TIS-B baseband signal processing method and transmitting device based on UAV cloud data

Abstract

The present application discloses a TIS‑B baseband signal processing method and transmitting device based on drone cloud data, which uses a drone cloud data server as the data support for the entire system, unifies the format of data from various data link sources, and has data universality. At the same time, the baseband signal processor is used to realize data acquisition, decoding and filtering, dynamic allocation of ICAO identity codes, signal transmission frequency control, and control signal modulation and transmission to ensure data reliability and scalability. The present invention also has the characteristics of high integration, and can integrate the interface circuit of data communication, the operation unit of baseband signal processing, etc., to reduce the size of the equipment and facilitate installation and deployment. At the same time, the present invention covers the mode monitoring signals of the two data links of TIS‑B in the current civil aviation industry, solves the problem of compatible applications of multiple data links of drones, and provides a feasible solution to avoid channel congestion.

Description

Technical Field

[0001] The present application relates to the fields of air traffic surveillance data processing and radio technology, and in particular to a TIS-B baseband signal processing method and transmitting device based on drone cloud data. Background Art

[0002] With the explosive growth of low-altitude vehicles like drones and electric vertical take-off and landing (eVTOL) vehicles, the low-altitude sector is characterized by significant heterogeneity, high density, and high complexity. Both the International Civil Aviation Organization (ICAO) and the Civil Aviation Administration of China (CAAC) have clearly designated Automatic Dependent Surveillance-Broadcast (ADS-B) technology as core infrastructure for low-altitude management. ADS-B uses satellite navigation and data link communications to broadcast real-time information such as aircraft position, altitude, and speed, supporting the construction of a global situational awareness network.

[0003] However, existing low-altitude surveillance systems face multiple technical bottlenecks. First, my country's "Concept of Operational Identification of Civilian Micro, Light, and Small Unmanned Aircraft Systems (Interim)" explicitly prohibits small and light unmanned aircraft from using ADS-B transmitters to broadcast operational identification data. As a result, a large number of micro, light, and small drones cannot be included in the traditional ADS-B-based surveillance system, forming a surveillance blind spot and seriously affecting the integrity of low-altitude global situational awareness. Second, in a heterogeneous low-altitude environment with diverse aircraft types, communication protocols, and surveillance standards, if all aircraft use ADS-B technology for data broadcasting, the high-frequency information exchange will lead to the risk of channel congestion for limited spectrum resources, especially interference from 1090ES on civil transport aircraft. Third, to achieve subsequent perception and avoidance services, a unified, interoperable shared data source must be established. Otherwise, the "data islands" formed by different communication protocols and data formats between different types of aircraft will lead to the failure of multi-source data interaction and coupling, making cross-platform collaborative perception and conflict avoidance impossible, thereby threatening low-altitude flight safety. These bottlenecks highlight the adaptability limitations of existing ADS-B technology in complex low-altitude scenarios, and there is an urgent need for innovative technical solutions to overcome surveillance coverage gaps, optimize spectrum resource utilization, and build a standardized data interaction system. Summary of the Invention

[0004] The embodiment of the present application provides a TIS-B baseband signal processing method and transmitting device based on drone cloud data, realizes decoding and filtering of drone cloud data server monitoring data, dynamic allocation module of identity code, and transmission frequency control module, and utilizes dual-mode link to transmit TIS-B signals, thereby solving the compatibility problem of different data links in the existing low-altitude environment.

[0005] In order to achieve the above-mentioned purpose, the technical solution of the embodiment of the present invention is:

[0006] In a first aspect, an embodiment of the present invention provides a TIS-B baseband signal processing method based on drone cloud data, comprising:

[0007] Obtain drone surveillance data from multiple communication links through the drone cloud data server, parse, filter, and fuse the data to generate standardized messages that comply with the ASTERIX CAT021 format;

[0008] Decode and filter ASTERIX CAT021 format messages to extract target location and status data, including but not limited to latitude, longitude, altitude, speed, and heading information;

[0009] For drones that have not been assigned an ICAO identity code, an identity code is dynamically assigned within a preset limited field range, including: giving priority to reusing expired identity codes, managing expired codes by maintaining a small top-level pile based on ASCII code sorting, and assigning new codes in order if the pile is empty;

[0010] According to the preset fixed time interval, the real-time status data of the UAV is calculated by combining the data timestamp and the preset kinematic model to control the TIS-B signal transmission frequency;

[0011] The processed target position and status data are encoded into TIS-B signals in 1090ES format and / or UAT format. The transmission frequency band and modulation mode are selected according to the control instructions, and the signals are transmitted to the transmitting module through the serial port for modulation, amplification and transmission.

[0012] In some possible implementations, decoding and filtering ASTERIX CAT021 format messages include:

[0013] Parse the message structure according to the ASTERIX CAT021 format specification and extract the target location and status fields;

[0014] The decoded target position status data is filtered according to preset rules to eliminate abnormal data and data that is not within the transmission range; the preset rules include but are not limited to data source, target altitude, range of action, and flight parameter range.

[0015] In some possible implementations, dynamic allocation of identity codes is used to establish a dual-mechanism ICAO identity code allocation system of priority reuse of expiration codes and ordered incremental allocation, including:

[0016] The initial allocation field is a 24-bit ICAO address segment starting with F, which is allocated in ascending order according to ASCII code, with the starting address being F00001;

[0017] When TIS-B stops forwarding data from a certain drone, it marks its ICAO address as invalid and stores it in the top heap;

[0018] When allocating, the minimum invalid code at the top of the stack is extracted first. If the stack is empty, a new code is generated incrementally from the current maximum allocation address;

[0019] Blacklist verification is used to exclude allocation codes that conflict with existing civil aviation addresses.

[0020] In some possible implementations, the real-time status data of the drone is calculated based on a preset fixed time interval by combining the data timestamp with a preset kinematic model to control the TIS-B signal transmission frequency, including:

[0021] Define a fixed transmission interval and trigger the data inference process by comparing the current data timestamp with the previous transmission timestamp;

[0022] Based on the uniform velocity motion model, the position and velocity of the UAV are extrapolated and calculated to generate Real-time status data corresponding to the interval;

[0023] The TIS-B signal data in 1090ES format is split into identity, location and status messages, which are transmitted at different periods. The TIS-B signal data in UAT format is transmitted as a complete message at a defined fixed transmission interval.

[0024] In some possible implementations, encoding the processed target position and status data into a TIS-B signal in 1090ES format and / or UAT format includes:

[0025] Pulse position modulation (PPM) is used on 1090ES format data, and it is split into multiple types of messages;

[0026] Continuous Phase Frequency Shift Keying (CPFSK) modulation is used for UAT format data and encapsulated into a single complete message.

[0027] In some possible implementations, the transmission frequency band selection includes:

[0028] Dynamically switch between 1090MHz and 978MHz bands according to user instructions;

[0029] The 1090ES mode signal is controlled by the STM32 chip, and the UAT mode signal is controlled by the Simplelink CC13XX chip.

[0030] In some possible implementations, the method further includes:

[0031] The linear interpolation method is used to smooth the continuous multi-frame data with time stamp fluctuations to ensure the stability of the transmission frequency;

[0032] In dual-mode transmission scenarios, 1090ES and UAT format signals are generated synchronously, and their transmission parameters are independently controlled.

[0033] In a second aspect, an embodiment of the present invention provides a TIS-B transmitter based on drone cloud data, for implementing the method described in the first aspect, including:

[0034] UAV cloud data server, baseband signal processor and TIS-B mode transmitter board;

[0035] The drone cloud data server is used to aggregate drone surveillance data from multiple communication links, and after parsing, filtering, and fusing, encodes it in accordance with the unified civil aviation ASTERIX CAT021 data format, and opens data services to authorized users using TCP / IP protocols.

[0036] The baseband signal processor includes an ASTERIX CAT021 format data decoding and filtering module, an identity code dynamic allocation module, a transmission frequency control module, and a TIS-B mode encoding and switching module;

[0037] The TIS-B mode transmitter board includes a mode command control module and a radio frequency signal processing and transmission module;

[0038] The TIS-B mode transmitter board is used to obtain the corresponding coded data from the baseband signal processor, control the transmission frequency band and signal transmission frequency of the TIS-B signal through the mode instruction control module, and modulate, amplify and transmit the 1090ES and / or UAT mode signals through the RF signal processing and transmission module.

[0039] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0040] The TIS-B baseband signal processing method based on drone cloud data in an embodiment of the present invention utilizes a drone cloud data server as the data foundation for the entire system, unifying the formats of data from various data link sources and achieving data universality. Simultaneously, a baseband signal processor is utilized to implement data acquisition, decoding, and filtering, dynamic allocation of ICAO identity codes, signal transmission frequency control, and control signal modulation and transmission, ensuring data reliability and scalability. The present invention also features a high level of integration, integrating data communication interface circuits and baseband signal processing arithmetic units, reducing equipment size and facilitating installation and deployment. Furthermore, the present invention encompasses the mode monitoring signals for the two TIS-B data links currently used in the civil aviation sector, addressing the issue of compatible applications for multiple drone data links (such as 4G / 5G / Beidou / RemoteID, etc.), and providing a feasible solution for avoiding channel congestion. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 A schematic flow chart of an embodiment of a TIS-B baseband signal processing method based on drone cloud data provided for the implementation of the present invention;

[0043] Figure 2 Schematic diagram of an application scenario of a TIS-B baseband signal processing method based on drone cloud data in an embodiment of the present invention;

[0044] Figure 3 Schematic diagram of the structure of a TIS-B transmitter based on drone cloud data in an embodiment of the present invention;

[0045] Figure 4 Schematic diagram of another TIS-B transmitter based on drone cloud data in an embodiment of the present invention;

[0046] Figure 5 The figure is a schematic diagram of the working principle of a TIS-B transmitting device based on drone cloud data in an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0048] In the relevant description of this embodiment, the terms "including, containing, having" and the like are open terms and are generally understood to include but not be limited to; the term "at least one" is generally understood to mean one or more, where "plurality" refers to two or more; the term "at least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items, for example, "at least one of a, b or c", or "at least one of a, b and c", can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple respectively; the symbol "A / B" is used to describe the selection relationship of associated objects, generally indicating an "or" relationship before and after.

[0049] In the following description of the present embodiment, the terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0050] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0051] It will be understood by those skilled in the art that the numerical ranges in the examples of the present application are to be understood as also specifically disclosing each intermediate value between the upper and lower limits of the ranges. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded in the scope.

[0052] Unless otherwise indicated, the technical / scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which this application belongs. Although this application describes only preferred methods and materials, any methods and materials similar or equivalent to those herein may also be used in the implementation or testing of this application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0053] In order to illustrate the technical solution of the present invention, specific embodiments are provided below.

[0054] With the explosive growth of low-altitude vehicles like drones and electric vertical takeoff and landing (EVTL) aircraft, the low-altitude sector is characterized by significant heterogeneity (diverse aircraft types, communication protocols, and surveillance standards), high density (exponentially increasing frequency of flight activity), and high complexity (meteorological conditions, ground obstacles, and the interactive coupling of multi-source data). Both the International Civil Aviation Organization and the Civil Aviation Administration of China have designated Automatic Dependent Surveillance-Broadcast (ADS-B) technology as core infrastructure for low-altitude management. Using satellite navigation and data link communications, it enables real-time broadcasting of aircraft position, altitude, speed, and other information, supporting the construction of a global situational awareness network.

[0055] However, existing low-altitude surveillance systems face multiple technical bottlenecks. Drones, general aviation aircraft, and eVTOLs utilize different surveillance protocols (such as RemoteID / 1090ES / Beidou / 5G / radar). This leads to differences in data formats, transmission frequency bands, and communication mechanisms, creating "information silos" and hindering coordinated surveillance and collision avoidance across different aircraft types. Traditional radar (such as primary and secondary radar) uses independent data formats from the ADS-B system, making aircraft without ADS-B terminals (such as older general aviation aircraft) unable to be effectively monitored by the ADS-B system. The 1090ES data link is primarily used for high-altitude civil aviation, low-altitude large drones, and general aviation aircraft. Operating in the 1090MHz frequency band, it shares channels with secondary radar signals, subjecting them to channel congestion and interference. The UAT978 data link operates exclusively in the 978MHz band, making it suitable for low-altitude general aviation and low-altitude unmanned aerial vehicles, while effectively avoiding the 1090MHz band exclusively used by civil aviation.

[0056] Based on this, an embodiment of the present invention provides a TIS-B transmitter baseband signal processing method based on drone cloud data, which realizes the decoding and filtering of drone cloud data server monitoring data, processes the baseband signal accordingly according to functional requirements, and uses the TIS-B signal of the dual-mode link for transmission, solving the compatibility problem of different data links in the existing low-altitude environment.

[0057] Figure 1 A flow chart of an embodiment of a TIS-B baseband signal processing method based on drone cloud data provided by the present invention is shown in FIG. Figure 1 As shown, the above method may include:

[0058] S101 obtains drone surveillance data from multiple communication links through the drone cloud data server, parses, filters, and fuses the data, generates standardized messages in the ASTERIX CAT021 format, and transmits them to the baseband signal processor;

[0059] The UAV cloud data server serves as both a data storage and input unit. Through various data links, it aggregates massive amounts of data from various low-altitude flight equipment, ground monitoring stations, and other relevant data sources. Leveraging its powerful computing capabilities, it enables long-term, secure, and organized online processing and storage of this data, building a comprehensive and detailed low-altitude flight data repository. Furthermore, it rapidly processes the continuous flow of incoming data, intelligently identifying and executing appropriate data preprocessing procedures based on different data formats and sources, and providing the data to users in the ASTERIX CAT021 format.

[0060] The drone cloud data server is used to connect with multiple communication links, obtain the target position status data of the corresponding signal, and encode it in accordance with the unified civil aviation ASTERIX CAT021 data format after parsing, filtering, and fusion. The ASTERIX CAT021 format encoding information of the target position status data is stored, and the ASTERIX CAT021 format encoding information can be accessed by other authorized users through the TCP / IP protocol and other methods.

[0061] The architecture of a drone cloud data server can be composed of a high-performance server cluster equipped with a high-speed, high-capacity disk array for data storage, and employing advanced distributed storage technology to ensure data redundancy and security. The server is equipped with a powerful processor and ample memory resources to handle highly concurrent data input and processing tasks. At the software level, it runs a professional cloud storage management system and data processing middleware, supporting multiple data transmission protocols (such as HTTP, FTP, and MQTT), enabling seamless integration with various data sources, and providing stable and reliable data support and input services for the entire low-altitude surveillance transmitter system.

[0062] S102, decoding and filtering the ASTERIX CAT021 format message through the baseband signal processor to extract the target position and status data, which includes but is not limited to latitude, longitude, altitude, speed and heading information;

[0063] The baseband signal processor serves as the system's central processing unit, responsible for data acquisition, baseband signal processing, transmit signal mode switching, and communication with the drone's cloud data server. It can be a compact, low-power, and highly integrated central computing system, with customized functional modules tailored to specific application requirements. It includes a low-power embedded microprocessor, such as the ARM Cortex-M series, along with an appropriate amount of RAM, ROM, or Flash memory, USB, serial, and Ethernet interfaces, and a Linux operating system.

[0064] The baseband signal processor can efficiently and quickly process the fused data from the drone cloud data server, decode large amounts of data in the ASTERIX CAT021 format, and filter the decoded data. It then processes the data in different ways based on the functional requirements of dynamic allocation of ICAO identity codes and transmission frequency control. After TIS-B mode encoding and switching, it is sent to the TIS-B mode transmitter for subsequent signal transmission.

[0065] The ASTERIX CAT021 format data decoding function parses aviation surveillance data that complies with the ASTERIX CAT021 standard. ASTERIX CAT021, an internationally recognized aviation data exchange format, contains densely encoded aircraft dynamic and attribute information (such as ICAO address, latitude and longitude, pressure altitude, velocity vector, and flight status flags). Data filtering is used to filter and purify data processed by the ASTERIX CAT021 format data decoding module.

[0066] In some embodiments, decoding and filtering the ASTERIX CAT021 format message includes:

[0067] Parse the message structure according to the ASTERIX CAT021 format specification and extract the target location and status fields;

[0068] The decoded target position status data is filtered according to preset rules to eliminate abnormal data and data that is not within the transmission range; the preset rules include but are not limited to data source, target altitude, range of action, and flight parameter range.

[0069] Understandably, in actual low-altitude flight surveillance scenarios, received data may contain anomalies and data irrelevant to the current surveillance mission. Based on pre-set rules and algorithms, data can be individually screened. For example, by setting reasonable flight parameter ranges (such as reasonable altitude intervals and speed ranges), unnecessary data can be filtered out. Aircraft identification information can be used to select data from aircraft that require special attention or are located in specific areas, eliminating irrelevant data interference.

[0070] S103, for drones that have not been assigned an ICAO identity code, dynamically assign an identity code within a preset limited field range, including: giving priority to reusing expired identity codes, managing expired codes by maintaining a small top-up pile based on ASCII code sorting, and assigning new codes in ascending order if the pile is empty;

[0071] It should be noted that since TIS-B forwarding is for monitoring data of non-ADS-B signal sources, ICAO identity codes are generally not assigned. In order to avoid conflicts with existing civil aviation address codes, the identity code dynamic allocation module can only dynamically allocate identity codes to drones that are not assigned ICAO identity codes within a reserved limited field.

[0072] Specifically, in some embodiments, dynamic allocation of identity codes is used to establish a dual-mechanism ICAO identity code allocation system of preferential reuse of expiration codes and orderly incremental allocation, including:

[0073] (1)Initial allocation logic: Strictly follow the setting rules of the 24-bit ICAO address code of the Civil Aviation Administration of China. Generally, the addresses reserved for ICAO start with F. The default first available address is F00001, and it increases sequentially in ASCII code order (such as F00002, F00003...), ensuring the orderliness of the initial allocation.

[0074] (2)Invalid code recycling mechanism: When TIS-B stops forwarding the surveillance data of a certain UAV, immediately mark its ICAO address code (such as F01234) as invalid, and insert the ASCII value of this address code into the min heap (such as F00123 < F01234 < F12345). The heap structure supports efficient insertion and extraction operations with a time complexity of O(logN), ensuring the quick acquisition of the smallest available code.

[0075] (3)Dynamic allocation strategy: When a distribution request is triggered, first check whether there is an available code at the top of the min heap (directly extract the smallest code at the top of the heap when it is not empty, such as F00123), to avoid re-occupying new fields; if the heap is empty (that is, there is no invalid code available for reuse), then automatically increment and generate a new code after the currently allocated maximum ASCII code address.

[0076] (4)Conflict verification: Before each allocation, perform real-time verification through the preset blacklist of civil aviation address codes (such as excluding the reserved segment F00000 and the existing registered code segments), ensuring that the newly allocated code has no conflict with the existing civil aviation / known TIS-B systems.

[0077] S104, according to the preset fixed time interval, combine the data timestamp and the preset kinematic model to calculate the real-time state data of the UAV, and control the TIS-B signal emission frequency;

[0078] In some embodiments, the above step S104 specifically realizes the stable emission frequency control of the UAV surveillance data through the "timestamp-driven calculation + motion model compensation" mechanism. The main process is as follows:

[0079] Define a fixed emission interval, and trigger the data calculation process by comparing the current data timestamp with the previous emission timestamp;

[0080] Based on the uniform variable motion model, extrapolate and calculate the position and speed of the UAV to generate The corresponding real-time state data at the interval;

[0081] Split the TIS-B signal data in 1090ES format into identity, position, and status messages, and transmit them in different cycles. Transmit the complete message of the TIS-B signal data in UAT format according to the defined fixed emission interval cycle.

[0082] Exemplarily, in the calculation process, if the fixed time interval set by the user is , the last launch time of a certain drone is The current time to obtain the UAV surveillance data is , .like , then you need to Calculate Real-time unmanned aerial vehicle surveillance data, Therefore, it is necessary to base The UAV surveillance data at all times is used to calculate the kinematic equations For example, for Vertical speed at the moment Calculation: , ,in, are the vertical acceleration of the UAV, Moment and Vertical speed at any moment. Latitude, longitude, altitude, and speed can all be calculated based on the above process.

[0083] In some embodiments, a linear interpolation method may be used to smooth multiple frames of data with fluctuating timestamps to ensure transmission frequency stability.

[0084] In the above process, since each message in the UAT format contains all the information, while the complete data in the 1090ES format is split into multiple messages and sent in multiple messages, including identity, location, and status messages, the two have slightly different signal transmission frequency control. Since a message in the UAT format contains all the information of the drone monitoring data, it is transmitted at a fixed interval. Transmit; multiple messages of 1090ES format data can also be transmitted at a fixed interval To alleviate congestion to a certain extent, the period of identity message can be set to be larger, generally 5 seconds, and other messages can be 1 second. Therefore, in addition to the fixed transmission interval, there is also a time interval between the transmission time of these messages. , and the time interval can be controlled at the microsecond level.

[0085] S105: Encode the processed target position and status data into a TIS-B signal in 1090ES format and / or UAT format, select the transmission frequency band and modulation mode according to the control instruction, and transmit it to the transmitting module through the serial port for modulation, amplification and transmission.

[0086] In some embodiments, the processed target position and status data is encoded into a TIS-B signal in 1090ES format and / or UAT format, including: applying pulse position modulation (PPM) to the 1090ES format data and splitting it into multiple types of messages; applying continuous phase frequency shift keying (CPFSK) modulation to the UAT format data and encapsulating it into a single complete message.

[0087] In some embodiments, transmission band selection includes dynamically switching between the 1090MHz and 978MHz bands based on user instructions; controlling 1090ES mode signals via an STM32 chip, and controlling UAT mode signals via a Simplelink CC13XX chip. In dual-mode transmission scenarios, 1090ES and UAT format signals can be generated simultaneously, with their transmission parameters independently controlled.

[0088] The following describes the working principle of a TIS-B baseband signal processing method based on drone cloud data provided by the present invention using a specific embodiment.

[0089] Figure 2 This is a schematic diagram of an application scenario of a TIS-B baseband signal processing method based on drone cloud data in an embodiment of the present invention. Figure 2 In this application scenario, the TIS-B baseband signal processing method based on drone cloud data, after monitoring valid ASTERIX CAT021 format messages, decodes them in a standardized manner to obtain target position status data. Based on this data, the dynamic identity code allocation module dynamically assigns ICAO identity codes to drones without ICAO addresses. The transmission frequency control module then controls the TIS-B signal transmission frequency according to actual needs. The TIS-B mode encoding and switching module then encodes the data into corresponding data frames (TIS-B format). Finally, PPM modulation and / or CPFSK modulation are performed. After passing through a signal amplifier, the TIS-B signal is transmitted via a 1090 MHz antenna and / or a 978 MHz antenna. Aircraft, eVTOLs, and unmanned aerial vehicles can receive TIS-B signals from TIS-B devices via ADS-B IN modules (supporting 1090ES and UAT formats). After appropriate data processing, the target position status data can be obtained. Then, navigation and avoidance algorithms can be used to maintain safe spacing and safe operation.

[0090] The TIS-B baseband signal processing method based on drone cloud data in the embodiment of the present invention uses the drone cloud data server as the data support for the entire system, unifies the format of data from various data link sources, and has data extensiveness. At the same time, the baseband signal processor is used to realize data acquisition, decoding and filtering, dynamic allocation of ICAO identity codes, signal transmission frequency control, and control signal modulation and transmission, to ensure data reliability and scalability. The present invention also has the characteristics of high integration, and can integrate the interface circuit of data communication, the operation unit of baseband signal processing, etc., to reduce the size of the equipment and facilitate installation and deployment. At the same time, the present invention covers the mode monitoring signals of the two data links of TIS-B in the current civil aviation industry, solves the problem of compatible applications of multiple data links of drones, and provides a feasible solution to avoid channel congestion.

[0091] Based on the same inventive concept, the embodiment of the present application also provides a TIS-B transmitting device based on the above-mentioned TIS-B baseband signal processing method based on drone cloud data. Figure 3 This is a schematic diagram of the structure of the TIS-B transmitter based on drone cloud data in an embodiment of the present invention. Figure 3 As shown, the TIS-B transmitting device may include:

[0092] UAV cloud data server 301, baseband signal processor 302 and TIS-B mode transmitter board 303;

[0093] The drone cloud data server 301 is used to aggregate drone surveillance data from multiple communication links, and after parsing, filtering, and fusing, encodes it in accordance with the unified civil aviation ASTERIX CAT021 data format, and opens data services to authorized users using TCP / IP protocols and other methods;

[0094] The baseband signal processor 302 includes an ASTERIX CAT021 format data decoding and filtering module, an identity code dynamic allocation module, a transmission frequency control module, and a TIS-B mode encoding and switching module;

[0095] The TIS-B mode transmitter board 303 includes a mode command control module and a radio frequency signal processing and transmission module;

[0096] The TIS-B mode transmitter board 303 is used to obtain the corresponding coded data from the baseband signal processor, control the transmission frequency band and signal transmission frequency of the TIS-B signal through the mode instruction control module, and modulate, amplify and transmit the 1090ES and / or UAT mode signals through the RF signal processing and transmission module.

[0097] In this embodiment of the present invention, drone cloud data server 301 is capable of integrating drone surveillance data from multiple data links, enabling comprehensive reception and processing of multiple surveillance signals. The various data processing modules of baseband signal processor 302 work together to perform data decoding, filtering, target data preparation, encoding of data in appropriate formats, and control of dual-mode signal transmission. Its powerful computing capabilities ensure data accuracy and real-time performance.

[0098] The baseband signal processor 302 is used to access the drone cloud data server 301 through the TCP / IP protocol to obtain the corresponding ASTERIX CAT021 format message, and then use the ASTERIX CAT021 format data decoding and filtering module to extract the target position status data of the corresponding requirements. The identity code dynamic allocation module then dynamically allocates the ICAO identity code to the drone without an ICAO address. The transmission frequency control module then controls the transmission frequency of the TIS-B signal according to actual needs. Finally, the TIS-B mode encoding and switching module encodes the target position status data into the corresponding 1090ES and / or UAT format data and sends it through the serial port.

[0099] Among them, the baseband signal processor 302 is connected to the drone cloud data server 301 through the TCP / IP protocol to obtain the ASTERIX CAT021 format message; it is also connected to the TIS-B mode transmitter board 303 through the serial port to transmit 1090ES and / or UAT format encoded data in real time.

[0100] In this embodiment of the present invention, the baseband signal processor 302 obtains the ASTERIX CAT021 format data from the drone cloud data server 301 and can immediately start the decoding and baseband signal processing process. Specifically, the following steps are included:

[0101] First, the computer performs a data structure check, including header and length, to ensure the integrity of the input data. It then performs field parsing, following the parameter encoding rules defined in the CAT021 standard. Once the decoding process is complete, the output structured data can be directly used by subsequent modules, providing standardized input for data filtering and baseband signal processing.

[0102] After obtaining the filtered target position status data, it is necessary to dynamically assign ICAO identity codes to drones without ICAO addresses. This process can be achieved by maintaining a small top stack and controlling the transmission frequency of the TIS-B signal according to actual needs through the transmission frequency control module.

[0103] The baseband signal processor 302 then sends the encoded 1090ES and / or UAT format data through the serial port to the TIS-B mode transmitter board 303. The TIS-B mode transmitter board 303 filters the signals in different operating frequency bands and then performs PPM modulation and CPFSK modulation on the encoded data in 1090ES and UAT formats, respectively, to generate the required TIS-B signal.

[0104] Finally, the TIS-B signal is amplified and then broadcasted through the RF signal processing and transmission module.

[0105] For example, Figure 4 This is a structural diagram of another TIS-B transmitter based on drone cloud data in an embodiment of the present invention, see Figure 4 As shown in the figure, the baseband signal processor includes an ASTERIX CAT021 format data decoding and filtering module, an identity code dynamic allocation module, a transmission frequency control module, and a TIS-B mode encoding and switching module. The drone cloud data server can send ASTERIX CAT021 format messages to the baseband signal processor via sockets and other methods, and the two communicate over the network. After the baseband signal processor processes the data through its various modules, it dynamically allocates identity codes and controls the signal transmission frequency. The resulting encoded data is then sent to the TIS-B mode signal transmitter board, and the two communicate via the serial port.

[0106] The drone cloud server connects to the baseband signal processor via a socket, and the TIS-B mode signal transmitter board connects to the baseband signal processor via a serial port. The baseband signal processor decodes and filters the acquired ASTERIX CAT021 format data, dynamically assigns ICAO identity codes to drones without assigned ICAO identity codes, and controls the signal transmission frequency based on actual needs. Kinematic principles are applied to infer the corresponding drone surveillance data, which is then transmitted via the serial port after data encoding and coded data switching. The corresponding signal control module in the TIS-B mode transmitter board generates, filters, modulates, and amplifies the signal before transmitting the corresponding TIS-B signal through the antenna.

[0107] In some embodiments, each module of the baseband signal processor and each signal transmission module can implement the above functions through a programming language.

[0108] For example, see Figure 5 As shown, Figure 5 This is a schematic diagram of the working principle of a TIS-B transmitter based on drone cloud data in an embodiment of the present invention. Figure 5 As shown, the baseband signal processor may include:

[0109] Message decoding and filtering module, the decoding function is used to decode the received data according to the ASTERIX CAT021 format;

[0110] The ASTERIX CAT021 format message is provided by the UAV cloud data server. The message decoding and filtering module runs on the Linux platform and uses the JAVA programming language through the Socket method to obtain the ASTERIX CAT021 format message and perform data decoding.

[0111] The data filtering function uses relevant data filtering algorithms and filtering conditions to filter the decoded target position status data and eliminate abnormal data and data that is not within the sending range;

[0112] For example, after decoding the ASTERIX CAT021 format data, unnecessary data is filtered out by setting a reasonable flight parameter range (such as a reasonable flight altitude range, speed range, etc.); using aircraft identification information, aircraft data that requires special attention or within a specific area is screened out to eliminate interference from irrelevant data.

[0113] The dynamic ID allocation module dynamically allocates IDs for unassigned ICAO IDs in China within a limited 6-digit field starting with F (e.g., F00001). This module initializes IDs using an incrementing strategy. It also maintains a small top-level stack, sorted by ICAO address ASCII codes, to recycle expired IDs when TIS-B stops forwarding surveillance data. When allocating IDs, the smallest available ID at the top of the stack is prioritized. If the stack is empty, a new ID is generated incrementally after the current largest ASCII address, enabling efficient reuse and orderly management of blank field resources.

[0114] The transmission frequency control module ensures that TIS-B signals are transmitted at fixed intervals set by the user. To address fluctuations in data acquisition time from the drone's cloud data server, a data extrapolation mechanism is triggered by timestamp comparison. Based on a kinematic model, the module extrapolates the drone's spatial coordinates (latitude, longitude, altitude), as well as motion parameters such as vertical and horizontal speed. Using the known state data from the previous transmission, the module infers the real-time state at the current transmission time. This ensures that surveillance data from the same drone is transmitted at a stable interval, eliminating the impact of data acquisition fluctuations on the transmission frequency.

[0115] The TIS-B mode encoding and switching module is used to write TIS-B data in the corresponding format according to the transmission signal format requirements, switch the transmission of data in different formats, and support the transmission of data in both 1090ES and UAT modes.

[0116] based on Figure 5As shown, the TIS-B mode transmitter board may include:

[0117] The core function of the mode command control module is to precisely control the TIS-B signal transmission band and frequency based on user-entered control commands. These control commands carry the user's specific requirements for the TIS-B signal transmission band and frequency. For example, the user may want to transmit the signal in the 1090MHz or 978MHz band, or set a specific transmission frequency to meet different application scenarios.

[0118] When the module receives a user control command, it parses and processes it, converting it into a control signal recognizable by the RF signal processing and transmission module. This module then performs a validity check on the command to ensure its legality and feasibility. If the command is valid, the module generates a corresponding control signal containing detailed information about the transmission band and frequency. This signal is then sent to the RF signal processing and transmission module, enabling precise control of TIS-B signal transmission parameters.

[0119] The RF signal processing and transmission module is primarily responsible for receiving coded data from the baseband signal processor and corresponding control signals from the mode command control module. Based on the type of coded data, this module generates the required TIS-B signal using the appropriate modulation scheme.

[0120] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0121] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A TIS-B baseband signal processing method based on drone cloud data, characterized in that: include: Acquire drone surveillance data from multiple communication links through a drone cloud data server, parse, filter, and fuse the data to generate standardized messages in the ASTERIX CAT021 format, and transmit them to the baseband signal processor; Decoding and filtering the ASTERIX CAT021 format message through the baseband signal processor to extract target position and status data, wherein the target position and status data include latitude, longitude, altitude, speed, and heading information; For drones that have not been assigned an ICAO identity code, an identity code is dynamically assigned within a preset limited field range, including: giving priority to reusing expired identity codes, managing expired codes by maintaining a small top-level pile based on ASCII code sorting, and assigning new codes in order if the pile is empty; According to the preset fixed time interval, the real-time status data of the UAV is calculated by combining the data timestamp and the preset kinematic model to control the TIS-B signal transmission frequency; The processed target position and status data are encoded into TIS-B signals in 1090ES format and / or UAT format. The transmission frequency band and modulation mode are selected according to the control instructions, and the signals are transmitted to the transmitting module through the serial port for modulation, amplification and transmission.

2. The method according to claim 1, characterized in that Decoding and filtering the ASTERIX CAT021 format message includes: Parse the message structure according to the ASTERIX CAT021 format specification and extract the target location and status fields; The decoded target position status data is filtered according to preset rules to eliminate abnormal data and data that is not within the transmission range; the preset rules include data source, target altitude, range of action, and flight parameter range.

3. The method according to claim 2, characterized in that The dynamic allocation of identity codes is used to establish a dual-mechanism ICAO identity code allocation system of priority reuse of expiration codes and orderly incremental allocation, including: The initial allocation field is a 24-bit ICAO address segment starting with F, which is allocated in ascending order according to ASCII code, with the starting address being F00001; When TIS-B stops forwarding data from a certain drone, it marks its ICAO address as invalid and stores it in the top heap; When allocating, the minimum invalid code at the top of the stack is extracted first. If the stack is empty, a new code is generated incrementally from the current maximum allocation address; Blacklist verification is used to exclude allocation codes that conflict with existing civil aviation addresses.

4. The method according to claim 3, characterized in that The method of calculating the real-time status data of the UAV based on a preset fixed time interval, combining the data timestamp with a preset kinematic model, and controlling the TIS-B signal transmission frequency includes: Define a fixed transmission interval and trigger the data inference process by comparing the current data timestamp with the previous transmission timestamp; Based on the uniform velocity motion model, the position and velocity of the UAV are extrapolated and calculated to generate Real-time status data corresponding to the interval; The TIS-B signal data in the 1090ES format is split into identity, location and status messages, which are transmitted at different periods. The TIS-B signal data in the UAT format is transmitted as a complete message at a defined fixed transmission interval period.

5. The method according to claim 4, characterized in that The step of encoding the processed target position and status data into a TIS-B signal in a 1090ES format and / or a UAT format includes: Pulse position modulation is applied to 1090ES format data, and the data is split into multiple types of messages; Continuous phase frequency shift keying modulation is used for UAT format data and encapsulated into a single complete message.

6. The method according to claim 5, characterized in that Transmit frequency band options include: Dynamically switch between 1090MHz and 978MHz bands according to user instructions; The 1090ES mode signal is controlled by the STM32 chip, and the UAT mode signal is controlled by the Simplelink CC13XX chip.

7. The method according to any one of claims 1 to 6, characterized in that The method further comprises: The linear interpolation method is used to smooth the continuous multi-frame data with time stamp fluctuations to ensure the stability of the transmission frequency; In dual-mode transmission scenarios, 1090ES and UAT format signals are generated synchronously, and their transmission parameters are independently controlled.

8. A TIS-B launcher based on drone cloud data, characterized in that: The method for implementing any one of claims 1 to 7 comprises: UAV cloud data server, baseband signal processor and TIS-B mode transmitter board; The drone cloud data server is used to aggregate drone surveillance data from multiple communication links, and after parsing, filtering, and fusing, encodes it in accordance with the unified ASTERIX CAT021 data format of the Civil Aviation Administration of China, and opens data services to authorized users using the TCP / IP protocol. The baseband signal processor includes an ASTERIX CAT021 format data decoding and filtering module, an identity code dynamic allocation module, a transmission frequency control module, and a TIS-B mode encoding and switching module; The TIS-B mode transmitter board includes a mode command control module and a radio frequency signal processing and transmission module; The TIS-B mode transmitting board is used to obtain the corresponding encoded data from the baseband signal processor, control the transmission frequency band and signal transmission frequency of the TIS-B signal through the mode instruction control module, and modulate, amplify and transmit the 1090ES and / or UAT mode signals through the RF signal processing and transmission module.

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