Cross-medium passive communication method, system and intelligent terminal in extreme environment

Abstract

This application proposes a method, system, and smart terminal for cross-medium passive communication in extreme environments. It utilizes a multi-dimensional environmental sensor array to collect real-time medium characteristic parameters and interference signal characteristics; determines the current communication medium type and selects a passive communication mode; determines reference signal parameters; calculates adjustment parameters based on the reference signal parameters and interference signal characteristics; adjusts the parameters of a metamaterial reflective array according to the adjustment parameters; and uses the metamaterial reflective array to encode and modulate external incident signals to obtain the reference signal, thus achieving cross-medium passive communication. This application achieves precise adaptation of the smart terminal for cross-medium passive communication in extreme scenarios through the collaborative mechanism of the multi-dimensional environmental sensor array and the metamaterial reflective array. While ensuring the accuracy of information transmission, the continuity of passive communication, and the reliability against interference, it significantly reduces reliance on active power supply and extends the communication endurance of the device in scenarios without external power.

Description

Technical Field

[0001] This application relates to the field of smart terminals, and more specifically, to a cross-medium passive communication method, system, and smart terminal under extreme environments. Background Technology

[0002] In extreme environments such as volcanoes and the deep sea, communication is a critical requirement for ensuring personnel safety and operational collaboration. These scenarios are often accompanied by complex conditions such as high / low temperatures, high pressure, and strong electromagnetic interference, requiring highly protective intelligent terminals with the ability to withstand harsh environments to achieve communication.

[0003] However, existing communication technologies have significant limitations in extreme environments: active communication solutions such as satellite and radio communication rely on a continuous power supply, which can easily damage the power module or deplete its energy in extreme environments, making long-term passive communication impossible; traditional passive communication solutions such as single sonar reflection and simple electromagnetic induction suffer from poor media adaptability and weak anti-interference capabilities, making it difficult to operate stably in complex media. Although existing devices can withstand extreme physical environments through structural design, their integrated communication modules often lack real-time perception and dynamic adaptation capabilities to the environmental media, making it impossible for communication devices to continuously provide stable passive communication support in extreme cross-media scenarios, thus failing to meet the core requirement of communication reliability.

[0004] Therefore, a communication solution is needed to address the above problems. Summary of the Invention

[0005] To address the problems existing in current technologies, this application provides a method, system, and smart terminal for cross-medium passive communication under extreme environments. The specific solution is as follows:

[0006] In its first part, this application proposes a passive cross-medium communication method under extreme environments, including:

[0007] The system uses a pre-set multi-dimensional environmental sensor array built into the smart terminal to collect in real time the medium characteristics parameters and interference signal features of the environment in which the smart terminal is currently located.

[0008] Based on a preset decision algorithm, the current communication medium type is determined according to the medium characteristic parameters, and a passive communication mode matching the communication medium type is selected.

[0009] Determine the reference signal parameters of the passive communication mode, and calculate the adjustment parameters of the preset metamaterial reflective array in the passive communication mode by combining the reference signal parameters with the characteristics of the interference signal;

[0010] The metamaterial reflective array is adjusted according to the adjustment parameters, including impedance value, phase offset, absorption frequency band and overall array reflection angle.

[0011] By using an adjusted metamaterial reflective array to encode and modulate external incident signals to obtain a reference signal carrying communication information and adapted to the current communication medium type, passive cross-medium communication can be achieved.

[0012] In some specific embodiments, the medium characteristic parameters include at least the medium refractive index, ambient pressure, and ambient temperature;

[0013] The characteristics of the interference signal include at least the frequency and intensity of the interference signal;

[0014] The external incident signals include natural environmental signals and artificial rescue signals, and the artificial rescue signals include sonar signals, infrared laser signals and radar wave signals.

[0015] In some specific embodiments, within the multi-dimensional environmental sensor array:

[0016] The system collects refractive index data of the current environment medium through a medium refractive index sensor to distinguish between land and water; it simultaneously collects current environmental pressure and temperature through pressure and temperature sensors to help determine extreme scenarios, including deep sea and volcanic areas; it collects the frequency and intensity of interference signals through a broadband electromagnetic sensor to identify volcanic geothermal electromagnetic noise and thunderstorm EMP signals; and it collects acoustic interference signals in underwater and cave scenarios through a passive acoustic sensor.

[0017] In some specific embodiments, if the refractive index and pressure of the medium in the medium characteristic parameters simultaneously meet the preset first condition, then the communication medium type is determined to be an underwater medium, and a first communication mode that uses an acoustic signal as the reference signal and is adapted to the low attenuation characteristics of seawater acoustic transmission is selected.

[0018] If the electromagnetic signal strength and temperature in the medium characteristic parameters simultaneously meet the preset second condition, then the communication medium type is determined to be volcanic medium, and the second communication mode, which is an ultra-low frequency electromagnetic signal and adapted to the geothermal electromagnetic environment of the volcanic area, is selected as the reference signal.

[0019] If the refractive index and temperature of the medium in the medium characteristic parameters simultaneously meet the preset third condition, then the communication medium type is determined to be ice medium, and the reference signal is selected as a composite signal of near-infrared light and ice vibration, and the third communication mode is adapted to the low absorption of near-infrared light and stable vibration transmission characteristics of ice.

[0020] If the ambient light intensity and electromagnetic intensity in the medium characteristic parameters simultaneously meet the preset fourth condition, then the communication medium type is determined to be a dark low electromagnetic medium, and the fourth communication mode, which is a blue-green light pulse signal that is adapted to visual perception in dark environments and has low electromagnetic interference characteristics, is selected.

[0021] In some specific embodiments, the metamaterial reflective array is provided with multiple adjustment clusters composed of nanoscale graphene sheets. The cluster impedance value is controlled by changing the curvature of the graphene sheets, and the phase shift is controlled by adjusting the tilt angle of the graphene sheets. The overall reflection angle of the array is adjusted by adjusting the overall tilt angle of the metamaterial reflective array.

[0022] The metamaterial reflective array is coated with an absorption coating of multiple frequency bands. The absorption coating of the corresponding frequency band is activated by electromagnetic induction to adjust the absorption frequency band.

[0023] In some specific embodiments, encoding and modulating the physical characteristics of the incident signal specifically includes:

[0024] The communication information is converted into a binary data stream according to a preset encoding rule; the adjustment parameters of the metamaterial reflective array are dynamically switched according to the timing of the data stream based on the binary data stream, so that the physical characteristics of the incident signal change with the binary data stream to form a modulation signal, and a reference signal is obtained.

[0025] In some specific embodiments, during the modulation process, the switching frequency of the adjustment parameters of the metamaterial reflective array is matched with the bit rate of the binary data stream, and the switching action is synchronized with the period of the incident signal; the modulation parameters are optimized according to the current communication medium type to ensure that the reference signal is transmitted with low attenuation in the medium.

[0026] In some specific embodiments, when the external incident signal is an optical signal, the encoding and modulation process is as follows:

[0027] The modulation pulse period of the optical signal is divided into two time windows, and different bit values ​​in the binary data stream converted from the communication information are mapped to the reflection state of the optical signal in different time windows; at the same time, different bit values ​​correspond to the activation or deactivation state of the absorption band.

[0028] By controlling the on / off state of graphene sheets in the metamaterial reflective array to achieve different time window selections, and combining this with electromagnetic induction to activate or deactivate the absorption coating corresponding to the absorption frequency band, the reflected light signal forms a jointly modulated reference signal.

[0029] Part Two, this application proposes a passive cross-medium communication system for extreme environments, comprising:

[0030] The signal acquisition unit is used to collect in real time the medium characteristic parameters and interference signal characteristics of the environment in which the smart terminal is currently located through a multi-dimensional environmental sensor array built into the smart terminal.

[0031] The mode selection unit is used to determine the current communication medium type based on the medium characteristic parameters according to the preset decision algorithm, and select a passive communication mode that matches the communication medium type.

[0032] The parameter calculation unit is used to determine the reference signal parameters of the passive communication mode, and calculate the adjustment parameters of the preset metamaterial reflective array in the passive communication mode by combining the reference signal parameters with the characteristics of the interference signal.

[0033] An array adjustment unit is used to perform parameter adjustment operations on the metamaterial reflective array according to the adjustment parameters, including impedance value, phase offset, absorption frequency band and overall array reflection angle.

[0034] The passive communication unit is used to encode and modulate external incident signals using an adjusted metamaterial reflective array to obtain a reference signal carrying communication information and adapted to the current communication medium type, thereby realizing cross-medium passive communication.

[0035] In the third part, this application proposes a smart terminal for cross-medium passive communication, which is used to implement the cross-medium passive communication method in extreme environments as described in any one of the first parts.

[0036] Beneficial Effects: This application proposes a cross-medium passive communication method, system, and intelligent terminal for extreme environments. Through the collaborative mechanism of a multi-dimensional environmental sensor array and a metamaterial reflective array, it achieves precise adaptation of intelligent terminals for cross-medium passive communication in extreme scenarios such as volcanoes and deep seas. While ensuring the accuracy of information transmission, the continuity of passive communication, and the reliability of anti-interference, it significantly reduces the dependence on active power supply and extends the communication endurance of devices in scenarios without external power supply. It effectively improves the communication adaptability, scenario coverage, and emergency communication stability of intelligent terminals such as ruggedized devices in complex extreme environments, and solves the problems of traditional passive communication being difficult to adapt to multiple media, being susceptible to signal interference in extreme environments, and having limited endurance due to dependence on active power supply.

[0037] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1This is a schematic diagram of the cross-media passive communication method of this application;

[0040] Figure 2 This is a schematic diagram illustrating the principle of the cross-media passive communication method of this application;

[0041] Figure 3 This is a schematic diagram of the control process of the metamaterial reflective array in this application;

[0042] Figure 4 This is a schematic diagram of the optical signal encoding and modulation process of this application;

[0043] Figure 5 This is a schematic diagram of the cross-media passive communication system module of this application.

[0044] Reference numerals in the attached figures: 1-Signal acquisition unit; 2-Mode selection unit; 3-Parameter calculation unit; 4-Array adjustment unit; 5-Passive communication unit. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0046] This application proposes a cross-medium passive communication method under extreme environments. Through real-time acquisition of the medium characteristics and interference signals from a multi-dimensional environmental sensor array, communication medium determination and passive mode matching via a decision algorithm, dynamic adjustment of multiple parameters of a metamaterial reflective array, and a collaborative mechanism of encoding and modulating external incident signals, precise adaptation of intelligent terminals for cross-medium passive communication in extreme scenarios is achieved. A schematic diagram of the cross-medium passive communication method is attached. Figure 1 As shown in the attached diagram, the principle is as follows: Figure 2 As shown, the specific solution is as follows:

[0047] A passive cross-medium communication method under extreme environments includes:

[0048] 101. By using a pre-set multi-dimensional environmental sensor array built into the smart terminal, the medium characteristic parameters and interference signal characteristics of the current environment of the smart terminal are collected in real time.

[0049] 102. Based on a preset decision algorithm, determine the current communication medium type according to the medium characteristic parameters, and select a passive communication mode that matches the communication medium type;

[0050] 103. Determine the reference signal parameters for the passive communication mode, and calculate the adjustment parameters of the preset metamaterial reflective array in the passive communication mode by combining the reference signal parameters with the characteristics of the interference signal;

[0051] 104. Adjust the parameters of the metamaterial reflective array according to the adjustment parameters, including impedance value, phase offset, absorption frequency band and overall reflection angle of the array;

[0052] 105. By using an adjusted metamaterial reflective array to encode and modulate external incident signals to obtain a reference signal carrying communication information and adapted to the current communication medium type, cross-medium passive communication can be realized.

[0053] This application addresses the challenges of traditional passive communication in extreme environments, such as difficulty in cross-media adaptation, susceptibility to signal interference, and reliance on active power supply, through a coherent process involving environmental perception, pattern matching, parameter calculation, array adjustment, and communication. The intelligent terminal serves as the carrier of this method and is typically a device with extreme environment protection capabilities, such as a rugged terminal. Its built-in components must be adaptable to extreme conditions such as high temperature, high pressure, low temperature, and strong electromagnetic fields to ensure stable operation even in harsh environments.

[0054] Step 101 aims to provide accurate environmental data support for subsequent communication adaptation. The multi-dimensional environmental sensor array is an integrated sensing module built into the smart terminal, not a single sensor. Its design principle is based on the dual impact of medium transmission characteristics and environmental interference on communication in extreme environments. For example, different media such as water, ice, and air have vastly different attenuation rates and propagation directions for sound, light, and electromagnetic signals. Furthermore, specific interference is prevalent in extreme environments. Relying on a single parameter cannot accurately determine communication adaptation requirements; therefore, multi-dimensional data collection is necessary to achieve comprehensive environmental understanding.

[0055] In some specific embodiments, the dielectric characteristic parameters include at least the dielectric refractive index, ambient pressure, ambient temperature, and electromagnetic signal intensity; the interference signal characteristics include at least the frequency and intensity of the interference signal and the ambient light intensity.

[0056] The refractive index of a medium is the most direct indicator for distinguishing the type of medium. Because the refractive indices of land, water, and ice are significantly different, this parameter alone can be used to preliminarily determine the major category of the medium in which the communication takes place. Ambient pressure is used to help determine the extreme degree of the medium. For example, the difference between normal pressure and high pressure directly affects the attenuation rate of signal transmission and also determines the protection requirements of smart terminals. Ambient temperature is used to identify special scenarios such as high temperature and low temperature. These scenarios will change the speed of signal propagation and need to be adapted accordingly.

[0057] The selection of frequency and intensity for interference signal characteristics is based on the fact that the core impact differences of different interferences are reflected in these two dimensions. Frequency determines the type of interference, such as 0.1-1Hz for volcanic geothermal electromagnetic noise and 10-30kHz for underwater sonar interference, which can be used to determine the signal frequency bands to be avoided; intensity determines the degree of impact of interference on communication, interference with an intensity ≥80dB will severely mask the reference signal, which can be used to set the priority of interference avoidance.

[0058] In some embodiments, external incident signals include natural environmental signals and artificial rescue signals. Artificial rescue signals include sonar signals, infrared laser signals, and radar wave signals. This classification of external incident signals ensures the reliability of signal sources for passive communication. Natural environmental signals are signals that naturally exist in extreme scenarios, such as geothermal electromagnetic signals from volcanoes and underwater background noise in the deep sea, enabling communication without external intervention. Artificial rescue signals are signals actively emitted during rescue scenarios. Sonar signals are suitable for underwater positioning, infrared laser signals are suitable for dark / ice-covered environments, and radar wave signals are suitable for long-distance coverage, improving communication efficiency during rescue operations. The combination of these two types of signals can cover the two core communication needs of daily monitoring and emergency rescue in extreme environments, avoiding communication interruptions caused by the lack of a single signal source.

[0059] The sensor array collects data in real time at a preset sampling frequency and transmits the data to the processing module of the smart terminal to ensure data timeliness. This provides a basis for subsequent steps, avoiding blind selection of communication modes and array adjustments, and ensuring communication compatibility from the source.

[0060] In some specific embodiments, within a multi-dimensional environmental sensor array: a medium refractive index sensor collects refractive index data of the current environmental medium to distinguish between land and water; pressure and temperature sensors simultaneously collect current environmental pressure and temperature to assist in determining extreme scenarios, including deep sea and volcanic areas; a broadband electromagnetic sensor collects the frequency and intensity of interference signals to identify volcanic geothermal electromagnetic noise and thunderstorm EMP signals; and a passive acoustic sensor collects acoustic interference signals in underwater and cave scenarios. The precise matching of each sensor's function with the scenario requirements ensures the efficiency and accuracy of environmental data acquisition.

[0061] The working principle of the medium refractive index sensor is based on the law of refraction of light. The sensor emits probe light of a fixed wavelength and calculates the refractive index of the medium by detecting the change in the angle of refraction of the light in the current medium and combining it with the law of refraction. The pressure sensor and temperature sensor adopt a synchronous acquisition design. The principle is that pressure and temperature often coexist in extreme scenarios, such as the deep sea with high pressure and low temperature, and volcanoes with high temperature and normal pressure. Individual acquisition is prone to misjudgment. The implementation method adopts an integrated pressure and temperature sensor to avoid communication mode mismatch caused by scene misjudgment. The design of the broadband electromagnetic sensor is based on the fact that the frequency range of volcanic geothermal electromagnetic noise (0.1-1Hz) and thunderstorm EMP signal (1kHz-1GHz) is large, and a wide frequency band coverage is required for effective acquisition. The electromagnetic signals in the environment are captured by electromagnetic induction coils, converted into electrical signals, and then analyzed for frequency and intensity to accurately identify the two types of strong interference signals, providing a precise basis for subsequent adjustment of the absorption frequency band of the metamaterial reflective array. The application scenarios of passive acoustic sensors are focused on underwater and cave environments because acoustic interference signals are significant in these two scenarios. Furthermore, the passive design does not require additional power supply, which is suitable for the low power consumption requirements of smart terminals in extreme environments and ensures the anti-interference capability of acoustic reference signals in underwater and cave scenarios.

[0062] Step 102 determines the communication medium type and selects a matching passive communication mode based on a preset decision algorithm. After inputting the parameters from step 101 into decision algorithms such as decision tree algorithms, the medium type is quickly output according to preset logical rules. Then, the mode is selected according to the preset correspondence between medium type and communication mode. The calculation is simplified by logical rules to ensure that the device can still respond quickly even in extreme environments with limited computing power. This achieves accurate adaptation between the communication mode and the current medium, avoiding the use of an incompatible mode that would cause the signal to attenuate rapidly in the medium.

[0063] Among them, the preset decision algorithm is a lightweight logic algorithm that is embedded in the main control module of the smart terminal in advance. It is not a complex deep learning model. Its design takes into account the low power consumption and fast response requirements of the device in extreme environments, and avoids communication delays caused by excessive algorithm operation time.

[0064] The principle for determining the current communication medium type is to use the combination of medium characteristic parameters collected in step 101 to form medium features. Different extreme environments have unique parameter combinations. For example, the refractive index and pressure in an underwater environment will simultaneously be within a specific range, while a volcanic environment will simultaneously exhibit high temperature and high electromagnetic signal intensity. The algorithm can accurately determine the medium type by comparing it with preset parameter threshold ranges. Relying solely on a single parameter, such as using only temperature to determine a volcanic environment, may lead to confusion with other high-temperature scenarios. Therefore, multi-parameter combination determination is crucial to ensuring accuracy.

[0065] Passive communication refers to a mode of communication that does not require the intelligent terminal to actively emit energy, but relies solely on reflecting or modulating external signals to achieve communication. The core difference between different modes lies in the type of signal they adapt to, such as sound waves, near-infrared light, and ultra-low frequency electromagnetic signals. The selection principle is based on the transmission attenuation characteristics of different media for different signals. For example, seawater attenuates sound waves much less than it attenuates electromagnetic signals, therefore underwater media are suitable for passive communication modes based on sound waves. Ice has a low absorption rate of near-infrared light, therefore ice media are suitable for passive communication modes related to near-infrared light.

[0066] Step 103 determines the reference signal parameters for the passive communication mode and calculates the adjustment parameters for the metamaterial reflective array. The corresponding reference signal parameters are retrieved from a preset communication mode and reference parameter library, and combined with the interference signal characteristics acquired in step 101, the adjustment parameters are output using a preset calculation formula. This provides a specific and executable control basis for subsequent array adjustments, preventing array adjustments from being haphazard and resulting in the inability to reflect qualified reference signals or avoid interference.

[0067] Reference signal parameters refer to the standard attributes of a signal that can be transmitted with low attenuation in the current medium under the corresponding passive communication mode. These include the signal frequency, amplitude, and pulse interval. The principle for determining these parameters is based on the transmission characteristics of the selected communication mode and the current medium. For example, the reference signal frequency for underwater acoustic wave mode needs to be selected from the frequency band with the lowest seawater attenuation. If the frequency is too high, the signal will be rapidly lost in seawater, while if the frequency is too low, it will be easily affected by environmental noise.

[0068] The adjustment parameters of a metamaterial reflective array refer to the specific control indicators that enable the metamaterial array to achieve a state of adapting to the reference signal and avoiding interference. These include impedance value, phase offset, absorption frequency band, and overall array reflection angle. The principle of calculating these parameters is to combine the reference signal parameters with the characteristics of the interference signal. For example, when the reference signal frequency is 15kHz, the array impedance value needs to be adjusted to ensure the reflection efficiency of the signal at that frequency. If there is an interference signal of 10-30kHz, the absorption frequency band parameters need to be calculated to allow the array to absorb the interference of that frequency band and avoid the interference from superimposing on the reference signal.

[0069] Step 104 involves adjusting multiple parameters of the metamaterial reflective array based on the adjustment parameters. The intelligent terminal main control module sends control signals to the array's driving components according to the adjustment parameters. The driving components adjust the array structure according to the signals. The principle is to utilize the adjustable characteristics of metamaterials and the precise control capabilities of the driving components to achieve coordinated adjustment of multiple parameters. The effect is to put the metamaterial array in an optimal working state, which can both efficiently reflect reference signals and selectively absorb interference, laying the foundation for subsequent signal modulation.

[0070] The metamaterial reflective array is the core component of this method. Composed of nanoscale materials, it possesses tunable signal reflection and absorption characteristics, unlike traditional fixed-characteristic reflective devices. Impedance adjustment changes the array's impedance matching state to the signal. This is achieved by altering the material structure within the array through a driving unit, adjusting the impedance value to ensure efficient reflection of the reference signal. Impedance mismatch leads to significant signal absorption rather than reflection, reducing communication efficiency. Phase offset adjustment changes the phase of the reflected signal. This is achieved by adjusting the tilt angle of the material to match the phase of the reflected signal to the reference signal requirements, ensuring directional signal propagation and preventing signal diffusion due to phase disturbances. Absorption band adjustment allows the array to absorb only interference signals in specific frequency bands. This is achieved through a frequency band-zoned absorption coating on the array surface. Activating the corresponding zone allows absorption of specific interference frequencies, while inactive zones maintain their reflection characteristics of the reference signal, avoiding absorption. Overall array reflection angle adjustment changes the overall tilt direction of the array. This is achieved by adjusting the array's reflection angle, enabling the reflected signal to be directionally transmitted to the target direction, reducing multipath attenuation.

[0071] Step 105 utilizes the adjusted metamaterial reflective array to encode and modulate the external incident signal into a reference signal, achieving passive cross-medium communication. The metamaterial array adjusts its state in real time to modulate the incident signal according to the control commands corresponding to the communication information. The modulated signal is transmitted to the receiving end through the medium, and the receiving end obtains the communication information through decoding. The principle is to utilize the dynamic adjustment capability of the metamaterial array to achieve signal modulation, eliminating the need for an additional signal transmission module. The effect is to achieve cross-medium communication without active power supply, solving the problem of short device endurance in extreme environments while ensuring stable transmission of communication information and improving the reliability of emergency communication.

[0072] External incident signals refer to naturally occurring signals in the environment or artificial rescue signals. Choosing such signals as the modulation target is the core manifestation of passive characteristics. It eliminates the need for smart terminals to actively emit energy, significantly reducing device power consumption and extending battery life in extreme environments. Encoding modulation is the process of integrating communication information into the incident signal. The principle is to control the metamaterial array to dynamically switch and adjust parameters according to preset rules based on the content of the communication information, so that the physical characteristics of the incident signal change with the information. For example, after converting the "distress" information into a binary data stream, the array is controlled to maintain a certain impedance value when there are "0" bits and switch to another impedance value when there are "1" bits, so that the reflected signal carries the binary information.

[0073] The modulated final signal has signal properties consistent with the transmission characteristics of the current medium. For example, the reference signal for the underwater environment is sound wave, ensuring low attenuation transmission in seawater, and the reference signal for the ice environment is near-infrared light, ensuring low absorption transmission in ice.

[0074] This application determines the unique medium properties of extreme environments by combining two parameters, and then matches a dedicated passive communication mode based on the medium's signal transmission characteristics, thus avoiding communication failure caused by misjudgment of a single parameter or mode mismatch.

[0075] In some specific embodiments, if the refractive index and pressure of the medium simultaneously meet a preset first condition, the communication medium type is determined to be an underwater medium, and a first communication mode that uses an acoustic signal as the reference signal and is adapted to the low attenuation characteristics of seawater acoustic transmission is selected. The preset first condition is that the refractive index of the medium is between 1.32 and 1.34 and the ambient pressure is ≥0.5 atm. The refractive index of seawater is naturally stable in the range of 1.32-1.34, unlike the 1.0 of land air and the 1.30-1.32 of ice. A pressure of ≥0.5 atm can exclude shallow freshwater areas or humid air. The combination of these two factors can accurately pinpoint the seawater environment. The first communication mode, which uses sound wave signals as the reference signal and is adapted to the low attenuation characteristics of seawater sound transmission, is chosen because seawater has a great attenuation effect on electromagnetic waves (especially high-frequency electromagnetic waves). For example, high-frequency electromagnetic signals will be completely lost after only a few meters of transmission in seawater. However, the transmission attenuation of sound waves (especially low-frequency sound waves of 1-10kHz) in seawater is much lower than that of electromagnetic waves, enabling transmission over distances of several kilometers or even longer. Adapting to the sound transmission characteristics of seawater means matching the frequency and amplitude of the sound wave signal with the speed of sound and attenuation law of seawater, ensuring stable signal propagation in seawater and avoiding communication distances that are too short or signal loss due to signal type mismatch.

[0076] If the electromagnetic signal strength and temperature in the medium characteristic parameters simultaneously meet the preset second condition, the communication medium type is determined to be volcanic medium, and a second communication mode is selected, with the reference signal being an ultra-low frequency electromagnetic signal adapted to the geothermal electromagnetic environment of the volcanic area. The second condition is an electromagnetic signal strength ≥ 50V / m and an ambient temperature ≥ 80℃. Volcanic areas, due to frequent geothermal activity, continuously release large amounts of geothermal electromagnetic radiation, resulting in environmental electromagnetic signal intensity significantly higher than in ordinary scenarios. This, combined with high temperatures, eliminates scenarios such as industrial high-temperature zones (high temperature but no high electromagnetic radiation) or areas near high-voltage power lines (high electromagnetic radiation but no high temperature). The second communication mode, using an ultra-low frequency electromagnetic signal adapted to the geothermal electromagnetic environment of volcanic areas, is chosen because geothermal electromagnetic noise in volcanic areas is mostly concentrated in the mid-to-high frequency band (e.g., above 1kHz). Ultra-low frequency electromagnetic signals (typically below 300Hz) can penetrate this noise and are not easily interfered with. Furthermore, the rock geological structure of volcanic areas attenuates ultra-low frequency electromagnetic waves less, making them easier to penetrate rock layers compared to high-frequency signals. Adapting to the geothermal electromagnetic environment means ensuring that the ultra-low frequency signal's frequency band avoids the main frequency band of geothermal noise, guaranteeing that the signal is not masked by noise, achieving anti-interference communication in volcanic environments, and avoiding communication failures due to signal frequency band overlap with noise.

[0077] In some embodiments, if the refractive index and temperature of the medium simultaneously meet a preset third condition, the communication medium type is determined to be an ice medium, and a third communication mode is selected that uses a composite signal of near-infrared light and ice vibration, and is adapted to the low absorption of near-infrared light and stable vibration transmission characteristics of ice. The third condition is that the refractive index of the medium is between 1.30 and 1.32 and the ambient temperature is ≤5℃. Ice has a refractive index between that of seawater and air, and its temperature is consistently below freezing. Combining these factors allows for precise differentiation between ice and other low-temperature media. The third communication mode, which uses a composite signal of near-infrared light and ice vibration as the reference signal and is adapted to the characteristics of ice, is chosen because ice absorbs near-infrared light much less than visible light, enabling rapid transmission over a certain distance. However, near-infrared light is susceptible to ice cracks, which can reflect light and cause signal interruption. Ice vibration (mechanical waves transmitted through ice) experiences minimal attenuation within ice and is unaffected by electromagnetic interference, allowing for stable transmission, albeit at a slower speed. Combining these two technologies can compensate for each other's shortcomings. Adapting to the characteristics of ice involves selecting near-infrared light at the wavelength with the lowest absorption in ice (e.g., 1500-2000nm) and vibration signals at frequencies with the lowest transmission loss in ice (e.g., 10-50Hz), ensuring that the composite signal is both fast and stable within ice and avoiding the transmission defects of a single signal.

[0078] If both ambient light intensity and electromagnetic intensity in the medium characteristic parameters simultaneously meet the preset fourth condition, the communication medium type is determined to be a dark, low electromagnetic medium. The fourth communication mode, which uses a blue-green light pulse signal as the reference signal and is adapted to visual perception in dark environments with low electromagnetic interference characteristics, is selected. The fourth condition is that the ambient light intensity is ≤0.5 lux and the electromagnetic intensity is ≤20 V / m. For scenarios such as underground caves and deep-sea dark areas, where ambient light intensity ≤0.5 lux represents a low-light or dark environment, and electromagnetic intensity ≤20V / m represents extremely weak electromagnetic interference, the fourth communication mode, which uses blue-green light pulse signals as the reference signal and is adapted to the characteristics of this environment, is selected because blue-green light has high visibility in dark environments and is easily captured by optical detection equipment even in low light conditions. Furthermore, in low electromagnetic environments, there is no need to consider the impact of electromagnetic interference on the signal. The pulse mode can significantly reduce the modulation power consumption of the metamaterial array. Adapting to the environmental characteristics means controlling the pulse interval to 1-2 seconds / time and the signal strength to a range that can be captured without excessive power consumption. This ensures low-power, high-recognition passive communication in dark, low-interference environments, avoiding communication problems caused by using visible light or electromagnetic signals.

[0079] In some specific embodiments, the metamaterial reflective array is provided with multiple adjustment clusters composed of nanoscale graphene sheets. The cluster impedance value is controlled by changing the curvature of the graphene sheets, and the phase shift is controlled by adjusting the tilt angle of the graphene sheets. The overall reflection angle of the array is adjusted by adjusting the overall tilt angle of the metamaterial reflective array. The metamaterial reflective array is coated with an absorption coating of multiple frequency bands. The absorption coating of the corresponding frequency band is activated by electromagnetic induction to achieve adjustment of the absorption frequency band.

[0080] The multiple adjustment clusters set on the metamaterial reflective array are core functional units built on nanoscale graphene sheets. Nanoscale graphene sheets were chosen because they have excellent flexibility, conductivity, and resistance to extreme environments. They can withstand temperature differences of -80℃ to 800℃, are corrosion-resistant, and do not easily deform under high pressure, making them suitable for scenarios such as volcanoes and the deep sea. Each adjustment cluster consists of 10-20 nanoscale graphene sheets, which are arranged in an array or connected independently to form an independent control unit. This enables precise local control and avoids overall signal distortion caused by local errors when adjusting the entire array. At the same time, it reduces the energy consumption of adjusting a single sheet, meeting the low power consumption requirements of passive communication.

[0081] The impedance value of a graphene cluster is controlled by changing the curvature of the graphene sheet. The principle is that bending the nanoscale graphene sheet changes the length and cross-sectional area of ​​its conductive path. When the graphene sheet bends to one side, the conductive path lengthens and the cross-sectional area decreases, thus increasing the impedance value; conversely, bending to the other side decreases the impedance value.

[0082] The core of impedance adjustment is to achieve impedance matching. Based on the reference signal frequency determined in step 103, the cluster impedance value is adjusted to match the signal at that frequency. At this point, the signal reflection efficiency is the highest, which can reduce the energy loss caused by impedance mismatch. For example, in underwater acoustic wave mode, if the reference signal frequency is 15kHz, the cluster impedance value needs to be adjusted to the 50-100Ω range to ensure that the reflected energy loss of the acoustic wave at that frequency is less than 10%, thus avoiding the waste of limited signal energy in passive mode and ensuring communication distance.

[0083] The phase shift is controlled by adjusting the tilt angle of the graphene sheet. The principle is that tilting the graphene sheet alters the reflection path of the incident signal. When the graphene sheet is horizontal, the incident signal is reflected perpendicularly with no phase shift. When the sheet is tilted at a certain angle (adjustable from 0-5°) towards the signal's incident direction, an additional optical or acoustic path difference is generated in the reflection path, leading to a phase shift. Precise control of the phase shift is crucial for the signal directionality of passive communication. For example, in icy environments, if a near-infrared reference signal needs to be directionally reflected towards rescue equipment, adjusting the tilt angle of different clusters of graphene sheets can ensure that the reflected signals from each cluster are in phase, forming a directional beam that concentrates signal energy in the target direction, thus increasing the transmission distance.

[0084] By adjusting the overall tilt angle of the metamaterial reflective array to change the overall reflection angle of the array, this adjustment differs from the tilting of individual graphene sheets in a cluster. The former achieves the angle deflection of the entire array through micro-shape memory alloy driving components connected to the array edge, while the latter involves the local tilting of sheets within the cluster. The core function of adjusting the overall reflection angle is to quickly adapt to the communication direction. For example, in a deep-sea environment, if the rescue equipment is located above a smart terminal, the array can be tilted upwards by 15° through the driving components, directly reflecting the acoustic reference signal towards the water surface. This eliminates the need to adjust the phase of each cluster individually, significantly reducing adjustment time and preventing the loss of rescue signals due to adjustment delays, while also reducing driving energy consumption.

[0085] The metamaterial reflective array is coated with a multi-band zoned absorption coating, a composite functional coating with a thickness ≤50μm. It is divided into three independent zones based on the frequency band of the interfering signal: a low-frequency zone (0.1-1Hz), a mid-frequency zone (10-30kHz), and a high-frequency zone (900-1100nm). Each zone contains specific functional particles; for example, the low-frequency zone contains carbonyl iron powder, and the high-frequency zone contains nano-titanium dioxide. These particles can change their arrangement under electromagnetic induction. The absorption coating of the corresponding frequency band zone is activated by electromagnetic induction. The principle is to apply a weak electromagnetic signal of a specific frequency to the target zone, causing the functional particles within the zone to form absorption channels. When an interfering signal enters the zone, the energy is absorbed by the particles and converted into weak heat energy, rather than being reflected. The advantage of this adjustment method is that it can specifically avoid interference. For example, in volcanic areas where there is mid-to-high frequency geothermal electromagnetic interference above 1kHz, activating only the high-frequency absorption coating is sufficient to absorb the interference in that frequency band without affecting the reflection of the ultra-low frequency reference signal. Furthermore, electromagnetic induction activation requires no physical contact, allowing it to operate stably in extreme environments such as deep-sea high pressure and volcanic high temperature, preventing coating failure due to mechanical wear.

[0086] The metamaterial reflective array can accurately respond to the adjustment parameters calculated in step 103, providing a stable signal reflection carrier for signal encoding and modulation in step 105. This ensures that the external incident signal can be modulated into a reference signal that meets the requirements, while avoiding interference signals that could cause communication information distortion. At the same time, the energy consumption of all adjustment processes is controlled at an extremely low level, meeting the endurance requirements of passive communication in extreme environments and preventing the device from stopping work prematurely due to excessive energy consumption.

[0087] In some specific embodiments, encoding and modulating the physical characteristics of the incident signal specifically includes: converting communication information into a binary data stream according to a preset encoding rule; dynamically switching the adjustment parameters of the metamaterial reflective array according to the timing of the data stream based on the binary data stream, so that the physical characteristics of the incident signal change with the binary data stream to form a modulated signal, thereby obtaining a reference signal. The encoding and modulation of the metamaterial reflective array and the incident signal are shown in the attached figure. Figure 3 As shown.

[0088] Encoding and modulating the physical characteristics of the incident signal is the core step in realizing passive communication. Essentially, it transforms abstract communication information into signal characteristics that can be transmitted through a medium. This involves converting the communication information into a binary data stream according to a preset encoding rule. The communication information is crucial content that smart terminals need to transmit, including device location coordinates, user status, and environmental data. This type of information needs to be transmitted in a concise form to reduce energy consumption and avoid redundant data consuming communication resources.

[0089] The preset encoding rules are lightweight encoding logic embedded in the terminal's main control module beforehand. They are not complex encryption codes, but rather designed to adapt to the low computational demands of passive communication. For example, fixed-length encoding or simple checksum encoding is used to avoid communication delays caused by complex encoding operations. The principle of converting to a binary data stream utilizes the characteristic that binary only contains two states, 0 and 1, which is compatible with the parameter switching capabilities of the metamaterial reflective array. Using multi-level encoding would exceed the array's controllability, leading to inaccurate information conversion. This process is implemented by the terminal's main control module first breaking down the communication information into the smallest information units, then converting each unit into a sequence of 0s and 1s according to the encoding rules, ultimately forming a continuous binary data stream. The effect is to simplify complex information into simple states that the array can control, providing a clear control basis for subsequent parameter adjustments and avoiding modulation failures due to mismatches between the information format and the array's capabilities.

[0090] The adjustment parameters of the metamaterial reflective array controlled by binary data stream are dynamically switched according to the data stream timing. The adjustment parameters include adjustable indicators such as the array impedance value and phase offset, and these indicators directly affect the reflection characteristics of the incident signal. Dynamic switching according to the data stream timing means that the switching rhythm of the array parameters is completely synchronized with the transmission rhythm of the binary data stream. For example, for every "0" or "1" that appears in the data stream, the array parameters are switched once, and the switching timing strictly follows the order of data transmission to avoid information confusion caused by misalignment between parameter switching and data transmission.

[0091] The terminal main control module breaks down the binary data stream into individual bits, assigns a corresponding array parameter value to each bit, and then sends parameter adjustment commands to the array in bit-to-bit transmission order via the drive circuit, achieving real-time parameter switching. This is achieved by connecting the drive circuit to each adjustment cluster of the array individually, ensuring rapid response to parameter switching and avoiding signal distortion due to differences in response speed between clusters. The effect of this step is to imbue the incident signal with "information identification" through parameter switching, transforming the originally meaningless incident signal into a carrier of communication information, laying the foundation for the subsequent formation of a reference signal.

[0092] The physical characteristics of the incident signal are varied according to the binary data stream to form a modulated signal, thus obtaining a reference signal. The physical characteristics of the incident signal refer to its detectable attributes such as amplitude, phase, and frequency; changes in these characteristics are crucial for information transmission. After array parameter adjustment, the physical characteristics of the incident signal exhibit a variation pattern consistent with the binary data stream, no longer a random natural signal; the reference signal ensures compatibility with the current communication medium.

[0093] Variations in the parameters of a metamaterial reflective array alter the reflection path or energy distribution of the incident signal, leading to changes in the signal's physical properties. For example, increasing the array impedance reduces energy loss and increases amplitude; changes in phase offset shift the phase of the reflected signal. This is achieved by continuously adjusting the array's parameters to ensure that each bit of the incident signal exhibits predetermined characteristic changes, ultimately forming a continuous signal that meets reference parameter requirements. By completing the conversion from information to data stream to signal, passive transmission of communication information is possible, avoiding excessive energy consumption caused by active signal transmission from the terminal. Simultaneously, it ensures the signal meets the medium's transmission requirements, providing a suitable signal carrier for subsequent cross-medium communication.

[0094] In some specific embodiments, during modulation, the switching frequency of the adjustment parameters of the metamaterial reflective array is matched with the bit rate of the binary data stream, and the switching action is synchronized with the period of the incident signal. The modulation parameters are optimized according to the current communication medium type to ensure that the reference signal is transmitted with low attenuation in the medium. Synchronization control and parameter optimization during modulation are key supplements to ensuring communication quality. Their core is to solve the problems of signal distortion and medium adaptation, ensuring that the reference signal can be transmitted accurately and stably.

[0095] The switching frequency of the adjustment parameters of the metamaterial reflective array is matched with the bit rate of the binary data stream. The switching frequency refers to the number of times the array completes parameter switching per second, while the bit rate refers to the number of binary bits transmitted per second. The core reason for matching the two is that if the switching frequency is lower than the bit rate, some bits will not correspond to the parameter switching, while if the switching frequency is too high, it will cause energy waste. The terminal main control module has a built-in synchronous clock that controls the transmission rhythm of the data stream and the switching rhythm of the parameters, ensuring that each bit corresponds to one parameter switching, achieving a precise "1 bit - 1 switching" correspondence. The clock signal is simultaneously sent to the data stream generation module and the parameter driving module to avoid asynchrony caused by clock deviation. The effect of this synchronous control is to avoid information errors caused by bit loss or repeated modulation, ensuring that the receiving end can accurately reconstruct the binary data stream.

[0096] The switching action is synchronized with the period of the incident signal. The period of the incident signal refers to the time it takes for the external incident signal to complete one full oscillation. Synchronizing the switching action with the period means that the array parameters are switched at a fixed point in the incident signal's period, rather than at a random time. Switching in the middle of the period would cause the signal within the same period to exhibit two different characteristics, making it impossible for the receiver to accurately identify the bit information. To avoid this problem, the terminal uses sensors to detect the period of the incident signal in real time and feeds this period information back to the main control module. The main control module generates parameter switching instructions based on the period node, ensuring that the switching action is aligned with the start of the period. The effect of this synchronization is to prevent signal characteristics from becoming confused within the same period, ensuring that the signal characteristics corresponding to each bit are complete and clear, and reducing the decoding error rate at the receiver.

[0097] The modulation parameters are optimized based on the current communication medium type. These parameters include bit rate, signal amplitude deviation range, and parameter switching delay. The core logic of the optimization is that different media have different signal transmission capabilities, requiring targeted parameter adjustments to adapt to the medium's characteristics. For example, in underwater media, due to the slow speed of sound wave transmission, a high bit rate can cause overlapping of consecutive bits during transmission, making them indistinguishable at the receiver. Therefore, the bit rate needs to be optimized to 50-100 bps. In ice media, near-infrared light has a fast transmission speed and low attenuation, allowing the bit rate to be optimized to 500-1000 bps to improve communication efficiency. Based on the medium type determined in step 102, the main control module calls a preset medium-modulation parameter correspondence library to automatically adjust the modulation parameters. This parameter library is pre-stored in the terminal's storage module, requiring no additional computation during retrieval and ensuring a fast response.

[0098] In some specific embodiments, when the external incident signal is an optical signal, the encoding and modulation process is as follows: the modulation pulse period of the optical signal is divided into two time windows; different bit values ​​in the binary data stream converted from communication information are mapped to the reflection states of the optical signal within different time windows; simultaneously, different bit values ​​correspond to the activation or deactivation of the absorption band; different time windows are selected by controlling the on / off state of the graphene sheets in the metamaterial reflective array; combined with the electromagnetic induction activation or deactivation of the absorption coating corresponding to the absorption band, the reflected optical signal forms a jointly modulated reference signal. The optical signal includes natural light and artificial light. The modulation process for the optical signal is shown in the attached figure. Figure 4 As shown.

[0099] First, the modulation pulse period of the optical signal is divided into two time windows. The "modulation pulse period" refers to the basic time unit of the optical signal as the modulation carrier. A fixed period is chosen so that the receiver can identify the signal through the synchronization period and avoid decoding failure due to period disorder. Two time windows, rather than more, are used because the binary data stream contains only two bit values, "0" and "1". The two time windows can be directly mapped one-to-one with the bit values, which is suitable for the control capability of the metamaterial reflective array. In addition, the two time windows are usually divided into equal-length windows to ensure that the receiver can clearly distinguish them through the time interval and avoid bit misjudgment due to differences in window length.

[0100] Next, the different bit values ​​in the binary data stream converted from communication information are mapped to the reflection states of optical signals within different time windows. The reflection state specifically refers to the "reflected" or "non-reflected" state of the optical signal within the time window. These two states were chosen because the metamaterial reflective array can be directly implemented by switching graphene sheets on and off, without the need for complex control of light intensity or frequency, thus meeting the low-power requirements of extreme environments. Utilizing the characteristic that optical signals are "detectable by reflection and identifiable by non-reflection," abstract bit values ​​are transformed into differences in light state that the receiver can intuitively capture, allowing previously meaningless ambient light signals to carry communication content.

[0101] Meanwhile, different bit values ​​correspond to the active or inactive state of the absorption band. The absorption band refers to a specific frequency band in the metamaterial reflective array coating that is designed to withstand ambient light interference. Activating the absorption band means that the corresponding coating section absorbs the interference light in that frequency band, while deactivating it maintains the transmittance of the coating to the reference light signal. On the basis of the time window reflection state mapping, an additional layer of anti-interference control is added. This layer does not replace the reflection state mapping, but rather aims to prevent ambient light interference from masking the differences in reflection state, ensuring that the differences in reflection state can be clearly identified, and improving the anti-interference capability of the modulated signal.

[0102] Subsequently, different time windows are selected by controlling the on / off state of graphene sheets in the metamaterial reflective array. The on / off state of the graphene sheet refers to two optical states exhibited by the nanoscale graphene sheet under electrical signal control: when "on," the graphene sheet maintains good light reflectivity, and when "off," the reflectivity of the graphene sheet is significantly reduced. Controlling the on / off state of the graphene sheet within the corresponding window segment ensures precise alignment of the reflection state with the time window. By accurately executing the time window reflection state mapping, it is ensured that the light reflection state corresponding to each bit is presented in the correct time period, avoiding information errors caused by time misalignment.

[0103] Finally, by combining electromagnetic induction to activate or deactivate the absorption coating corresponding to the absorption frequency band, the reflected optical signal forms a jointly modulated reference signal. Within the same bit modulation period, both the sheet reflection state and the coating absorption state are controlled by time windows and bit values, respectively, with complete timing synchronization. After dual modulation of the reflection and absorption states, the reference signal carries binary information, eliminates environmental interference, and its signal parameters fully meet the reference signal requirements determined in step 103. By generating an optical reference signal adapted to the current medium, this signal can be transmitted with low attenuation in the medium and accurately decoded and restored by the receiving end, ultimately realizing cross-medium passive communication in optical signal scenarios.

[0104] This application also proposes a passive cross-medium communication system for extreme environments, the system's module diagram is attached. Figure 5 As shown, the system includes:

[0105] Signal acquisition unit 1 is used to collect in real time the medium characteristic parameters and interference signal characteristics of the environment in which the smart terminal is currently located through a multi-dimensional environmental sensor array built into the smart terminal.

[0106] The mode selection unit 2 is used to determine the current communication medium type based on the medium characteristic parameters according to the preset decision algorithm, and select a passive communication mode that matches the communication medium type.

[0107] The parameter calculation unit 3 is used to determine the reference signal parameters of the passive communication mode, and calculate the adjustment parameters of the preset metamaterial reflective array in the passive communication mode by combining the reference signal parameters and the characteristics of the interference signal.

[0108] The array adjustment unit 4 is used to adjust parameters of the metamaterial reflective array, including impedance value, phase offset, absorption frequency band and overall array reflection angle, according to the adjustment parameters.

[0109] The passive communication unit 5 is used to encode and modulate the external incident signal using the adjusted metamaterial reflective array to obtain a reference signal carrying communication information and adapted to the current communication medium type, thereby realizing cross-medium passive communication.

[0110] This application also proposes a smart terminal for cross-medium passive communication, used to implement a cross-medium passive communication method under extreme conditions as described above.

[0111] This application proposes a cross-medium passive communication method, system, and smart terminal for extreme environments. Through the collaborative mechanism of a multi-dimensional environmental sensor array and a metamaterial reflective array, it achieves precise adaptation of the smart terminal for cross-medium passive communication in extreme scenarios such as volcanoes and deep seas. While ensuring the accuracy of information transmission, the continuity of passive communication, and the reliability of anti-interference, it significantly reduces the dependence on active power supply and extends the communication endurance of the device in scenarios without external power supply. It effectively improves the communication adaptability, scenario coverage, and emergency communication stability of smart terminals such as ruggedized devices in complex extreme environments, and solves the problems of traditional passive communication being difficult to adapt to multiple media, being susceptible to signal interference in extreme environments, and having limited endurance due to dependence on active power supply.

[0112] Those skilled in the art will understand that the modules described above can be implemented using general-purpose computing systems. They can be centralized on a single computing system or distributed across a network of multiple computing systems. Optionally, they can be implemented using computer-executable program code, allowing them to be stored in a storage system for execution by the computing system. Alternatively, they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0113] Note that the above description is merely a preferred embodiment and the technical principles employed in this application. Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments. Many other equivalent embodiments may be included without departing from the concept of this application, and the scope of this application is determined by the scope of the appended claims.

[0114] The above disclosures are only a few specific implementation scenarios of this application. However, this application is not limited to these. Any variations that can be conceived by those skilled in the art should fall within the protection scope of this application.

Claims

1. A passive cross-medium communication method under extreme environments, characterized in that, The extreme environments include volcanoes, deep seas, caves, and glaciers, and the methods include: The system uses a pre-set multi-dimensional environmental sensor array built into the smart terminal to collect in real time the medium characteristics parameters and interference signal features of the environment in which the smart terminal is currently located. Based on a preset decision algorithm, the current communication medium type is determined according to the medium characteristic parameters, and a passive communication mode matching the communication medium type is selected. Determine the reference signal parameters of the passive communication mode, and calculate the adjustment parameters of the preset metamaterial reflective array in the passive communication mode by combining the reference signal parameters with the characteristics of the interference signal; The metamaterial reflective array is adjusted according to the adjustment parameters, including impedance value, phase offset, absorption frequency band and overall array reflection angle. By using an adjusted metamaterial reflective array to encode and modulate external incident signals to obtain a reference signal carrying communication information and adapted to the current communication medium type, cross-medium passive communication can be realized. In the multi-dimensional environmental sensor array: the refractive index data of the current environmental medium is collected by a medium refractive index sensor to distinguish between land and water; the current environmental pressure and temperature are collected simultaneously by pressure and temperature sensors to help determine the scene, including deep sea and volcanic areas; the frequency and intensity of interference signals are collected by a broadband electromagnetic sensor to identify volcanic geothermal electromagnetic noise and thunderstorm EMP signals; and acoustic interference signals are collected in underwater and cave scenes by a passive acoustic sensor.

2. The cross-medium passive communication method according to claim 1, characterized in that, The medium characteristic parameters include at least the medium refractive index, ambient pressure, and ambient temperature; The characteristics of the interference signal include at least the frequency and intensity of the interference signal; The external incident signals include natural environmental signals and artificial rescue signals, and the artificial rescue signals include sonar signals, infrared laser signals and radar wave signals.

3. The cross-medium passive communication method according to claim 1, characterized in that, If the refractive index and pressure of the medium in the medium characteristic parameters simultaneously meet the preset first condition, then the communication medium type is determined to be an underwater medium, and a first communication mode that uses an acoustic signal as the reference signal and is adapted to the low attenuation characteristics of seawater acoustic transmission is selected. If the electromagnetic signal strength and temperature in the medium characteristic parameters simultaneously meet the preset second condition, then the communication medium type is determined to be volcanic medium, and the second communication mode, which is an ultra-low frequency electromagnetic signal and adapted to the geothermal electromagnetic environment of the volcanic area, is selected as the reference signal. If the refractive index and temperature of the medium in the medium characteristic parameters simultaneously meet the preset third condition, then the communication medium type is determined to be ice medium, and the reference signal is selected as a composite signal of near-infrared light and ice vibration, and the third communication mode is adapted to the low absorption of near-infrared light and stable vibration transmission characteristics of ice. If the ambient light intensity and electromagnetic signal intensity in the medium characteristic parameters simultaneously meet the preset fourth condition, then the communication medium type is determined to be a dark low electromagnetic medium, and the fourth communication mode, which is a blue-green light pulse signal as the reference signal and is adapted to the visual perception of dark environments and has low electromagnetic interference characteristics, is selected.

4. The cross-medium passive communication method according to claim 1, characterized in that, The metamaterial reflective array is provided with multiple adjustment clusters composed of nanoscale graphene sheets. The cluster impedance value is controlled by changing the curvature of the graphene sheets, and the phase shift is controlled by adjusting the tilt angle of the graphene sheets. The overall reflection angle of the array is adjusted by adjusting the overall tilt angle of the metamaterial reflective array. The metamaterial reflective array is coated with an absorption coating of multiple frequency bands. The absorption coating of the corresponding frequency band is activated by electromagnetic induction to adjust the absorption frequency band.

5. The cross-medium passive communication method according to claim 4, characterized in that, Encoding and modulating the physical characteristics of the incident signal specifically includes: The communication information is converted into a binary data stream according to a preset encoding rule; the adjustment parameters of the metamaterial reflective array are dynamically switched according to the timing of the data stream based on the binary data stream, so that the physical characteristics of the incident signal change with the binary data stream to form a modulation signal, and a reference signal is obtained.

6. The cross-medium passive communication method according to claim 5, characterized in that, During modulation, the switching frequency of the adjustment parameters of the metamaterial reflective array is matched with the bit rate of the binary data stream, and the switching action is synchronized with the period of the incident signal; the adjustment parameters are optimized according to the current communication medium type.

7. The cross-medium passive communication method according to claim 5, characterized in that, When the external incident signal is an optical signal, the encoding and modulation process is as follows: The modulation pulse period of the optical signal is divided into two time windows, and different bit values ​​in the binary data stream converted from the communication information are mapped to the reflection state of the optical signal in different time windows; at the same time, different bit values ​​correspond to the activation or deactivation state of the absorption band. By controlling the on / off state of graphene sheets in the metamaterial reflective array to achieve different time window selections, and combining this with electromagnetic induction to activate or deactivate the absorption coating corresponding to the absorption frequency band, the reflected light signal forms a jointly modulated reference signal.

8. A passive cross-medium communication system for extreme environments, characterized in that, The extreme environments include volcanoes, deep seas, caves, and glaciers; the system includes: The signal acquisition unit is used to collect in real time the medium characteristic parameters and interference signal characteristics of the environment in which the smart terminal is currently located through a multi-dimensional environmental sensor array built into the smart terminal. The mode selection unit is used to determine the current communication medium type based on the medium characteristic parameters according to the preset decision algorithm, and select a passive communication mode that matches the communication medium type. The parameter calculation unit is used to determine the reference signal parameters of the passive communication mode, and calculate the adjustment parameters of the preset metamaterial reflective array in the passive communication mode by combining the reference signal parameters with the characteristics of the interference signal. An array adjustment unit is used to perform parameter adjustment operations on the metamaterial reflective array according to the adjustment parameters, including impedance value, phase offset, absorption frequency band and overall array reflection angle. The passive communication unit is used to encode and modulate external incident signals using an adjusted metamaterial reflective array to obtain a reference signal carrying communication information and adapted to the current communication medium type, thereby realizing cross-medium passive communication. In the multi-dimensional environmental sensor array: the refractive index data of the current environmental medium is collected by a medium refractive index sensor to distinguish between land and water; the current environmental pressure and temperature are collected simultaneously by pressure and temperature sensors to help determine the scene, including deep sea and volcanic areas; the frequency and intensity of interference signals are collected by a broadband electromagnetic sensor to identify volcanic geothermal electromagnetic noise and thunderstorm EMP signals; and acoustic interference signals are collected in underwater and cave scenes by a passive acoustic sensor.

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