Communication perception integrated waveform design method and system under optical fiber based on water injection method

Abstract

The invention discloses an optical fiber lower sensing integrated waveform design method and system based on a water injection method, and the method comprises the following steps: 1, calculating system sensing mutual information in combination with communication signal power spectrum distribution and the like of a communication-centered ISAC-OF system; 2, calculating the maximum value of system sensing mutual information in combination with system sensing signal transmitting power limitation; 3, calculating system perception link noise through the maximum value of system perception mutual information, and calculating perception signal power spectrum distribution through a water injection method; 4, selecting a system sensing signal waveform, setting parameters to enable the power spectrum distribution of the system sensing signal waveform to accord with the power spectrum distribution of the sensing signal, and obtaining a system sensing signal; 5, adding the sensing signal and the system communication signal, modulating into an optical signal, and coupling into an optical fiber for transmission; 6, after optical fiber transmission, a communication signal is filtered out at a communication receiving end, and the communication signal is received by an optical communication receiver to obtain communication data; at a sensing receiving end, sensing signals are filtered out, and sensing data are received and obtained by a light sensing receiver.

Description

Technical Field

[0001] The present invention belongs to the field of optical communication technology, and in particular, relates to an integrated waveform design method and system for a communication-centric optical fiber communication perception integrated system. Background Art

[0002] In recent years, with the rapid development of emerging network service technologies such as cloud computing, the Internet of Things, and virtual reality, network users' demand for high speed, large bandwidth, and low latency is also gradually increasing. According to research, by 2025, the total number of Internet users in the world is expected to reach 5.7 billion, accounting for about 70% of the world's total population. As the main infrastructure for data transmission today, the scale of optical fiber networks is also growing rapidly. Intelligent management and health detection of such large infrastructures have gradually become new challenges. In addition, with the emergence of emerging technologies such as smart cities and telemedicine, the stable combination of high-quality communication and high-precision perception has become a new demand. At the same time, as the potential of the perception function of optical fiber itself has been explored, the Integrated Sensing and Communication on Optical Fiber (ISAC-OF) technology has emerged. ISAC-OF technology uses various technical means to achieve the organic combination of communication and perception functions under the same optical fiber link, thereby more effectively utilizing limited system resources. Among them, the applied technical means include but are not limited to resource reuse technology, integrated hardware integration technology, and integrated waveform design technology. Through the above technologies, the existing fiber optic network will have the ability to perceive itself and the surrounding environment while maintaining the original communication capabilities, making network management more intelligent and network services more diversified. However, ISAC-OF technology still faces many challenges, such as communication perception signal crosstalk and system resource allocation compromise. From the perspective of information and business goals, the above problems are essentially caused by the different ways of acquiring and processing communication and perception information. Therefore, how to solve the inherent conflict between communication and perception in the ISAC system in terms of signal and system design is an important research issue. At the same time, the system's compromise between communication and perception performance is also the key to the research.

[0003] After searching the existing literature, it is known that for the above problems, the main research direction in wireless ISAC is to analyze the performance limits of the ISAC system and design integrated waveforms and system architectures. Among them, Xiong Yifeng et al. published "Information Theoretic Limits of Communication-Perception Integration" in "Science China" in 2023, analyzing the performance limits of the ISAC system in four different scenarios based on wireless channels, and pointed out that the performance tradeoff of the wireless ISAC system can be further divided into deterministic-random tradeoff and subspace tradeoff. In addition, Rang Liu et al. published "Cramér-Rao Bound Optimization for Joint Radar-Communication Beamforming" in "IEEE Transactions on Signal Processing" in 2021, proposing to use the Cramér-Rao Bound (CRB) as the performance indicator of target estimation, while ensuring the preset signal-to-interference-noise ratio level of each communication user, minimizing the CRB of radar perception, thereby realizing multi-input and multi-output beamforming design for joint radar perception and multi-user communication. However, due to the different optimization goals and application scenarios caused by the different system links, the above-mentioned wireless ISAC technical solution is difficult to be directly applied to the ISAC-OF system. To this end, Haijun He1 et al. published "Integrated sensing and communication in an optical fibre" in "Light: Science & Applications" in 2023. The article proposed the use of linear frequency modulation signals as carriers, which can realize high-speed optical communication and optical fiber vibration monitoring in the same wavelength channel, thereby realizing the organic integration of high-speed communication and high-precision perception under optical fiber. However, the above scheme still lacks an in-depth discussion on the performance of the ISAC-OF system, and lacks theoretical analysis of the impact of system signal crosstalk. To this end, the present invention proposes an integrated waveform design method and system based on the water injection method for an integrated optical fiber communication perception system centered on communication. Summary of the invention

[0004] In view of the lack of theoretical analysis of signal crosstalk and system performance of the current communication-centered optical fiber integrated communication system, the present invention provides an integrated waveform design method and system based on the water injection method. The water injection method is a system optimization method that injects signal power at the noise level in order to achieve optimal system performance. The present invention analyzes the crosstalk situation and system performance and optimizes parameters by establishing a mathematical model. After the optimization is completed, it is only necessary to calculate the parameters based on the results to perceive the channel noise, and the perception signal spectrum distribution can be obtained based on the water injection method, thereby generating the optimal integrated waveform of the system and realizing a high-performance optical fiber communication perception integrated system.

[0005] The present invention adopts the following technical scheme:

[0006] A method for designing an integrated waveform for optical fiber communication and sensing based on a water injection method, the specific steps of which are as follows:

[0007] Step 1, combining the communication signal power spectrum distribution, optical fiber channel dispersion, channel noise power spectrum distribution and perception target unit impulse response of the communication-centered optical fiber communication perception integrated system, and calculating the system perception mutual information;

[0008] Step 2, combining the system perception signal transmission power limit, calculating the maximum value of the system perception mutual information in step 1;

[0009] Step 3, calculating the system perception link noise and water injection level by the maximum value of the system perception mutual information obtained in step 2, and calculating the perception signal power spectrum distribution by water injection method;

[0010] Step 4, selecting a system perception signal waveform, and setting its parameters so that its power spectrum distribution is consistent with the power spectrum distribution of the perception signal obtained in step 3, to obtain a system perception signal;

[0011] Step 5, adding the sensing signal obtained in step 4 to the system communication signal to generate a corresponding electrical signal, modulating it into an optical signal, and transmitting it through an optical fiber;

[0012] Step 6: After the optical signal is transmitted through the optical fiber and affected by the sensing target, at the communication receiving end, the communication signal is filtered out and received by the optical communication receiver to obtain the communication information; at the sensing receiving end, the sensing signal is filtered out and received by the optical sensing receiver to obtain the sensing target information.

[0013] Furthermore, in step 1, in the spectrum range W = [f0, f0 + W] starting from the lowest frequency f0 of the system transmission signal, the power spectrum distribution of the communication signal of the optical fiber communication perception integrated system centered on communication is combined Optical fiber channel dispersion CD(f), channel noise power spectrum distribution P nn (f) and the perceived target unit impulse response g(t), calculate the system perception mutual information, the expression is as follows:

[0014]

[0015] Among them, y sc (t) is the system synaesthesia integrated waveform signal, x s (t) is the perception signal to be designed, and its power spectrum distribution is X s (f); is the signal transmission duration; is the variance of the power spectrum distribution G(f) of g(t).

[0016] Furthermore, in step 2, the perceived signal power limit is determined by the parameters of the system transmitter device.

[0017] Furthermore, in step 2, the system senses the signal transmission power limit. Under this power limit, calculate the maximum value of the system-perceived mutual information in step 1:

[0018]

[0019] Among them, E x To perceive the signal energy limitation.

[0020] Further, step 3 is as follows: the system perceived link noise r(f) and the injection level A are calculated by maximizing the system perceived mutual information obtained in step 2:

[0021]

[0022] And the power spectrum distribution of the perception signal is calculated by the water injection method:

[0023] |X s (f)| 2 =max[0,Ar(f)] (5)

[0024] In step 2, the maximum value of the system-perceived mutual information is calculated by constructing a constraint function using the Lagrange multiplier method; the constraint function is as follows:

[0025]

[0026] Furthermore, in step 4, the selection of the sensing signal waveform is determined by the specific system and application scenario, and commonly used waveforms are pulse signals or linear frequency modulation signals.

[0027] Furthermore, step 5 is specifically as follows: the sensing signal obtained in step 4 is added to the system communication signal, a corresponding electrical signal is generated by an arbitrary signal generator, modulated into an optical signal by an optical modulator, and coupled into an optical fiber for transmission.

[0028] Furthermore, step 6 is specifically as follows: after the optical signal is transmitted through the optical fiber and affected by the perception target, at the communication receiving end, the communication signal is filtered out by an optical filter, and the optical communication receiver receives and obtains the communication information; at the perception receiving end, the perception signal is filtered out by an optical filter, and the optical perception receiver receives and obtains the perception target information.

[0029] The present invention also discloses a waveform design system for integrated communication perception under optical fiber based on water injection method, which is used to execute the above method and includes the following modules:

[0030] Transmission module: Calculate the system perception mutual information by combining the communication signal power spectrum distribution, optical fiber channel dispersion, channel noise power spectrum distribution and perception target unit pulse response of the communication-centered optical fiber communication perception integrated system; Calculate the maximum value of the system perception mutual information by combining the system perception signal transmission power limit; Calculate the system perception link noise and injection level by the maximum value of the system perception mutual information, and calculate the perception signal power spectrum distribution by the water injection method; Select the system perception signal waveform, and set its parameters so that its power spectrum distribution is consistent with the obtained perception signal power spectrum distribution, and obtain the system perception signal; Add the obtained perception signal to the system communication signal to generate a corresponding electrical signal, modulate it into an optical signal, and transmit it to the receiving module through the optical fiber;

[0031] Receiving module: After the optical signal is transmitted through the optical fiber and affected by the sensing target, at the communication receiving end, the communication signal is filtered out and received by the optical communication receiver to obtain the communication information; at the sensing receiving end, the sensing signal is filtered out and received by the optical sensing receiver to obtain the sensing target information.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. Simple and fast waveform design: When the system parameters are known, the power spectrum distribution of the perceived signal can be obtained by calculating the perceived link noise and combining it with the water injection method through simple calculation. The actual perception only needs to make its power spectrum density consistent with the calculated result to obtain excellent system perception performance.

[0034] 2. Good generalization ability: Compared with the existing integrated waveform design method that is closely integrated with the system architecture, the present invention can be used for the design of integrated waveforms without recalculating the perceived link noise when the system parameters and communication signals do not change. Therefore, the present invention can be deployed in a wide range of ISAC-OF systems and has good generalization ability.

[0035] 3. Comprehensive analysis of system performance: The present invention analyzes the main influencing factors of the short-distance ISAC-OF system, such as fiber dispersion and thermal noise, and provides a comprehensive analysis of system performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a block diagram of a communication perception integrated waveform design system based on a water injection method according to a preferred embodiment of the present invention;

[0037] Figure 2It is a flow chart of a communication perception integrated waveform design method based on a water injection method according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0038] In order to more clearly illustrate the embodiments of the present invention, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other accompanying drawings and other implementation methods can be obtained based on these accompanying drawings without creative work.

[0039] like Figure 1-2 As shown, this embodiment proposes a waveform design method for integrated communication perception under optical fiber based on water injection method, and the specific steps are as follows:

[0040] Step 1: In the spectrum range W = [f0, f0 + W], combine the communication signal power spectrum distribution of the communication-centric fiber-optic communication-sensing integrated system Optical fiber channel dispersion CD(f), channel noise power spectrum distribution P nn (f) and the perceived target unit impulse response g(t), the calculation system perception mutual information expression is:

[0041]

[0042] Among them, y sc (t) is the system synaesthesia integrated waveform signal, x s (t) is the perception signal to be designed, and its power spectrum distribution is X s (f); is the signal transmission duration; is the variance of the power spectrum distribution G(f) of g(t);

[0043] Step 2: Combine system-aware signal transmission power limits Under this power limit, calculate the maximum value of the system-perceived mutual information in step 1:

[0044]

[0045] Among them, E x To perceive the signal energy limitation.

[0046] By using the Lagrange multiplier method, the constraint function is constructed:

[0047]

[0048] Calculate the maximum value of the perceived mutual information of the calculated system.

[0049] In this step 2, the perceived signal power limit is determined by the parameters of the system transmitter device.

[0050] Step 3: Calculate the system perceived link noise r(f) and the injection level A by maximizing the system perceived mutual information obtained in step 2:

[0051]

[0052] And the power spectrum distribution of the perception signal is calculated by the water injection method:

[0053] X s (f) 2 =max[0,Ar(f)] (12)

[0054] Step 4: Select the system perception signal waveform and set its parameters so that its power spectrum distribution is as consistent as possible with the perception signal power spectrum distribution obtained in step 3, thereby obtaining the system perception signal. The selection of the perception signal waveform is determined by the specific system and application scenario. Common waveforms are pulse signals or linear frequency modulation signals.

[0055] Step 5: Add the sensing signal obtained in step 4 to the system communication signal, generate a corresponding electrical signal by an arbitrary signal generator, modulate it into an optical signal by an optical modulator, and couple it into the optical fiber for transmission.

[0056] Step 6: After the optical signal is transmitted through the optical fiber and affected by the sensing target, at the communication receiving end, the communication signal is filtered out by an optical filter, and the optical communication receiver receives and obtains the communication information; at the sensing receiving end, the sensing signal is filtered out by an optical filter, and the optical sensing receiver receives and obtains the sensing target information.

[0057] The present invention firstly establishes a mathematical model for the communication-centered optical fiber synaesthesia integrated system, uses system parameters and communication signals in combination with the model to calculate the perception link noise, and uses the water injection method to design the perception signal power spectrum distribution based on the noise, and finally designs an integrated waveform to optimize the system performance and realize a simple and fast synaesthesia integrated waveform design, thereby constructing a high-performance optical fiber synaesthesia integrated system.

[0058] like Figure 1As shown, this embodiment discloses an integrated waveform design system for communication and perception under optical fiber based on water injection method, which is used to execute the above method. The system includes a transmission module and a receiving module. The transmission module includes an arbitrary signal generator and an optical modulator. The waveform signal designed by offline processing of the integrated waveform design method based on water injection method generates a corresponding electrical signal through an arbitrary signal generator, which is then converted into an optical signal through an optical modulator and coupled into the optical fiber for transmission to the receiving module. The receiving module is composed of an optical filter module, an optical communication receiver module, an optical perception receiver module, etc., wherein the two optical filter modules are respectively used to filter out the communication receiving signal and the perception receiving signal. The two signals enter the corresponding optical receiver for demodulation to obtain the corresponding communication and perception information. The specific structure of the optical communication receiving module and the optical perception receiving module is determined according to the communication mode and perception mode adopted. Specifically:

[0059] Transmission module: Calculate the system perception mutual information by combining the communication signal power spectrum distribution, optical fiber channel dispersion, channel noise power spectrum distribution and perception target unit pulse response of the communication-centered optical fiber communication perception integrated system; Calculate the maximum value of the system perception mutual information by combining the system perception signal transmission power limit; Calculate the system perception link noise and injection level by the maximum value of the system perception mutual information, and calculate the perception signal power spectrum distribution by the water injection method; Select the system perception signal waveform, and set its parameters so that its power spectrum distribution is consistent with the obtained perception signal power spectrum distribution, and obtain the system perception signal; Add the obtained perception signal to the system communication signal to generate a corresponding electrical signal, modulate it into an optical signal, and transmit it to the receiving module through the optical fiber;

[0060] Receiving module: After the optical signal is transmitted through the optical fiber and affected by the sensing target, at the communication receiving end, the communication signal is filtered out and received by the optical communication receiver to obtain the communication information; at the sensing receiving end, the sensing signal is filtered out and received by the optical sensing receiver to obtain the sensing target information.

[0061] For other contents of this embodiment, please refer to the above method embodiment.

[0062] In summary, the present invention analyzes the performance of the ISAC-OF system and designs an optimized integrated waveform, which can effectively reduce the impact of system signal crosstalk and improve the system communication and perception performance.

[0063] It should be noted that the above description is only a detailed description of the preferred embodiments and principles of the present invention. For ordinary technicians in this field, there will be changes in the specific implementation methods based on the ideas provided by the present invention, and these changes should also be regarded as the scope of protection of the present invention.

Claims

1. A waveform design method for integrated communication and perception under optical fiber based on water injection method, characterized by: Follow these steps: Step 1, combining the communication signal power spectrum distribution, optical fiber channel dispersion, channel noise power spectrum distribution and perception target unit impulse response of the communication-centered optical fiber communication perception integrated system, and calculating the system perception mutual information; Step 2, combining the system perception signal transmission power limit, calculating the maximum value of the system perception mutual information in step 1; Step 3, calculating the system perception link noise and water injection level by the maximum value of the system perception mutual information obtained in step 2, and calculating the perception signal power spectrum distribution by water injection method; Step 4, selecting a system perception signal waveform, and setting parameters so that its power spectrum distribution is consistent with the power spectrum distribution of the perception signal obtained in step 3, to obtain a system perception signal; Step 5, adding the sensing signal obtained in step 4 to the system communication signal to generate a corresponding electrical signal, modulating it into an optical signal, and transmitting it through an optical fiber; Step 6: After the optical signal is transmitted through the optical fiber and affected by the sensing target, at the communication receiving end, the communication signal is filtered out, and the optical communication receiver receives and obtains the communication information; at the sensing receiving end, the sensing signal is filtered out, and the optical sensing receiver receives and obtains the sensing target information.

2. The integrated waveform design method for optical fiber communication and sensing based on water injection method as claimed in claim 1 is characterized in that: Step 1 is as follows: In the spectrum range W = [f0, f0 + W] with the lowest frequency f0 of the system transmission signal as the starting point, the power spectrum distribution of the communication signal of the optical fiber communication perception integrated system centered on communication is combined Optical fiber channel dispersion CD(f), channel noise power spectrum distribution P nn (f) and the perceived target unit impulse response g(t), calculate the system perception mutual information, the expression is as follows: Among them, y sc (t) is the system synaesthesia integrated waveform signal, x s (t) is the perception signal to be designed, and its power spectrum distribution is X s (f); is the signal transmission duration; is the variance of the power spectrum distribution G(f) of g(t).

3. The integrated waveform design method for optical fiber communication perception based on water injection method as claimed in claim 2 is characterized in that: Step 2 is as follows: Combined with the system perception signal transmission power limit Under this power limit, calculate the maximum value of the system-perceived mutual information in step 1: Among them, E x To perceive the signal energy limitation.

4. The integrated waveform design method for optical fiber communication and sensing based on water injection method as claimed in claim 3 is characterized in that: Step 3 is as follows: Calculate the system perceived link noise r(f) and the injection level A by maximizing the system perceived mutual information obtained in step 2: And the power spectrum distribution of the perception signal is calculated by the water injection method: X s (f) 2 =max[0,A-r(f)] (5)。 5. The method for designing an integrated waveform for optical fiber communication and sensing based on water injection as claimed in claim 4, characterized in that: In step 2, the maximum value of the system-perceived mutual information is calculated by using the Lagrange multiplier method to construct a constraint function; the constraint function is as follows:

6. The method for designing an integrated waveform for communication and sensing under optical fiber based on water injection method according to any one of claims 1 to 5, characterized in that: In step 2, the perceived signal power limit is determined by the parameters of the system transmitter device.

7. The method for designing an integrated waveform for communication and sensing under optical fiber based on water injection method according to any one of claims 1 to 5, characterized in that: Step 5 is specifically as follows: the sensing signal obtained in step 4 is added to the system communication signal, and a corresponding electrical signal is generated by an arbitrary signal generator, which is modulated into an optical signal by an optical modulator and coupled into an optical fiber for transmission.

8. The method for designing an integrated waveform for communication and sensing under optical fiber based on water injection method according to any one of claims 1 to 5, characterized in that: Step 6 is as follows: after the optical signal is transmitted through the optical fiber and affected by the sensing target, at the communication receiving end, the communication signal is filtered out by an optical filter, and the optical communication receiver receives and obtains the communication information; at the sensing receiving end, the sensing signal is filtered out by an optical filter, and the optical sensing receiver receives and obtains the sensing target information.

9. An integrated waveform design system for communication perception under optical fiber based on water injection method, used to execute the method according to any one of claims 1 to 8, characterized in that Includes the following modules: Transmission module: Calculate the system perception mutual information by combining the communication signal power spectrum distribution, optical fiber channel dispersion, channel noise power spectrum distribution and perception target unit pulse response of the communication-centered optical fiber communication perception integrated system; Calculate the maximum value of the system perception mutual information by combining the system perception signal transmission power limit; Calculate the system perception link noise and injection level by the maximum value of the system perception mutual information, and calculate the perception signal power spectrum distribution by the water injection method; Select the system perception signal waveform, and set its parameters so that its power spectrum distribution is consistent with the obtained perception signal power spectrum distribution, and obtain the system perception signal; Add the obtained perception signal to the system communication signal to generate a corresponding electrical signal, modulate it into an optical signal, and transmit it to the receiving module through the optical fiber; Receiving module: After the optical signal is transmitted through the optical fiber and affected by the sensing target, at the communication receiving end, the communication signal is filtered out and received by the optical communication receiver to obtain the communication information; at the sensing receiving end, the sensing signal is filtered out and received by the optical sensing receiver to obtain the sensing target information.

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