Method for timing coordination of distributed radars and radar system

Abstract

This invention discloses a timing coordination method and radar system for distributed radar, belonging to the field of radar control technology. The main technical solution of this invention is to synchronize the clocks of all radar devices to a unified time axis, and then allocate non-overlapping detection time slots to each radar on this time axis. The unified time axis and the order of each radar device are determined by the timing packets exchanged by each radar device in a first frequency band, and each radar device transmits radar waveforms in a second frequency band according to its order in the corresponding detection time slot. This invention enables multiple independently operating radar devices to achieve time synchronization in a distributed environment without a central control node, and on this basis, coordinates the transmission timing of their respective radar waveforms to stagger them, thereby fundamentally avoiding interference between radars.

Description

Technical Field

[0001] This invention belongs to the field of radar control technology, specifically relating to a timing coordination method and radar system for distributed radar. Background Technology

[0002] In applications such as smart homes where multiple radars coexist, multiple independently operating radars (such as FMCW millimeter-wave radars) are highly susceptible to mutual interference in both the time and frequency domains, leading to a deterioration in the signal-to-noise ratio and false alarms, severely impacting the accuracy of target perception. While existing technologies have adopted the following control schemes, they still have their own shortcomings:

[0003] Centralized coordination schemes rely on a single master device (such as a gateway) for unified time synchronization and scheduling. Their disadvantages include a single point of failure risk; failure of the master device will cause the entire system to crash, and poor network topology flexibility.

[0004] Competition-based random access schemes (such as carrier sensing): The radar listens to the channel before transmission. Its disadvantage is that for radar sensing tasks requiring periodic, deterministic detection time slots, the uncertainty in transmission time caused by random backoff can lead to scheduling conflicts and performance instability, making it impossible to guarantee long-term interference-free operation.

[0005] Traditional distributed time synchronization protocols (such as NTP) only achieve clock alignment for each device, but do not have the function of allocating a unique and deterministic detection time slot for each device. They cannot directly solve the problem of physical layer waveform conflict, and the clock alignment accuracy is usually at the millisecond level, which is far from the timing accuracy of less than 1 microsecond required by radar.

[0006] In summary, existing solutions struggle to simultaneously meet the requirements of decentralization, high availability, and deterministic detection time slots. Therefore, a distributed self-organizing mechanism that integrates time synchronization and time slot allocation is urgently needed. Summary of the Invention

[0007] This invention provides a timing coordination method and system for distributed radar. By integrating time synchronization and time slot allocation into a distributed self-organizing mechanism, interference between radars is fundamentally avoided. This invention is achieved through the following technical solution:

[0008] In a first aspect, the present invention provides a timing coordination method for distributed radar, comprising:

[0009] S100: Preset a first frequency band dedicated to the periodic transmission and reception of timing packets by radar equipment and a second frequency band dedicated to the transmission of radar waveforms by radar equipment; define a global superframe period, each superframe period including a transmission period, and the transmission period including multiple detection time slots dedicated to the transmission of radar waveforms by each radar equipment respectively;

[0010] S200: Configure local IDs for multiple radar devices in the initial coordinated network, distinguished by size. Each radar device will treat itself as the root device, set its local ID pool to empty, and allow its local timer to run freely.

[0011] S300 controls each radar device to operate independently and exchange timing packets with each other on the first frequency band. The timing packet includes an ID field that records the local ID, an ID pool field that records the local ID pool, and a period field that records the timing period. The timing period is the duration of the superframe period. Each radar device updates its locally recorded local ID pool and timing period by identifying and determining the relative front-end device ID.

[0012] S400. Each radar device sorts its position in the local ID pool according to the updated and stabilized local ID, and matches it with the detection time slot order of the superframe period in step S100. Each device then transmits its radar waveform in the second frequency band within its corresponding detection time slot.

[0013] As a preferred technical solution, after step S400, if a new radar device joins the coordinated network, the following steps are performed:

[0014] S510, new radar equipment has its local ID pre-emptively set;

[0015] S520 and newly acquired radar equipment first receive timed packets from the current network within a preset time period, update the local ID pool, and set the local ID to the maximum ID in the local ID pool +1;

[0016] S530, newly added radar equipment and other radar equipment in the current network exchange timing packets on the first frequency band. Each radar equipment updates its local ID pool and timing period by identifying and determining the relative front-end device ID and back-end device ID.

[0017] S540. Each radar device sorts its position in the local ID pool according to the updated and stabilized local ID, matches it with the detection time slot order of the superframe period in step S100, and transmits its own radar waveform in the second frequency band within its corresponding detection time slot.

[0018] As a preferred technical solution, the superframe period also includes a common signaling period and a protection interval period located before and after the transmission period, respectively; the common signaling period includes multiple synchronization time slots for multiple radar devices to transmit timing packets, and the synchronization time slot occupied by the timing packet is determined by the sorting position of the device ID in the local ID pool.

[0019] As a preferred technical solution, in step S300, when exchanging timing packets, the radar device sends and receives timing packets during the common signaling period of the preceding superframe period; in step S400, each radar device sends its own radar waveform in the following superframe period, according to the sorting order, in the multiple detection time slots.

[0020] As a preferred technical solution, the information in the timing packet includes a preamble and a payload field. The payload field includes a synchronization field for frame delimitation, a period field for recording the timing period, an ID field for recording the local ID, an ID pool field for recording the local ID pool, and a checksum field.

[0021] As a preferred technical solution, in step S300, when each radar device receives a timing packet, it extracts the ID field and the ID pool field from it; if the value of the ID field is less than the ID of the preceding device currently tracked by the local timer, the local timer is corrected based on the arrival time of the timing packet, the value of the period field, and the synchronization time slot it occupies, and the preceding device ID and timing period are updated. At the same time, all unknown radar device IDs carried in the timing packet are added to the local ID pool.

[0022] As a preferred technical solution, in step S300, if the radar device does not receive any timing packets from the preceding device within the preset timeout period, or if the radar device finds that the value of the ID field in the received timing packet is the same as its own ID (i.e., ID conflict), then the current radar device will execute steps S510 to S540 as if it were a newly arrived radar device.

[0023] As a preferred technical solution, the preamble includes a single-tone waveform for packet detection and frequency offset estimation; and / or, the payload field also includes a radar waveform field for unifying or distributing radar waveform parameters and / or a time slice field for transmitting time slot division rules.

[0024] As a preferred technical solution, the modulation mechanism used in the payload field includes one or more of FSK, MFSK, CPFSK, LFM and M-ary CPFSK; the checksum field is implemented using CRC, Checksum, HMAC, AES or digital signature methods.

[0025] Secondly, the present invention provides a radar system comprising multiple radar devices, wherein the multiple radar devices cooperate to perform the timing coordination method of the distributed radar described above.

[0026] The timing coordination method and radar system for distributed radar provided by this invention have the following advantages: they enable multiple independently operating radar devices to achieve time synchronization in a distributed environment without a central control node, and on this basis, coordinate the transmission timing of their respective radar waveforms to stagger them, thereby fundamentally avoiding interference between radars. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is the main flowchart of the timing coordination method for distributed radar provided in the embodiments of the present invention.

[0029] Figure 2 This is a flowchart of the new radar networking process in the timing coordination method for distributed radar provided in the embodiments of the present invention.

[0030] Figure 3 This is a structural diagram of the radar system provided in an embodiment of the present invention. Detailed Implementation

[0031] To make the technical solution of the present invention clearer and its technical advantages more apparent, the technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of the present invention.

[0032] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of this application may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0033] It should be understood that although the steps in the flowcharts of this application's embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0034] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0035] Before describing the specific implementation methods, the definitions of the terms used in this document are explained as follows:

[0036] 1. Front-end equipment: The radar with the smallest device ID among all other radars that can receive its timing packets is called the front-end equipment of the current radar.

[0037] 2. Subsequent equipment: If the enemy radar uses it as a front-end equipment, the enemy radar is referred to as the current radar's subsequent equipment.

[0038] 3. Root device: The radar with the smallest device ID in the current environment is called the root device.

[0039] 4. Local ID pool: A storage space containing several distinct device IDs.

[0040] 5. Field of view: The field of view of the current radar is the range of all radars whose timing packets it can receive.

[0041] 6. Overall network view: The sum of all radar devices participating in timed synchronization.

[0042] In order to completely avoid radar mutual interference in a distributed environment, the main idea and key technical means of this invention are: first, to synchronize the clocks of all radars to a unified time axis; and second, to allocate non-overlapping detection time slots for each radar on this time axis.

[0043] Based on this, see Figure 1As shown, as a basic implementation method, this embodiment provides a timing coordination method for distributed radar, including:

[0044] S100: A first frequency band is preset for the periodic transmission and reception of timing packets by radar equipment, and a second frequency band is preset for the transmission of radar waveforms by radar equipment. The first frequency band and the second frequency band do not overlap in the spectrum. A global superframe period is defined. Each superframe period includes a transmission period. The transmission period includes multiple detection time slots for each radar equipment to transmit radar waveforms respectively.

[0045] S200. Initialize the multiple radar devices in the initial coordinated network: Configure local IDs for the multiple radar devices in the initial coordinated network, distinguished by size. Each radar device will treat itself as the root device, set its local ID pool to empty, and allow its local timer to run freely. Since the front-end device ID record of each radar device cannot be empty during initialization, the local ID of each radar device will be temporarily recorded as the front-end device ID. It will be updated when the radar devices exchange timed packets and obtain the real front-end device ID.

[0046] S300 controls each radar device to operate independently, exchanging timing packets with each other on the first frequency band. The timing packet includes an ID field recording the local ID, an ID pool field recording the local ID pool, and a period field recording the timing period, which is the duration of the superframe period. Each radar device identifies and determines the relative front-end device ID (and can also simultaneously identify and determine the relative back-end device ID), and updates its locally recorded local ID pool and timing period. Specifically, when each radar device receives a timing packet, it extracts the ID field and ID pool field. If the value of the ID field is less than the front-end device ID currently being tracked by the local timer, the local timer is corrected based on the arrival time of the timing packet, the value of the period field, and the synchronization time slot it occupies, and the front-end device ID and timing period are updated. At the same time, all unknown radar device IDs carried in the timing packet are added to the local ID pool.

[0047] S400: Each radar device sorts its position in the local ID pool according to its updated and stabilized local ID, aligning it with the superframe period division of the detection time slots in step S100, and transmits its radar waveform in the second frequency band within its respective corresponding detection time slot. In step S400, it is possible that after transmitting its radar waveform in the second frequency band within its corresponding detection time slot, each radar device may simultaneously complete echo reception within that same detection time slot.

[0048] The basic principle of the above embodiments is as follows:

[0049] Monitoring and Learning: Each radar device continuously monitors the first frequency band, analyzes the ID pool information in the timing packets, and updates its local field of view. Upon receiving a timing packet, it learns the network topology (updates its local ID pool) and determines whether the sender is a superior "predecessor device" (i.e., a device with a smaller ID). If so, it strictly aligns its clock with it. This process allows time synchronization information and global network topology information to spread outwards from the root device with the smallest ID in a "relay" manner, ultimately forming a "synchronization tree" originating from the root device.

[0050] Unique time slot determination: As the ID pool stabilizes (encompassing all device IDs in the network), each device can determine its unique ranking position within the entire network. Based on this position, a conflict-free transmission time window specific to the device can be calculated using a defined algorithm (such as multiplying a fixed time slot length by the ranking number).

[0051] Unified configuration: To ensure network consistency, downstream devices must comply with and implement the network parameters such as time slot allocation method and radar waveform configuration issued by their upstream devices in the time packets.

[0052] In this way, by completing the closed loop of "discovering neighbors - synchronizing time - determining position - calculating time slot" in a distributed manner, all radars can autonomously achieve precise staggering of their launch timing without central scheduling, thus avoiding mutual interference.

[0053] The beneficial effects of the above embodiments are as follows: (1) Decentralization and high robustness: No central node is required, and the failure of any device does not affect the overall operation of the system, which has the ability to self-organize and self-recover. (2) Deterministic scheduling and zero conflict: Time slots are allocated based on globally unique IDs, which fundamentally avoids any overlap of radar waveforms in the time domain, and the probability of interference is zero. (3) Synchronization and scheduling integration: Time synchronization and time-division multiplexing scheduling mechanism are deeply coupled, which simplifies system design and makes the goal direct and clear.

[0054] Combination Figure 2 As shown, as an extended implementation, after step S400, if a new radar device joins the coordination network, the timing coordination method for the distributed radar described above will perform the following steps:

[0055] S510, new radar equipment has its local ID pre-emptively set;

[0056] S520: New radar equipment first receives timed packets from the current network within a preset time period, updates the local ID pool, and sets the local ID to the maximum ID in the local ID pool + 1; Note: ID + 1 here can be considered as a general increment, for example, it can be "001 + 1 = 010" or "C + 1 = D";

[0057] S530, newly added radar equipment and other radar equipment in the current network exchange timing packets on the first frequency band. Each radar equipment updates its local ID pool and timing period by identifying and determining the relative front-end device ID and back-end device ID.

[0058] S540. Each radar device sorts its position in the local ID pool according to the updated and stabilized local ID, aligns it with the detection time slot order of the superframe period in step S100, and transmits its own radar waveform in the second frequency band within its respective corresponding detection time slot. In step S540, it is possible that after each radar device transmits its own radar waveform in the second frequency band within its corresponding detection time slot, it also completes echo reception within that corresponding detection time slot.

[0059] The advantage of the above extended implementation method is that when a new radar device is added to an already stable network, it is not necessary to pre-set a local ID for the new radar device, which is convenient for consumers. Specifically, considering which radar device IDs in the current network have already been occupied, consumers may have forgotten which ones, making it inconvenient to configure the local ID of the new radar device according to a predetermined size or format; of course, unless the local ID is uniformly numbered and burned into all radar devices manufactured by the radar factory, this method solves the ID conflict problem, but it will result in a particularly long ID, increasing the length of the timing packet (for example, the MAC address in Wi-Fi is as long as 48 bits).

[0060] In addition, in step S300, if the radar device does not receive any timing packets from the preceding device within the preset timeout period, the ID of the preceding device currently being tracked by the local timer is set to the local ID; or if the radar device finds that the value of the ID field in the received timing packet is the same as the local ID (i.e., ID conflict), the current radar device executes steps S510 to S540 as if it were a newly arrived radar device.

[0061] As a preferred embodiment, the superframe period described above further includes a common signaling period and a guard interval period located before and after the transmission period, respectively. The common signaling period includes multiple synchronization time slots for multiple radar devices to transmit timing packets, and the synchronization time slot occupied by the timing packet is determined by the device ID's ranking in the local ID pool. This ensures that the timing packet is transmitted at a known time point within the agreed superframe, preventing downstream devices from failing to align the superframe's timing phase with the upstream devices. Based on this, in step S300, the radar device transmits and receives timing packets during the common signaling period of an earlier superframe period; in step S400, each radar device transmits its own radar waveform sequentially in multiple detection time slots according to the ranking in a later superframe period.

[0062] In a specific implementation, the information within the timing packet includes a preamble and a payload field. The payload field includes a synchronization field for frame delimitation, a period field for recording the timing period, an ID field for recording the local ID, an ID pool field for recording the local ID pool, and a checksum field for ensuring data integrity. Preferably, the preamble includes a single-tone waveform for packet detection and frequency offset estimation. Preferably, the payload field may also include a radar waveform field for unifying or distributing radar waveform parameters; or, the payload field may also include a time slice field for transmitting time slot division rules. Furthermore, the modulation mechanism used by the payload field includes one or more of FSK, MFSK, CPFSK, LFM, and M-ary CPFSK; the checksum field is implemented using methods such as CRC, Checksum, HMAC, AES, or digital signature.

[0063] See Figure 3 As shown, another embodiment of the present invention provides a radar system including multiple radar devices, which cooperate to perform the timing coordination method of the distributed radar described above.

[0064] Combination Figure 3 As shown, in order to make the specific embodiments of the present invention clearer and easier to understand, a specific example is given below:

[0065] 1. Application scenario setting:

[0066] Suppose that in a smart home living room, three independent FMCW millimeter-wave radar devices are deployed: radar device A for human presence detection, radar device B for gesture recognition, and radar device C for sleep monitoring. Their device IDs are preset at the factory and satisfy: ID_A < ID_B < ID_C. The three radar devices are spatially close, and their wireless signals (on the first frequency band) can be mutually received; that is, each radar device's field of view includes the other two devices.

[0067] 2. System Initialization and Key Parameters:

[0068] Frequency band allocation: The first frequency band (e.g., 59GHz~59.005GHz) is used to transmit timing packets; the second frequency band (e.g., 59.005GHz~64GHz) is used to transmit FMCW radar waveforms; the two frequency bands are separated and do not interfere with each other.

[0069] Timing parameters: The system defines a global superframe period, for example, T_frame = 100 ms. Each superframe will be divided into several time slots for the device to send timing packets and radar waves.

[0070] Device local status: When each radar device is initialized, it regards itself as the root device, records the local ID of each radar device as the ID of the previous device, the local ID pool is empty, and the local timer runs freely.

[0071] 3. Workflow and interaction timing:

[0072] Initial moment: The three radar devices operate independently, each regarding itself as the root device, and each sends a timing packet (content: its own ID, its own ID pool (empty), timing period, etc.) at a random moment.

[0073] Synchronization tree establishment: By exchanging timing packets, both radar devices B and C will find that the ID of radar device A is the smallest, so they both regard device A as their "previous device" and synchronize with it; device A becomes the de facto root device. At this time, the ID pool of device A is {B, C}, the ID pool of device B is {A, C}, and the ID pool of device C is {A, B}. The network forms a tree topology with A as the root: A is the previous device of B and C; B and C are the subsequent devices of A.

[0074] Time slot allocation: According to the sorting (A < B < C) and the preset time slot division algorithm (such as equal division), time slots are allocated within T_frame. For example: Time slots 0 - 5 ms are for common signaling, and the synchronization time slot 0 - 1 ms is for radar device A to send a timing packet, the synchronization time slot 1 ms - 2 ms is for radar device B to send a timing packet, the synchronization time slot 2 - 3 ms is for radar device C to send a timing packet, the detection time slot 5 - 35 ms is for radar device A to send radar waves, the detection time slot 35 - 65 ms is for radar device B, the detection time slot 65 - 95 ms is for radar device C, and the last 5 ms is for the protection interval.

[0075] The following describes an exemplary interaction process in combination with the text:

[0076] Moment t0: Device A (root device) broadcasts its timing packet during the common signaling period of the first frequency band. The structure of this timing packet is as follows:

[0077] Preamble: A single - tone signal segment for device B and C to perform packet detection and synchronization;

[0078] Payload, which specifically includes the following fields:

[0079] Synchronization field: A fixed - bit pattern for frame delimitation.

[0080] ID field: The value is ID_A.

[0081] Period field: The value is T_frame = 100 ms.

[0082] ID pool field: Encodes a list of all known device IDs for device A. This field is empty, for example, {empty}.

[0083] Verification field: CRC checksum, to ensure data integrity.

[0084] Time t1: Devices B and C receive the timing packet from device A. The processing flow of device B is as follows:

[0085] a. After successful verification, analyze the load;

[0086] b. Compare the ID field (ID_A) with the local front-end device ID (currently ID_B), and find that ID_A < ID_B;

[0087] c. Perform synchronization: Based on the precise arrival timestamp and period field of this packet, calibrate its own local timer to align its phase with that of device A's timer. Then update the preceding device ID to ID_A;

[0088] d. Learning Topology: Compare and merge ID_A, ID_B, and ID_C in the ID pool field with its own ID pool; at this point, device B also obtains the full network view {A, B, C}.

[0089] e. Calculate its own position: In the ID pool {A, C}, device B's ID is ranked 2nd.

[0090] The processing flow of device C is similar to that of device B: synchronization, learning, and calculation of its own position as the 3rd.

[0091] Time t2 (in the next superframe): All devices determine the transmission time based on a unified timer and their own sorting position.

[0092] Specifically, devices A, B, and C transmit FMCW radar waveforms on the second frequency band for detection within the radar detection time slots allocated to "rank 1", "rank 2", and "rank 3" (5-35ms, 35-65ms, and 65-95ms, respectively). Because the time slots are strictly non-overlapping, the transmission times of the three radars are completely staggered, achieving zero-interference parallel sensing.

[0093] Meanwhile, devices A, B, and C will broadcast their respective timing packets on the first frequency band within their allocated signaling time slots to maintain synchronization and topology information propagation.

[0094] In the example above, the fault tolerance and self-recovery steps are as follows:

[0095] Assume that during operation, root device A fails due to a power outage;

[0096] Detection of devices B and C: In several consecutive superframe cycles, neither device B nor C received a timing packet from its predecessor device A;

[0097] Triggering the timeout mechanism: Device B first reaches the timeout threshold of "not receiving a timed packet with a smaller or equal ID for an extended period of time";

[0098] Bootstrapping as root: Device B executes a self-recovery process, sets its own predecessor device ID to ID_B, and clears its local ID pool; at this point, Device B considers itself the new root.

[0099] Network Reconfiguration: Device B begins broadcasting timed packets with itself as the time base. Device C receives Device B's packet (ID_B) and finds that it is less than its current predecessor ID (originally ID_A, but A is invalid, so this information is outdated). Therefore, it will synchronize with Device B and update its ID pool to {B}. Device B will also learn ID_C from Device C's timed packets, thus updating its ID pool to {C}.

[0100] The new schedule is established: Under the new stable state, devices B (rank 1) and C (rank 2) recalculate their time slots according to the new ID pool and continue to operate without interference on the new timeline. The system self-organizes from a two-device network without manual intervention.

[0101] The above examples clearly demonstrate the complete closed loop from initialization discovery -> distributed synchronization -> topology learning -> time slot computation -> deterministic scheduling. Through the specific interactions of devices A, B, and C, the core ideas of decentralized, self-organizing, ID-based deterministic TDMA (Time Division Multiple Access) are embodied. Furthermore, the case of device A failure verifies the distributed fault tolerance and self-recovery capabilities of the solution.

[0102] Furthermore, once the network of devices A, B, and C is stable, if a new radar device wants to join, the new radar device does not need to pre-configure its local ID, for example, it does not need to be pre-configured as device D. Instead, the new radar device first receives timing packets from the current network within a preset time period, updates its local ID pool, and sets its local ID to the largest ID in the local ID pool + 1, i.e., C + 1 = D. Then, the new radar device (i.e., device D) exchanges timing packets with other radar devices in the current network on the first frequency band. Each radar device identifies and determines the relative preceding and following device IDs, updates its locally recorded local ID pool and timing period, so that the local ID pools of devices A, B, C, and D are {B, C, D}, {A, C, D}, {A, B, D}, and {A, B, C}, respectively. Finally, each radar device sorts its position according to the size of its updated and stable local ID in the local ID pool, and arranges the transmission time corresponding to its radar waveform according to the detection time slot of the superframe period in step S100, and transmits it on the second frequency band.

[0103] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A timing coordination method for distributed radar, characterized in that, include: S100, a first frequency band is preset for the periodic transmission and reception of timing packets by radar equipment, and a second frequency band is preset for the transmission of radar waveforms by radar equipment. Define a global superframe period, each superframe period includes a transmission period, and the transmission period includes multiple detection time slots dedicated to each radar device to transmit radar waveforms respectively; S200: Configure local IDs for multiple radar devices in the initial coordinated network, distinguished by size. Each radar device will treat itself as the root device, set its local ID pool to empty, and allow its local timer to run freely. S300 controls each radar device to operate independently and exchange timing packets with each other on the first frequency band. The timing packet includes an ID field that records the local ID, an ID pool field that records the local ID pool, and a period field that records the timing period. The timing period is the duration of the superframe period. Each radar device updates its locally recorded local ID pool and timing period by identifying and determining the relative front-end device ID. S400. Each radar device sorts its position in the local ID pool according to the updated and stabilized local ID, and matches it with the detection time slot order of the superframe period in step S100. Each device then transmits its radar waveform in the second frequency band within its corresponding detection time slot.

2. The timing coordination method for distributed radar according to claim 1, characterized in that, After step S400, if a new radar device joins the coordination network, the following steps are executed: S510, new radar equipment has its local ID pre-emptively set; S520 and newly acquired radar equipment first receive timed packets from the current network within a preset time period, update the local ID pool, and set the local ID to the maximum ID in the local ID pool +1; S530, newly added radar equipment and other radar equipment in the current network exchange timing packets on the first frequency band. Each radar equipment updates its local ID pool and timing period by identifying and determining the relative front-end device ID and back-end device ID. S540. Each radar device sorts its position in the local ID pool according to the updated and stabilized local ID, matches it with the detection time slot order of the superframe period in step S100, and transmits its own radar waveform in the second frequency band within its corresponding detection time slot.

3. The timing coordination method for distributed radar according to claim 1, characterized in that, The superframe period also includes a common signaling period and a protection interval period located before and after the transmission period, respectively. The common signaling period includes multiple synchronization time slots for multiple radar devices to transmit timing packets, and the synchronization time slot occupied by the timing packet is determined by the sorting position of the device ID in the local ID pool.

4. The timing coordination method for distributed radar according to claim 3, characterized in that, In step S300, when exchanging timing packets, the radar devices send and receive timing packets during the common signaling period of the preceding superframe period; in step S400, each radar device, in the subsequent superframe period, sequentially sends its own radar waveform in the multiple detection time slots according to the sorting order.

5. The timing coordination method for distributed radar according to claim 4, characterized in that, The timing packet includes a preamble and a payload field. The payload field includes a synchronization field for frame delimitation, the period field, the ID field, the ID pool field, and a checksum field.

6. The timing coordination method for distributed radar according to claim 5, characterized in that, In step S300, when each radar device receives a timing packet, it extracts the ID field and the ID pool field. If the value of the ID field is less than the ID of the preceding device currently tracked by the local timer, the local timer is corrected based on the arrival time of the timing packet, the value of the period field, and the synchronization time slot it occupies. The preceding device ID and the timing period are updated, and all unknown radar device IDs carried in the timing packet are added to the local ID pool.

7. The timing coordination method for distributed radar according to claim 2, characterized in that, In step S300, if the radar device does not receive any timing packets from the preceding device within the preset timeout period, or if the radar device finds that the value of the ID field in the received timing packet is the same as its own ID, then the current radar device will execute steps S510 to S540 as if it were a newly arrived radar device.

8. The timing coordination method for distributed radar according to claim 5, characterized in that, The preamble includes a single-tone waveform for packet detection and frequency offset estimation; and / or, the payload field also includes a radar waveform field for unifying or distributing radar waveform parameters and / or a time slice field for transmitting time slot division rules.

9. The timing coordination method for distributed radar according to claim 5, characterized in that, The modulation mechanism used in the payload field includes one or more of FSK, MFSK, CPFSK, LFM, and M-ary CPFSK; the checksum field is implemented using CRC, Checksum, HMAC, AES, or digital signature methods.

10. A radar system comprising multiple radar devices, characterized in that, Multiple radar devices cooperate to perform the timing coordination method of distributed radar as described in any one of claims 1-9.

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