Wireless communication anti-interference method of avionics system

Abstract

The invention relates to the technical field of wireless communication networks, and discloses a wireless communication anti-interference method of an avionics system, which comprises the following steps: nodes in a network autonomously and synchronously switch channels based on a shared key and a public time reference, and when the public time reference is invalid, a mobile node calibrates a local clock by monitoring the channel switching time of a central node, according to the method, synchronization can be achieved without real-time signaling, interference can be avoided, the problem of network lock losing caused by coordination signaling failure is solved, when the external public time reference is lost, the hopping behavior of the network itself is used as an internal clock beacon, the nodes can be self-healed to recover synchronization, and the reliability of avionics communication is ensured.

Description

Technical Field

[0001] This invention relates to a wireless communication anti-interference method for avionics systems, belonging to the field of wireless communication network technology. Background Technology

[0002] In current applications such as avionics systems that have high requirements for communication continuity, anti-interference capabilities are necessary to cope with external interference sources in the channel. Currently, one anti-interference technology in this field is based on coordinated channel switching. The network central node monitors the communication quality of the current working channel. When interference is detected and the communication quality degrades beyond a preset threshold, the central node decides on a backup channel and broadcasts control signaling to notify all subordinate mobile nodes to switch to the new backup channel. Even with advanced cluster collaboration schemes, existing technologies still struggle to overcome their dependence on the communication link itself when dealing with anti-interference coordination issues. For example, Chinese invention patent CN106961700B discloses a wireless communication method for dynamic remote fault-tolerant reconfiguration of computing resources in a cluster avionics system. The scheme is based on a fixed time slot time frame structure. The master control node broadcasts command messages or remote reconfiguration command messages to subordinate nodes within the allocated active time frame to schedule network resources and handle faults. It can manage resources when the channel quality is good. However, the anti-interference strategy is inherently passive and depends on signaling reachability. The mechanism operates under the strict premise that the control signaling used for coordinated switching must still be reachable when interference occurs.

[0003] The design and operation of this method, which coordinates the control signaling for handover, must be reachable when interference occurs. However, its limitations in specific application scenarios such as complex electromagnetic environments or malicious interference suppression faced by avionics systems are as follows: When a strong external interference source suppresses the current working channel, not only is the data link interrupted, but the control link used by the central node to send handover commands also fails. At this time, although the central node broadcasts the handover command on the interfered channel as planned, the command itself is also covered by interference, causing subordinate mobile nodes to be unable to receive it correctly. The consequence of this mechanism's flaw is that mobile nodes still attempt to reconnect on the original interfering channel, while the central node may have already switched to a new channel. Ultimately, the network undergoes logical splitting and network lockout to avoid failed attempts, leading to system communication interruption. To address this situation, attempts have been made in the field to introduce complex handshake protocols or use independent out-of-band control channels to transmit handover commands. However, these methods not only increase system complexity and deployment costs but also introduce additional dependence on new communication links, failing to solve the problem of how network nodes can achieve synchronous decision-making without real-time signaling coordination in the case of complete suppression of the working channel and instantaneous communication interruption.

[0004] Therefore, the technical problem to be solved by this invention is how to provide a wireless communication anti-interference method that gets rid of the dependence on real-time coordination signaling and enables all nodes in the network to autonomously and deterministically switch to a secure channel in the event of communication interruption caused by strong interference. Summary of the Invention

[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: A wireless communication anti-interference method for an avionics system, the method being applied to a wireless communication network including a central node and at least one mobile node, the method comprising: The central node and mobile nodes, based on a shared key, independently generate identical channel hopping sequences; obtain a common time reference and share time slot period parameters; and independently and periodically execute the following first logic: calculate the current time slot index based on the common time reference and time slot period parameters, determine the current working channel from the channel hopping sequence based on the current time slot index, and autonomously switch their respective communication channels to the current working channel. The method also includes: the mobile node continuously monitoring the signal quality of the common time reference; When the mobile node detects that the signal quality is lower than a preset failure threshold, it initiates a clock resynchronization mode. In the clock resynchronization mode, the mobile node executes the following second logic: by monitoring the channel switching that occurs on the channel transition sequence of the central node, it identifies and determines the time of occurrence of the channel switching; it marks the time of occurrence as the starting reference point of the new time slot period of the mobile node's local clock; and based on the starting reference point of the new time slot period and the time slot period parameters, it resumes the execution of the first logic.

[0006] Preferably, the method further includes: pre-defining a fixed anchoring channel and an anchoring time interval, wherein the period of the anchoring time interval is greater than the time slot period parameter; when the anchoring time interval arrives, the central node suspends the execution of the first logic and autonomously switches to the fixed anchoring channel to reside in the time slot period; the newly joined mobile node listens to and accesses the central node during the anchoring time interval on the fixed anchoring channel to obtain the shared key and the time slot period parameter.

[0007] Preferably, the channel transition sequence is generated using a pair of shared keys and a preset pseudo-random algorithm.

[0008] Preferably, the public time reference is derived from the timestamp of the satellite positioning system.

[0009] Preferably, in the first logic, the step of calculating the current time slot index specifically includes: obtaining the current time value of the common time base. ; Obtain the sequence length of the channel transition sequence Current time slot index Determined through the following calculations: ,in, The duration of the time slot period parameter. and Having the same time unit This is for floor operations and modulo operations.

[0010] Preferably, in the clock resynchronization mode, the steps of the mobile node executing the second logic include: the mobile node stops executing the first logic; the mobile node sets its receiver to scanning mode and polls the channels in the channel transition sequence one by one until it captures the signal of the central node on a certain channel; the mobile node continues to reside on that certain channel until the signal of the central node disappears, and identifies the time when the signal disappears as the occurrence time.

[0011] Preferably, the method further includes: the central node determines the interference level by monitoring the packet loss rate or signal-to-noise ratio in the wireless communication network; when the interference level is higher than a preset first threshold, the central node broadcasts an instruction to shorten the duration of the time slot period parameter.

[0012] Preferably, the time slot period parameter is a time slot period sequence; the central node and at least one mobile node, while generating the channel transition sequence, independently generate a time slot period sequence corresponding to the sequence number of the channel transition sequence based on the shared key; in the first logic, the step of calculating the current time slot index is replaced by iteratively accumulating the time slot period in the time slot period sequence and comparing it with the common time reference to determine the current time slot index.

[0013] Preferably, newly joined mobile nodes only know the fixed anchoring channel and the anchoring time interval in advance; the newly joined mobile nodes obtain a common time reference, and when the anchoring time interval arrives, they wait on the fixed anchoring channel and receive the beacon frame from the central node, and initiate the association process.

[0014] Preferably, the method further includes: when the interference level is lower than a preset second threshold, the central node broadcasts a command to extend the duration of the time slot period parameter.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The decision-making mechanism for anti-interference in wireless communication networks is changed from relying on real-time, easily interfered coordination signaling to a deterministic autonomous synchronization method that relies on shared keys and a common time reference among nodes. When communication on the working channel is interrupted, neither the central node nor the mobile node in the network needs to send or listen for any handover instructions. Based on their respective calculations of the common time reference, they autonomously and synchronously switch to the next channel in the channel transition sequence to resume communication when the predetermined time slot boundary is reached. From the perspective of network management logic, this eliminates the risk of network logic splitting or loss of lock due to coordination signaling failure.

[0016] 2. By introducing a unified time slot period parameter, the longest network interruption time after encountering interference is limited to the remaining duration of that time slot period. This design transforms the network recovery time from an unpredictable random value dependent on signaling retries into a mechanism with a deterministic upper bound pre-set by system parameters. This provides a predictable quality of service (QoS) foundation for wireless communication networks applied to critical systems such as avionics with high reliability and low latency requirements. It also provides a network accessibility management mechanism, utilizing the common time reference of the main scheme to define a fixed anchoring period on a longer time scale. When the anchoring period arrives, the central node suspends the execution of the secure channel transition sequence and instead resides on a pre-set public anchoring channel. This time-domain isolation design allows the secure transition network and the public access network to coexist under the same time reference. New nodes do not need to know the secure sequence; they can deterministically access the network based solely on the public time and channel parameters, resolving the contradiction between high-security networks and open node access.

[0017] 3. When a mobile node loses its external common time reference, a clock self-healing mechanism is provided. The network behavior of the periodic channel switching of the central node of the main scheme is transformed into an observable new clock calibration beacon. The node that lost its clock can identify the network time slot boundary by monitoring the precise moment when the central node's signal disappears, thereby resetting the local clock origin and restoring relative synchronization with the network. The risk of failure of external dependencies in system operation is offset by reusing the system's own operating characteristics, so that the network has the ability to degrade operation and logical self-healing when the critical clock source fails. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the autonomous synchronization channel switching process of the avionics system of the present invention; Figure 2 This is a comparison chart of packet loss rates for the time slot periodic strategy under different interference levels according to the present invention; Figure 3 This is a flowchart illustrating the normal operation of nodes and the self-healing process of clock failure in this invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all 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 protection of the present invention.

[0020] This invention provides a wireless communication anti-interference method for avionics systems, applied to a wireless communication network including a central node and at least one mobile node. All nodes in the network, including the central node and at least one mobile node, pre-share a key and can obtain a common time reference. Through pre-agreed logic, all nodes can autonomously and synchronously switch on a preset channel sequence without relying on real-time coordination signaling, thereby avoiding interference. This method also provides a clock self-healing mechanism; when the common time reference fails, nodes restore synchronization by monitoring communication behavior within the network. During network initialization or node joining phases, the central node and at least one mobile node... Mobile nodes, based on a shared key, independently generate identical channel hopping sequences. Specifically, the shared key can be used as a seed, input into a pre-defined pseudo-random algorithm known to all nodes in the network, ensuring that the sequence content generated by all legitimate nodes within the network is consistent. Unauthorized devices outside the network, lacking the key, cannot predict the sequence. The channel hopping sequence can be a list containing multiple channel indices in a deterministic order. The central node and at least one mobile node obtain a common time reference and share time slot period parameters. In typical avionics system applications, the common time reference can be derived from the timestamp of a satellite positioning system, and the time slot period parameters are... This means that the standard dwell time of the network on each channel in the sequence is defined and uniformly issued by the central node when the node first joins the network and shared by the entire network.

[0021] During stable network operation, the central node and at least one mobile node independently and periodically execute the following first logic: the node continuously obtains the current time value of the common time base. Based on shared time slot period parameters and the sequence length of the pre-known channel transition sequence The current time slot index is obtained through a deterministic computation procedure. The calculation procedure is as follows: ,in and Having the same time unit This is a floor function, a modulo operation; the node calculates the current time slot index. Then, determine from the locally stored channel transition sequence The corresponding current working channel is used to autonomously switch each node's communication channel to the current working channel. Since all nodes use the same key, algorithm, time base, and time slot parameters, this calculation process does not require any real-time signaling coordination, ensuring that all nodes in the network switch to the same channel in the sequence at the same time slot boundary. To address the risk of the common time base failing in the complex electromagnetic environment of avionics, the method also includes: the mobile node continuously monitors the signal quality of the common time base; when the mobile node detects that the signal quality is lower than a preset failure threshold, the mobile node initiates a clock resynchronization mode; in the clock resynchronization mode, the mobile node executes the following second logic: the mobile node stops executing the first logic; the mobile node sets its receiver to scanning mode, polls the known channels in the channel switching sequence one by one, and re-acquires the signal of the central node; when the mobile node acquires the signal of the central node on a certain channel in the sequence, it continuously resides on that channel and continuously listens until the signal of the central node disappears; the mobile node identifies the moment when the signal disappears as the moment when the channel switching occurs; the moment of occurrence is immediately marked as the starting reference point of the new time slot period of its local clock; based on the newly marked starting reference point and the known time slot period parameters... Resume execution of the first logic.

[0022] To address the access issue for newly joined nodes, this method may further include: pre-defining a fixed anchoring channel and an anchoring time interval, with the period of the anchoring time interval being greater than the time slot period parameter; when the anchoring time interval arrives, the central node suspends the execution of the first logic based on the channel transition sequence, autonomously switches to the fixed anchoring channel, and resides for the time slot period; newly joined mobile nodes need to know the fixed anchoring channel and anchoring time interval in advance, and after obtaining a common time reference, wait on the fixed anchoring channel and receive the beacon frame from the central node when the anchoring time interval arrives, initiate an association process, and after successful association, obtain the shared key and time slot period parameter, and join the network's synchronous transition; to enable the network's anti-interference behavior to adapt to changes in the electromagnetic environment, the method may further include: the central node determines the interference level by monitoring the packet loss rate or signal-to-noise ratio in the wireless communication network; when the interference level is higher than a preset first threshold, the central node broadcasts a command to shorten the time slot period parameter. The duration of the interference; when the interference level is lower than a preset second threshold, the central node broadcasts a command to extend the duration of the time slot period parameter; in a further embodiment, to counteract the prediction of network transition rhythm by advanced interference sources, the time slot period parameter is not a fixed value, but a time slot period sequence; the central node and at least one mobile node, while generating the channel transition sequence based on the shared key, additionally and independently generate a time slot period sequence corresponding to the sequence number of the channel transition sequence; in the first logic, the original fixed and The modular arithmetic step is replaced by a stateful iterative accumulation process. Nodes determine the current common time slot index by comparing with the common time base and accumulating the time slot periods in the time slot period sequence one by one.

[0023] Example 1: This example demonstrates a specific application of the method in an avionics communication scenario. The wireless communication network employing this invention includes a central node deployed in the airport tower and mobile nodes located on the aircraft during the approach phase. Based on the aforementioned specific implementation method, the network pre-shares a key, a pseudo-random algorithm, and a channel transition sequence. Time slot period parameters The unified access satellite positioning system serves as a common time reference. The network was originally operating stably at the time calculated by the first logic. In each time slot, all network nodes work synchronously within the channel transition sequence. The corresponding current working channel A; in the time slot Before the event was over, a sudden external strong interference source appeared and completely suppressed channel A, causing an instantaneous interruption of communication between the central node and the mobile node.

[0024] When channel A is suppressed, neither the central node nor the mobile node relies on any signaling interaction and both independently execute the aforementioned first logic; each node processor continuously acquires a common time reference. Independent calculation When the public time base Crossing the first The boundary of the first time slot enters the second time slot. In each time slot, the computational procedures of all nodes in the entire network are affected by... The new current time slot index is calculated independently and synchronously as it changes. Then determine from the channel transition sequence with the same content stored locally. The corresponding current working channel B is autonomously switched to channel B; channel B is unaffected, and the central node and mobile node immediately restore communication links on the new channel; this process achieves interference avoidance without any real-time signaling coordination, and the longest network outage time is minimized. The remaining time limit; the sequence consistency guaranteed by shared keys and algorithms, and the timing consistency guaranteed by public time base and time slot parameters, transform the anti-interference mechanism from relying on fragile coordination signaling to relying on deterministic autonomous synchronous computation.

[0025] Example 2: This example quantitatively verifies the clock resynchronization mode in the method of this invention under simulated avionics conditions, verifying the ability of a mobile node to restore synchronization by utilizing the hopping behavior of the central node after losing the common time reference. The test platform is built in a hardware-in-the-loop simulation environment, including a central node simulator, a mobile node simulator, and a broadband radio frequency channel simulator. Both the central node and the mobile node load the method logic defined in the aforementioned specific implementation and share a key. Test network parameters are set as follows: channel hopping sequence. Includes 40 preset channels, time slot period parameters The time reference is set to 100ms; the common time reference is provided by an external high-precision satellite positioning system signal simulator; the local clock of the mobile node is simulated as a non-temperature compensated crystal oscillator with a clock drift rate of 50ppm, which starts drift accumulation after GPS signal loss; the network synchronization tolerance threshold is set to 1.5ms, and the network is considered to have lost lock when the clock deviation between the central node and the mobile node exceeds 1.5ms; the preset failure threshold is set to a GPS signal carrier-to-noise ratio of less than 35dB-Hz and the state lasting for more than 500ms; the test is set up with two groups: the control group adopts the same first logic based on the common time reference as this invention, without loading the clock resynchronization mode, and when GPS signal loss occurs... After the signal loss, the system relies solely on local clock drift for operation. The sample of this invention fully loads all the methods of the aforementioned specific implementation, including the first logic and clock resynchronization mode. At T=0 seconds, both sets of experiments are started, and the GPS signal simulator provides a normal signal with a C / N0 of 48dB-Hz. The network packet loss rate of both sets is maintained at a baseline level below 0.5%. At T=30.0 seconds, the GPS signal simulator instantaneously reduces the signal quality to 30dB-Hz to simulate a GPS signal loss event. The network packet loss rate and clock synchronization status of the two test groups are continuously monitored after T=30.0 seconds until T=120.0 seconds. The key test data records are shown in Table 1.

[0026] Table 1: Comparison of Network Status After Signal Loss

[0027] Referring to Table 1, in the control group, after losing the GPS signal at T=30.0 seconds, the local clock began to accumulate a drift of 50 ppm; at T=60.0 seconds, the accumulated drift reached 1.5 ms, triggering the network synchronization tolerance threshold, causing the network packet loss rate to jump to 100%, resulting in network lockout; the sample of this invention lost the signal at T=30.0 seconds, and met the preset failure threshold at T=30.5 seconds, initiating the clock resynchronization mode; causing the network to be in a scanning and calibration state from T=30.5 seconds to T=32.3 seconds, with a packet loss rate of 100%; at T=32.2 seconds, the mobile node identified the occurrence time of the time slot boundary by monitoring the channel switching of the central node, and used this to calibrate the local clock; starting from T=32.3 seconds, the sample of this invention recovered to a baseline packet loss rate of 0.6% under the condition of continuous GPS signal loss, and maintained internal synchronization throughout.

[0028] Example 3: This example combines Figures 1 to 3 This describes a method for resisting interference in wireless communication of an avionics system, such as... Figure 1 As shown, the system involves four entities: a satellite positioning system, a central node, mobile nodes, and a wireless channel. Starting in the network initialization phase, the central node distributes a shared key and configures time slot period parameters to the mobile nodes. Both the central node and the mobile nodes generate identical channel transition sequences based on the shared key. During the normal synchronous channel switching process, the satellite positioning system provides a common time reference to both the central node and the mobile nodes. Each node calculates its current time slot index. When the time slot boundary is reached, the central node and the mobile nodes autonomously switch to the new working channel for data communication. Throughout this process, all nodes do not require real-time signaling coordination, achieving autonomous synchronous switching.

[0029] like Figure 2 As shown, the horizontal axis represents the interference level, including low interference, medium interference, high interference, and extremely high interference, while the vertical axis represents the network packet loss rate in percentage. The legend shows that the packet loss rate for the fixed time slot period is represented by horizontal bars, while the packet loss rate for the adaptive time slot period is represented by diagonal bars. This graph shows that under all four interference levels—low, medium, high, and extremely high—the network packet loss rate of the adaptive time slot period strategy is lower than that of the fixed time slot period strategy. Figure 3As shown, the process begins with system initialization and access, i.e., the central node and mobile nodes join the network and obtain basic parameters, with the input being the shared key / common time reference. Then, a channel transition sequence is generated, and a consistent sequence is generated using a pseudo-random algorithm. The process then enters the common time reference signal quality monitoring stage. If the signal quality is normal, the left-hand logic is executed, sequentially calculating the current time slot index. Based on the current time and time slot period parameters, and switching to the current working channel, the frequency switching is completed autonomously, ultimately restoring / maintaining communication and avoiding external interference sources. After the next cycle, the process returns to the monitoring stage. If the signal quality monitoring fails, the right-hand clock resynchronization mode is activated, the first logic is stopped, the receiver switches to scanning, and sequentially captures the central node signal, i.e., polls the channel transition sequence and resides there. Then, the time of channel switching is identified, i.e., the disappearance of the monitoring signal is used as the reference point. Then, the local clock is calibrated, i.e., the starting reference point of the time slot period is updated. Finally, the first logic is restored and the process returns to the monitoring stage.

[0030] Example 4: The channel transition sequence can be generated using a linear feedback shift register (LFSR). A 128-bit shared key is used as the initial state value of the LFSR. All nodes in the network adopt the same preset LFSR polynomial structure and start at the initial time point of the common time base. Each time the LFSR runs for one clock cycle, the output bits are mapped to the channel transition sequence. The channel index is specified in the table. To achieve adaptive adjustment of the time slot period parameter, the central node uses the following procedure to calculate the interference level: The central node maintains a 1-second sliding time window on the processor and continuously calculates the network packet loss rate (PLR) within the window. The interference level is determined as the weighted moving average of the PLR ​​within the sliding window. The determination of the preset first threshold is completed through an offline calibration procedure. In a laboratory environment, an interference signal with known increasing strength is injected into the network, and the network packet loss rate and the avionics data link service quality (QoS) index are monitored simultaneously. When the QoS index drops to the preset minimum acceptable level, the corresponding sliding window PLR average value is calibrated as the preset first threshold. In the clock resynchronization mode, the specific logic for the mobile node to identify and determine the channel handover time is as follows: When the mobile node is camped on a channel that has captured the signal of the central node, it samples the received signal strength indication (RSSI) of that channel at a high frequency. The node presets a signal disappearance threshold. The signal disappearance time is identified by the receiver front-end using a sliding window energy detection method, with a sampling frequency of... The calibration procedure is as follows: Determine the maximum allowable synchronization error tolerance of the system. like ms; sets the number of consecutive sampling points below the threshold required to determine the confidence level. For example, point 3; according to the formula Determine the minimum sampling frequency, where The engineering margin coefficient ranges from 0.1 to 0.5, based on... ms , set up for kHz is the sampling interval. Processor maintenance length Sliding window, when the received signal strength indicator RSSI moving average is within the window continuous This is below the preset noise threshold. like When the signal loss threshold is reached, the processor triggers a signal loss interrupt and sets the local receiver to detect a noise floor plus a fixed margin, such as -85dBm; the mobile node continuously compares the RSSI sample value with the signal loss threshold.

[0031] When a mobile node detects that the RSSI value of three consecutive sampling points is lower than the signal disappearance threshold, the timestamp corresponding to the first sampling point that is lower than the threshold is marked as the occurrence time and the starting reference point of the new time slot period. The clock resynchronization mode includes a handover verification procedure, which is executed by the processor as follows: Step 1, the mobile node monitors the disappearance of the current channel A signal and marks the candidate handover time. Then, according to the channel hopping sequence, the mobile node switches to the next logical channel, Channel B; in step two, the mobile node initiates the verification time window on Channel B. , Duration is expressed by formula Calculation determined, where The preset minimum number of preamble detections is set to a value between 2 and 5. For standard frame length, The maximum allowable clock drift; Step 3, if the processor is in During this period, ChannelB demodulates the valid preamble sequence of the central node and determines... Update the local clock reference to the effective time slot boundary; Step 4, if the processor is in At the end, Channel B did not detect a legitimate signal, and it was determined that the disappearance of the Channel A signal was caused by interference suppression. The processor discarded the signal. Keep the local clock running freely and control the receiver to perform a full-band scanning procedure to re-search for the center node signal.

[0032] Example 5: This example illustrates the generation and indexing procedure when the network uses a time-slot periodic sequence to combat timing prediction interference: During the initialization phase, the central node and mobile nodes independently generate two sequences based on a shared key and a preset pseudo-random algorithm: a channel hopping sequence. and time slot periodic sequence ; Is with The corresponding serial number includes An array of duration entries, where the value of each duration entry is pseudo-randomly distributed between a preset minimum dwell time of 80ms and a maximum dwell time of 150ms. In the physical layer communication protocol, the central node transmits a wireless data frame containing a synchronization information field (SIF). The SIF is located at a fixed offset position in the PLCP header of the physical layer aggregation process, and its length is set to... For example, 8 bits carry the current public time slot index value. When the mobile node captures the central node's signal during the clock resynchronization mode scan phase, the physical layer processor demodulates the SIF field to obtain... processor with To address the key value, retrieve the local storage time slot period sequence. Search for the current dwell time From channel transition sequence Retrieve the next-hop target channel index and utilize Calculate the remaining time of the current time slot, at the moment the detection signal disappears and... Channel switching is performed when the theoretical boundary conditions are met.

[0033] use At that time, the calculation procedure used to determine the current time slot index in the first logic is adjusted to a stateful iterative accumulation method: all nodes in the network share the global cycle start time reference point. Set the network-enabled UTC zero point; obtain the current public time base. Then, the node processor performs the following operation: initialize the current index. and cumulative time ; The following logic is executed in a loop: from local storage Get from Corresponding time slot period ; Calculate the end time of the current time slot ;like Less than Loop terminates, processor determines This is the current time slot index, from Search in As the current working channel; if Greater than or equal to Then update ,and Returns to the beginning of the loop.

[0034] Example 6: This example illustrates the procedure for a newly joined mobile node to access the network; the central node and existing mobile nodes execute the first logic, in... Synchronous transitions are defined on the channel; the network is also predefined. Other fixed anchored channels and periods are much larger than The anchoring time interval; when the central node executes the first logic, an additional anchor point judgment logic is added: the central node continuously compares its local public time base with the anchoring time interval; when the start time of the anchoring time interval is determined, the central node suspends the channel switching calculated by the first logic and instead autonomously forces its communication channel to switch to the fixed anchoring channel, and stays on the anchoring channel for a period of time. During this period, beacon frames are broadcast; After the allotted time expires, the central node resumes execution of the first logic and switches to... The corresponding next time slot channel; newly joined mobile nodes only have local knowledge of the fixed anchor channel, anchor time interval, and common time reference acquisition method; after startup, the new mobile node acquires the common time reference and sets the receiver to the fixed anchor channel when the anchor time interval arrives; during this period, the new node listens for and receives beacon frames from the central node and connects to the central node through the standard association process; after successful association, the central node sends the shared key, time slot period parameters, and channel transition sequence generation algorithm to the new mobile node through a secure link; the new node uses the acquired information to generate a message identical to that of the central node. Starting from the next time slot boundary, network synchronization transitions are added.

[0035] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A wireless communication anti-jamming method of avionics system, applied to a wireless communication network comprising a center node and at least one mobile node, characterized in that, The method comprises: The central node and the mobile node independently generate the same channel hopping sequence based on the shared key; obtain a common time reference and share a time slot cycle parameter; and independently periodically perform the following first logic: calculate a current time slot index according to the common time reference and the time slot cycle parameter, determine a current working channel from the channel hopping sequence according to the current time slot index, and autonomously switch the respective communication channel to the current working channel; The method further comprises: the mobile node continuously monitoring the signal quality of the common time reference; When the signal quality is detected to be lower than a preset failure threshold, the mobile node starts a clock resynchronization mode; In the clock resynchronization mode, the mobile node performs the following second logic: identifies the occurrence time of the channel switching by monitoring the channel switching of the central node on the channel hopping sequence; marks the occurrence time as a starting reference point of a new time slot cycle of the local clock of the mobile node; and resumes the execution of the first logic based on the starting reference point of the new time slot cycle and the time slot cycle parameter.

2. The anti-jamming method of wireless communication of avionics system according to claim 1, characterized in that, The method further comprises: defining a fixed anchor channel and an anchor time interval in advance, the period of the anchor time interval being greater than the time slot cycle parameter; the central node suspends the execution of the first logic and autonomously switches to the fixed anchor channel to reside in a time slot cycle when the anchor time interval arrives; and a newly added mobile node listens to and accesses the central node to obtain the shared key and the time slot cycle parameter during the anchor time interval.

3. The anti-jamming method of wireless communication of avionics system according to claim 1, characterized in that, The channel hopping sequence is generated by a pair of shared keys and a preset pseudo-random algorithm.

4. The anti-jamming method of wireless communication of avionics system according to claim 1, characterized in that, The common time reference is derived from the timestamp of a satellite positioning system.

5. The anti-jamming method of wireless communication of avionics system according to claim 1, characterized in that, In the first logic, the step of calculating the current time slot index specifically comprises: obtaining a current time value of the common time reference ; obtaining a sequence length of the channel hopping sequence ; the current time slot index is determined by the following operation: wherein, is the duration of the time slot period parameter, and have the same time unit.

6. The anti-jamming method of wireless communication of avionics system according to claim 1, characterized in that, In the clock resynchronization mode, the step of the mobile node performing the second logic comprises: the mobile node stops executing the first logic; the mobile node sets its receiver to a scanning mode and polls the channels in the channel hopping sequence one by one until the signal of the central node is captured on a certain channel; and the mobile node continuously resides in the certain channel until the signal of the central node disappears, and identifies the time when the signal disappears as the occurrence time.

7. The anti-jamming method of wireless communication of avionics system according to claim 1, characterized in that, The method further comprises: the central node determines the interference level by monitoring the packet loss rate or the signal-to-noise ratio in the wireless communication network; and when the interference level is higher than a preset first threshold, the central node broadcasts an instruction to shorten the duration of the time slot cycle parameter.

8. The anti-jamming method of wireless communication of avionics system according to claim 1, wherein, The time slot cycle parameter is a time slot cycle sequence; the central node and at least one mobile node independently generate the time slot cycle sequence corresponding to the sequence number of the channel hopping sequence based on the shared key at the same time as the generation of the channel hopping sequence; in the first logic, the step of calculating the current time slot index is replaced by determining the current time slot index by iteratively accumulating the time slot cycles in the time slot cycle sequence and comparing the common time reference.

9. The anti-jamming method of wireless communication of avionics system according to claim 2, characterized in that, The newly added mobile node only knows the fixed anchor channel and the anchor time interval; the newly added mobile node obtains the common time reference and waits for and receives the beacon frame of the central node on the fixed anchor channel when the anchor time interval arrives, and initiates an association process.

10. The anti-jamming method of wireless communication of avionics system according to claim 7, characterized in that, The method further comprises: when the interference level is lower than a preset second threshold, the central node broadcasts an instruction to lengthen the duration of the time slot cycle parameter.

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