Automatic synchronization method for fixed frequency mode and frequency hopping mode

Abstract

The application discloses an automatic synchronization method of fixed frequency mode and frequency hopping mode, relates to the technical field of wireless communication, and is applied to a wireless ad hoc network system containing at least one master node and at least one slave node and comprises the following steps: N fixed frequency points and M groups of frequency hopping sequences are pre-stored in all devices to be networked; a working mode and a corresponding working frequency point are selected by the master node; if the fixed frequency working mode is selected, one frequency point is selected from the N fixed frequency points as the working frequency point; if the frequency hopping working mode is selected, one working sequence is selected from the M groups of frequency hopping sequences. The automatic synchronization method of the fixed frequency mode and the frequency hopping mode can switch the fixed frequency mode and the frequency hopping mode of the master node, other slave nodes can automatically perceive and change to the corresponding working mode after being switched to the pre-set working frequency point, synchronization network is completed, and therefore, rapid deployment is realized.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and more specifically to an automatic synchronization method for fixed-frequency mode and frequency hopping mode. Background Technology

[0002] In disaster relief, field reconnaissance, agricultural plant protection, and power line inspection scenarios, drones, ground stations, relay nodes, and handheld terminals often need to quickly build collaborative communication networks in the absence of fixed communication infrastructure. Currently, wireless ad hoc network systems mainly include two working modes: fixed-frequency communication and frequency-hopping communication. Fixed-frequency mode has simple hardware implementation and stable transmission delay, making it suitable for scenarios with clean electromagnetic environments and high transmission efficiency requirements. Frequency-hopping mode uses carrier frequency to periodically change according to a preset pattern, providing strong resistance to narrowband interference and interception, making it suitable for complex electromagnetic interference environments.

[0003] Currently, the pairing methods for operating modes of wireless communication devices generally rely on pre-set fixed operating modes. Both ends of a network must pre-set completely identical operating modes, frequencies, or frequency hopping sequences to establish a communication link. Therefore, when one end of the network modifies its operating mode, the other end must manually synchronize the modification to restore normal communication. This dependency limits the flexibility and dynamic adjustment capabilities of communication between devices, leading to the following technical problems in practical applications: low network deployment efficiency, difficulty in meeting rapid network deployment needs, and the requirement for unified configuration of operating modes and frequency parameters for each device before deployment. In scenarios requiring rapid network setup, such as emergency rescue, manual configuration is cumbersome and time-consuming. Furthermore, the more nodes there are, the more difficult it is to ensure parameter consistency, easily leading to communication failures due to parameter mismatches. Therefore, a method that can automatically synchronize fixed-frequency and frequency-hopping modes is needed. This invention addresses this technical problem. Summary of the Invention

[0004] This invention proposes an automatic synchronization method for fixed-frequency and frequency-hopping modes. When the master node switches between fixed-frequency and frequency-hopping modes, other slave nodes can automatically sense this switch and switch to the corresponding working mode to complete the synchronization network, thereby achieving rapid deployment.

[0005] An automatic synchronization method for fixed-frequency and frequency-hopping modes, applied to a wireless ad hoc network system comprising at least one master node and at least one slave node, includes the following steps:

[0006] N fixed frequency points and M frequency hopping sequences are pre-stored in all devices to be networked, with the first frequency point of each frequency hopping sequence being the fixed frequency point;

[0007] The master node selects the working mode and corresponding working frequency. If the fixed frequency working mode is selected, one frequency is selected from the N fixed frequency points as the working frequency. If the frequency hopping working mode is selected, one working sequence is selected from the M frequency hopping sequences.

[0008] The master node transmits synchronization information carrying the working mode flag at the first frequency point position of each scheduling minimum unit. The scheduling minimum unit is a basic time block for frequency switching and time slot scheduling, which contains several frequency point transmission positions.

[0009] In fixed-frequency operation mode, all frequency points within the smallest scheduling unit transmit data using the selected fixed-frequency point; in frequency-hopping operation mode, each frequency point within the smallest scheduling unit switches frequencies sequentially according to the selected frequency-hopping sequence to transmit data.

[0010] The node iterates through the N fixed-frequency points in a preset order, receives and parses synchronization information at the current scanned frequency point, and if valid synchronization information is obtained, determines the current working mode based on the working mode flag in the synchronization information:

[0011] If the working mode in the synchronization information is fixed frequency working mode, the slave node continues to use the current frequency to receive data at the subsequent frequency point position of the smallest scheduling unit; if it is frequency hopping working mode, the slave node matches the frequency hopping sequence corresponding to the current scanning frequency point, and switches the frequency to receive data according to the matched frequency hopping sequence at the subsequent frequency point position of the smallest scheduling unit, thus completing the automatic synchronization of the working mode.

[0012] Further, the available frequency band is divided at equal intervals using a first frequency interval to obtain the N fixed frequency points; the available frequency band is divided at equal intervals using a second frequency interval to obtain the frequency points used by the frequency hopping sequence; the second frequency interval is smaller than the first frequency interval.

[0013] Furthermore, the number M of the frequency hopping sequences satisfies M≤N, and the first frequency point of each group of frequency hopping sequences is different from each other.

[0014] Furthermore, each of the minimum scheduling units contains K frequency points arranged in sequence, with the first frequency point used to transmit synchronization information and the remaining frequency points used to transmit service data.

[0015] Furthermore, the synchronization information includes information such as working mode, node ID, and MCS gear. The automatic synchronization of fixed frequency mode and frequency hopping mode mainly depends on the working mode (frequency hopping or fixed frequency).

[0016] Furthermore, after completing mode self-synchronization, the slave node sends a network access request to the master node in the same working mode as the master node; after receiving the access request, the master node returns an access permission instruction or an access rejection instruction to the slave node according to the preset network node number strategy.

[0017] After receiving the access permission instruction, the node joins the network and completes the establishment of the communication link.

[0018] Furthermore, if a slave node receives an access rejection instruction from the master node, it continues to scan the remaining fixed frequency points in a loop, attempting to capture synchronization information from other master nodes and initiate access requests.

[0019] Furthermore, the scanning duration of the slave node at each fixed frequency point is not less than the total duration of the minimum scheduling unit.

[0020] Furthermore, after the master node actively switches its working mode, if the slave node still fails to detect valid synchronization information after passing through multiple consecutive scheduling minimum units, it is determined that it has lost synchronization with the master node, and the slave node exits the current working mode and re-scans the fixed frequency point in a loop.

[0021] Furthermore, each set of frequency hopping sequences is pre-generated based on a preset algorithm and stored in the wireless ad hoc network device.

[0022] One or more technical solutions proposed in this application have at least the following technical effects:

[0023] In this application, the N fixed-frequency points in the fixed-frequency mode are the same as the first frequency point in each frequency hopping sequence. This ensures that the synchronization entry point for each frequency hopping sequence falls within the range of the fixed-frequency points. The slave node does not need to scan every frequency point in each frequency hopping sequence; it only needs to iterate through and scan the N fixed-frequency points to simultaneously cover the synchronization entry points of both fixed-frequency and frequency hopping modes. This significantly reduces the number of frequency points that need to be scanned, thereby greatly reducing the synchronization time for switching operating modes and enabling rapid network deployment. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the self-synchronization of fixed frequency and frequency hopping in this invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0027] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0028] See Figure 1 This invention proposes an automatic synchronization method for fixed-frequency mode and frequency-hopping mode, applicable to a wireless ad hoc network system containing at least one master node and at least one slave node, comprising the following steps:

[0029] N fixed frequency points and M frequency hopping sequences are pre-stored in all devices to be networked, with the first frequency point of each frequency hopping sequence being a fixed frequency point;

[0030] The master node selects the working mode and corresponding working frequency. If the fixed frequency working mode is selected, one frequency is selected from N fixed frequency points as the working frequency. If the frequency hopping working mode is selected, one working sequence is selected from M frequency hopping sequences.

[0031] The master node transmits synchronization information carrying the working mode flag at the first frequency point position of each scheduling minimum unit. The scheduling minimum unit is the basic time block for frequency switching and time slot scheduling, which contains several frequency point transmission positions.

[0032] In fixed-frequency operation mode, all frequency points within the smallest scheduling unit transmit data using the selected fixed-frequency point; in frequency-hopping operation mode, each frequency point within the smallest scheduling unit switches frequencies sequentially according to the selected frequency-hopping sequence to transmit data.

[0033] The node iterates through N fixed-frequency points in a preset order, receives and parses synchronization information at the current scanned frequency point, and if valid synchronization information is obtained, determines the current working mode based on the working mode flag in the synchronization information:

[0034] If the working mode in the synchronization information is fixed frequency working mode, the slave node continues to use the current frequency to receive data at the subsequent frequency point position of the smallest scheduling unit; if it is frequency hopping working mode, the slave node matches the frequency hopping sequence corresponding to the current scanning frequency point, and switches the frequency to receive data according to the matched frequency hopping sequence at the subsequent frequency point position of the smallest scheduling unit, thus completing the automatic synchronization of the working mode.

[0035] This solution can select between fixed-frequency mode and frequency hopping mode according to actual needs. If the environmental interference is weak, for example, the noise floor is not high and is much lower than the device's receiving sensitivity in the entire available frequency band, there is no obvious narrowband interference peak, and there are no significant external interference sources, then the fixed-frequency mode, which has lower power consumption and is simpler to implement, can be used. In fixed-frequency mode, all time slots in the smallest scheduling unit work at the same frequency, there is no frequency switching, the physical layer demodulation algorithm is simple, and higher transmission throughput, more stable transmission latency and lower device power consumption can be obtained.

[0036] If environmental interference is strong, a frequency hopping mode with strong anti-interference capabilities is adopted. This mode actively avoids narrowband interference frequencies by periodically switching the carrier frequency between multiple frequency points. Only a few frequency hopping slots will hit the interference frequency, while most slots can communicate normally, thus minimizing the impact of local interference. However, existing frequency hopping modes are relatively complex to deploy, requiring manual switching between the master and slave nodes' operating modes. The technical solution provided in this application allows the slave node to automatically switch to the corresponding operating mode based on the master node's current operating mode, thereby simplifying the deployment process.

[0037] The master node's working mode can be selected manually or switched automatically, specifically in the following ways:

[0038] Manual selection: Staff can use relevant equipment to test the noise floor and channel quality of several fixed-frequency points. If the noise floor of most fixed-frequency points is normal, the fixed-frequency mode is selected, and the frequency point with the best quality is chosen for operation; if more than half of the fixed-frequency points are significantly interfered with, the frequency hopping mode is adopted, and the frequency hopping sequence with the lowest interference level is selected for operation.

[0039] Automatic switching: When the number of available, undisturbed fixed-frequency points is lower than the preset number within multiple consecutive detection cycles, the master node automatically switches from fixed-frequency mode to frequency hopping mode; when the number of undisturbed fixed-frequency points recovers to the preset number or higher within multiple consecutive detection cycles, the master node automatically switches back from frequency hopping mode to fixed-frequency mode.

[0040] Based on the above methods, combined with the automatic synchronization method of this solution, the slave nodes can automatically switch modes after the master node switches modes, thus completing the adaptive adjustment of the entire network's working mode.

[0041] Furthermore, the available frequency band is divided into N fixed frequency points at equal intervals using a first frequency interval; the available frequency band is divided into N fixed frequency points at equal intervals using a second frequency interval; the frequency points used by the frequency hopping sequence are obtained; the second frequency interval is smaller than the first frequency interval.

[0042] In this embodiment, there are 10 fixed frequency points, i.e., N=10. The fixed frequency points are divided in the following way: For example, with a total bandwidth of 200M, starting from 1300Mhz, 10 fixed frequency points are divided at 20Mhz intervals: 1300Mhz, 1320Mhz, 1340Mhz, 1360Mhz, 1380Mhz, 1400Mhz, 1420Mhz, 1440Mhz, 1460Mhz, and 1480Mhz. These ten fixed frequency points serve as the first frequency point for network synchronization.

[0043] In this embodiment, the number M of frequency hopping sequences is 10, and they are divided in the following way: For example, with a bandwidth of 200M, 100 frequency points numbered 1~100 can be divided at 2MHz intervals, with the following correspondence: number 1->1300MHz, number 2->1302MHz, number 3->1304MHz...number 100->1498MHz, resulting in a total of 10 groups of frequency hopping sequences. Each group of frequency hopping sequences contains ten frequency points, as detailed below:

[0044] Frequency hopping sequence number M=10 Frequency hopping frequency point number (first frequency point, second frequency point... tenth frequency point) 1 1 (1300Mhz), 10 (1318Mhz), 20, 30, 40, 50, 60, 70, 80, 90 2 11 (1320Mhz), 20 (1338Mhz), 30, 40, 50, 60, 70, 80, 90, 100 3 21 (1340Mhz), 30 (1358Mhz), 40, 50, 60, 70, 80, 90, 100, 10 4 31 (1360Mhz), 40 (1378Mhz), 50, 60, 70, 80, 90, 100, 10, 20 5 41 (1380Mhz), 50 (1398Mhz), 60, 70, 80, 90, 100, 10, 20, 30 6 51 (1400Mhz), 60 (1418Mhz), 70, 80, 90, 100, 10, 20, 30, 40 7 61 (1420Mhz), 70 (1438Mhz), 80, 90, 100, 10, 20, 30, 40, 50 8 71 (1440Mhz), 80 (1458Mhz), 90, 100, 10, 20, 30, 40, 50, 60 9 81 (1460Mhz), 90 (1478Mhz), 100, 10, 20, 30, 40, 50, 60, 70 10 91 (1480Mhz), 100 (1498Mhz), 10, 20, 30, 40, 50, 60, 70, 80

[0045] As shown above, the first frequency point in a frequency hopping sequence belongs to one of N fixed-frequency points. For example, the first frequency point of frequency hopping sequence 1 is 1 (1300MHz), and the first frequency point of frequency hopping sequence 2 is 11 (1320MHz). Both the first frequencies of 1300MHz and 1320MHz are among the N fixed-frequency points. The frequency values ​​of each frequency point in each frequency hopping sequence are only illustrative examples and are not limitations on the frequency values. Other frequency values ​​can be configured according to actual needs.

[0046] Furthermore, the number M of frequency hopping sequences satisfies M≤N, and the first frequency point of each group of frequency hopping sequences is different.

[0047] The value of N can be flexibly adjusted according to the actual total bandwidth and the operating bandwidth of the equipment. It should be noted that the larger N is, the more frequency points there are, and the longer it takes for a node to complete one round of frequency scanning. That is, the synchronization acquisition delay in the worst case will increase accordingly. Furthermore, each scheduling minimum unit contains K frequency point positions arranged in sequence. The first frequency point position is used to transmit synchronization information, and the remaining frequency point positions are used to transmit service data.

[0048] The minimum scheduling unit in this application is the smallest basic time period for time-domain scheduling, frequency switching, and synchronous broadcasting in a wireless communication system, with a fixed duration. All synchronous broadcasting, service transmission, and frequency switching actions are periodically repeated using this minimum scheduling unit as the basic unit.

[0049] The first to tenth frequency points refer to 10 transmission positions arranged chronologically within the smallest scheduling unit, not 10 different frequencies. The first position is fixed for transmitting synchronization information, i.e., the "first frequency point position." The second to tenth positions are used to transmit service data. The Xth frequency point is merely a position number, not a frequency value. The 1300MHz, 1320MHz, etc., mentioned above are the frequencies at which the equipment transmits signals. For clarity, the following examples illustrate this:

[0050] In fixed-frequency mode, the master node selects 1300MHz as the fixed frequency point. At the first time position of the smallest scheduling unit (frequency point 1), synchronization information is transmitted using 1300MHz; at the second time position (frequency point 2), service data is transmitted using 1300MHz; and so on; at the tenth time position (frequency point 10), service data is transmitted using 1300MHz. Therefore, in fixed-frequency mode, there are ten time positions, and the radio frequency at each time position remains unchanged, always fixed at the same fixed frequency point. While 1300MHz is used as the fixed frequency point in the above description, 1320MHz, etc., can also be selected according to actual needs.

[0051] In frequency hopping mode, taking frequency hopping sequence 1 above as an example, at the first time position, i.e., frequency point 1, synchronization information is transmitted using 1300MHz; at the second time position, i.e., frequency point 2, service data is transmitted using 1318MHz; ...; at the tenth time position, i.e., frequency point 10, service data is transmitted using 1478MHz. That is, the radio frequency is switched every time a time position is reached, with different positions corresponding to different frequencies.

[0052] In this way, the slave node only needs to capture the synchronization information at the first frequency point and then decide whether to keep the frequency unchanged (fixed frequency mode) or hop frequencies sequentially (frequency hopping mode) based on the working mode.

[0053] Compared to traditional frequency-hopping communication, which requires traversing all frequency hopping points to complete initial acquisition, this solution compresses the frequency sweep range from all frequency hopping points to N fixed-frequency points. Taking the solution example, with a 200MHz bandwidth, the number of frequency sweep points is reduced from 100 to 10, shortening the worst-case synchronization acquisition time by 90%, significantly reducing initial synchronization latency. Furthermore, only one set of frequency sweeping logic is needed to be compatible with dual-mode synchronization, eliminating the need to design two separate acquisition processes for fixed-frequency and frequency-hopping frequencies. This simplifies the synchronization control logic of slave nodes, thus adapting to the service requirements of rapid network deployment.

[0054] In this scheme, both fixed-frequency and frequency-hopping modes share the same scheduling structure with the same number of time slots, the same duration, and the same synchronization position, which is the smallest scheduling unit. This allows for high reuse of the synchronization acquisition and data parsing logic of slave nodes, eliminating the need to design two completely independent frame structures for the two working modes and effectively reducing the implementation complexity of the dual-mode system.

[0055] Furthermore, the synchronization information includes working mode, node ID, MCS level, etc. In this embodiment, the automatic synchronization of fixed frequency mode and frequency hopping mode mainly depends on the working mode, namely frequency hopping mode and fixed frequency mode. When the master node's working mode is frequency hopping mode, the slave node automatically synchronizes to frequency hopping mode, and vice versa.

[0056] Furthermore, after completing mode self-synchronization, the slave node sends a network access request to the master node in the same working mode as the master node; after receiving the access request, the master node returns an access permission instruction or an access rejection instruction to the slave node according to the preset network node number strategy.

[0057] After receiving the access permission instruction, the node joins the network and completes the establishment of the communication link.

[0058] Furthermore, if a slave node receives an access rejection instruction from the master node, it continues to scan the remaining fixed frequency points in a loop, attempting to capture synchronization information from other master nodes and initiate access requests.

[0059] In this embodiment, the principle of the rejection instruction is as follows: taking two group tasks as an example, each group connects to 10 nodes. After group 1 connects to 10 nodes, the ground point of group 1 will reject the nodes that attempt to connect.

[0060] Based on the above principles, multiple independent master nodes can be deployed simultaneously within the same area, each forming an independent subnet that does not interfere with each other, adapting to scenarios where multiple work teams collaborate in the same area. Staff can control the network size as needed, avoiding channel congestion caused by too many nodes; slave nodes can autonomously select available networks, improving the flexibility of network deployment and scenario adaptability.

[0061] Furthermore, the scanning duration of each node at each fixed frequency point is not less than the total duration of the smallest scheduling unit. This avoids omissions.

[0062] Furthermore, after the master node actively switches its working mode, if the slave node still fails to detect valid synchronization information after passing through multiple consecutive scheduling minimum units, it is determined that it has lost synchronization with the master node, and the slave node exits the current working mode and re-scans the fixed frequency point in a loop.

[0063] Furthermore, each frequency hopping sequence is pre-generated based on a preset algorithm and stored in the wireless ad hoc network device.

[0064] Preferably, each frequency hopping sequence in this embodiment consists of a set of frequency points arranged in a specific order. It is not completely random, but is generated based on a preset algorithm (such as a pseudo-random code) and pre-stored in the wireless ad hoc network device.

[0065] All networking parameters in this application, such as fixed frequency point set, frequency hopping sequence set, and scheduling unit rules, are pre-installed in all devices. Staff can configure the working mode and corresponding parameters on the master node, and the slave node can automatically identify the working mode of the master node through frequency scanning and synchronously follow the working mode. When the master node switches the working mode, fixed frequency point, or frequency hopping sequence, the slave node detects the loss of synchronization and automatically restarts the frequency scanning process to complete the synchronization.

[0066] The device in this application can automatically synchronize and join the network upon power-on, eliminating the need to configure the operating parameters of each slave node individually. This effectively reduces the amount of manual operation required for on-site deployment and avoids parameter mismatch errors that are prone to occur during manual configuration of multiple nodes, significantly improving network deployment efficiency in scenarios such as emergency rescue and field inspection. When the electromagnetic interference environment changes, the master node can adjust communication parameters through manual or automatic switching, enabling all slave nodes in the network to automatically adapt without requiring manual modification of each slave node. This effectively improves the system's response speed and adaptability to interference environments.

[0067] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An automatic synchronization method for fixed-frequency mode and frequency-hopping mode, applied to a wireless ad hoc network system comprising at least one master node and at least one slave node, characterized in that, Includes the following steps: N fixed frequency points and M frequency hopping sequences are pre-stored in all devices to be networked, with the first frequency point of each frequency hopping sequence being the fixed frequency point; Select the working mode and corresponding working frequency point through the master node; If the fixed-frequency working mode is selected, one frequency point is selected from the N fixed-frequency points as the working frequency point; if the frequency hopping working mode is selected, one working sequence is selected from the M frequency hopping sequences. The master node transmits synchronization information carrying the working mode flag at the first frequency point position of each scheduling minimum unit. The scheduling minimum unit is a basic time block for frequency switching and time slot scheduling, which contains several frequency point transmission positions. In fixed-frequency operation mode, all frequency points within the smallest scheduling unit transmit data using the selected fixed-frequency point; In frequency hopping mode, each frequency point within the smallest scheduling unit switches frequencies sequentially according to the selected frequency hopping sequence to transmit data. The node iterates through the N fixed-frequency points in a preset order, receives and parses synchronization information at the current scanned frequency point, and if valid synchronization information is obtained, determines the current working mode based on the working mode flag in the synchronization information: If the working mode in the synchronization information is fixed frequency working mode, the slave node continues to use the current frequency to receive data at the subsequent frequency point position of the smallest scheduling unit; if it is frequency hopping working mode, the slave node matches the frequency hopping sequence corresponding to the current scanning frequency point, and switches the frequency to receive data according to the matched frequency hopping sequence at the subsequent frequency point position of the smallest scheduling unit, thus completing the automatic synchronization of the working mode.

2. The automatic synchronization method for fixed-frequency mode and frequency-hopping mode according to claim 1, characterized in that, The available frequency band is divided into N fixed frequency points by equal intervals of a first frequency interval; the available frequency band is divided into N fixed frequency points by equal intervals of a second frequency interval; the frequency points used by the frequency hopping sequence are obtained; the second frequency interval is smaller than the first frequency interval.

3. The automatic synchronization method for fixed-frequency mode and frequency-hopping mode according to claim 1, characterized in that, The number M of the frequency hopping sequences satisfies M≤N, and the first frequency point of each group of frequency hopping sequences is different.

4. The automatic synchronization method for fixed-frequency mode and frequency-hopping mode according to claim 1, characterized in that, Each of the minimum scheduling units contains K frequency points arranged in sequence. The first frequency point is used to transmit synchronization information, and the remaining frequency points are used to transmit service data.

5. The automatic synchronization method for fixed-frequency mode and frequency-hopping mode according to claim 1, characterized in that, The synchronization information includes information such as working mode, node ID, and MCS level.

6. The automatic synchronization method for fixed-frequency mode and frequency-hopping mode according to claim 1, characterized in that, After completing mode self-synchronization, the slave node sends a network access request to the master node in the same working mode as the master node; after receiving the access request, the master node returns an access allow instruction or access deny instruction to the slave node according to the preset network node number strategy. After receiving the access permission instruction, the node joins the network and completes the establishment of the communication link.

7. The automatic synchronization method for fixed-frequency mode and frequency-hopping mode according to claim 6, characterized in that, If a slave node receives an access rejection instruction from the master node, it continues to scan the remaining fixed frequency points in a loop, attempting to capture synchronization information from other master nodes and initiate access requests.

8. The automatic synchronization method for fixed-frequency mode and frequency-hopping mode according to claim 7, characterized in that, The scanning time of the slave node at each fixed frequency point is not less than the total time of the smallest scheduling unit.

9. The automatic synchronization method for fixed-frequency mode and frequency-hopping mode according to claim 8, characterized in that, If a slave node fails to detect valid synchronization information after the master node actively switches its working mode, it is determined that it has lost synchronization with the master node after passing through multiple consecutive scheduling minimum units. The slave node then exits the current working mode and begins to scan the fixed frequency point again.

10. The automatic synchronization method for fixed-frequency mode and frequency-hopping mode according to claim 1, characterized in that, Each set of frequency hopping sequences is pre-generated based on a preset algorithm and stored in the wireless ad hoc network device.

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