Adaptive modulation and power joint control method and device for WAIC

Abstract

This invention relates to an adaptive modulation and power joint control method and apparatus for WAIC (Web Application Compliance Center), comprising: reading the control state and WAIC compliance configuration; calculating the comprehensive channel quality index; generating a set of permissible modulation and coding schemes (MCSs) and an operational power spectral density window based on the compliance configuration and operating parameters; comparing the channel quality with a preset threshold and combining the MCS set and operational power spectral density window to determine the control direction, generating candidate MCSs and candidate transmit powers; performing compliance verification; writing the MCS indicator, power level indicator, protection status flag, compliance configuration version field, and verification field into the frame header and transmitting it, with the payload transmitted according to the verified scheme; the receiving end parses the frame header, matches and demodulates, and provides feedback, while the transmitting end updates the control state based on the feedback to form a closed loop. Advantages: Achieving coordinated control of modulation and coding schemes and transmit power within the WAIC compliance boundary, improving spectral efficiency while reducing bit error rate and power consumption.

Description

Technical Field

[0001] This invention relates to the field of wireless avionics internal communication technology, and in particular to an adaptive modulation and power joint control method and apparatus for WAIC. Background Technology

[0002] Wireless Avionics Internal Communication (WAIC) refers to data communication between electronic devices, sensors, actuators, etc., inside an aircraft via wireless links. WAIC systems operate in the 4.2–4.4 GHz frequency band and employ Time Division Multiple Access (TDMA) and other methods to complete data transmission between nodes within allocated time slots. Unlike ground mobile communication, WAIC communication faces challenges such as multipath reflections caused by the cabin's metal structure, equipment obstruction, differences in installation location, and strict aviation electromagnetic compatibility constraints. Link quality dynamically changes with time, space, and flight status.

[0003] Currently, existing technologies related to WAIC include the following aspects: (1) WAIC Protocol Framework and Frequency Band Conditions. Li Shining et al., in "Current Status and Analysis of Wireless Avionics Internal Communication Network Protocols", proposed a WAIC network system model and a five-layer protocol model, pointing out that the physical layer can use the 4.2-4.4 GHz frequency band and adopt OFDM to improve anti-interference capability, and associate high-speed and low-speed services with different modulation methods respectively. This literature provides a framework for WAIC protocol stack and physical layer candidate schemes, but does not provide a closed-loop control method for adjusting the modulation order and transmit power spectral density in conjunction with real-time channel quality during sensor node operation. ITU-R Recommendation M.2085-0 provides the technical requirements for WAIC systems in the 4.2–4.4 GHz band for aeronautical mobile services. RTCA DO-402 / EUROCAEED-319 further specifies requirements such as a maximum equivalent isotropic radiated power spectral density of 6 dBm / MHz, a minimum configurable power spectral density of -30 dBm / MHz or lower, and maintenance mode configuration lockout for WAIC equipment. However, the above standards are equipment performance and testing specifications and do not disclose the control method for converting compliant configurations into modulation and coding scheme (MCS) and power joint decision conditions during node operation. ITU-R M.2067, M.2283, and M.2319 define WAIC as a closed wireless network within a single aircraft used to support the safe operation of the aircraft. They distinguish four application categories—LI, LO, HI, and HO—based on data rate and installation location. LI represents low-speed internal applications, and HI represents high-speed internal applications. Both typically benefit from fuselage shielding and controlled in-flight installation environments, but still need to meet requirements for radio altimeter protection, receiver blocking / desensitization, coexistence of multiple WAIC networks, and aggregation interference analysis. The above documents provide WAIC application classifications and coexistence responsibility boundaries, but do not provide information on how internal LI / HI nodes dynamically select MCS, power spectral density, and abnormal backoff states among different service rates, link quality, and compliance margins.

[0004] (2) WAIC Channel Measurement and Feasibility Verification. Bang et al.'s "Channel Measurement and Feasibility Test for Wireless Avionics Intra-Communications" conducted WAIC band channel measurement and feasibility tests in a real aircraft environment, verifying the feasibility of IEEE 802.11 protocols in in-flight sensor networks and evaluating the bit error rate and the effectiveness of multi-antenna technology. Fan et al.'s "Mixed-Numerology Channel Division for Wireless Avionics Intra-Communication" proposed a hybrid parameter set channel division framework to improve the carrying capacity of the 4.2–4.4 GHz band for the large number of in-flight communication demands. The above works proved that there is a practical basis for the deployment of in-flight WAIC links, but did not propose an integrated control device for channel quality assessment, MCS switching, power spectral density limiting, and time slot frame indication for WAIC sensor nodes.

[0005] (3) In-flight wireless communication and WAIC applications. Patent CN110365355A discloses a portable adapter that transmits and receives data in the 4.2–4.4 GHz WAIC frequency range. It determines the adapter's location through a position sensing module and selectively starts and stops the wireless transmitter, but does not involve MCS selection and power spectral density constraint control based on real-time channel quality. CN109818699A discloses a system that broadcasts an avionics time reference using the WAIC band. The focus of this scheme is time reference broadcasting, without involving adaptive modulation and coding of the data link and joint optimization of transmit power.

[0006] (4) Adaptive modulation and power control in the field of general communication. CN112188604A discloses a method for combining location information, channel state, power control and MCS selection in mobile communication scenarios, but it depends on the location of user equipment and mobile communication carrier system, and does not consider the 4.2-4.4 GHz frequency band, low power consumption of sensor nodes, hard limits of equivalent omnidirectional power spectral density and aviation electromagnetic compatibility constraints in WAIC scenarios. CN122052949A discloses an intelligent transceiver system based on dynamic channel awareness for robust communication in high-speed mobile and high-interference scenarios. This scheme belongs to the field of general communication engineering, emphasizing multi-dimensional channel evolution modeling and forward-looking parameter adjustment, but it does not specifically design for the regulatory power spectral density limits and sensor node time slot frame structure of WAIC intra-aircraft communication.

[0007] In summary, the existing technology has the following shortcomings: (1) Existing WAIC protocol and measurement literature mostly provide candidate physical layers, frequency bands and feasibility analysis, but lack adaptive modulation and power closed-loop control schemes oriented towards node operating status.

[0008] (2) When using fixed modulation, if low-order modulation is used for a long time, the spectral efficiency will be low when the channel conditions are good; if high-order modulation is used for a long time, the bit error rate will increase when the channel deteriorates, making it difficult to meet the reliability requirements of avionics communication.

[0009] (3) When using a fixed transmit power, unnecessary energy consumption and radiation are generated when the channel is good, and the link budget cannot be adequately compensated within the compliance boundary when the channel is poor.

[0010] (4) MCS and power control schemes in the general communication field are usually geared towards cellular or high-speed mobile communication and do not directly solve the problems of metal multipath environment, TDMA time slot, low power sensor node, 4.2-4.4 GHz frequency band and equivalent omnidirectional power spectral density hard constraint in WAIC.

[0011] (5) Existing WAIC application patents focus more on local functions such as adapters, time reference broadcasting, and antennas, and have not formed a complete control closed loop of modulation, power, frame structure and receiver demodulation synchronization.

[0012] (6) Although existing WAIC standards and industrialization data specify requirements such as 4.2 to 4.4 GHz, maximum eirp spectral density, occupied bandwidth, maintenance mode configuration, receiver blocking / desensitization and radio altimeter protection, these requirements mainly exist as equipment testing or installation verification conditions, and lack a real-time control mechanism to transform them into MCS step-up / down, power back-off, power compensation and abnormal protection states when the node is running.

[0013] (7) There are differences in data rate, reliability, power consumption and spectral efficiency between internal low-speed (LI) and high-speed (HI) WAIC applications. Low-speed internal nodes are more concerned with long-term low power consumption and reliable transmission, while high-speed internal nodes are more concerned with throughput and bandwidth utilization. Existing general adaptive communication solutions usually do not take LI / HI application category as a control input, nor do they link application category with compliance margin, power spectral density and MCS level.

[0014] Therefore, there is an urgent need for a technical solution that can integrate real-time channel quality estimation, MCS selection, transmit power spectral density adjustment, power hard limiting, frame header synchronization indication, and abnormal backoff organization into a closed-loop control within the WAIC compliance boundary. Based on this, the present invention is proposed. Summary of the Invention

[0015] The purpose of this invention is to provide an adaptive modulation and power joint control method and apparatus for WAIC, enabling internal LI / HI WAIC wireless nodes to automatically select MCS and transmit power spectral density based on real-time channel quality and WAIC compliance configuration under dynamically changing wireless channel conditions within the cabin. Under the premise of meeting aviation electromagnetic compatibility, spectrum coexistence, occupied bandwidth, maintenance mode configuration locking and regulatory limits, it improves spectrum efficiency, reduces bit error rate and reduces unnecessary transmit power consumption.

[0016] To achieve the above objectives, the present invention provides the following technical solution: An adaptive modulation and power joint control method for WAIC includes: S1, read the control status of the previous time slot; S2, read the WAIC compliance configuration of the current node; if there is an error, proceed to S10; otherwise, proceed to S3. S3: Receive channel estimation information and determine if the information is valid; if valid, proceed to S4; otherwise, proceed to S10. S4. Calculate the comprehensive channel quality index based on the channel estimation information; S5 generates the set of allowed MCS and the power spectral density window for operation based on the WAIC compliance configuration and the operating parameters of the current time slot; S6. The integrated channel quality index is compared with the preset first threshold and second threshold. The first threshold is higher than the second threshold. Combining the MCS set, the power spectral density window during operation and the control state in S1, the control direction is determined and candidate MCS instructions and candidate transmit power adjustment instructions are generated. S7: Determine the candidate MCS and candidate bandwidth according to the candidate MCS instruction, determine the candidate transmit power according to the candidate transmit power adjustment instruction, and perform compliance verification. If the verification is successful, proceed to S8; otherwise, truncate the candidate transmit power and / or trigger the candidate MCS to be downgraded within the MCS set before proceeding to S8. S8 determines the MCS indicator and power level based on the MCS and transmit power output from S7, determines the compliance configuration version field based on the WAIC compliance configuration, and determines the protection status flag based on whether the preceding steps have triggered an anomaly or protection action. Write the MCS indicator, power level indicator, protection status flag, compliance configuration version field, and verification field generated according to preset rules into the frame header and send it. The payload part is sent according to the MCS output by S7. S9, the receiving end parses the frame header. If there is an abnormality, it feeds back to the sending end and enters S10. Otherwise, it selects the corresponding demodulation method according to the MCS indicator and protection status flag to complete the payload recovery, feeds back to the sending end and enters S11. S10, after the sending end enters the preset state, it enters S11; S11, the transmitting end updates the control status of the next time slot based on the feedback.

[0017] Furthermore, in S1, the control state includes at least MCS, transmit power spectral density, number of consecutive successful feedbacks, number of consecutive failed feedbacks, state hold count, cooling count, and protection state flag.

[0018] Furthermore, in S2, the WAIC compliance configuration includes at least the application category, operating channel, required bandwidth, occupied bandwidth boundary, power spectral density upper limit, maintenance mode configuration lock flag, aggregated interference margin, radio altimeter protection margin, and version information.

[0019] Furthermore, in S3, the channel estimation information includes at least pilot signals, synchronization frames, and confirmation frames of historical time slots from the root node or the sink node. In S4, the integrated channel quality index is obtained by weighted combination of signal-to-noise ratio, received signal strength indication and packet error rate; wherein, the signal-to-noise ratio and received signal strength indication are both measured using pilot signals or synchronization frames, and the packet error rate is obtained by statistics based on acknowledgment frames of historical time slots.

[0020] Furthermore, in S5, the operating parameters include at least the occupied bandwidth of the current time slot, the power spectral density compliance margin, and the load criticality category. The occupied bandwidth is determined based on the previous time slot MCS in the control state read by S1, the power spectral density compliance margin is calculated based on the upper limit of power spectral density in the WAIC compliance configuration and the transmit power spectral density in the control state read by S1, and the payload criticality category is determined by the attributes of the payload to be transmitted in the current time slot.

[0021] Furthermore, in S5, the allowed MCS set is obtained by taking the intersection of the basic MCS set, the bandwidth-compatible MCS set, and the security-compliant MCS set; The basic MCS set is determined by application category and payload criticality category; the bandwidth compatible MCS set is determined by necessary bandwidth and occupied bandwidth boundary; and the safety compliant MCS set is determined by power spectral density compliance margin, radio altimeter protection margin, aggregated interference margin, and maintenance mode configuration lock flag. The upper and lower bounds of the power spectral density window during operation are determined by the maintenance mode configuration; wherein, the upper bound does not exceed the hard upper limit of the equivalent isotropic power spectral density as stipulated by law or preset, and the lower bound is determined according to the lowest equivalent isotropic radiation power spectral density configured in the maintenance mode; when the maintenance mode configuration lock flag in the WAIC compliance configuration is locked, the upper and lower bounds of the power spectral density window during operation remain unchanged in the current time slot and subsequent time slots.

[0022] Furthermore, in S6, determining the control direction and generating candidate MCS commands and candidate transmit power adjustment commands specifically includes: When the integrated channel quality index is higher than the first threshold, the current state has met the minimum number of hold slots, the cooling count is zero, and there is a higher-order alternative in the MCS set, the higher-order MCS is selected as the candidate MCS instruction, and a transmit power back-off instruction is generated as the candidate transmit power adjustment instruction. When the overall channel quality index is lower than the second threshold, or the number of consecutive failure feedbacks reaches a preset threshold, a more robust MCS is selected as a candidate MCS instruction, and a limited power compensation instruction is generated as a candidate transmit power adjustment instruction within the power spectral density window during operation. When the integrated channel quality index is between the first threshold and the second threshold, or has not yet met the minimum number of hold slots, or is within the cooling slot, the current MCS is maintained as the candidate MCS command, and the current transmit power spectral density is maintained as the candidate transmit power adjustment command. When the occupied bandwidth exceeds the limit, the power spectral density compliance margin is insufficient, the radio altimeter protection margin is insufficient, the aggregated interference margin is insufficient, or the maintenance mode configuration lock is triggered, the allowed MCS set is shrunk, MCS upgrade and out-of-limit power compensation are prohibited, the current MCS is maintained or a more robust MCS is selected as a candidate MCS instruction, and a power back-off instruction or a zero compensation instruction is generated as a candidate transmit power adjustment instruction. The minimum number of holding time slots is a preset value. The cooling count is obtained by reading the control state through S1. When MCS or power level changes in the previous time slot, it is set to the preset number of cooling time slots. Otherwise, it is obtained by decreasing the cooling count of the previous time slot.

[0023] Furthermore, in S7, the compliance verification includes: Verify whether the power spectral density of the candidate transmit power, after being converted by the occupied bandwidth, exceeds the upper limit of the power spectral density in the WAIC compliance configuration; Verify whether the occupied bandwidth corresponding to the candidate bandwidth exceeds the occupied bandwidth boundary in the WAIC compliance configuration; If any verification item exceeds the limit, the verification is deemed unqualified.

[0024] Furthermore, S7 includes a security and stability verification step after the compliance verification: After compliance verification, the output MCS and transmit power are subjected to safety and stability verification. The verification items include whether the cooling time slot has ended, whether the control decision has timed out, whether the configuration version is consistent, and whether the compliance margin is reliable. If any verification item fails, the configuration of the previous time slot is used. The consistency of configuration versions refers to whether the version information of the WAIC compliance configuration read by S2 is the same as the version of the compliance configuration stored locally. The compliance margins include power spectral density compliance margin, radio altimeter protection margin, and aggregated interference margin. The reliability of the compliance margins refers to whether the above margins are valid in the current time slot.

[0025] An adaptive modulation and power joint control device for WAIC based on the above method includes: The channel quality assessment unit is used to calculate the comprehensive channel quality index based on the information received by the current node that can be used for channel estimation. The compliance constraint perception unit is used to read the WAIC compliance configuration of the current node and generate the set of allowed MCS and the power spectral density window during operation based on the WAIC compliance configuration and the operating parameters of the current time slot. The compliance-gated adaptive decision-maker is used to compare the comprehensive channel quality index with a preset first threshold and a second threshold. The first threshold is higher than the second threshold. Combining the MCS set, the power spectral density window during operation and the control state of the previous time slot, it determines the control direction and generates candidate MCS commands and candidate transmit power adjustment commands. The cooling control unit is used to set the minimum number of hold time slots and the number of cooling time slots during the control direction determination process of the compliant gating adaptive decision-maker; The radio frequency power adjustment unit is used to adjust the transmit power spectral density of the current time slot according to the candidate transmit power adjustment command and output the candidate transmit power; The modulation and coding configuration unit is used to configure the candidate MCS according to the candidate MCS instruction and determine the candidate bandwidth according to the candidate MCS. The PSD hard clipping and MCS inverse order reduction unit is used to perform compliance verification on candidate transmit power and candidate bandwidth. When the verification fails, the candidate transmit power is truncated and / or the candidate MCS is reduced in order within the MCS set. The protection status synchronization frame header unit is used to determine the MCS indicator and power level indicator based on the verified MCS and transmit power, determine the compliance configuration version field based on the WAIC compliance configuration, determine the protection status flag based on whether the preceding steps trigger an anomaly or protection action, and write the MCS indicator, power level indicator, protection status flag, compliance configuration version field and verification field generated according to preset rules into the frame header. The fail-safe and compliance protection state machine is used to control the current node to enter a preset state when there are abnormal compliance configurations, invalid channel estimation information, or abnormal feedback from the receiver.

[0026] Compared with the prior art, the present invention has the following advantages: 1. By comparing the comprehensive channel quality index with preset first and second thresholds, a higher-order MCS is selected to improve throughput when channel quality is good, and a more robust MCS is selected to reduce bit error rate when channel quality deteriorates. This avoids the problem of spectral efficiency and reliability being mutually exclusive under fixed modulation schemes. Simultaneously, a minimum hold slot count and a cooling count are set, employing an asymmetric state transition strategy of slow upgrades and fast downgrades. Upgrading requires multiple conditions to be met simultaneously, including channel quality exceeding the high threshold, minimum hold slot count being met, cooling count being zero, and the existence of higher-order schemes in the allowed set. Downgrading only requires a single event trigger, such as channel quality falling below the low threshold or consecutive negative acknowledgments reaching a threshold. This strategy prevents frequent switching when channel quality fluctuates near the threshold, ensuring link stability.

[0027] 2. This solution proactively performs transmit power backoff when the channel is good, reducing unnecessary energy consumption and internal electromagnetic radiation, and no longer maintains a fixed high transmit power. When the channel deteriorates, it performs limited power compensation within the power spectral density window during operation, and the compensation process is hard-constrained by the upper limit of the power spectral density, avoiding exceeding compliance boundaries in order to maintain link quality. At the same time, WAIC compliance configuration is incorporated into the same decision chain. When the power spectral density compliance margin, radio altimeter protection margin, and aggregation interference margin are insufficient, MCS upgrade and out-of-bounds power compensation are prohibited. This ensures that adaptive transmission control no longer only pursues throughput based on channel quality, but always operates within the boundaries of aviation spectrum coexistence and equipment configuration, transforming WAIC equipment-level compliance requirements into executable and verifiable control conditions during operation.

[0028] 3. When a candidate transmit power is truncated due to non-compliance verification, a synchronous trigger MCS can be configured to downgrade to a more robust level within the allowed MCS set, avoiding link mismatch issues where the power is limited but the modulation order remains high. Power hard limiting and modulation / coding scheme downgrading are integrated and linked, ensuring from a control logic perspective that link reliability does not deteriorate after power limitation. When the occupied bandwidth exceeds the limit or the compliance margin is insufficient, the allowed MCS set is narrowed, removing high-order schemes from the selection range, preventing non-compliant modulation / coding schemes from being selected at the source.

[0029] 4. The frame header is transmitted using a fixed robust modulation scheme and carries a modulation and coding scheme indicator, power level indicator, protection status flag, and compliance configuration version field. This allows the receiver to know the demodulation parameters and the current protection status of the transmitter before the payload arrives. The receiver only demodulates the payload according to the indicator if the frame header verification passes and the configuration version is consistent; otherwise, it processes it using the default robust method and reports the anomaly. This mechanism solves the problem of mismatched demodulation parameters at the receiver when the transmitter temporarily switches the modulation scheme due to channel changes or compliance protection, and also avoids demodulation errors caused by "the transmitter has switched but the receiver is unaware." Power spectral density hard limiting, joint decision-making of modulation and coding scheme, frame header synchronization indication, receiver matching demodulation, and anomaly backoff status mechanism form a mutually triggered and mutually constrained restricted control closed loop, which is fundamentally different from the practice in general communication schemes where adaptive modulation and power control are treated as independent optional functions. This invention also incorporates adaptive designs for the 4.2~4.4GHz frequency band of aircraft internal wireless communication, the multipath environment of cabin metal, the time division multiple access time slot structure, and low-power sensor nodes, making it more suitable for avionics internal communication scenarios compared to general communication adaptive solutions.

[0030] 5. When pilot signals are missing, feedback fails, frame header parsing fails, compliance margin is insufficient, or configuration versions are inconsistent, the current node will not perform MCS upgrade. Instead, it will prioritize entering the fail-safe state, the default robust state, the compliance protection state, or continue using the safe configuration. It will not default to operating under the most favorable link conditions and will prioritize maintaining a predictable and recoverable communication state, which complies with the conservative requirements of aviation communication for fail-safety.

[0031] 6. The WAIC compliance configuration includes application categories. For low-speed internal applications, the set of modulation and coding schemes allowed is restricted to low-order or low-to-mid-order schemes to reduce power consumption and maintain a large compliance margin. For high-speed internal applications, high-order schemes are allowed to be selected when the compliance margin is sufficient to improve spectral efficiency. This allows the same control framework to adapt to different application scenarios from low-power sensors to high-speed data acquisition, taking into account different industrialization paths for internal low-speed sensing applications and internal high-speed data applications. Attached Figure Description

[0032] 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the architecture of the adaptive modulation and power joint control device for WAIC in the embodiment; Figure 2This is a flowchart illustrating the adaptive modulation and power joint control method for WAIC in this embodiment. Detailed Implementation

[0034] 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 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.

[0035] Terminology Explanation WAIC (Wireless Avionics Intra-Communications): Wireless avionics intra-communication refers to wireless communication between electronic devices, sensors, actuators, etc. inside an aircraft. It operates in the 4.2 to 4.4 GHz frequency band and uses time division multiple access to complete data transmission between nodes within allocated time slots.

[0036] Time Division Multiple Access (TDMA): A multiple access method in which different nodes transmit data in different time slices or time slots. In this embodiment, the current node completes frame transmission within the allocated transmission time slot.

[0037] MCS (Modulation and Coding Scheme): A modulation and coding scheme, representing a combination of communication parameters such as modulation method, coding method, or coding rate. In this embodiment, the order of the MCS gradually increases from low to high, with spectral efficiency gradually improving, but also requiring higher channel quality. The lower the order of the MCS, the stronger its anti-interference capability, i.e., it has higher robustness. In this embodiment, QPSK, 16QAM, or 64QAM are taken as examples, with their orders arranged from low to high, defined as low-order MCS, mid-low-order MCS, and high-order MCS, respectively. QPSK, as the lowest-order MCS, has the strongest anti-interference capability but the lowest spectral efficiency; 64QAM, as the highest-order MCS, has the highest spectral efficiency but the highest requirements for channel quality.

[0038] EIRP (Equivalent Isotropically Radiated Power): Equivalent Isotropically Radiated Power, representing the equivalent radiated power after considering antenna gain.

[0039] Transmitted power spectral density (PSD, also known as power spectral density or conducted transmitted power spectral density): represents the transmitted power per unit bandwidth, usually expressed in dBm / MHz. The relationship between transmitted power spectral density and transmitted power in the logarithmic domain is: Transmitted power spectral density = Transmitted power - 10 × log 10 (Occupied bandwidth) means that knowing the occupied bandwidth and transmit power allows you to calculate the transmit power spectral density, or vice versa. The occupied bandwidth is determined by the selected MCS. The scheme may use terms related to power spectral density and power simultaneously, implicitly involving the aforementioned well-known conversion process.

[0040] Equivalent omnidirectional power spectral density: This is the equivalent radiated power per unit bandwidth after considering antenna gain and RF link loss, and is the main constraint for power hard limiting in this invention. In actual operation, the equivalent omnidirectional power spectral density is calculated by adding the antenna gain to the transmit power spectral density and then subtracting the RF link loss.

[0041] Power spectral density compliance margin: refers to the difference between the current transmit power spectral density and the upper limit of the power spectral density specified in the compliance configuration, and is used to measure the compliance safety space of the current time slot.

[0042] RSSI (Received Signal Strength Indicator): Received signal strength indication, which can be used as one of the input parameters for channel quality assessment.

[0043] SNR (Signal-to-Noise Ratio): This measure is used to assess the strength of a received signal relative to noise.

[0044] ACK / NACK: Acknowledgment / negative acknowledgment feedback, used to indicate whether the receiver successfully or failed to receive the previous time slot or the previous data frame.

[0045] LI (Low-speed Internal): Low-speed internal applications, such as low data rate sensing applications like temperature, pressure, and structural health monitoring.

[0046] HI (High-speed Internal): High-speed internal applications, such as high-speed data applications like internal maintenance data and batch uploading of equipment status.

[0047] Hysteresis mechanism: By using two thresholds (high and low), the number of state holding time slots, or switching cooling conditions, frequent switching of MCS or transmit power is avoided when the channel quality fluctuates near the threshold.

[0048] Cooling time slot number: a preset positive integer. When the MCS or power level changes, the cooling count is set to the preset cooling time slot number and decreases in each time slot. Time slots with a cooling count greater than zero are called cooling time slots, and MCS upgrades are prohibited within the cooling time slots.

[0049] Preset states include fail-safe state, default robust state, and compliance protection state. In fail-safe state, the current node prioritizes sending necessary control information or safety-critical payloads using the default robust modulation scheme. In default robust state, the default robust modulation scheme is used and MCS upgrade is not performed. In compliance protection state, compliance constraints take precedence over efficient transmission and out-of-bounds power compensation is not performed.

[0050] Occupied bandwidth: The bandwidth occupied by the transmitted signal in the frequency domain. In this embodiment, the occupied bandwidth needs to be kept within the 4.2 to 4.4 GHz operating frequency band.

[0051] Required bandwidth: The bandwidth requirement parameter given by the system or device configuration. The occupied bandwidth corresponding to different MCS must meet the constraints of the required bandwidth and occupied bandwidth boundaries.

[0052] Frame header: The part before the payload data in each TDMA transmission slot.

[0053] Please refer to Figure 2 This embodiment provides an adaptive modulation and power joint control method for WAIC, including the following steps: Step S1: At the start of the current time slot, the current node reads the control state saved at the end of the previous time slot. The control state includes the MCS of the previous time slot, the transmit power spectral density of the previous time slot, the number of consecutive successful feedbacks (number of consecutive ACKs), the number of consecutive failed feedbacks (number of consecutive NACKs), the state hold count, the cooling count, and the protection status flag.

[0054] The status hold count is used to record the number of time slots in which the current MCS and power level have been continuously held. The cooling count is passed across time slots through control status. When an MCS or power level change occurs in the previous time slot, the cooling count is set to the preset cooling time slot number. When no MCS or power level change occurs in the previous time slot, the cooling count is obtained by subtracting one from the cooling count of the previous time slot, until it is reduced to zero and then remains at zero.

[0055] These two counts together form the basis of the hysteresis mechanism that prevents frequent switching: the state retention count ensures a sufficient period of stable observation before the upgrade, and the cooling count ensures a sufficient period of cooling observation after the upgrade.

[0056] Step S2: The current node reads its WAIC compliance configuration. The WAIC compliance configuration includes application category (LI or HI), operating channel, required bandwidth, occupied bandwidth boundary, power spectral density limit, maintenance mode configuration lock flag, aggregated interference margin, radio altimeter protection margin, and version information.

[0057] If the WAIC compliance configuration is missing or the version is incompatible, the current node will not perform an MCS upgrade and will proceed directly to step S10 to ensure that no potentially non-compliant adaptive adjustments are made in the event of a configuration anomaly. If the configuration is normal, proceed to step S3.

[0058] Step S3: The current node receives information from the root node or the sink node that can be used for channel estimation. The channel estimation information includes pilot signals, synchronization frames, acknowledgment frames, or other signals that can be used for channel estimation.

[0059] The current node determines whether the received channel estimation information meets the preset validity conditions. If the pilot or synchronization frame is missing, the information is determined to be invalid, and the process proceeds to step S10; if the information is valid, the process continues to step S4.

[0060] Step S4: The current node calculates the comprehensive channel quality index based on the channel estimation information received in step S3. The comprehensive channel quality index is obtained by a weighted combination of signal-to-noise ratio (SNR), received signal strength indication (RSI), and packet error rate (PER). The SNR and RSI are measured using pilot signals or synchronization frames, and the PER is calculated based on acknowledgment frames (ACK / NACK) from historical time slots. The comprehensive channel quality index for the k-th time slot is... It can be calculated as follows: ; in, and These represent the normalized signal-to-noise ratio and received signal strength of the k-th time slot, respectively. This represents the packet error rate in the k-th time slot; , , These are preset non-negative weighting coefficients. If a certain indicator is temporarily missing, its corresponding weight can be reset to 0, and the remaining weights can be renormalized. The higher the value of the comprehensive channel quality index, the better the link quality.

[0061] Step S5: Based on the WAIC compliance configuration and operating parameters of the current time slot read in step S2, generate the set of MCSs allowed to be used in the current time slot and the power spectral density window during operation.

[0062] The operating parameters include the occupied bandwidth of the current time slot, the power spectral density compliance margin, and the payload criticality category. The occupied bandwidth is determined based on the previous time slot's MCS read in step S1. The power spectral density compliance margin is calculated based on the upper limit of the power spectral density in the WAIC compliance configuration and the transmit power spectral density of the previous time slot read in step S1; specifically, it is the difference between the upper limit of the power spectral density and the transmit power spectral density of the previous time slot. The payload criticality category is determined by the attributes of the payload to be transmitted in the current time slot, such as a safety-critical payload, an important maintenance payload, or a non-critical maintenance payload.

[0063] The allowed set of MCSs is obtained by taking the intersection of three subsets: the basic set of MCSs, the bandwidth-compatible set of MCSs, and the security-compliant set of MCSs. The MCS set is generated before the control direction decision, which means that the selection of higher-order MCSs must simultaneously meet the requirements of link quality and WAIC compliance margin, and cannot be selected solely based on good channel quality.

[0064] The basic MCS set is determined by the application category (LI / HI) and the payload criticality category. For LI low-speed internal applications, the basic MCS set is preferentially restricted to low-order or mid-to-low-order modulation and coding schemes (such as QPSK, 16QAM) to reduce power consumption and maintain a large compliance margin; for HI high-speed internal applications, the basic MCS set is allowed to include high-order modulation and coding schemes (such as 64QAM) when there is sufficient compliance margin.

[0065] The set of bandwidth-compatible MCSs is determined by the required bandwidth and the occupied bandwidth boundary. Only MCSs that meet the required bandwidth requirement and whose occupied bandwidth does not exceed the occupied bandwidth boundary can be included in this set.

[0066] The safety-compliant MCS set is determined by the power spectral density compliance margin, radio altimeter protection margin, aggregated interference margin, and maintenance mode configuration lock flag. That is, when any margin is insufficient or the maintenance configuration is locked, the safety-compliant MCS set shrinks accordingly, and MCSs that may trigger compliance risks are removed.

[0067] The set of allowed MCSs can be generated by the set intersection method of Equation (9): in, Indicates the set of MCSs that are allowed to be used; Represents the basic MCS set, Indicates a bandwidth-compatible MCS collection. Represents a set of security-compliant MCS (Multi-Channel Systems). Indicates the WAIC application category. Indicates the load criticality category, Indicates the required bandwidth. This represents the bandwidth occupied in the k-th time slot. This represents the compliance margin of the power spectral density in the k-th time slot. This represents the protection margin of the radio altimeter in the k-th time slot. This represents the aggregation interference margin in the k-th time slot. This indicates that the maintenance mode configuration is locked. When this is the case, it indicates that the channel remains locked during operation. Therefore, channel quality can only be maintained within a certain range. Internal trigger for advancement cannot be achieved solely through... Higher-order MCS is directly selected.

[0068] The upper and lower bounds of the power spectral density window during operation are determined by the maintenance mode configuration. The upper bound is based on the maximum permissible transmit power spectral density configured in the maintenance mode. The lower bound is determined based on the lowest equivalent isotropic radiative power spectral density configured in maintenance mode. It is confirmed that the upper bound does not exceed the hard upper limit of the equivalent isotropic power spectral density set by regulations or the system. The power spectral density window during operation can be expressed as: ; when During normal operation, the window shown in equation (8) remains locked, and the controller only allows time-slot-level power back-off or limited compensation to be performed within this window, without changing the upper and lower bounds of the window. In the equation, This represents the transmit power spectral density of the k-th time slot.

[0069] Step S6: Calculate the integrated channel quality index obtained in step S4. Compared with the preset first threshold (i.e., the high threshold) ) and the second threshold (low threshold) The comparison is performed and combined with the set of allowed MCS generated in step S5. The system uses the power spectral density window during operation and the control status read in step S1 to determine the control direction and generate candidate MCS commands and candidate transmit power adjustment commands.

[0070] The determination of the control direction includes the following four scenarios: Scenario 1 (Upgrade Backoff): When the overall channel quality index is higher than the first threshold, i.e. If the current state meets the minimum holding time slot count and the cooling count is zero, and there is a higher-order alternative in the set of allowed MCSs, then the higher-order MCS (such as upgrading from QPSK to 16QAM, or from 16QAM to 64QAM) is selected as the candidate MCS instruction, and a transmit power backoff instruction is generated as the candidate transmit power adjustment instruction.

[0071] Power rollback is performed as follows: ; in, To achieve the minimum permissible transmit power spectral density, The transmit power spectral density of the previous time slot, This is the preset power backoff step size.

[0072] Scenario 2 (De-order Compensation): When the overall channel quality index is lower than the second threshold, i.e. If the number of consecutive failure feedbacks (number of consecutive NACKs) reaches a preset threshold, a more robust MCS (such as reducing from 64QAM to 16QAM, or from 16QAM to QPSK) is selected as a candidate MCS command, and a limited power compensation command is generated within the power spectral density window during operation as a candidate transmit power adjustment command.

[0073] Power compensation is performed as follows: ; in, For the maximum permissible transmit power spectral density, This is the maximum permissible transmit power spectral density configured for maintenance mode. The hard upper limit for the equivalent isotropic power spectral density. For antenna gain, For radio frequency transmission line loss, This is the preset power compensation step size.

[0074] Equivalent Isotropic Power Spectral Density Calculate as follows: ; Equivalent Isotropic Power Spectral Density And subject to hard limiting: .

[0075] Scenario 3 (Hold): When the overall channel quality index is between the first and second thresholds, If the minimum hold time slot requirement has not yet been met, or if the channel is within a cooling time slot, the current MCS is maintained as the candidate MCS command, and the current transmit power spectral density is maintained as the candidate transmit power adjustment command. This is used to avoid frequent handovers caused by short-term fluctuations in channel quality near a threshold.

[0076] Scenario 4 (Compliance Protection): When the occupied bandwidth exceeds the limit, the power spectral density compliance margin is insufficient, the radio altimeter protection margin is insufficient, the aggregated interference margin is insufficient, or the maintenance mode configuration lock is triggered, the set of allowed MCSs is reduced, MCS upgrades and out-of-limit power compensation are prohibited, the current MCS is maintained, or a more robust MCS is selected as a candidate MCS command, and a power back-off command or a zero-compensation command is generated as a candidate transmit power adjustment command. This scenario ensures that when compliance constraints are triggered, the system does not continue to pursue higher-order MCSs or higher power, but is forced to return to operation within the compliance boundaries.

[0077] The minimum hold time slot number is a preset value. The cooling count is set to the preset cooling time slot number when an MCS or power level change occurs in the previous time slot; otherwise, it is obtained by decreasing the cooling count of the previous time slot until it reaches zero and is then maintained at zero. The state hold count and the cooling count together constitute a hysteresis mechanism: upgrading requires multiple conditions to be met simultaneously, such as channel quality being higher than the first threshold, the minimum hold time slot number being met, the cooling count being zero, and the existence of higher-order schemes in the MCS set being allowed. Degradation, on the other hand, only requires a single event to trigger, such as channel quality being lower than the second threshold or consecutive negative acknowledgments reaching a threshold. This reflects an asymmetric strategy of slow upgrading and fast degradation, effectively reducing frequent handovers caused by cabin multipath, obstruction, or vibration.

[0078] Step S7: The current node determines the candidate MCS and candidate bandwidth according to the candidate MCS instruction generated in step S6. If the candidate MCS instruction is "select a higher-order MCS", then the corresponding specific scheme (such as 16QAM or 64QAM) is determined as the candidate MCS, and the candidate bandwidth is determined according to the scheme. If the candidate MCS instruction is "maintain the current MCS", then the current MCS is determined as the candidate MCS, and the candidate bandwidth follows the occupied bandwidth of the previous time slot.

[0079] The current node determines the candidate transmit power based on the candidate transmit power adjustment command: if it is a backoff command, the preset backoff step size is subtracted from the current transmit power spectral density, and then the candidate transmit power is calculated based on the occupied bandwidth; if it is a compensation command, the preset compensation step size is added to the current transmit power spectral density, but does not exceed the upper limit of the power spectral density window during operation, and then the candidate transmit power is calculated based on the occupied bandwidth.

[0080] The compliance verification includes the following verification items: (1) Verify whether the power spectral density of the candidate transmit power after being converted by the occupied bandwidth exceeds the upper limit of the power spectral density in the WAIC compliance configuration; (2) Verify whether the occupied bandwidth corresponding to the candidate bandwidth exceeds the occupied bandwidth boundary in the WAIC compliance configuration.

[0081] If any of the above verification items exceeds the limit, the verification is deemed unqualified.

[0082] If the verification passes, the system proceeds to the security and stability verification. If the verification fails, the candidate transmit power is truncated (the power spectral density of the candidate transmit power after being converted to occupied bandwidth is truncated to not exceed the upper limit of the power spectral density), and / or the candidate MCS is downgraded within the set of allowed MCSs (an MCS with higher robustness than the candidate MCS is selected from the allowed set), and then the system proceeds to the security and stability verification.

[0083] The security and stability verification includes checks on whether the cooling time slot has ended, whether the control decision has timed out, whether the configuration version is consistent, and whether the compliance margin is reliable. If any check fails, the configuration from the previous time slot is used. Whether the configuration version is consistent refers to whether the version information of the WAIC compliance configuration read in step S2 is the same as the locally stored compliance configuration version. The compliance margin includes power spectral density compliance margin, radio altimeter protection margin, and aggregation interference margin; whether the compliance margin is reliable refers to whether the above margins are valid in the current time slot. Whether the control decision has timed out refers to whether the computation time for determining the control direction and generating candidate MCS commands and candidate transmit power adjustment commands in step S6 exceeds the preset time limit.

[0084] Step S8: Based on the MCS and transmit power verified and output in step S7, determine the MCS indicator and power level indicator. Determine the compliance configuration version field based on the WAIC compliance configuration. Determine the protection status flag based on whether the preceding steps (S2, S3, S7, etc.) triggered any abnormalities or protection actions.

[0085] The MCS indicator, power level indicator, protection status flag, compliance configuration version field, and verification field generated according to preset rules (such as Cyclic Redundancy Check CRC) are written into the frame header of the TDMA transmission slot. The frame header is transmitted using a fixed robust modulation scheme (such as BPSK or QPSK). The payload is transmitted according to the MCS determined after verification in step S7.

[0086] Step S9: The receiving end (i.e., the target node of the current time slot) parses the frame header. If the frame header cannot be parsed, or the compliance configuration version is inconsistent, or the verification fails, the receiving end sends a parsing failure message to the sending end, and the sending end proceeds to step S10 based on the feedback. Otherwise, the receiving end selects the corresponding demodulation method based on the MCS indicator and protection status flag to complete the payload recovery, sends an acknowledgment message (ACK) to the sending end, and proceeds to step S11.

[0087] After the receiver parses the frame header to obtain the power level indication, it can estimate the path loss based on the power level indication and the received signal strength, and use the path loss for link quality feedback.

[0088] Step S10: When any of the following situations occur, the sending end enters a preset state, which includes a fail-safe state, a default robust state, or a compliance protection state.

[0089] In fail-safe mode, the current node prioritizes sending necessary control information or safety-critical payloads using the default robust modulation method; in default robust mode, the default robust modulation method is used and MCS upgrade is not performed; in compliance protection mode, compliance constraints take precedence over efficient transmission and out-of-bounds power compensation is not performed.

[0090] Step S11: The transmitting end updates the control state of the next time slot based on the feedback information from the receiving end (ACK / NACK, link quality feedback, etc.), including MCS, transmit power spectral density, number of consecutive successful feedbacks (incremented if the feedback is an acknowledgment, otherwise cleared), number of consecutive failed feedbacks (incremented if the feedback is a negative acknowledgment, otherwise cleared), state hold count (incremented if the MCS has not changed, otherwise cleared), cooling count (set to the preset cooling time slot number if the MCS or power level changes, otherwise decremented), and protection status flag. The updated control state is saved for use in the next time slot step S1, thus forming a complete closed-loop control chain of "compliance gating → channel measurement → restricted decision → PSD limiting and reverse order reduction → protection status synchronization → matched demodulation → failover security feedback".

[0091] refer to Figure 1 This embodiment also provides an adaptive modulation and power joint control device for WAIC, applied to wireless sensor nodes operating in the 4.2 to 4.4 GHz frequency band inside aircraft. This device is used to execute all the steps of the above method embodiments and specifically includes the following units: The channel quality assessment unit is used to calculate the comprehensive channel quality index based on the information received by the current node that can be used for channel estimation.

[0092] The compliance constraint perception unit is used to read the WAIC compliance configuration of the current node and generate the set of allowed MCS and the power spectral density window during operation based on the compliance configuration and the operating parameters of the current time slot.

[0093] The compliance-gated adaptive decision-maker compares the comprehensive channel quality index with the preset first threshold and second threshold. If the first threshold is higher than the second threshold, it combines the allowed MCS set, the operating power spectral density window, and the control state of the previous time slot to determine the control direction and generate candidate MCS commands and candidate transmit power adjustment commands.

[0094] The cooling control unit is used to set the minimum number of hold time slots and the preset number of cooling time slots for the compliance gating adaptive decision-maker.

[0095] The modulation and coding configuration unit is used to configure the candidate MCS according to the candidate MCS instruction and to determine the candidate bandwidth according to the candidate MCS.

[0096] The radio frequency power adjustment unit is used to back off or compensate based on the current transmit power spectral density according to the candidate transmit power adjustment command, and output the candidate transmit power.

[0097] The PSD hard clipping and MCS inverse order reduction unit is used to perform compliance verification on the power spectral density (PSD) of candidate transmit power after occupancy bandwidth reduction and the candidate bandwidth. It verifies whether the PSD of the candidate transmit power after occupancy bandwidth reduction exceeds the upper limit of the PSD in the WAIC compliance configuration, and whether the occupancy bandwidth corresponding to the candidate bandwidth exceeds the occupancy bandwidth boundary. If the verification fails, the candidate transmit power is truncated and / or the candidate MCS is triggered to reduce its order within the allowed MCS set, ensuring that the final output MCS and transmit power are both within the compliance boundaries.

[0098] The safety and stability verification unit is used to perform safety and stability verification on the output MCS and transmit power after compliance verification. Verification items include whether the cooling time slot has ended, whether the control decision has timed out, whether the configuration version is consistent, and whether the compliance margin is reliable. If any verification item fails, the configuration of the previous time slot will be used.

[0099] The protection status synchronization frame header unit is used to determine the MCS indicator and power level indicator based on the verified output MCS and transmit power, determine the compliance configuration version field based on the WAIC compliance configuration, and determine the protection status flag based on whether the preceding steps triggered an anomaly or protection action. The MCS indicator, power level indicator, protection status flag, compliance configuration version field, and verification field generated according to preset rules are written into the frame header. The frame header is transmitted using a fixed robust modulation method, and the payload is transmitted according to the verified MCS.

[0100] The fail-safe and compliance protection state machine is used to control the current node to enter a preset state when there are abnormal compliance configurations, invalid channel estimation information, or abnormal feedback from the receiver. The preset states include a fail-safe state, a default robust state, or a compliance protection state.

[0101] The control process of this embodiment will be described below in conjunction with a specific working scenario. Taking a WAIC wireless sensor node inside an aircraft as an example, it operates in the 4.2 to 4.4 GHz frequency band, with the MCS settings set to QPSK (low-order robust solution), 16QAM (mid-order solution), and 64QAM (high-order solution), the preset number of cooling time slots is 2, the minimum number of hold time slots is 3, and the threshold for consecutive failure feedback times is 3.

[0102] Operating Condition 1: High-efficiency transmission when the channel is good.

[0103] During a series of consecutive TDMA time slots When the current state meets the minimum hold slot count, the cooling count is zero, and 16QAM or 64QAM is allowed in the MCS set, the compliance gating adaptive decision-maker selects a higher-order MCS as the candidate MCS instruction (e.g., from QPSK to 16QAM, or from 16QAM to 64QAM) and generates a transmit power backoff instruction. The modulation and coding configuration unit determines the candidate MCS as 16QAM and the corresponding candidate bandwidth. The RF power adjustment unit subtracts the preset backoff step size from the current transmit power spectral density to obtain the candidate transmit power spectral density, which is then converted into the candidate transmit power. After passing compliance verification and security and stability verification, the protection state synchronization frame header unit writes the corresponding MCS indicator into the frame header. The frame header is transmitted using BPSK, and the payload is transmitted using 16QAM. The receiver parses the frame header, demodulates the payload using 16QAM, and sends back confirmation information. This operating condition improves the effective throughput per unit time slot while reducing transmit power consumption when the link quality is good.

[0104] Condition 2: The channel is normal or in the hysteresis range.

[0105] when If the threshold has been exceeded but the minimum number of state-maintaining time slots has not yet been met, or if the node is in a cooling-off time slot, the compliance-gated adaptive decision-maker maintains the current MCS as a candidate MCS command and the current transmit power spectral density as a candidate transmit power adjustment command. For example, if a node used 16QAM in the previous time slot, and the overall channel quality index in the current time slot has only slightly increased but has not yet reached the first threshold, the node will not switch to 64QAM, but will maintain 16QAM and the current power. This operation avoids frequent ping-pong handovers near the threshold and maintains link stability.

[0106] Operating Condition 3: Robust transmission under poor channel conditions.

[0107] when If the number of consecutive failure feedbacks reaches three, the compliance-gated adaptive decision maker selects a more robust MCS as a candidate MCS instruction (e.g., downgrading from 16QAM to QPSK) and generates a constrained power compensation instruction within the operational power spectral density window. The RF power adjustment unit adds a preset compensation step size to the current transmit power spectral density, but not exceeding the upper limit of the power window, to obtain the candidate transmit power spectral density, which is then converted into a candidate transmit power. After verification, the MCS indicator corresponding to QPSK is written into the frame header, and the payload is transmitted in QPSK. In this mode, link reliability is prioritized when the channel deteriorates, rather than continuing to use higher-order modulation methods that may produce high bit error rates.

[0108] Operating Condition 4: Limiting protection when the power spectral density reaches its upper limit.

[0109] When channel quality is poor, and the power spectral density (PSD) of the candidate transmit power generated by the RF power conditioning unit exceeds the upper limit of the PSD after being adjusted for occupied bandwidth, the PSD hard clipping and MCS inverse order reduction unit truncate the candidate transmit power to the transmit power corresponding to the upper limit value, and simultaneously triggers the candidate MCS order reduction. For example, if the previous time slot of a node uses 16QAM, and the current time slot experiences a sharp increase in packet error rate due to blockage, maintaining 16QAM requires increasing the transmit power to a level exceeding the upper limit of the PSD. In this case, the power is truncated to the compliance boundary, and the MCS is reduced from 16QAM to QPSK. The reduced MCS indicator and the corresponding protection status flag are written into the frame header. The receiver demodulates the payload according to the frame header indication, avoiding the mismatch problem of "power being clipped but the receiver still demodulating according to the higher order expected".

[0110] Condition 5: MCS indicator parsing failed or there were consecutive negative confirmations.

[0111] When the receiver reports an MCS indicator parsing failure or three consecutive failures, the transmitter does not perform an MCS upgrade, maintaining the current configuration or reverting to the default robust MCS (such as QPSK or BPSK). The default robust MCS is used for transmitting frame headers and control information. This operation avoids accidental switching to a higher-order MCS or excessively high power level due to missing measurement information or abnormal feedback, thereby improving the system's anomaly recovery capability.

[0112] Operating Condition 6: OFDM Subcarrier Group-Level Extension.

[0113] In WAIC nodes employing OFDM, the channel quality assessment unit can calculate the comprehensive channel quality index for different subcarrier groups. The compliance-gated adaptive decision-maker selects the corresponding MCS based on the channel quality of each subcarrier group. For example, a higher-order MCS is used for subcarrier groups with better channel quality, and a lower-order MCS is used for subcarrier groups with poorer channel quality. Even if different subcarrier groups use different MCS or different power allocation strategies, the PSD hard limiting and MCS inverse order reduction unit still uniformly verify the total equivalent omnidirectional power spectral density to ensure compliance constraints are met in any time slot.

[0114] Condition 7: Optional channel trend prediction enhancement.

[0115] In an optional implementation, the compliance-gated adaptive decision-maker can incorporate a channel trend prediction module. This module estimates the channel quality change trend for the next time slot based on the comprehensive channel quality indicators, acknowledgment / negative acknowledgment feedback, and state transition records from the most recent TDMA cycles. When channel deterioration is predicted, the node can preemptively lower the MCS level or stop power backoff; when channel improvement is predicted, the node can switch to a higher-order MCS and gradually backoff power, provided the upgrade conditions are met. This prediction enhancement is only an optional feature and is not a necessary component of the device in this embodiment.

[0116] Operating Condition 8: Low-power compliance control of internal LI low-speed sensor nodes.

[0117] For internal low-speed applications such as temperature, pressure, and structural health monitoring, the compliance constraint sensing unit identifies the application category as a low-speed internal application and prioritizes restricting the allowed MCS set to low-order or low-to-medium-order schemes. Even if the overall channel quality index is higher than the first threshold, the node prioritizes power backoff, reducing occupied bandwidth, or delaying the transmission of non-critical data, rather than immediately switching to the highest-order MCS.

[0118] Under this operating condition, the control objective is to reduce the average transmit power consumption and internal cumulative radiation of battery-powered nodes, while maintaining the reliable arrival of necessary sensor data. If the compliance margin is close to the threshold, the node maintains a low-order MCS and increases retransmission or coding redundancy, without increasing the power spectral density to obtain link margin.

[0119] Operating Condition 9: Throughput and bandwidth limitation control of internal HI high-speed nodes.

[0120] For high-speed internal applications such as batch uploading of internal maintenance data or high-speed internal sensor data, the compliance constraint perception unit identifies the application category as a high-speed internal application. When the occupied bandwidth is within the 4.2 to 4.4 GHz operating boundary, the protection margin is sufficient, and the maintenance configuration lock flag does not prevent configuration use, higher-order MCSs such as 16QAM or 64QAM are allowed. When high-speed internal nodes need to increase throughput, the compliance gating adaptive decision-maker still first verifies the necessary bandwidth, occupied bandwidth, power spectral density compliance margin, radio altimeter protection margin, and aggregation interference margin. If any margin is insufficient, even if the current channel quality is good, the node will only select a lower-order MCS within the allowed MCS set, distribute the transmission to subsequent time slots, or reduce the net payload rate to avoid turning high-speed requirements into over-limit transmissions.

[0121] Condition 10: Compliance protection status triggered.

[0122] When the compliance constraint sensing unit detects that the occupied bandwidth is close to or exceeds the boundary, the power spectral density compliance margin is lower than the threshold, the radio altimeter protection margin is insufficient, the aggregation interference margin is insufficient, or the maintenance mode configuration lock flag is locked, the node enters the compliance protection state. In the compliance protection state, the MCS set is allowed to shrink, MCS scaling up and out-of-bounds power compensation are prohibited, and the node performs power backoff, load reduction, or retransmission. The corresponding protection status flag is synchronously written to the frame header, enabling the receiver to configure demodulation according to the actual load in the protection state, avoiding mis-modulation caused by asynchronous protection actions at the transmitting and receiving ends.

[0123] Operating Condition 11: Power-limited triggering of MCS reverse order reduction.

[0124] When channel quality degrades and the candidate transmit power adjustment command is a compensation command, the RF power adjustment unit generates a candidate transmit power. If the power spectral density of this candidate transmit power, after being converted to the occupied bandwidth, exceeds the upper limit of the power spectral density, the PSD hard clipping and the MCS inverse order reduction unit cut off the power, and at the same time triggers the candidate MCS to be reduced to a more robust level within the allowed MCS set.

[0125] Operating Condition 12: Aeronautical Stability and Failure Safety Rollback.

[0126] When a node upgrades from QPSK to 16QAM or from 16QAM to 64QAM, the cooling count is set to the preset cooling time slot number of 2. During the next two time slots, even if the overall channel quality index remains above the first threshold, the compliance gating adaptive decision maker will not select an upgrade direction, only allowing maintenance or degradation. If a negative acknowledgment, frame header verification failure, configuration version inconsistency, or unavailable compliance margin occurs during the cooling period, the node is only allowed to downgrade or enter a fail-safe state. In the fail-safe state, the node uses the default robust MCS and conservative power window to transmit necessary control information or safety-critical payloads; non-critical maintenance payloads are deferred to the time slot when compliance margin is restored.

[0127] Operating Condition 13: Configure version consistency protection.

[0128] In maintenance mode, the system generates a compliant configuration version number for the power spectral density window, necessary bandwidth, operating channel, and allowed MCS policy. During normal operation, the transmitter carries this version number and a checksum field in the frame header. After parsing the frame header, the receiver first verifies the version and integrity, and then demodulates the payload according to the MCS indicator.

[0129] If the receiving end detects that the compliant configuration version field is inconsistent with the local configuration version or that the frame header verification fails, the receiving end will not use the demodulation method corresponding to the MCS indicator and will report a configuration error to the sending end. Upon receiving this feedback, the sending end enters a preset state and uses the default robust MCS to send necessary control information until the maintenance configuration version is restored to consistency.

[0130] As can be seen from the above-described operating conditions, the method and apparatus of this embodiment can integrate real-time channel quality estimation, MCS selection, transmit power spectral density adjustment, power hard limiting, frame header synchronization indication, and abnormal backoff organization into a complete closed-loop control within the WAIC compliance boundary. Power spectral density hard limiting, joint MCS decision-making, frame header synchronization indication, receiver matching demodulation, and abnormal backoff state machine mutually trigger and constrain each other, avoiding mismatch issues in WAIC scenarios such as "power limited but still maintaining a high-order MCS," "transmitter has switched but receiver is unaware," and "erroneous upscaling under abnormal feedback." Furthermore, by distinguishing between low-speed and high-speed internal applications by application category, the same control framework can adapt to different industrialization paths from low-power sensors to high-speed data acquisition, accommodating the different needs of internal low-speed sensing applications and internal high-speed data applications.

[0131] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0132] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. Furthermore, the above embodiments only illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. For those skilled in the art, several modifications and improvements can be made, and these all fall within the protection scope of the present invention.

Claims

1. An adaptive modulation and power joint control method for WAIC, characterized in that, include: S1, read the control status of the previous time slot; S2, read the WAIC compliance configuration of the current node; if there is an error, proceed to S10; otherwise, proceed to S3. S3: Receive channel estimation information and determine if the information is valid; if valid, proceed to S4; otherwise, proceed to S10. S4. Calculate the comprehensive channel quality index based on the channel estimation information; S5 generates the set of allowed MCS and the power spectral density window for operation based on the WAIC compliance configuration and the operating parameters of the current time slot; S6. The integrated channel quality index is compared with the preset first threshold and second threshold. The first threshold is higher than the second threshold. Combining the MCS set, the power spectral density window during operation and the control state in S1, the control direction is determined and candidate MCS instructions and candidate transmit power adjustment instructions are generated. S7: Determine the candidate MCS and candidate bandwidth according to the candidate MCS instruction, determine the candidate transmit power according to the candidate transmit power adjustment instruction, and perform compliance verification. If the verification is successful, proceed to S8. Otherwise, the candidate transmit power is truncated and / or the candidate MCS is downgraded within the MCS set before entering S8; S8 determines the MCS indicator and power level based on the MCS and transmit power output from S7, determines the compliance configuration version field based on the WAIC compliance configuration, and determines the protection status flag based on whether the preceding steps have triggered an anomaly or protection action. Write the MCS indicator, power level indicator, protection status flag, compliance configuration version field, and verification field generated according to preset rules into the frame header and send it. The payload part is sent according to the MCS output by S7. S9, the receiving end parses the frame header. If there is an abnormality, it feeds back to the sending end and enters S10. Otherwise, it selects the corresponding demodulation method according to the MCS indicator and protection status flag to complete the payload recovery, feeds back to the sending end and enters S11. S10, after the sending end enters the preset state, it enters S11; S11, the transmitting end updates the control status of the next time slot based on the feedback.

2. The adaptive modulation and power joint control method for WAIC as described in claim 1, characterized in that, In S1, the control state includes at least MCS, transmit power spectral density, number of consecutive successful feedbacks, number of consecutive failed feedbacks, state hold count, cooling count, and protection state flag.

3. The adaptive modulation and power joint control method for WAIC as described in claim 2, characterized in that, In S2, the WAIC compliance configuration includes at least the application category, working channel, required bandwidth, occupied bandwidth boundary, power spectral density limit, maintenance mode configuration lock flag, aggregated interference margin, radio altimeter protection margin, and version information.

4. The adaptive modulation and power joint control method for WAIC as described in claim 1, characterized in that, In S3, the channel estimation information includes at least pilot signals, synchronization frames, and confirmation frames from historical time slots from the root node or the sink node. In S4, the integrated channel quality index is obtained by weighted combination of signal-to-noise ratio, received signal strength indication and packet error rate; wherein, the signal-to-noise ratio and received signal strength indication are both measured using pilot signals or synchronization frames, and the packet error rate is obtained by statistics based on acknowledgment frames of historical time slots.

5. The adaptive modulation and power joint control method for WAIC as described in claim 3, characterized in that, In S5, the operating parameters include at least the current time slot's occupied bandwidth, power spectral density compliance margin, and load criticality category; The occupied bandwidth is determined based on the previous time slot MCS in the control state read by S1, the power spectral density compliance margin is calculated based on the upper limit of power spectral density in the WAIC compliance configuration and the transmit power spectral density in the control state read by S1, and the payload criticality category is determined by the attributes of the payload to be transmitted in the current time slot.

6. The adaptive modulation and power joint control method for WAIC as described in claim 5, characterized in that, In S5, the allowed MCS set is obtained by taking the intersection of the basic MCS set, the bandwidth compatible MCS set, and the security compliant MCS set; The basic MCS set is determined by application category and payload criticality category; the bandwidth compatible MCS set is determined by necessary bandwidth and occupied bandwidth boundary; and the safety compliant MCS set is determined by power spectral density compliance margin, radio altimeter protection margin, aggregated interference margin, and maintenance mode configuration lock flag. The upper and lower bounds of the power spectral density window during operation are determined by the maintenance mode configuration; wherein, the upper bound does not exceed the hard upper limit of the equivalent isotropic power spectral density as stipulated by law or preset, and the lower bound is determined according to the lowest equivalent isotropic radiation power spectral density configured in the maintenance mode; when the maintenance mode configuration lock flag in the WAIC compliance configuration is locked, the upper and lower bounds of the power spectral density window during operation remain unchanged in the current time slot and subsequent time slots.

7. The adaptive modulation and power joint control method for WAIC as described in claim 6, characterized in that, In S6, determining the control direction and generating candidate MCS commands and candidate transmit power adjustment commands specifically includes: When the integrated channel quality index is higher than the first threshold, the current state has met the minimum number of hold slots, the cooling count is zero, and there is a higher-order alternative in the MCS set, the higher-order MCS is selected as the candidate MCS instruction, and a transmit power back-off instruction is generated as the candidate transmit power adjustment instruction. When the overall channel quality index is lower than the second threshold, or the number of consecutive failure feedbacks reaches a preset threshold, a more robust MCS is selected as a candidate MCS instruction, and a limited power compensation instruction is generated as a candidate transmit power adjustment instruction within the power spectral density window during operation. When the integrated channel quality index is between the first threshold and the second threshold, or has not yet met the minimum number of hold slots, or is within the cooling slot, the current MCS is maintained as the candidate MCS command, and the current transmit power spectral density is maintained as the candidate transmit power adjustment command. When the occupied bandwidth exceeds the limit, the power spectral density compliance margin is insufficient, the radio altimeter protection margin is insufficient, the aggregated interference margin is insufficient, or the maintenance mode configuration lock is triggered, the allowed MCS set is shrunk, MCS upgrade and out-of-limit power compensation are prohibited, the current MCS is maintained or a more robust MCS is selected as a candidate MCS instruction, and a power back-off instruction or a zero compensation instruction is generated as a candidate transmit power adjustment instruction. The minimum number of holding time slots is a preset value. The cooling count is obtained by reading the control state through S1. When MCS or power level changes in the previous time slot, it is set to the preset number of cooling time slots. Otherwise, it is obtained by decreasing the cooling count of the previous time slot.

8. The adaptive modulation and power joint control method for WAIC as described in claim 3, characterized in that, In S7, the compliance verification includes: Verify whether the power spectral density of the candidate transmit power, after being converted by the occupied bandwidth, exceeds the upper limit of the power spectral density in the WAIC compliance configuration; Verify whether the occupied bandwidth corresponding to the candidate bandwidth exceeds the occupied bandwidth boundary in the WAIC compliance configuration; If any of the above verification items exceeds the limit, the verification is deemed unqualified.

9. The adaptive modulation and power joint control method for WAIC as described in claim 8, characterized in that, In S7, a security and stability verification step is included after the compliance verification: After compliance verification, the output MCS and transmit power are subjected to safety and stability verification. The verification items include whether the cooling time slot has ended, whether the control decision has timed out, whether the configuration version is consistent, and whether the compliance margin is reliable. If any verification item fails, the configuration of the previous time slot is used. The consistency of configuration versions refers to whether the version information of the WAIC compliance configuration read by S2 is the same as the version of the compliance configuration stored locally. The compliance margins include power spectral density compliance margin, radio altimeter protection margin, and aggregated interference margin. The reliability of the compliance margins refers to whether the above margins are valid in the current time slot.

10. An adaptive modulation and power joint control device for WAIC based on the method of any one of claims 1 to 9, characterized in that, include: The channel quality assessment unit is used to calculate the comprehensive channel quality index based on the information received by the current node that can be used for channel estimation. The compliance constraint perception unit is used to read the WAIC compliance configuration of the current node and generate the set of allowed MCS and the power spectral density window during operation based on the WAIC compliance configuration and the operating parameters of the current time slot. The compliance-gated adaptive decision-maker is used to compare the comprehensive channel quality index with a preset first threshold and a second threshold. The first threshold is higher than the second threshold. Combining the MCS set, the power spectral density window during operation and the control state of the previous time slot, it determines the control direction and generates candidate MCS commands and candidate transmit power adjustment commands. The cooling control unit is used to set the minimum number of hold time slots and the number of cooling time slots during the control direction determination process of the compliant gating adaptive decision-maker; The radio frequency power adjustment unit is used to adjust the transmit power spectral density of the current time slot according to the candidate transmit power adjustment command and output the candidate transmit power; The modulation and coding configuration unit is used to configure the candidate MCS according to the candidate MCS instruction and determine the candidate bandwidth according to the candidate MCS. The PSD hard clipping and MCS inverse order reduction unit is used to perform compliance verification on candidate transmit power and candidate bandwidth. When the verification fails, the candidate transmit power is truncated and / or the candidate MCS is reduced in order within the MCS set. The protection status synchronization frame header unit is used to determine the MCS indicator and power level indicator based on the verified MCS and transmit power, determine the compliance configuration version field based on the WAIC compliance configuration, determine the protection status flag based on whether the preceding steps trigger an anomaly or protection action, and write the MCS indicator, power level indicator, protection status flag, compliance configuration version field and verification field generated according to preset rules into the frame header. The fail-safe and compliance protection state machine is used to control the current node to enter a preset state when there are abnormal compliance configurations, invalid channel estimation information, or abnormal feedback from the receiver.

Images