electrical signal corresponding to the Q n light field in the Q-component signal.

[0027] The beneficial effect of the present application is that in the scheme of the present application, a known continuous laser is input as a test carrier in the chaotic module link system to be tested, and the test carrier is mixed with the output of the chaotic decryption device of the chaotic module link system to be tested to realize self-homodyne coherent detection, obtain a mixed light field, and output a Q component signal after photoelectric conversion of the mixed light field; the input Q component signal is high-speed sampled, and a Q component digital signal is obtained by calculation, and the Q component digital signal is subjected to autocorrelation operation to obtain a correlation curve, and the time delay corresponding to the secondary peak is calculated according to the correlation curve to obtain the measured time delay mismatch Δt. It can be seen that the whole scheme is simple and easy to implement, and the measured time delay mismatch Δt calculated is relatively accurate, which can reach the order of ~ 10 ps, and provides corresponding time delay mismatch Δt data for subsequent adjustment of the time delay mismatch Δt of the chaotic module link system to be tested. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a schematic system block diagram of the chaotic module link delay test system provided by the first aspect of the present application after being connected with the chaotic module link system to be tested. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application. In the following description, specific details such as specific system structures, technologies, etc. are proposed for the purpose of explanation rather than limitation, so as to thoroughly understand the embodiments of the present application. However, it should be clear to those skilled in the art that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits and methods are omitted to avoid unnecessary details that hinder the description of the present application.

[0030] It should be understood that when used in the specification and the appended claims of the present application, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or sets thereof.

[0031] It should also be understood that the term "and / or" used in the specification and the appended claims of the present application means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0032] As used in the description of the application and the appended claims, the term "if' can be interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [a described condition or event] is detected" can be interpreted to mean "upon determining" or "in response to determining" or "upon detecting [the described condition or event]" or "in response to detecting [the described condition or event]," depending on the context.

[0033] In addition, the terms "first", "second", "third", etc. as used in the description of the application and the appended claims are merely used to differentiate descriptions and cannot be understood as indicating or implying relative importance.

[0034] Reference in the specification to "one embodiment" or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase "in one embodiment", "in some embodiments", "in other embodiments", "in additional embodiments", etc. in various places in the specification are not necessarily all referring to the same embodiment, although it can. The terms "comprising", "including", "having" and their variants are meant to be construed as "including but not limited to", unless otherwise indicated.

[0035] Figure 1 A schematic system block diagram of the chaotic module link delay test system provided by the first aspect of the embodiments of the application connected with the measured chaotic module link system is shown, as an example but not limitation, the chaotic module link delay test system includes a laser beam splitting module, a balanced coherent receiving module and a sampling analysis module, wherein the first output end of the laser beam splitting module is used to connect with the business carrier input end of the measured chaotic module link system, the second output end of the laser beam splitting module is connected with the second input end of the balanced coherent receiving module, the first input end of the balanced coherent receiving module is connected with the output end of the chaotic decryption device of the measured chaotic module link system, and the Q component output end of the balanced coherent receiving module is connected with the input end of the sampling analysis module.

[0036] Here, the laser beam splitting module, the input end of which is used to input a continuous laser as a test carrier, and the test carrier is split and output through the first output end and the second output end respectively.

[0037] The balanced coherent receiving module is used to perform 90° mixing of the test carrier and the output of the chaotic decryption device of the measured chaotic module link system to realize self-zero difference coherent detection, and obtain a mixed light field, and output a Q component signal after photoelectric conversion of the mixed light field.

[0038] a sampling analysis module, configured to sample the input Q component signal at a high speed, calculate a Q component digital signal, perform autocorrelation operation on the Q component digital signal, obtain a correlation curve, calculate a time delay corresponding to a secondary peak of the correlation curve, and obtain the measured time delay mismatch Δt.

[0039] It can be understood that, in the chaotic module link delay test system, a known continuous laser is used as a test carrier, the laser beam splitting module is used to split the test carrier, one of the split test carriers is input to the chaotic module link system to be measured, and the test carrier is output to the chaotic decryption device after being scrambled by the encryption link and the decryption link. The test carrier and the output of the chaotic decryption device of the chaotic module link system to be measured are mixed by 90° by the balanced coherent receiving module to realize self-homodyne detection, obtain a mixed light field, output a Q component signal after photoelectric conversion of the mixed light field, and finally sample the Q component signal at a high speed by the sampling analysis module, calculate a Q component digital signal, perform autocorrelation operation on the Q component digital signal, obtain a correlation curve, calculate a time delay corresponding to a secondary peak of the correlation curve, and obtain the measured time delay mismatch Δt.

[0040] Here, the secondary peak refers to a minimum value other than the main peak.

[0041] Referring to Figure 1 To provide a sampling analysis module, in some embodiments, the sampling analysis module can include a high-speed sampling unit and a digital processing unit, wherein the input end of the high-speed sampling unit is connected with the Q component output end of the balanced coherent receiving module, and the output end of the high-speed sampling unit is connected with the digital processing unit.

[0042] Here, the high-speed sampling unit is configured to sample the Q component signal output by the Q component output end of the balanced coherent receiving module at a high speed to obtain a Q component sampling signal.

[0043] The digital processing unit is configured to calculate a Q component digital signal according to the Q component sampling signal obtained by the high-speed sampling, perform autocorrelation operation on the Q component digital signal, obtain a correlation curve, calculate a time delay corresponding to a secondary peak of the correlation curve, and obtain the measured time delay mismatch Δt.

[0044] It can be understood that, in the above embodiments, to meet the subsequent analysis and calculation, the digital processing unit should be used preferentially, and the high-speed sampling unit is used at the same time to reduce errors and make the subsequent analysis and calculation results more accurate.

[0045] Since the Q component signal output by the balanced coherent receiving module generally includes Q p corresponding to the electric signal of the light field and the Q nThe electrical signal corresponding to the optical field, thus in some embodiments, the Q component output end of the balanced coherent receiving module can include Q p The output end and Q n The output end, wherein Q p The output end is used for outputting Q p The electrical signal corresponding to the optical field, denoted as Q p (t); Q n The output end is used for outputting Q n The electrical signal corresponding to the optical field, denoted as Q n (t).

[0046] It can be understood that in the above embodiments, Q p The output end and Q n The output end is the corresponding output end in the existing balanced coherent receiver, which is a relatively mature technology in the prior art, and will not be described in detail here.

[0047] Since in the balanced coherent receiving module, the input end generally includes a signal light port and a local oscillator light port, in some embodiments, the first input end of the balanced coherent receiving module can be the signal light port, and the second input end of the balanced coherent receiving module is the local oscillator light port.

[0048] It can be understood that in the above embodiments, the output of the chaotic decryption device of the chaotic module link system to be tested is input into the balanced coherent receiving module through the signal light port, and the test carrier is input into the balanced coherent receiving module through the local oscillator light port.

[0049] In some embodiments, the first input end of the balanced coherent receiving module can also be set as the local oscillator light port, and the second input end of the balanced coherent receiving module is set as the signal light port.

[0050] It can be understood that in the above embodiments, the output of the chaotic decryption device of the chaotic module link system to be tested is input into the balanced coherent receiving module through the local oscillator light port, and the test carrier is input into the balanced coherent receiving module through the signal light port.

[0051] In some embodiments, the calculation method of the Q component digital signal is as follows:

[0052] Q(t) = Q p (t) - Q n (t)

[0053] Here, Q(t) represents the Q component digital signal.

[0054] It can be understood that according to the above formula, only Q p (t) and Q n(t), namely the corresponding Q component digital signal can be calculated, and then autocorrelation operation is performed on the Q component digital signal, and the time delay corresponding to the secondary peak (minimum value) of the corresponding curve is the time delay mismatch Δt to be found.

[0055] The principle of the present application is as follows:

[0056] It is assumed that the light field emitted by the continuous wave laser CW can be represented by the following formula:

[0057] E CW (t) = A CW ·exp[i·(ω0t+φ0+φ N (t))]

[0058] Wherein, A CW represents the amplitude of the light field of the continuous wave laser, which is a constant value, ω0 represents the angular frequency of the continuous wave laser, φ0 represents the initial phase of the continuous wave laser, and φ N (t) represents the phase noise of the continuous wave laser, and i represents the imaginary unit.

[0059] The light field after being disturbed by the encryption link and the decryption link can be represented as:

[0060]

[0061] Wherein, C A (t) and C B (t) represent the electrical signals detected by the respective photodetectors after the chaotic encryption light field (the light field input to the chaotic decryption device after the encryption link) and the chaotic decryption light field (the light field input to the chaotic decryption device after the decryption link), respectively, V π is the half-wave voltage of the phase modulator used by the chaotic module link system, and A PM represents the amplitude of the light field output by the output end of the chaotic decryption device of the chaotic module link system to be measured.

[0062] Generally, the high-speed photodetector has a direct current blocking characteristic, and therefore C A (t) and C B (t) are alternating current signals fluctuating up and down around 0, and the modulation depth is defined as follows:

[0063]

[0064] Wherein, C(t) represents C A (t) or C B (t) described above, and V pp represents the peak-to-peak value of the corresponding signal (C A (t) or C B (t)), and max{} and min{} represent the maximum and minimum values of the time domain variable, respectively.

[0065] The AC signal approximately satisfies:

[0066] max{C(t)}≈-min{C(t)}

[0067] The peak-to-peak value V of C(t) can be controlled by controlling the optical power incident to the photodetector pp , so that PM ≤1.

[0068] Then:

[0069]

[0070] After performing kπ+π / 2 phase shift and self-coherent mixing on E PM (t), the photoelectrically converted electrical signal can be expressed as:

[0071]

[0072] where R d represents the photoelectric conversion efficiency (i.e., the responsivity of the photodetector in the balanced receiving module), and k can be any integer, including negative integers, 0, and positive integers.

[0073] From the above equation, we have:

[0074]

[0075] where U(t) represents an intermediate quantity for subsequent calculations, and R d A CW 2 and R d A PM 2 correspond to the detected electrical signals of E CW (t) and E PM (t), respectively, and can be tested separately.

[0076] When k is an even number (including negative even numbers), according to the above equation and the periodicity of the cosine function, we have:

[0077]

[0078] Therefore, we have:

[0079]

[0080] When k is an odd number (including negative odd numbers), according to the above equation and the periodicity of the cosine function, we have:

[0081]

[0082] Therefore, there are:

[0083]

[0084] And since C A (t-Δt) and C B (t) are chaotic synchronization signals with a high correlation coefficient (usually more than 92%), the time delay corresponding to the secondary peak of the autocorrelation curve of Δφ(t) is the time delay mismatch Δt. At the same time, because C A (t-Δt) and C B (t) are subtracted, the secondary peak should have a downward concave feature (minimum value).

[0085] In reality, a coherent receiver can be easily used to achieve a phase shift of ±π / 2. Usually, a coherent receiver uses a balanced detection method, i.e., a balanced coherent receiver, which can further improve the signal-to-noise ratio.

[0086] Let the balanced coherent receiver have a transmission function S of the optical field as follows:

[0087]

[0088] Input E PM (t) and E CW (t) into the signal light port (S port) and the local oscillator light port (LO port) of the balanced coherent receiver for mixing, respectively, to obtain four optical fields, which are represented as follows:

[0089]

[0090] The four optical fields in the above formula are detected by a photodetector to obtain corresponding electrical signals, which are represented as follows:

[0091]

[0092] R d represents the responsivity of the photodetector in the balanced receiving module.

[0093] Substituting E CW (t) = A CW ·exp[i·(ω0t+φ0+φ N (t)] and in the above formula, we obtain:

[0094]

[0095] After differentiating the I and Q signals, respectively, we obtain:

[0096]

[0097]

[0098] At this time, the case corresponding to k is odd, that is, the phase term in the above formula satisfies the formula Thus:

[0099]

[0100] Therefore:

[0101]

[0102] Again, the autocorrelation operation is performed on Δφ(t), and the time delay corresponding to the secondary peak of the correlation curve is the time delay mismatch Δt.

[0103] At the same time, the input light fields of the local oscillator and the signal light port can also be exchanged, that is, E PM (t) and E CW (t) are input into the local oscillator (LO port) and the signal light port (S port) of the balanced coherent receiver for mixing, at this time four light fields are obtained, which are represented as follows:

[0104]

[0105] In the above formula, the four light fields are detected by a photodetector to obtain corresponding electrical signals, which are represented as follows:

[0106]

[0107] R d represents the responsivity of the photoelectric conversion of the photodetector in the balanced receiving module.

[0108] In the above formula, substitute E CW (t) = A CW ·exp[i·(ω0t+φ0+φ N (t))] and Thus:

[0109]

[0110]

[0111] After differentiating the I channel signal and the Q channel signal respectively, we get:

[0112]

[0113] At this time, the case corresponding to k is even, that is, the phase term in the above formula satisfies the formula Thus:

[0114]

[0115] Therefore:

[0116]

[0117] The time delay mismatch amount Δt is obtained by finding the time delay corresponding to the secondary peak of the correlation curve.

[0118] According to the characteristics of the cosine function, when the independent variable is between [mπ, mπ+π] (m can be any integer), it is a monotonic function. Therefore, there is a one-to-one mapping relationship between Q(t) and Δφ(t), and the two have obvious correlation. The autocorrelation characteristics of Δφ(t) are also "transferred" to Q(t). Therefore, under the condition that the signal-to-noise ratio is sufficient, the autocorrelation operation can also be directly performed on Q(t), and then the time delay corresponding to the secondary peak (minimum value) of the correlation curve is found, which is the time delay mismatch amount Δt.

[0119] However, if the independent variable of the cosine function is not between [mπ, mπ+π], for example, in the most extreme case, between [-π / 2, π / 2], the one-to-one mapping relationship between the independent variable and the cosine value is broken, and the correlation between the two disappears, which is the reason why the time delay mismatch amount cannot be calculated based on the post-processing operation of the I(t) component (i.e., the I component digital signal).

[0120] As can be seen from the whole scheme, it is more simple and convenient to calculate the Q component digital signal than to calculate Δφ(t), and there is no need to care about the types of the first input end and the second input end of the balanced coherent receiving module (i.e., there is no need to care about whether the k value is odd or even), so the calculation of the system is more simple and convenient, and the calculation speed can be improved.

[0121] The second aspect of the embodiment of the application provides a chaotic module link delay test method, comprising the following steps:

[0122] A continuous laser is selected as a test carrier, and the test carrier is split into two paths, one of which is output to the chaotic module link system to be tested;

[0123] The other path of the test carrier is mixed with the output of the chaotic decryption device of the chaotic module link system to be tested by 90° to realize self-zero difference coherent detection, and a mixed light field is obtained. After photoelectric conversion, a Q component signal is output.

[0124] The input Q component signal is high-speed sampled, and a Q component digital signal is calculated. Autocorrelation operation is performed on the Q component digital signal, a correlation curve is obtained, and the time delay corresponding to the secondary peak of the correlation curve is calculated to obtain the measured time delay mismatch amount Δt.

[0125] It can be understood that the embodiment finds the time delay mismatch amount Δt of the chaotic module link system, that is, a known continuous laser is used as a test carrier (corresponding to a service carrier) to accurately calculate the time delay mismatch amount Δt of the entire chaotic module link system, so that the chaotic module link system can be adjusted through the time delay mismatch amount Δt to make the time delay mismatch amount Δt of the adjusted chaotic module link system meet the predetermined requirements.

[0126] In some embodiments, the 90° mixing can include:

[0127] The output of the chaotic decryption device of the measured chaotic module link system is subjected to a kπ+π / 2 phase shift and then subjected to self-coherent mixing with the test carrier, where k is an integer.

[0128] It can be understood that, as can be known from the above description, k can be a positive integer, 0, and a negative integer.

[0129] In some embodiments,

[0130] The calculation method of the Q component digital signal is:

[0131] Q(t)=Q p (t)-Q n (t)

[0132] Here, Q(t) represents the Q component digital signal, Q p (t) refers to the Q p electrical signal corresponding to the optical field in the Q n (t) represents the Q n electrical signal corresponding to the optical field in the Q

[0133] It should be understood that the size of the serial number of each step in the above embodiment does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0134] It should be noted that the information interaction, execution process and the like between the above devices / units / modules, since the same concept as the method embodiment of the present application, the specific functions and the technical effects brought by it, specific can be seen from the method embodiment part, here will not be repeated.

[0135] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above-mentioned division of each functional unit and module is exemplified, and in actual application, the above-mentioned functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or software function unit. In addition, the specific name of each functional unit and module is only for easy distinction, and does not limit the protection scope of the present application. The specific working process of the unit and module in the above system can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

[0136] The integrated unit, if realized in the form of a software function unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on such understanding, all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing related hardware, and the computer program can be stored in a computer-readable storage medium. When the processor executes the computer program, the steps of each method embodiment described above can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, executable file or some intermediate form. The computer-readable medium at least includes any entity or device capable of carrying the computer program code to the photographing device / terminal equipment, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium. For example, U disk, mobile hard disk, magnetic disk or optical disk, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0137] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0138] Those skilled in the art can appreciate that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solutions. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0139] In the embodiments provided by the present application, it should be understood that the disclosed apparatus / network device and method can be implemented in other ways. For example, the apparatus / network device embodiments described above are merely schematic. The division of the modules or units is merely a logical function division. There can be another division manner in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the display or discussion of the coupling or direct coupling or communication connection between the units can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0140] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. they can be located in one place, or distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0141] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

[0142] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A chaotic module link delay testing system, characterized in that, The system includes a laser beam splitter module, a balanced coherent receiver module, and a sampling analysis module. The first output of the laser beam splitter module is connected to the service carrier input of the chaotic module link system under test. The second output of the laser beam splitter module is connected to the second input of the balanced coherent receiver module. The first input of the balanced coherent receiver module is connected to the output of the chaotic decryption device of the chaotic module link system under test. The Q component output of the balanced coherent receiver module is connected to the input of the sampling analysis module. The laser beam splitting module has an input terminal for inputting a continuous laser as a test carrier, and splits the test carrier into beams and outputs them through a first output terminal and a second output terminal respectively. The balanced coherent receiving module is used to perform 90° mixing between the test carrier and the output of the chaotic decryption device of the link system of the chaotic module under test to achieve self-zero difference coherent detection, obtain the mixed optical field, and output the Q component signal after photoelectric conversion of the mixed optical field. The sampling and analysis module is used to sample the input Q component signal at high speed, calculate the Q component digital signal, perform autocorrelation operation on the Q component digital signal to obtain the correlation curve, and then calculate the time delay corresponding to the second peak based on the correlation curve to obtain the measured time delay mismatch Δt.

2. The chaotic module link delay testing system as described in claim 1, characterized in that, The sampling and analysis module includes a high-speed oscilloscope unit and a digital processing unit. The input terminal of the high-speed oscilloscope unit is connected to the Q component output terminal of the balanced coherent receiving module, and the output terminal of the high-speed oscilloscope unit is connected to the digital processing unit. The high-speed oscilloscope unit is used to perform high-speed sampling of the Q component signal output from the Q component output terminal of the balanced coherent receiver module to obtain the Q component sampling signal. The digital processing unit is used to calculate the Q component digital signal based on the Q component sampling signal acquired by the high-speed sampling, perform autocorrelation operation on the Q component digital signal to obtain the correlation curve, and then calculate the time delay corresponding to the second peak based on the correlation curve to obtain the measured time delay mismatch Δt.

3. The chaotic module link delay testing system as described in claim 1, characterized in that, The Q component output of the balanced coherent receiver module includes Q... p Output terminal and Q n At the output terminal, the Q p The output terminal is used to output Q. p The electrical signal corresponding to the light field is denoted as Q. p (t); the Q n The output terminal is used to output Q. n The electrical signal corresponding to the light field is denoted as Q. n (t).

4. The chaotic module link delay testing system as described in claim 3, characterized in that, The first input terminal of the balanced coherent receiving module is a signal optical port, and the second input terminal of the balanced coherent receiving module is a local oscillator optical port; or, the first input terminal of the balanced coherent receiving module is a local oscillator optical port, and the second input terminal of the balanced coherent receiving module is a signal optical port.

5. The chaotic module link delay testing system as described in claim 4, characterized in that, The Q component digital signal is calculated as follows: Where Q(t) represents the Q component digital signal.

6. A method for testing the link delay of a chaotic module, characterized in that, Includes the following steps: Select a continuous laser as the test carrier, and split the test carrier into beams, outputting one beam to the link system of the chaotic module under test; Another test carrier is mixed with the output of the chaotic decryption device of the chaotic module link system under test by 90° to achieve self-zero difference coherent detection, and the mixed optical field is obtained. The mixed optical field is then converted by photoelectric conversion to output the Q component signal. The input Q component signal is sampled at high speed, and the Q component digital signal is calculated. The autocorrelation operation is performed on the Q component digital signal to obtain the correlation curve. Then, the time delay corresponding to the second peak is calculated based on the correlation curve to obtain the measured time delay mismatch Δt.

7. The chaotic module link delay test method as described in claim 6, characterized in that, The 90° mixing includes: The output of the chaotic decryption device of the chaotic module link system under test is phase-shifted by kπ+π / 2 and then coherently mixed with the test carrier, where k is an integer.

8. The chaotic module link delay test method as described in any one of claims 6-7, characterized in that, The Q component digital signal is calculated as follows: Here, Q(t) represents the Q-component digital signal, Q p (t) refers to the Q component signal in the Q component signal. p The electrical signal Q corresponding to the light field n (t) represents the Q component signal in the Q component signal. n The electrical signal corresponding to the light field.

Images