CN115085819B - A method and system for information transmission of natural electromagnetic pulse vector signal energy spectrum - Google Patents

Abstract

The invention discloses an information transmission method and system of a natural electromagnetic pulse vector signal energy spectrum, which relate to the technical field of vector signal transmission, and comprise the following steps: the laser emits a plurality of laser beams to the multi-carrier signal generator, the multi-carrier signal generator emits light multi-carriers, the light multi-carriers are decomposed into multiple paths by using the demultiplexer, and then the light waves of one orthogonal polarized wave are transmitted to the double parallel Mach-Zehnder modulator; two vector signals are modulated on a double parallel Mach-Zehnder modulator by matching with light waves of internal orthogonal polarized waves; then, multiplexing is carried out by using a multiplexer to obtain a normalized lightwave signal; transmitting the data to a digital watermark encryption unit by using a single mode fiber, and embedding a digital watermark; and finally, the receiving end outputs the originally transmitted first vector signal and second vector signal according to the received encrypted light wave signal to finish the transmission of the vector signal. The invention relates to an information transmission method and system of a natural electromagnetic pulse vector signal energy spectrum, which has good transmission effect and high safety performance.

Description

A method and system for information transmission of natural electromagnetic pulse vector signal energy spectrum

technical field

The invention relates to the technical field of vector signal transmission, in particular to an information transmission method and system for the energy spectrum of a natural electromagnetic pulse vector signal.

Background technique

The vector signal refers to the IQ two-way signal generated by the quadrature modulation during digital modulation. A certain point on the coordinate can be determined on the coordinate map, which is called the reference point. When receiving, the reference point will deviate from a series of deteriorations such as channel interference. The position of the source reference point is called the measurement point at this time. In order to measure the quality of the signal, that is, the gap between the measurement signal and the reference signal, EVM (vector magnitude error) is quoted, that is, the vector distance between the measurement point and the reference point and the reference point The ratio of the amplitude, so the reference point and the measurement point can be regarded as a vector, so the I/Q data is called a vector signal. The so-called vector signal is the superposition of two or more sine wave signals with the same frequency and different phases. The phases of different signals are used to represent different information. Therefore, the desired information can be obtained by measuring the phase difference between the signals. Therefore, in the vector signal transmission process, an information transmission method and system involving the energy spectrum of the vector signal is required.

However, in the existing vector signal energy spectrum information transmission methods and systems, the vector signal is often sent directly from the vector signal transmitter to the oscilloscope. Since the oscilloscope has the function of vector signal analysis, the error vector magnitude, phase error, etc. Vector signal parameters are tested and displayed. Due to the phase difference between vector signals in the traditional vector signal transmission process, the display of the phase difference between vector signals is not clear, and the information carried by the vector signal is easily intercepted by extracting the phase difference, which makes the vector signal transmission process safe. Poor, resulting in vector signal information leakage, so it is necessary to propose a new solution.

The existing vector signal energy spectrum information transmission method and system have the disadvantages of poor vector signal transmission security performance, easy to cause vector signal information leakage, and high requirements for the transmission system in the process of vector signal transmission. Therefore, we propose a natural An information transmission method and system for an energy spectrum of an electromagnetic pulse vector signal.

Contents of the invention

The main purpose of the present invention is to provide an information transmission method and system of a natural electromagnetic pulse vector signal energy spectrum, which can effectively solve the problem of poor vector signal transmission safety performance in the existing vector signal energy spectrum information transmission method and system in the background art. It is easy to cause the leakage of vector signal information, and the problem of high requirements on the transmission system in the process of vector signal transmission.

In order to achieve the above object, the technical solution adopted by the present invention is: a method for information transmission of natural electromagnetic pulse vector signal energy spectrum, comprising the following steps:

S1: The laser emits multiple laser beams of different frequencies to the multi-carrier signal generator, and the multi-carrier signal generator emits an optical multi-carrier. The multi-carrier signal generator uses AWG5200 arbitrary waveform generator, which can meet the demanding requirements. Signal generation requirements, with high signal fidelity, can be expanded to up to 32 channels through multi-unit synchronous combination, suitable for advanced research, electronic testing and radar, complex electromagnetic environment system design and testing;

S2: Use a demultiplexer to decompose the optical multi-carrier into multiple paths, wherein two paths of lightwave signals are directly transmitted to the multiplexer, and the other path of lightwave signals is transmitted to the first polarization beam splitter. The beam splitter is split into two orthogonally polarized light waves, and then one of the orthogonally polarized light waves is transmitted to a dual parallel Mach-Zehnder modulator, which splits the input light into two The equal signals respectively enter the two optical branches of the modulator, and the materials used in the two optical branches are electro-optical materials, whose refractive index changes with the magnitude of the externally applied electrical signal. Since the change of the refractive index of the optical branch will lead to the change of the signal phase, when the output terminals of the two branch signal modulators are combined again, the synthesized optical signal will be an interference signal with a change in intensity, which is equivalent to the electrical signal The change of the light signal is converted into the change of the light signal, and the modulation of the light intensity is realized;

S3: The transmitting end of the natural electromagnetic pulse vector signal sends the first microwave vector signal and the second microwave vector signal to the dual-parallel Mach-Zehnder modulator, and cooperates with the internal orthogonally polarized waves on a dual-parallel Mach-Zehnder modulator the light wave modulating the first vector signal and the second vector signal;

S4: The signals modulated by the dual parallel Mach-Zehnder modulators and another light wave of the orthogonally polarized wave are transmitted to the second polarization beam splitter for processing and combining, and the processed and combined signals are combined with the two signals in step S2 The light wave signal in the road is transmitted to the multiplexer for multiplexing to obtain a normalized light wave signal. The polarization beam splitter is used to couple two beams of orthogonally polarized light into an optical fiber or combine orthogonal linearly polarized light The single output of the single-mode fiber is coupled to the two fiber outputs respectively, and it can also be applied in reverse to couple the two orthogonally polarized beams input from the polarization-maintaining fiber branch into a single-mode output fiber, which can be used for power combining of pump lasers , improve the extinction ratio of the fiber laser;

S5: The normalized light wave signal is amplified by an erbium-doped fiber amplifier, and then transmitted to a digital watermark encryption unit using a single-mode optical fiber. The digital watermark encryption unit reorders the database through a hash function to deal with reorganization attacks, based on The cuckoo algorithm finds the best position to embed the digital watermark, inserts the reversible digital watermark through the differential expansion technology, and completes the encryption of the light wave signal. The erbium-doped fiber amplifier is an optical fiber doped with a small amount of rare earth element erbium (Er) ions in the quartz fiber , it is the core of the erbium-doped fiber amplifier, which greatly increases the capacity of optical fiber communication and improves the efficiency of data transmission;

S6: The encrypted light wave signal is transmitted to the receiving end through a single-mode optical fiber again, and the receiving end outputs the originally transmitted first vector signal and the second vector signal according to the received encrypted light wave signal to complete the vector signal transmission,

The photon method based on light wave signal modulation and coherent detection is used to transmit two microwave vector signals. A Mach-Zehnder modulator is used in the light wave to modulate two vector signals with the same microwave carrier frequency, and there is no modulation in the same optical fiber. Under normal circumstances, when transmitting orthogonally polarized light waves for coherent detection, the number of optical carriers and modulators carrying vector signals only needs to be half of the original, improving the efficiency of vector signal transmission. The use of balanced detection and coherent detection instruments can reduce the noise of vector signal transmission and ensure the high performance of vector signals. Compared with conventional microwave vector signal transmission methods in optical fiber links, by using a single optical fiber carrier to transmit two different microwave vector signals with the same microwave carrier frequency, the required optical carrier for carrying microwave vector signals is greatly reduced and the number of modulators. In addition, in the proposed coherent detection method, the influence of photodetector noise is thus reduced.

Preferably, in step S6, the specific steps of outputting the first vector signal and the second vector signal after receiving the encrypted light wave at the receiving end are as follows:

S601: Use a second demultiplexer to separate wavelengths of the encrypted light waves to obtain multiple wavelength signals;

S602: One of the wavelengths is transmitted to the third polarization beam splitter and split into two light waves to be output with orthogonally polarized waves;

S603: Send one of the light waves to be output with orthogonally polarized waves to a coherent detector, where the Mach-Zehnder modulator is used for modulation again in the coherent detector, and then transmitted to the output of the coherent detector after the modulation is completed The terminal completes outputting the first vector signal and the second vector signal.

式子中，输入到所述双平行马赫曾德调制器的幅度为Ex，角度频率为

所述双平行马赫曾德调制器的半波电压为Vπ，γ＝π/V_π，两个矢量信号分别在光载波上的调制，E_y是未调制光载波光场的振幅，

通过所述单模光纤传输的两个正交极化光波，两个正交级化光波发送到相干检测器上，本实施例中，线性偏振光波被分成两个正交极化光波，一个被调制的两个微波矢量信号和其他的无调制，但在同一根光纤中传输调制光波，在接收器处，这两个光波的正交偏振态被分离并传送到一个相干检测器，这里两个微波矢量信号被分离和解调。Preferably, in step S603, two vector signals to be transmitted are set, the first vector signal is I(t), the second vector signal is Q(t), and the two parallel Mach-Zehnder modulators are transmitted at a minimum The point sub-basis and main bias are introduced into π/21 as the modulation condition, under which then the optical signal at the output of the dual-parallel Mach-Zehnder modulator can be expressed as:

In the formula, the amplitude input to the dual-parallel Mach-Zehnder modulator is Ex, and the angular frequency is

The half-wave voltage of the dual-parallel Mach-Zehnder modulator is Vπ, γ=π/ _Vπ , two vector signals are respectively modulated on the optical carrier, E _y is the amplitude of the unmodulated optical carrier light field,

The two orthogonally polarized light waves transmitted through the single-mode optical fiber are sent to the coherent detector. In this embodiment, the linearly polarized light waves are divided into two orthogonally polarized light waves, one of which is The two microwave vector signals modulated and the other unmodulated, but modulated light waves are transmitted in the same optical fiber. At the receiver, the orthogonal polarization states of the two light waves are separated and sent to a coherent detector, where the two The microwave vector signal is separated and demodulated.

另一个所述电探测器设备的输出信号可表示为：

通过上式最终输出所述第一矢量信号I(t)和所述第二矢量信号Q(t)。Preferably, an optical mixer is provided on the coherent detection, and the output terminal is an output terminal on the optical mixer, and the output terminal of the optical mixer generates four output signals, and the four output signals pass through two For photodetector output, the output signal of one of said photodetector devices can be expressed as:

The output signal of another said electrical detector device can be expressed as:

The first vector signal I(t) and the second vector signal Q(t) are finally output through the above formula.

Preferably, in step S5, first use P cuckoos to create an initial population, calculate the cuckoo function values of the solutions given by different cuckoos, and sort them, and the vector signals I(t) and Q(t) to be embedded in the watermark , specifically I(t)∈(p,I ₁ ,I ₂ ,..., _In ), where: p is the primary key of each element of I(t), and I ₁ ,I ₂ ,..., _In are n attributes of I(t), I(t) consists of m tuples r ₁ , r ₂ ,..., r _m , each tuple has and only one primary key rp and n attributes Column rI ₁ , rI ₂ ,..., rI _n , then the initial population size represents the number of cuckoos used to find the optimal solution, and then find the optimal solution of the cuckoo function , and then the watermark to be embedded u=(u ₁ ,u ₂ ,...,u _k ), u∈{0,1}, k≤m, according to the watermark preference selection calculated by the optimal solution of the cuckoo function , the watermark insertion position information is obtained, and the cuckoo function Aiming at minimizing the distortion after embedding the watermark, the cuckoo algorithm selects the best position to embed the watermark for each tuple. In this embodiment, the digital watermark is added to the vector signal by using the cuckoo algorithm. Embedding a watermark in the vector signal can effectively prevent the vector signal from being distorted during transmission. By embedding a watermark on the vector signal instead of encrypting the vector signal, it is possible to prevent criminals from obtaining the transmitted vector signal privately. Further guarantee the security of vector signal transmission.

An information transmission system of a natural electromagnetic pulse vector signal energy spectrum, the transmission system includes a preprocessing module, an input module, a watermark embedding module and an output module;

In the preprocessing module, an optical multi-carrier is generated by a laser and a multi-carrier signal generator; and then a demultiplexer is used to decompose the optical multi-carrier into multiple optical wave signals;

The input module includes a dual-parallel Mach-Zehnder modulator, which simultaneously enters the dual-parallel Mach-Zehnder modulator for two sets of vector signals to be transmitted and one of the optical wave signals;

The watermark embedding module is mainly used to embed a watermark into the light wave signal modulated by the dual parallel Mach-Zehnder modulator, and complete the encryption;

The output module outputs again through a coherent detector, and in the coherent detector again modulates through a dual-parallel Mach-Zehnder modulator and then outputs the first vector signal and the second vector signal after embedding the watermark.

Preferably, the preprocessing module, the input module, the watermark embedding module and the output module are communicatively connected through a single-mode optical fiber.

Compared with the prior art, the present invention has the following beneficial effects:

In the present invention, two microwave vector signals are transmitted based on light wave signal modulation and coherent detection of photons, a Mach-Zehnder modulator is used in the light wave to modulate two vector signals with the same microwave carrier frequency, and in the same When the optical fiber is not modulated, the orthogonally polarized light waves are transmitted for coherent detection, and the number of optical carriers and modulators carrying vector signals only needs half of the original number, which improves the efficiency of vector signal transmission. The use of balanced detection and coherent detection instruments can reduce the noise of vector signal transmission and ensure the high performance of vector signals. Compared with conventional microwave vector signal transmission methods in optical fiber links, by using a single optical fiber carrier to transmit two different microwave vector signals with the same microwave carrier frequency, the required optical carrier for carrying microwave vector signals is greatly reduced and the number of modulators. In addition, in the proposed coherent detection method, thereby reducing the influence of the noise of the photodetector, ensuring the efficiency of vector signal transmission, the performance of vector signal transmission, reducing the requirements for the transmission system, and reducing the transmission system's influence on the vector signal influences.

In the present invention, based on the cuckoo algorithm, the best position to embed the digital watermark is found, and the reversible digital watermark is inserted through the differential extension technology to complete the encryption of the light wave signal, and the digital watermark mark is added to the vector signal by using the cuckoo algorithm. The watermark is embedded in the signal to effectively prevent the vector signal from being distorted during transmission. By embedding a watermark on the vector signal instead of encrypting the vector signal, it is possible to prevent criminals from obtaining the transmitted vector signal privately. The security of vector signal transmission is guaranteed.

Description of drawings

Fig. 1 is the system block diagram of the information transmission method of a kind of natural electromagnetic pulse vector signal energy spectrum of the present invention;

Fig. 2 is the information transmission method flowchart of a kind of natural electromagnetic pulse vector signal energy spectrum of the present invention;

Fig. 3 is the specific flowchart of step S6 in the information transmission method of a kind of natural electromagnetic pulse vector signal energy spectrum of the present invention;

Fig. 4 is a system block diagram of a natural electromagnetic pulse vector signal energy spectrum information transmission system of the present invention.

Detailed ways

In order to make the technical means, creative features, goals and effects achieved by the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "another end" The orientation or positional relationship indicated by etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, use a specific Azimuth configuration and operation, therefore, should not be construed as limiting the invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise specified and limited, the terms "installed", "set with", "connected", etc. should be understood in a broad sense, such as "connected", which may be a fixed connection , can also be detachably connected, or integrally connected; can be mechanically connected, can also be electrically connected; can be directly connected, can also be indirectly connected through an intermediary, and can be internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

Please refer to shown in Fig. 1-4, the present invention is a kind of information transmission method of natural electromagnetic pulse vector signal energy spectrum, comprises the following steps:

As shown in Figure 1 and Figure 2, S1: The laser emits multiple laser beams of different frequencies to the multi-carrier signal generator, and the multi-carrier signal generator emits an optical multi-carrier. The multi-carrier signal generator uses an AWG5200 arbitrary waveform generator. AWG5200 Arbitrary Waveform Generator can meet demanding signal generation requirements with high signal fidelity and can be expanded to up to 32 channels through multi-unit synchronous combination, suitable for advanced research, electronic testing and radar, complex electromagnetic environment system design and testing ;

S2: Use the demultiplexer to decompose the optical multi-carrier into multiple channels, in which two optical wave signals are directly transmitted to the multiplexer, and the other optical wave signal is transmitted to the first polarization beam splitter, and the first polarization beam splitter is split into two orthogonally polarized light waves, and then one of the orthogonally polarized light waves is transmitted to a dual-parallel Mach-Zehnder modulator. The Mach-Zehnder modulator splits the input light into two equal signals, respectively The two optical branches entering the modulator are made of electro-optical materials whose refractive index changes with the magnitude of the externally applied electrical signal. Since the change of the refractive index of the optical branch will lead to the change of the signal phase, when the output terminals of the two branch signal modulators are combined again, the synthesized optical signal will be an interference signal with a change in intensity, which is equivalent to the electrical signal The change of the light signal is converted into the change of the light signal, and the modulation of the light intensity is realized;

S3: The transmitting end of the natural electromagnetic pulse vector signal sends the first microwave vector signal and the second microwave vector signal to the dual-parallel Mach-Zehnder modulator, and cooperates with the internal orthogonally polarized light wave on a dual-parallel Mach-Zehnder modulator modulating the first vector signal and the second vector signal;

S4: The signal modulated by the dual-parallel Mach-Zehnder modulator and the light wave of another orthogonally polarized wave are transmitted to the second polarization beam splitter for processing and combining, and the processed and combined signal is transmitted to the two-way light wave signal in step S2 The multiplexer is multiplexed to obtain a normalized light wave signal, and the polarization beam splitter is used to couple two beams of orthogonally polarized light into one optical fiber or couple a single output containing orthogonal linearly polarized light to In the two fiber outputs, it can also be reversely applied to couple two orthogonally polarized beams input from the polarization-maintaining fiber branch into a single-mode output fiber, which can be used to combine the power of the pump laser and improve the extinction of the fiber laser Compare;

S5: The normalized light wave signal is amplified by an erbium-doped fiber amplifier for signal amplification, and then transmitted to the digital watermark encryption unit using a single-mode fiber. The digital watermark encryption unit reorders the database through the hash function to deal with reorganization attacks, and finds the data based on the cuckoo algorithm. The best place to embed the digital watermark is to insert a reversible digital watermark through the differential expansion technology to complete the encryption of the light wave signal. The erbium-doped fiber amplifier is an optical fiber doped with a small amount of rare earth element erbium (Er) ions in the quartz fiber. The core of the erbium fiber amplifier greatly increases the capacity of optical fiber communication and improves the efficiency of data transmission;

S6: The encrypted light wave signal is transmitted to the receiving end through the single-mode optical fiber again, and the receiving end outputs the original transmitted first vector signal and the second vector signal according to the received encrypted light wave signal to complete the vector signal transmission,

The photon method based on light wave signal modulation and coherent detection is used to transmit two microwave vector signals. A Mach-Zehnder modulator is used in the light wave to modulate two vector signals with the same microwave carrier frequency, and there is no modulation in the same optical fiber. Under normal circumstances, when transmitting orthogonally polarized light waves for coherent detection, the number of optical carriers and modulators carrying vector signals only needs to be half of the original, improving the efficiency of vector signal transmission. The use of balanced detection and coherent detection instruments can reduce the noise of vector signal transmission and ensure the high performance of vector signals. Compared with conventional microwave vector signal transmission methods in optical fiber links, by using a single optical fiber carrier to transmit two different microwave vector signals with the same microwave carrier frequency, the required optical carrier for carrying microwave vector signals is greatly reduced and the number of modulators. In addition, in the proposed coherent detection method, the influence of photodetector noise is thus reduced.

Wherein, as shown in FIG. 3, in step S6, the receiving end outputs the first vector signal and the second vector signal after receiving the encrypted light wave. The specific steps are as follows:

S601: Using a second demultiplexer to separate the encrypted light waves into wavelengths to obtain multiple wavelength signals;

S602: One of the wavelengths is transmitted to the third polarization beam splitter and split into two light waves to be output with orthogonally polarized waves;

S603: Send one of the light waves to be output with orthogonally polarized waves to a coherent detector, and then use the Mach-Zehnder modulator to modulate again in the coherent detector. After the modulation is completed, it is transmitted to the output terminal of the coherent detector to complete the output The first vector signal and the second vector signal.

式子中，输入到双平行马赫曾德调制器的幅度为Ex，角度频率为

双平行马赫曾德调制器的半波电压为Vπ，γ＝π/V_π，两个矢量信号分别在光载波上的调制，E_y是未调制光载波光场的振幅，

通过单模光纤传输的两个正交极化光波，两个正交级化光波发送到相干检测器上，本实施例中，线性偏振光波被分成两个正交极化光波，一个被调制的两个微波矢量信号和其他的无调制，但在同一根光纤中传输调制光波，在接收器处，这两个光波的正交偏振态被分离并传送到一个相干检测器，这里两个微波矢量信号被分离和解调。Wherein, in step S603, two vector signals to be transmitted are set, the first vector signal is I(t), and the second vector signal is Q(t), and the two-parallel Mach-Zehnder modulator is set at the minimum transmission point The base and main biases introduce π/21 as the modulation condition, under which then the optical signal at the output of the dual parallel Mach-Zehnder modulator can be expressed as:

In the formula, the amplitude input to the dual parallel Mach-Zehnder modulator is Ex, and the angular frequency is

The half-wave voltage of the dual-parallel Mach-Zehnder modulator is Vπ, γ=π/V _π , two vector signals are respectively modulated on the optical carrier, E _y is the amplitude of the unmodulated optical carrier light field,

Two orthogonally polarized light waves are transmitted through a single-mode fiber, and the two orthogonally polarized light waves are sent to a coherent detector. In this embodiment, the linearly polarized light wave is divided into two orthogonally polarized light waves, and one modulated Two microwave vector signals and others without modulation, but modulated light waves transmitted in the same fiber, at the receiver, the orthogonal polarization states of these two light waves are separated and sent to a coherent detector, where the two microwave vector Signals are separated and demodulated.

另一个电探测器设备的输出信号可表示为：

通过上式最终输出第一矢量信号I(t)和第二矢量信号Q(t)。Among them, the coherent detection is equipped with an optical mixer, and the output end is the output end of the optical mixer. The output end of the optical mixer generates four output signals, and the four output signals are respectively output through two pairs of photodetectors, one of which is a photoelectric The output signal of the detector device can be expressed as:

The output signal of another electrical detector device can be expressed as:

The first vector signal I(t) and the second vector signal Q(t) are finally output through the above formula.

Among them, in step S5, first use P cuckoos to create an initial population, calculate the cuckoo function values of the solutions given by different cuckoos, and sort them, and the vector signals I(t) and Q(t) to be embedded in the watermark, Concrete I(t)∈(p,I ₁ ,I ₂ ,...,I _n ), where: p is the primary key of each element of I(t), I ₁ ,I ₂ ,...,In is _I (t) has n attributes, I(t) consists of m tuples r ₁ , r ₂ ,..., r _m , each tuple has one and only one different primary key rp and n attribute columns rI ₁ , rI ₂ ,..., rI _n , then the initial population size represents the number of cuckoos used to find the optimal solution, and then find the optimal solution of the cuckoo function, and then the watermark to be embedded u=(u ₁ ,u ₂ ,...,u _k ), u∈{0,1}, k≤m, according to the watermark preference selection calculated by the optimal solution of the cuckoo function, the watermark insertion position information is obtained. The cuckoo function aims to embed the watermark After the distortion is reduced to a minimum value, the cuckoo algorithm selects the best position for embedding the watermark for each tuple. In this embodiment, the digital watermark is added to the vector signal by using the cuckoo algorithm. By embedding the watermark in the vector signal , to effectively prevent the vector signal from being distorted during transmission. By embedding a watermark on the vector signal instead of encrypting the vector signal, criminals can be prevented from obtaining the transmitted vector signal privately. Transmission Security.

As shown in Figure 4, a natural electromagnetic pulse vector signal energy spectrum information transmission system, the transmission system includes a preprocessing module, an input module, a watermark embedding module and an output module;

In the preprocessing module, an optical multi-carrier is generated by a laser and a multi-carrier signal generator; and then a demultiplexer is used to decompose the optical multi-carrier into multiple optical wave signals;

The input module includes a dual-parallel Mach-Zehnder modulator, which simultaneously enters the dual-parallel Mach-Zehnder modulator for two sets of vector signals to be transmitted and one of the optical wave signals;

The watermark embedding module is mainly used to embed the watermark into the light wave signal modulated by the dual-parallel Mach-Zehnder modulator and complete the encryption;

The output module outputs again through the coherent detector, and in the coherent detector again modulates through the dual parallel Mach-Zehnder modulator and then outputs the first vector signal and the second vector signal after embedding the watermark.

Wherein, the preprocessing module, the input module, the watermark embedding module and the output module are connected by single-mode fiber for communication.

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments, and what described in the above-mentioned embodiments and the description only illustrates the principles of the present invention, and the present invention will also have other functions without departing from the spirit and scope of the present invention. Variations and improvements are possible, which fall within the scope of the claimed invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (8)

1. An information transmission method of a natural electromagnetic pulse vector signal energy spectrum is characterized in that: the method comprises the following steps:

s1: the laser emits a plurality of laser beams with different frequencies to the multi-carrier signal generator, and the multi-carrier signal generator emits one optical multi-carrier;

s2: the optical multi-carrier is decomposed into multiple paths by using a demultiplexer, wherein two paths of optical wave signals are directly transmitted to the multiplexer, the other path of optical wave signals are transmitted to a first polarization beam splitter and split into two optical waves of orthogonal polarization waves in the first polarization beam splitter, and then one optical wave of the orthogonal polarization waves is transmitted to a double parallel Mach-Zehnder modulator;

s3: a natural electromagnetic pulse vector signal sending end sends a microwave first vector signal and a microwave second vector signal to the double parallel Mach-Zehnder modulators, and the first vector signal and the second vector signal are modulated on one double parallel Mach-Zehnder modulator by matching with light waves of internal orthogonal polarized waves;

s4: transmitting the signal modulated by the double parallel Mach-Zehnder modulator and the optical wave of the other orthogonal polarized wave to a second polarization beam splitter for processing and combining, and transmitting the processed and combined signal and the two paths of optical wave signals in the step S2 to a multiplexer for multiplexing to obtain a normalized optical wave signal;

s5: the normalized light wave signal is subjected to signal amplification through an erbium-doped fiber amplifier, and then is transmitted to a digital watermark encryption unit by using a single mode fiber, the digital watermark encryption unit reorders the database through a hash function to cope with recombination attack, the optimal position where the digital watermark is embedded is found based on a cuckoo algorithm, and reversible digital watermark is inserted through a difference expansion technology to complete light wave signal encryption;

s6: and the encrypted light wave signal is transmitted to a receiving end again through the single-mode optical fiber, and the receiving end outputs the originally transmitted first vector signal and the second vector signal according to the received encrypted light wave signal to finish vector signal transmission.

2. The method for transmitting information of natural electromagnetic pulse vector signal energy spectrum according to claim 1, characterized in that: in step S6, the step of outputting the first vector signal and the second vector signal after the receiving end receives the encrypted optical signal includes:

s601: separating wavelengths of the encrypted light waves by using a second demultiplexer to obtain a plurality of wavelength signals;

s602: one path of wavelength is transmitted to a third polarization beam splitter and is split into two optical waves of orthogonal polarization waves to be output;

s603: and sending one optical wave of the orthogonal polarization wave to be output to a coherent detector, modulating the optical wave by using the Mach-Zehnder modulator again in the coherent detector, and transmitting the modulated optical wave to the output end of the coherent detector to finish outputting a first vector signal and a second vector signal.

3. The method for transmitting information of natural electromagnetic pulse vector signal energy spectrum according to claim 2, characterized in that: in step S603, two vector signals to be transmitted are set, a first vector signal is I (t), a second vector signal is Q (t), pi/21 is introduced into the sub-base and the main bias of the minimum transmission point of the dual-parallel mach-zehnder modulator as a modulation condition, and under the condition, the optical signal output by the dual-parallel mach-zehnder modulator can be represented as:

in the formula, the amplitude input to the double parallel Mach-Zehnder modulator is Ex, and the angular frequency is

The half-wave voltage of the double parallel Mach-Zehnder modulator is V pi, and gamma = pi/V _π Modulation of two vector signals on an optical carrier, respectively, E _y Is the amplitude of the optical field of the unmodulated optical carrier,

two orthogonally polarized light waves, two orthogonal orders, transmitted through said single mode optical fibreThe polarized light waves are sent to a coherent detector.

4. The method for transmitting information of natural electromagnetic pulse vector signal energy spectrum according to claim 3, characterized in that: the coherent detection is provided with an optical mixer, the output end of the optical mixer is the output end of the optical mixer, the output end of the optical mixer generates four output signals, the four output signals are output through two pairs of photoelectric detectors respectively, and the output signal of one of the photoelectric detector devices can be expressed as:

the output signal of another said electrical detector device may be expressed as:

the first vector signal I (t) and the second vector signal Q (t) are finally output by the above expression.

5. The method for transmitting information of natural electromagnetic pulse vector signal energy spectrum according to claim 1, characterized in that: in step S5, P cuckoos are used for creating an initial population, the cuckoo function values of solutions given by different cuckoos are calculated and then sequenced, and vector signals I (t) and Q (t) to be embedded with watermarks are sequenced, wherein the specific I (t) belongs to (P, I) e ₁ ,I ₂ ,...,I _n ) Wherein: p is the primary bond of each element of I (t), I ₁ ,I ₂ ,...,I _n Is n attributes of I (t), I (t) is composed of m tuples r ₁ ，r ₂ ，…，r _m Each tuple has one and only one different primary key r.p and n attribute columns r.I ₁ ，r.I ₂ ，…，r.I _n Then the initial population number represents the number of cuckoos used to find the optimal solution, then the cuckoo function optimal solution is found, and then the watermark u = (u) to be embedded ₁ ,u ₂ ,...,u _k ) U belongs to {0,1}, k is less than or equal to m, and watermark insertion position information is obtained according to watermark preference selection obtained by calculation of the optimal solution of the Cuckoo function.

6. The method for transmitting information of natural electromagnetic pulse vector signal energy spectrum according to claim 5, characterized in that: the cuckoo function aims at minimizing distortion after embedding the watermark, and the cuckoo algorithm selects the best position for embedding the watermark for each tuple.

7. An information transmission system of a natural electromagnetic pulse vector signal energy spectrum is characterized in that: the transmission system is an operation system of the information transmission method of the natural electromagnetic pulse vector signal energy spectrum, which is defined by any one of claims 1 to 6, and comprises a preprocessing module, an input module, a watermark embedding module and an output module;

an optical multi-carrier is generated in the preprocessing module through a laser and a multi-carrier signal generator; then, a demultiplexer is used for decomposing the optical multi-carrier into multi-path optical wave signals;

the input module comprises a double parallel Mach-Zehnder modulator, and two groups of vector signals to be transmitted and one path of light wave signal enter the double parallel Mach-Zehnder modulator to be modulated at the same time;

the watermark embedding module is mainly used for embedding watermarks into the light wave signals modulated by the double parallel Mach-Zehnder modulators and completing encryption;

and the output module outputs the first vector signal and the second vector signal after embedding the watermark through the coherent detector, and the first vector signal and the second vector signal are modulated through the double parallel Mach-Zehnder modulator again in the coherent detector.

8. The system according to claim 7, wherein the system further comprises: the preprocessing module, the input module, the watermark embedding module and the output module are in communication connection through a single mode fiber.

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