5g-satellite fusion low-altitude high-speed data transmission device and communication method

Abstract

The application relates to the technical field of low-altitude communication equipment, in particular to a 5G-satellite fusion low-altitude high-speed data transmission device and a communication method; the device comprises a 5G communication unit, a satellite communication unit, a beam forming unit, a multi-link switching unit, an encryption and authentication unit, a power supply and protection unit; the units work cooperatively through standardized interfaces; the 5G communication unit provides high-speed low-delay transmission, the satellite communication unit realizes blind area compensation, the beam forming unit optimizes signal coverage, the multi-link switching unit realizes intelligent and rapid switching, the encryption and authentication unit guarantees data safety, and the power supply and protection unit adapts to harsh environments; the application realizes full-area coverage, low-delay, high-reliability and strong-safety data transmission, reduces 5G coverage blind areas and satellite delays in low-altitude communication, and improves safety and environmental adaptability.

Description

Technical Field

[0001] This application relates to the field of low-altitude communication equipment technology, specifically to a 5G-satellite fusion low-altitude high-speed data transmission device and communication method. Background Technology

[0002] Against the backdrop of the rapid development of the new energy industry, the operation and maintenance needs of large-scale new energy bases, such as photovoltaic power stations in Inner Mongolia and wind farms in Northwest China, are becoming increasingly urgent. Drone inspections, with their high flexibility and wide coverage, have gradually replaced traditional manual inspections, becoming a core means of operation and maintenance for large-scale new energy bases. As the core hub for interaction between drones and ground stations, the data transmission device's transmission performance, coverage, security protection, and environmental adaptability directly determine inspection efficiency and data security, making it a key piece of equipment for ensuring the smooth operation of wide-area drone inspections.

[0003] Currently, commonly used communication devices for low-altitude drones are mainly divided into three categories, each with limitations in practical applications: A single 5G communication device relies on ground-based 5G base stations. While it boasts advantages such as high transmission speed and low latency, new energy bases are often located in remote areas with low 5G base station density and small average coverage radius. When drones fly at low altitudes, signal blind spots can easily occur due to base station signals being blocked by mountains or other obstacles, leading to interruptions in the transmission of critical data such as inspection images and control commands, severely impacting the continuity of inspections. A single satellite communication device uses low-orbit satellites such as BeiDou short message service, offering wide coverage and no geographical limitations. However, traditional satellite terminals suffer from low transmission speed and high latency, failing to meet core requirements such as real-time transmission of infrared fire images to trigger alarms and low-latency transmission of drone attitude control commands, making it unsuitable for the refined inspection scenarios of new energy bases. Simple 5G-satellite switching devices switch links by manually preset thresholds, but these devices lack effective data caching mechanisms, resulting in high switching latency and potential loss of critical information such as photovoltaic panel hotspot data. Furthermore, sensitive information contained in the inspection data, such as power station coordinates and component defects, poses a risk of leakage, creating security hazards for the operation and maintenance of new energy bases.

[0004] In addition, existing low-altitude data transmission devices generally have poor environmental adaptability and cannot withstand the harsh conditions common in new energy bases, such as high winds and sandstorms and strong corrosion.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this application is to provide a 5G-satellite fusion low-altitude high-speed data transmission device and communication method, which to some extent solves the problems raised in the background technology, reduces 5G coverage blind spots and satellite latency in low-altitude communication, and improves security protection and environmental adaptability.

[0007] To achieve the above objectives, this application provides the following technical solution:

[0008] In a first aspect, this application provides a 5G-satellite fusion low-altitude high-speed data transmission device, including a 5G communication unit, a satellite communication unit, a beamforming unit, a multi-link switching unit, an encryption and authentication unit, and a power supply and protection unit:

[0009] The 5G communication unit is connected to the Qualcomm SDX65M 5G module and the 4dBi omnidirectional high-gain antenna via the SMA interface, and is connected to the multi-link switching unit via the UART2 interface.

[0010] The satellite communication unit connects to the Iridium NEXT-Mini terminal and the 8dBi right-hand circularly polarized antenna via the SMA-K interface, and communicates with the multi-link switching unit via the UART3 interface;

[0011] The beamforming unit includes an 8-element phased array antenna and an ADI AD9361 RF chip. It communicates with the multi-link switching unit through the SPI1 interface and supports adaptive calibration algorithms.

[0012] The multi-link switching unit includes an STM32H743 microcontroller and a TI AWR1843 signal detection chip, which supports intelligent switching between 5G links and satellite links, and the SRAM uses dual-zone backup to cache data.

[0013] The encryption and authentication unit includes a Huada HC32F460 SM4 encryption chip and an NXP SE050 ECC authentication module, which are connected to the multi-link switching unit via an SPI3 interface; the power supply and protection unit includes a wide-voltage power supply module and a housing; the input terminal of the wide-voltage power supply module is connected in series with a TVS diode; the inside of the housing is filled with waterproof adhesive.

[0014] As a preferred embodiment of the 5G-satellite fusion low-altitude high-speed data transmission device described in this application, the main body of the data transmission device includes a 4-layer PCB board and an aluminum-magnesium alloy shell.

[0015] The top layer of the PCB board is equipped with a 5G communication unit and a satellite communication unit, the middle layer is a beamforming unit and a ground plane, and the bottom layer is a multi-link switching unit, an encryption and authentication unit, and a power supply and protection unit.

[0016] The aluminum-magnesium alloy shell adopts an IP68 protection design, with overall dimensions of 120mm×80mm×30mm and a weight of 180g; the aluminum-magnesium alloy shell is fixed to the middle of the drone's fuselage through four M3 threaded holes;

[0017] A 2oz copper sheet with a thickness of 0.07mm is laid on the bottom layer of the PCB board as a heat dissipation layer, and a graphite heat-conducting sheet with a thickness of 0.1mm is attached to the inside of the aluminum-magnesium alloy shell.

[0018] As a preferred embodiment of the 5G-satellite fusion low-altitude high-speed data transmission device described in this application, the Qualcomm SDX65M 5G module supports the entire Sub-6GHz frequency band, with a peak downlink rate of 1.2Gbps and an uplink rate of 200Mbps.

[0019] The radio frequency terminal of the Qualcomm SDX65M 5G module is connected to the beamforming unit via a microstrip line with a 50Ω impedance; a grounding via with a diameter of 0.3mm is provided every 10mm of the microstrip line.

[0020] The 4dBi omnidirectional high-gain antenna adopts an IP67 waterproof design; the coordinates of the ground base station are located by the drone's GPS, and the 4dBi omnidirectional high-gain antenna is oriented towards the ground base station.

[0021] The Qualcomm SDX65M 5G module supports dynamic adjustment of the working mode via AT commands: when the drone flies to the edge of the base station, it sends the AT+CNR=1 command and enables the signal enhancement mode, while extending the communication distance by increasing the transmission power of the Qualcomm SDX65M 5G module.

[0022] As a preferred embodiment of the 5G-satellite fusion low-altitude high-speed data transmission device described in this application, wherein: a 0.1mm thick polytetrafluoroethylene tape is wrapped around the SMA-K interface;

[0023] The Iridium NEXT-Mini terminal supports the L-band, with a bidirectional speed of 10Mbps;

[0024] The Iridium NEXT-Mini terminal supports a hot standby mode: when the 5G signal is normal, the Iridium NEXT-Mini terminal is in low-power standby mode, during which the Iridium NEXT-Mini terminal sends a heartbeat packet only once every 10 seconds to detect the satellite network; when the 5G signal is interrupted, the Iridium NEXT-Mini terminal wakes up and establishes a connection within 300ms.

[0025] The 8dBi right-hand circularly polarized antenna was calibrated using the UAV attitude sensor to be tilted upwards at an angle of 30°.

[0026] As a preferred embodiment of the 5G-satellite fusion low-altitude high-speed data transmission device described in this application, the 8-element phased array antenna is arranged in a ring with an element spacing of 0.08m.

[0027] The beam scanning angle of the 8-element phased array antenna is ±60°, and its maximum gain is greater than or equal to 12dB.

[0028] The ADI AD9361 RF chip supports dynamic adjustment of array element phase; when the ADI AD9361 RF chip detects multipath interference in the 5G signal, it automatically adjusts the main lobe direction of the beam.

[0029] The beamforming unit supports an adaptive calibration algorithm: it calculates the target angle using the drone's GPS and base station coordinates, and adjusts the phase based on the signal strength feedback collected by the ADI AD9361 RF chip.

[0030] As a preferred embodiment of the 5G-satellite fusion low-altitude high-speed data transmission device described in this application, the TI AWR1843 signal detection chip communicates with the STM32H743 microcontroller via an I2C interface; the TI AWR1843 signal detection chip collects 5G RSRP and satellite SNR in real time at a sampling rate of 10Hz.

[0031] The multi-link switching unit supports link quality prediction: using historical signal data collected by the TI AWR1843 signal detection chip over the past 10 seconds, a linear regression algorithm is used to predict signal changes within the next 2 seconds; if the 5G RSRP is predicted to be less than -110dBm, the Iridium NEXT-Mini terminal is woken up 1 second in advance.

[0032] In a preferred embodiment of the 5G-satellite fusion low-altitude high-speed data transmission device described in this application, the switching logic of the multi-link switching unit is as follows:

[0033] When the 5G RSRP is greater than or equal to -110dBm, the 5G link is used first.

[0034] When RSRP is less than -110dBm or the 5G link times out for 100ms without ACK, satellite link handover is triggered.

[0035] Before the satellite link switchover, data is temporarily stored in 1MB of SRAM according to data priority, and high-priority data is transmitted first after the satellite link switchover is completed.

[0036] The data priorities, from highest to lowest, are: control commands, infrared images, visible light images, and logs.

[0037] As a preferred embodiment of the 5G-satellite fusion low-altitude high-speed data transmission device described in this application, the Huada HC32F460 SM4 encryption chip supports the SM4 block encryption algorithm, with an encryption time of less than or equal to 1ms and an encryption rate of greater than or equal to 200Mbps.

[0038] The inspection data collected by the drone is encrypted by the Huada HC32F460 SM4 encryption chip and then transmitted to the ground station via a 5G link or satellite link. After decryption, the ground station verifies whether the device ID is on the whitelist through the NXP SE050 ECC authentication module. If it is on the whitelist, the data can be received.

[0039] For scenarios with low computing power for drones, the encryption and authentication unit removes two redundant rounds from the SM4 block encryption algorithm.

[0040] As a preferred embodiment of the 5G-satellite fusion low-altitude high-speed data transmission device described in this application, the wide-voltage power supply module has an input voltage of 9-36V, an output current of 2A when the output voltage is 5V, and an output current of 1.5A when the output voltage is 3.3V.

[0041] An SMBJ36CA TVS diode is connected in series at the input terminal of the wide voltage power supply module;

[0042] The outer shell is made of 2mm thick aluminum-magnesium alloy by die casting, and its surface is coated with a 0.05mm thick ceramic coating. Its interface end adopts an IP68 sealed connector.

[0043] When the drone battery's SOC is less than or equal to 30%, send the AT+PWR=1 command and shut down the Iridium NEXT-Mini terminal backup circuit.

[0044] Secondly, this application provides a 5G-satellite fusion low-altitude communication method, comprising the following steps:

[0045] After the data transmission device is powered on, it configures the APN and network mode of the Qualcomm SDX65M 5G module, the frequency and hot standby mode of the Iridium NEXT-Mini terminal, the automatic calibration of the beamforming unit, and the encryption mode and device ID of the encryption and authentication unit through AT commands.

[0046] The TI AWR1843 signal detection chip is used to collect 5G RSRP and satellite SNR in real time and determine the link quality. When the 5G signal is normal, the inspection data is encrypted by the Huada HC32F460 SM4 encryption chip and then transmitted through the 5G link. The control commands are certified by the NXP SE050 ECC certification module and then transmitted through the 5G link.

[0047] When the 5G signal is interrupted, the multi-link switching unit wakes up the Iridium NEXT-Mini terminal and transmits the cached data of SRAM through the satellite link;

[0048] When the data transmission device malfunctions, the fault is investigated and handled using AT commands, and transmission continues after communication is restored.

[0049] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0050] By constructing a dual-link communication architecture with 5G as the primary link and satellite as the secondary link, not only is the transmission latency in 5G coverage areas reduced compared to satellite transmission latency in areas without 5G, but the transmission rate in both 5G coverage and non-5G areas is also improved, achieving 100% coverage across the entire region. An intelligent link switching mechanism is designed to ensure a switching latency of less than or equal to 80ms, while data caching ensures no loss of critical data. Encryption and two-way authentication prevent data leakage and unauthorized device access, and protective measures enhance the environmental adaptability of the data transmission device and mitigate drone battery voltage fluctuations. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0052] Figure 1 A structural diagram of a 5G-satellite fusion low-altitude high-speed data transmission device provided in this application;

[0053] Figure 2 A test scene diagram of a 5G-satellite fusion low-altitude high-speed data transmission device provided for this application at a photovoltaic base in Inner Mongolia;

[0054] Figure 3 A flowchart of a 5G-satellite fusion low-altitude communication method provided in this application. Detailed Implementation

[0055] The technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of this application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other.

[0056] Example 1

[0057] like Figure 1As shown in the figure, this embodiment introduces a 5G-satellite fusion low-altitude high-speed data transmission device, including a 5G communication unit, a satellite communication unit, a beamforming unit, a multi-link switching unit, an encryption and authentication unit, and a power supply and protection unit;

[0058] The main body of the data transmission device adopts a 4-layer PCB board and an aluminum-magnesium alloy shell structure. The top layer of the PCB board deploys the 5G communication unit and the satellite communication unit. The middle layer of the PCB board is divided into middle layer 1 and middle layer 2, which correspond to the beamforming unit and the grounding plane, respectively. The bottom layer of the PCB board contains the multi-link switching unit, the encryption and authentication unit, and the power supply and protection unit. The aluminum-magnesium alloy shell adopts an IP68 protection design, with overall dimensions of 120mm×80mm×30mm and a weight of 180g. The aluminum-magnesium alloy shell is fixed to the middle of the drone fuselage through 4 M3 threaded holes to avoid obstruction by the wings and propellers.

[0059] The 5G communication unit, serving as the core of low-altitude high-speed transmission, employs a Qualcomm SDX65M 5G module and a 4dBi omnidirectional high-gain antenna. The Qualcomm SDX65M 5G module supports the entire Sub-6GHz frequency band, with a peak downlink rate of 1.2Gbps and an uplink rate of 200Mbps. The Qualcomm SDX65M 5G module has a receiver sensitivity of less than or equal to -108dBm, an 8dB improvement over the traditional Balong 5000 module, making it suitable for weak signal environments in new energy bases.

[0060] The 4dBi omnidirectional high-gain antenna, model TA-433-4dBi, adopts an IP67 waterproof design and connects to the Qualcomm SDX65M 5G module via an SMA interface. During installation, the coordinates of the ground base station are located using a drone's GPS, and the 4dBi omnidirectional high-gain antenna is tilted towards the ground base station at an angle of 3° to 5° to reduce ground clutter interference.

[0061] The Qualcomm SDX65M 5G module communicates with the STM32 controller of the multi-link switching unit via a UART2 interface with a baud rate of 115200bps; the RF end of the Qualcomm SDX65M 5G module is connected to the beamforming unit via a microstrip line with a 50Ω impedance; a grounding via with a diameter of 0.3mm is set every 10mm of the microstrip line to reduce signal crosstalk;

[0062] Optionally, the Qualcomm SDX65M 5G module supports dynamic adjustment of the working mode via AT commands: when the drone flies to the edge of the base station, it sends the AT+CNR=1 command to enable the signal enhancement mode, thereby increasing the communication distance by increasing the transmit power of the Qualcomm SDX65M 5G module from 23dBm to 27dBm, so as to avoid frequent switching to the satellite link.

[0063] The satellite communication unit uses an Iridium NEXT-Mini terminal and an 8dBi right-hand circularly polarized antenna; the Iridium NEXT-Mini terminal supports the L-band, with a bidirectional rate of 10Mbps, which is twice that of the traditional Iridium 9602 terminal; the Iridium NEXT-Mini terminal has an operating temperature of -40℃ to 70℃, meeting the requirements of cold environments.

[0064] The 8dBi right-hand circularly polarized antenna is model SAT-L-8dBi. The 8dBi right-hand circularly polarized antenna adopts an integrated die-cast structure, and its gain is 3dB higher than that of traditional linearly polarized antennas. During installation, the 8dBi right-hand circularly polarized antenna is calibrated in real time using the UAV attitude sensor and tilted at an elevation angle of 30° to ensure the stability of satellite signal reception.

[0065] The Iridium NEXT-Mini terminal communicates with the STM32H743 microcontroller of the multi-link switching unit via a UART3 interface with a baud rate of 9600bps; the 8dBi right-hand circularly polarized antenna is connected to the Iridium NEXT-Mini terminal via an SMA-K interface; the SMA-K interface is wrapped with 0.1mm thick polytetrafluoroethylene tape to prevent wind and sand intrusion that could cause poor contact.

[0066] Optionally, the Iridium NEXT-Mini terminal supports a hot standby mode: when the 5G signal is normal, the Iridium NEXT-Mini terminal is in low-power standby mode, i.e., the current is less than or equal to 10mA; at this time, the Iridium NEXT-Mini terminal only sends a heartbeat packet once every 10 seconds to detect the satellite network; when the 5G signal is interrupted, the Iridium NEXT-Mini terminal wakes up and establishes a connection within 300ms to reduce handover latency.

[0067] The beamforming unit is used to optimize 5G signal coverage and includes an 8-element phased array antenna and an ADI AD9361 RF chip. The 8-element phased array antenna is arranged in a ring with an element spacing of 0.08m. The beam scanning angle of the 8-element phased array antenna is ±60° and its maximum gain is greater than or equal to 12dB.

[0068] The ADI AD9361 RF chip communicates with the STM32H743 microcontroller of the multi-link switching unit via the SPI1 interface; the ADI AD9361 RF chip supports dynamic adjustment of array element phase; when the ADI AD9361 RF chip detects multipath interference in the 5G signal, i.e., bit error rate ≥ 10... -5 At the same time, the beam main lobe direction is automatically adjusted to ensure signal quality;

[0069] Optionally, the beamforming unit supports an adaptive calibration algorithm: the target angle is calculated using the UAV's GPS and base station coordinates, and the phase is adjusted based on the signal strength feedback collected by the ADI AD9361 RF chip; the calibration period of the adaptive calibration algorithm is 100ms to ensure that the beam is always aligned with the base station and that the signal strength fluctuation is less than or equal to 3dB.

[0070] In this embodiment, the adaptive calibration algorithm is as follows:

[0071] The drone obtains its own coordinates and ground base station coordinates using GPS, and then converts these coordinates into geocentric rectangular coordinates using the WGS-84 coordinate system.

[0072] Calculate the unit vector pointing from the UAV to the ground base station based on the geocentric rectangular coordinates; obtain the attitude angle of the UAV, and calculate the target angle in combination with the unit vector;

[0073] Based on the geometric distribution of the 8-element phased antenna, the phase offset of each element relative to the center of the antenna array is calculated to obtain a phase offset array; the calculation formula for the phase offset is as follows:

[0074] ;

[0075] in, The theoretical phase offset of the i-th element relative to the center of the antenna array; i is a positive integer; i is greater than or equal to 1 and less than or equal to 8; From the perspective of the target;

[0076] After the STM32H743 microcontroller writes the phase offset array into the corresponding phase control register of the ADI AD9361 RF chip through the SPI1 interface, the ADI AD9361 RF chip determines whether the current received signal strength is greater than or equal to the preset signal strength threshold, such as -105dBm.

[0077] If the current received signal strength is greater than the signal strength threshold, the STM32H743 microcontroller fine-tunes the phase of each array element in a step of 0.5° within a range of ±5° until the current received signal strength is greater than or equal to the signal strength threshold.

[0078] The multi-link switching unit, serving as the control center of the data transmission device, includes an STM32H743 microcontroller and a TIAWR1843 signal detection chip. The STM32H743 microcontroller supports multiple interfaces such as CAN, USART, and ETH, with a main frequency of 480MHz, 2MB of Flash memory, and 1MB of SRAM. The STM32H743 microcontroller simultaneously connects to the 5G communication unit, satellite communication unit, and encryption and authentication unit. The TIAWR1843 signal detection chip communicates with the STM32H743 microcontroller via an I2C interface. The TIAWR1843 signal detection chip collects 5G RSRP and satellite SNR in real time at a sampling rate of 10Hz.

[0079] The switching logic of the multi-link switching unit is as follows: when the 5G RSRP is greater than or equal to -110dBm, the 5G link is used first; when the RSRP is less than -110dBm or the 5G link times out for 100ms without ACK, satellite link switching is triggered; before satellite link switching, data is temporarily stored in 1MB SRAM according to data priority, and after satellite link switching is completed, data with higher priority is transmitted first; the data priority is ordered from high to low as follows: control commands, infrared images, visible light images, and logs.

[0080] Optionally, the multi-link switching unit supports link quality prediction: using historical signal data collected by the TI AWR1843 signal detection chip over the past 10 seconds, a linear regression algorithm is used to predict signal changes within the next 2 seconds; if the 5G RSRP is predicted to be less than -110dBm, the Iridium NEXT-Mini terminal is woken up 1 second in advance to further reduce the switching delay to less than or equal to 60ms.

[0081] In this embodiment, the specific method for predicting signal changes within the next 2 seconds using the linear regression algorithm is as follows: The 5G RSRP sequence of the past 10 seconds is collected using a TI AWR1843 signal detection chip at a sampling frequency of 10Hz. A circular buffer of length 100 is allocated within the STM32H743 microcontroller to store the 5G RSRP sequence; wherein, Let be the value of the t-th 5G RSRP in the 5G RSRP sequence over the past 10 seconds, where t∈[1,99]; when using a linear regression algorithm for prediction, the 5G RSRP at the current moment is used. Based on the baseline, a univariate linear regression equation is established using the 5G RSRP of the most recent 20 sampling points. The parameters of the univariate linear regression equation are estimated using the least squares method, resulting in the univariate linear regression equation. Based on this univariate linear regression equation, the predicted value of the 5G RSRP after ΔT = 20 sampling points, i.e., 2 seconds, is calculated. ;in, Here, 'a' represents the predicted 5G RSRP, 'a' is the intercept of the univariate linear regression equation, and 'b' is the slope of the univariate linear regression equation. Given the current time; determine whether the predicted value of 5G RSRP 2 seconds later is less than the preset 5G RSRP threshold, such as -110dBm; if the predicted value of 5G RSRP 2 seconds later is less than the 5G RSRP threshold, the STM32H743 microcontroller outputs a high-level trigger signal through GPIO to start the satellite terminal preheating process 1 second in advance.

[0082] The encryption and authentication unit is used to ensure data transmission security, including the Huada HC32F460 SM4 encryption chip and the NXP SE050 ECC authentication module; the Huada HC32F460 SM4 encryption chip supports the SM4 block cipher algorithm, with an encryption time of less than or equal to 1ms and an encryption rate of greater than or equal to 200Mbps; the NXP SE050 ECC authentication module supports the ECCsecp256r1 elliptic curve algorithm, with a key generation time of less than or equal to 50ms;

[0083] The encryption process of the encryption and authentication unit is as follows: Inspection data collected by the UAV, such as images and sensor data, is encrypted by the Huada HC32F460 SM4 encryption chip and then transmitted to the ground station via a 5G link or satellite link; after decryption, the ground station verifies whether the device ID is in the whitelist through the NXP SE050 ECC authentication module. If it is in the whitelist, the data can be received; when the HC32F460 SM4 encryption chip encrypts, it uses the NXP SE050 ECC authentication module to generate a key using a one-time key mechanism; a new key is generated for each communication; the key is transmitted asymmetrically encrypted through an encrypted channel to prevent key leakage;

[0084] Optionally, the encryption and authentication unit supports lightweight optimization: for low computing power scenarios of UAVs, two redundant rounds in the SM4 block encryption algorithm are removed, reducing the complexity of the SM4 block encryption algorithm by 15% and increasing the encryption rate to 220Mbps, while ensuring that the encryption strength meets the standard.

[0085] The standard SM4 algorithm is a 32-round nonlinear iterative structure, with each round of nonlinear iterative operation including XOR, S-box permutation, and linear transformation. In this embodiment, the lightweight optimization specifically involves: by analyzing the diffusion characteristics of the SM4 algorithm, deleting the functions of the intermediate 15th and 16th rounds of nonlinear iterative operation; and in the firmware implementation of the Huada HC32F460 SM4 encryption chip, modifying the round key generation scheme so that the original round key of the 17th round is directly used to encrypt the intermediate state data output from the original 14th round.

[0086] The power supply and protection unit ensures stable operation of the data transmission device in harsh environments. This unit includes an MPM3610 wide-voltage power module and its housing. The wide-voltage power module has an input voltage of 9-36V, an output current of 2A at 5V, and an output current of 1.5A at 3.3V, meeting the power supply requirements of each unit. An SMBJ36CA TVS diode is connected in series at the input of the wide-voltage power module to protect against sudden drops in battery voltage.

[0087] The outer shell is made of 2mm thick aluminum-magnesium alloy die casting, and its surface is coated with a 0.05mm thick ceramic coating; the corrosion resistance level of the outer shell is greater than or equal to level 9, and it shows no rust after 1000 hours of neutral salt spray testing; the interface end of the outer shell has an IP68 sealed joint, and its interior is filled with Dow Corning 734 waterproof adhesive to prevent wind, sand and rainwater from entering.

[0088] Optionally, the power supply and protection unit supports dynamic power consumption control: when the SOC of the drone battery is less than or equal to 30%, it sends the AT+PWR=1 command to reduce the transmit power of the Qualcomm SDX65M 5G module and shut down the backup circuit of the Iridium NEXT-Mini terminal, while reducing the overall power consumption of the data transmission device from 15W to 10W and extending the drone's flight time by at least 30 minutes.

[0089] The heat dissipation method of the data transmission device is as follows: a 2oz copper foil with a thickness of 0.07mm is laid on the bottom layer of the PCB board as a heat dissipation layer, and a graphite thermal conductive sheet with a thickness of 0.1mm is attached to the inside of the outer shell to conduct the heat of the Qualcomm SDX65M 5G module to the outer shell, ensuring that the outer shell temperature of the data transmission device is still less than or equal to 55℃ in a 70℃ environment, and there is no overheat protection trigger.

[0090] This embodiment uses a drone inspection of a 2 million kilowatt photovoltaic base in Inner Mongolia as an example to illustrate the installation, debugging and workflow of the data transmission device;

[0091] Specifically, a DJI M300 RTK vertical take-off and landing drone was selected, and the data transmission device was fixed to the middle of the drone's fuselage through four M3 threaded holes. The data transmission device was fixed at a distance of 300mm from the drone's nose and 150mm from the wing to avoid the wing blocking the antenna signal. A 0.5mm thick silicone pad was used during fixing to reduce the impact of drone vibration on the data transmission device.

[0092] The 5G antenna and satellite antenna are connected to the data transmission device via SMA interfaces. The 5G antenna faces the 5G base station near the photovoltaic base, and the tilt angle of the 5G antenna is adjusted to 4° by calculating the azimuth angle using the drone's GPS. The coordinates of the 5G base station are 40°22′N, 109°35′E. The direction of the satellite antenna is adjusted to a 30° upward tilt angle using the drone's attitude sensor to ensure it avoids metal parts on the drone's fuselage.

[0093] The input terminal of the wide-voltage power module of the data transmission device is connected to the 4S lithium battery of the UAV via the XT60 interface, and a 15A fuse is connected in series to prevent short circuit; the data transmission device is connected to the UAV flight controller via the CAN bus interface for transmitting control commands, and the UAV's onboard camera is connected via the USB Type-C interface for transmitting inspection images.

[0094] Connect the data transmission device to its USB Type-C interface using a serial port tool and send AT commands for configuration. The specific configuration method is as follows:

[0095] Set the 5G network mode by sending the AT+CNMP=38 command, and configure the APN to CMNET by sending the AT+CMNET=1 command; enable the signal enhancement mode by sending the AT+CNR=1 command, and determine that the 5G communication unit configuration is complete by receiving the OK response;

[0096] Set the satellite receiving frequency to 1626MHz by sending the AT+SAT_FREQ=1626 command, and enable hot standby mode by sending the AT+SAT_STBY=1 command; determine that the satellite communication unit configuration is complete by receiving the OK response;

[0097] Send the AT+BEAM=1 command to enable automatic calibration mode, and send the AT+BEAM_ANG=45 command to set the initial beam angle to 45° and point it towards the 5G base station; receive the OK response to determine that the beamforming unit configuration is complete;

[0098] Send the AT+ENCRYPT=1 command to enable SM4 encryption, and send AT+AUTH=1,123456 to add the device with ID 123456 to the ground station whitelist; receive the OK response to determine that the encryption and authentication unit configuration is complete.

[0099] Transmission performance testing, interference immunity testing, and protection testing were conducted in a laboratory environment; the transmission performance testing methods are as follows:

[0100] Agilent N5182A signal generator was used to simulate 5G base station signals, and Rohde & Schwarz FSV30 spectrum analyzer was used to monitor signal strength. Meanwhile, a gigabit Ethernet tester was used to test signal transmission rate and transmission delay.

[0101] A 5G signal with a frequency of 3.5GHz and a bandwidth of -30dBm is transmitted through a signal generator, and the receiving power of the data transmission device is detected by a spectrum analyzer. At the same time, the beamforming angle is adjusted so that the RSRP of the 5G signal is equal to -80dBm.

[0102] A 1080P video stream with a bitrate of 20Mbps was sent using an Ethernet tester, and the transmission delay was measured to be 42ms, with a bit error rate of less than 10%. -6 ;

[0103] The signal generator was turned off, and the satellite link was switched. A 1080P video stream with a bit rate of 20Mbps was sent through an Ethernet tester. The transmission rate was measured to be 8.5Mbps, the transmission delay was 480ms, and there was no data loss.

[0104] The anti-interference test specifically involved: using a 2.4GHz WiFi interference source with an output power of 20dBm; turning on the WiFi interference source and generating interference at a distance of 10m from the data transmission device; and using a Ethernet tester to monitor that the bit error rate of the 5G link increased to 10%. -5 At this point, the beamforming unit automatically adjusts the beam direction, restoring the bit error rate to 10%. -6 The bit error rate of the satellite link was consistently less than or equal to 10, as monitored using a Ethernet tester. -5 No interference;

[0105] The protection test includes a dustproof test and a high / low temperature test; the dustproof test involves immersing the data transmission device in a sandstorm with a concentration of 55 mg / m³. 3 The device was placed in a dust test chamber with a wind speed of 12 m / s for 24 hours. After that, it was removed and inspected. No dust had entered the interface, and the data transmission device was found to be working normally. The high and low temperature test was conducted by placing the data transmission device in a high and low temperature test chamber and setting the chamber to -40℃ for 4 hours and 70℃ for 4 hours. During the high and low temperature test, the data transmission device was powered on without interruption and the data transmission performance was not degraded.

[0106] In such Figure 2 Workflow testing was conducted in the photovoltaic base scenario shown. Specific test environmental conditions included geographical location, climate parameters, and drone parameters. The geographical location was a photovoltaic base in Inner Mongolia, characterized by unobstructed Gobi desert terrain. The climate parameters included a windblown sand concentration of 55 mg / m³. 3The wind speed was 12 m / s, the air temperature was -15℃, and the humidity was 30%. The parameters of the drone were: flight altitude 100 m, cruising speed 15 m / s, and range 20 km. Figure 2 The blue dashed box represents the coverage area of ​​the 5G base station, and the yellow dashed box represents the satellite coverage area; the specific steps of the workflow are as follows:

[0107] The drone flew to the eastern part of the photovoltaic base, which is within the coverage area of ​​the 5G base station. At this time, the 5G RSRP was -85dBm. The drone's onboard camera captured infrared images of the photovoltaic modules, which were then encrypted by the HC32F460 SM4 encryption chip and transmitted to the ground station via the 5G link. The transmission latency was measured to be 45ms, with each frame taking 20ms to transmit, and the transmission was uninterrupted.

[0108] The ground station sends a control command to adjust the flight altitude to 120m. After being certified by the NXP SE050 ECC certification module, the control command is transmitted through the 5G link, and the drone responds within 100ms.

[0109] The drone flew to the western part of the photovoltaic base, which is the edge of the 5G base station coverage area. At this time, the 5G RSRP dropped to -112dBm. The multi-link switching unit predicted that the signal would continue to weaken and woke up the Iridium NEXT-Mini terminal 1 second in advance. After the 5G link was interrupted, the satellite link connection was completed within 300ms. At this time, the 10 frames of infrared images temporarily stored in SRAM were not lost, and the switching delay was 75ms.

[0110] The drone flew to the northern part of the photovoltaic base, which is within the satellite coverage area. At this time, the satellite SNR was 12dB. The infrared image was transmitted through the satellite link with a transmission delay of 490ms and no frame loss. The ground station displayed the hot spots on the modules in real time. The ground station sent a return-to-home command, and the transmission delay of the satellite link was measured to be 485ms. The drone received the return-to-home command and executed it accurately.

[0111] Optionally, if the simulated device ID is not in the whitelist when sending the instruction to obtain inspection data, the data transmission device detects that the NXP SE050 ECC authentication module has failed to authenticate, triggers an alarm and disconnects the link, and records the illegal device ID and access time in the log.

[0112] Example 2

[0113] This embodiment is the second embodiment of this application; it is based on the same inventive concept as Embodiment 1, and refers to... Figure 3 This embodiment introduces a 5G-satellite fusion low-altitude communication method, including the following steps:

[0114] When the data transmission device is powered on, it configures the APN and network mode of the Qualcomm SDX65M 5G module, the frequency and hot standby mode of the Iridium NEXT-Mini terminal, the automatic calibration of the beamforming unit, and the encryption mode and device ID of the encryption and authentication unit via AT commands.

[0115] The multi-link switching unit uses the TI AWR1843 signal detection chip to collect 5G RSRP and satellite SNR in real time and determine the link quality.

[0116] When the 5G signal is normal, the inspection data is encrypted by the Huada HC32F460 SM4 encryption chip and then transmitted through the 5G link, and the control commands are certified by the NXP SE050 ECC certification module and then transmitted through the 5G link.

[0117] When the 5G signal is interrupted, the multi-link switching unit wakes up the Iridium NEXT-Mini terminal, enabling the SRAM cached data to be transmitted through the satellite link, with a switching delay of less than or equal to 80ms.

[0118] When the data transmission device malfunctions, the fault is troubleshooted and handled through AT commands. For example, if the 5G signal is weak, the beam is calibrated; if the satellite signal is interrupted, the SIM card is checked. After the fault is handled and communication is restored, transmission continues.

[0119] The specific functions of each step described above are explained in the relevant content of the 5G-satellite fusion low-altitude high-speed data transmission device described in Embodiment 1, and will not be repeated here.

[0120] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0121] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of protection of this application, and these forms are all within the protection scope of this application.

Claims

1. A 5G-satellite fusion low-altitude high-speed data transmission device, characterized in that, Includes 5G communication unit, satellite communication unit, beamforming unit, multi-link switching unit, encryption and authentication unit, and power supply and protection unit: The 5G communication unit is connected to the Qualcomm SDX65M 5G module and the 4dBi omnidirectional high-gain antenna via the SMA interface, and is connected to the multi-link switching unit via the UART2 interface. The satellite communication unit connects to the Iridium NEXT-Mini terminal and the 8dBi right-hand circularly polarized antenna via the SMA-K interface, and communicates with the multi-link switching unit via the UART3 interface; The beamforming unit includes an 8-element phased array antenna and an ADI AD9361 RF chip. It communicates with the multi-link switching unit through the SPI1 interface and supports adaptive calibration algorithms. The multi-link switching unit includes an STM32H743 microcontroller and a TI AWR1843 signal detection chip, which supports intelligent switching between 5G links and satellite links, and the SRAM uses dual-zone backup to cache data. The encryption and authentication unit includes a Huada HC32F460 SM4 encryption chip and an NXP SE050 ECC authentication module, which are connected to the multi-link switching unit via an SPI3 interface; the power supply and protection unit includes a wide-voltage power supply module and a housing; the input terminal of the wide-voltage power supply module is connected in series with a TVS diode; the inside of the housing is filled with waterproof adhesive.

2. The 5G-satellite converged low-altitude high-speed data transmission device of claim 1, wherein, The main body of the data transmission device includes a 4-layer PCB board and an aluminum-magnesium alloy shell; The top layer of the PCB board is equipped with a 5G communication unit and a satellite communication unit, the middle layer is a beamforming unit and a ground plane, and the bottom layer is a multi-link switching unit, an encryption and authentication unit, and a power supply and protection unit. The aluminum-magnesium alloy shell adopts an IP68 protection design, with overall dimensions of 120mm×80mm×30mm and a weight of 180g; the aluminum-magnesium alloy shell is fixed to the middle of the drone's fuselage through four M3 threaded holes; A 2oz copper sheet with a thickness of 0.07mm is laid on the bottom layer of the PCB board as a heat dissipation layer, and a graphite heat-conducting sheet with a thickness of 0.1mm is attached to the inside of the aluminum-magnesium alloy shell.

3. The 5G-satellite converged low-altitude high-speed data transmission device of claim 2, wherein, The Qualcomm SDX65M 5G module supports the entire Sub-6GHz frequency band, with a peak downlink speed of 1.2Gbps and an uplink speed of 200Mbps. The radio frequency terminal of the Qualcomm SDX65M 5G module is connected to the beamforming unit via a microstrip line with a 50Ω impedance; a grounding via with a diameter of 0.3mm is provided every 10mm of the microstrip line. The 4dBi omnidirectional high-gain antenna adopts an IP67 waterproof design; the coordinates of the ground base station are located by the drone's GPS, and the 4dBi omnidirectional high-gain antenna is oriented towards the ground base station. The Qualcomm SDX65M 5G module supports dynamic adjustment of the working mode via AT commands: when the drone flies to the edge of the base station, it sends the AT+CNR=1 command and enables the signal enhancement mode, while extending the communication distance by increasing the transmission power of the Qualcomm SDX65M 5G module.

4. The 5G-satellite converged low-altitude high-speed data transmission device of claim 3, wherein, The SMA-K interface is wrapped with 0.1mm thick polytetrafluoroethylene tape; The Iridium NEXT-Mini terminal supports the L-band, with a bidirectional speed of 10Mbps; The Iridium NEXT-Mini terminal supports a hot standby mode: when the 5G signal is normal, the Iridium NEXT-Mini terminal is in low-power standby mode, during which the Iridium NEXT-Mini terminal sends a heartbeat packet only once every 10 seconds to detect the satellite network; when the 5G signal is interrupted, the Iridium NEXT-Mini terminal wakes up and establishes a connection within 300ms. The 8dBi right-hand circularly polarized antenna was calibrated using the UAV attitude sensor to be tilted upwards at an angle of 30°.

5. A 5G-satellite fusion low-altitude high-speed data transmission device as described in claim 4, characterized in that, The 8-element phased array antenna is arranged in a ring with an element spacing of 0.08m. The beam scanning angle of the 8-element phased array antenna is ±60°, and its maximum gain is greater than or equal to 12dB. The ADI AD9361 RF chip supports dynamic adjustment of array element phase; when the ADI AD9361 RF chip detects multipath interference in the 5G signal, it automatically adjusts the main lobe direction of the beam. The beamforming unit supports an adaptive calibration algorithm: it calculates the target angle using the drone's GPS and base station coordinates, and adjusts the phase based on the signal strength feedback collected by the ADI AD9361 RF chip.

6. A 5G-satellite fusion low-altitude high-speed data transmission device as described in claim 5, characterized in that, The TI AWR1843 signal detection chip communicates with the STM32H743 microcontroller via an I2C interface; the TI AWR1843 signal detection chip acquires 5G RSRP and satellite SNR in real time at a sampling rate of 10Hz; The multi-link switching unit supports link quality prediction: using historical signal data collected by the TI AWR1843 signal detection chip over the past 10 seconds, a linear regression algorithm is used to predict signal changes within the next 2 seconds; if the 5G RSRP is predicted to be less than -110dBm, the Iridium NEXT-Mini terminal is woken up 1 second in advance.

7. A 5G-satellite fusion low-altitude high-speed data transmission device as described in claim 6, characterized in that, The switching logic of the multi-link switching unit is as follows: When the 5G RSRP is greater than or equal to -110dBm, the 5G link is used first. When RSRP is less than -110dBm or the 5G link times out for 100ms without ACK, satellite link handover is triggered. Before the satellite link switchover, data is temporarily stored in 1MB of SRAM according to data priority, and high-priority data is transmitted first after the satellite link switchover is completed. The data priorities, from highest to lowest, are: control commands, infrared images, visible light images, and logs.

8. A 5G-satellite fusion low-altitude high-speed data transmission device as described in claim 7, characterized in that, The Huada HC32F460 SM4 encryption chip supports the SM4 block encryption algorithm, with an encryption time of less than or equal to 1ms and an encryption rate of greater than or equal to 200Mbps. The inspection data collected by the drone is encrypted by the BGI HC32F460 SM4 encryption chip and then transmitted to the ground station via a 5G link or satellite link. After the ground station decrypts the device ID, it verifies whether the device ID is on the whitelist using the NXP SE050 ECC authentication module. If it is on the whitelist, it can receive data; For scenarios with low computing power for drones, the encryption and authentication unit removes two redundant rounds from the SM4 block encryption algorithm.

9. A 5G-satellite fusion low-altitude high-speed data transmission device as described in claim 8, characterized in that, The wide-voltage power supply module has an input voltage of 9-36V, an output current of 2A when the output voltage is 5V, and an output current of 1.5A when the output voltage is 3.3V. An SMBJ36CA TVS diode is connected in series at the input terminal of the wide voltage power supply module; The outer shell is made of 2mm thick aluminum-magnesium alloy by die casting, and its surface is coated with a 0.05mm thick ceramic coating. Its interface end adopts an IP68 sealed connector. When the drone battery's SOC is less than or equal to 30%, send the AT+PWR=1 command and shut down the Iridium NEXT-Mini terminal backup circuit.

10. A 5G-satellite fusion low-altitude communication method, implemented based on a 5G-satellite fusion low-altitude high-speed data transmission device as described in any one of claims 1-9, characterized in that, Includes the following steps: After the data transmission device is powered on, it configures the APN and network mode of the Qualcomm SDX65M 5G module, the frequency and hot standby mode of the Iridium NEXT-Mini terminal, the automatic calibration of the beamforming unit, and the encryption mode and device ID of the encryption and authentication unit through AT commands. The TI AWR1843 signal detection chip is used to collect 5G RSRP and satellite SNR in real time and determine the link quality. When the 5G signal is normal, the inspection data is encrypted by the Huada HC32F460 SM4 encryption chip and then transmitted through the 5G link, and the control commands are certified by the NXPSE050 ECC certification module and then transmitted through the 5G link. When the 5G signal is interrupted, the multi-link switching unit wakes up the Iridium NEXT-Mini terminal and transmits the cached data of SRAM through the satellite link; When the data transmission device malfunctions, the fault is investigated and handled using AT commands, and transmission continues after communication is restored.

Images