A signaling interaction method and device for adaptive coding and modulation of a UAV

Abstract

The application discloses a signaling interaction method and equipment for adaptive coding and modulation of a UAV. The method comprises the following steps: a receiving end performs channel estimation, and acquires an instantaneous signal-to-noise ratio and a line-of-sight state; a signal-to-noise ratio change trend is calculated according to a historical signal-to-noise ratio, a recent block error rate is calculated according to a historical acknowledgement / non-acknowledgement identification result, and a target is compared to generate an over-standard flag; a signal-to-noise ratio level, a trend flag, a line-of-sight state flag and a block error rate over-standard flag are combined into multi-dimensional state information, and the multi-dimensional state information is sent through uplink feedback signaling; a transmitting end receives and analyzes the multi-dimensional state information, indexes a Q table to obtain a modulation and coding mode index, and then notifies the receiving end through downlink control signaling; and the receiving end receives data according to the modulation and coding mode index. The application defines a multi-dimensional state information feedback format, so that the transmitting end can acquire rich information to support intelligent decision-making, has good backward compatibility, has low feedback overhead, and is suitable for low-altitude UAV communication.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and specifically to an adaptive coding modulation signaling interaction method, receiving device, transmitting device, and system for low-altitude unmanned aerial vehicles (UAVs). Background Technology

[0002] With the rapid development of UAV technology, low-altitude UAVs are increasingly widely used in emergency communications, aerial base stations, and environmental monitoring. Influenced by the UAV platform's altitude, trajectory, and surrounding environment, low-altitude channels exhibit significant non-stationarity and time-varying characteristics, posing a severe challenge to the effectiveness and reliability of communication links. Adaptive Modulation and Coding (AMC) dynamically adjusts the modulation and coding scheme (MCS) to match instantaneous channel quality, and is a key technology for improving spectral efficiency and maintaining the target block error rate.

[0003] The applicant's submission on the same day, titled "An Adaptive Coding and Modulation Decision-Making Method and System for Unmanned Aerial Vehicles Based on Enhanced Q-Learning," proposes a Q-learning decision-making method based on a multi-dimensional state space. This method requires querying a Q-table to make MCS (Multi-Channel Compression) decisions based on multi-dimensional state information, including instantaneous signal-to-noise ratio (SNR), SNR variation trends, line-of-sight / non-line-of-sight status, and recent block error rate. However, existing communication protocols lack a signaling interaction mechanism to carry this multi-dimensional state information.

[0004] In existing cellular communication systems (such as 3GPP LTE / NR), user terminals report Channel Quality Indicators (CQIs) to the base station via the uplink feedback channel. The CQI is typically a single 4-bit value representing the recommended MCS index. The base station selects the MCS based on the received CQI and notifies the terminal via downlink control signaling. Existing CQI feedback mechanisms have the following shortcomings: They offer limited information dimensions, reflecting only instantaneous channel quality and failing to express dynamic characteristics such as channel change trends and line-of-sight (LOS) status; they lack statistical information, omitting recent block error rate statistics, preventing the base station from perceiving the actual reliability of the link; and the existing CQI feedback format is relatively fixed, failing to meet the needs of schemes requiring multi-dimensional state information for decision-making. Summary of the Invention

[0005] The present invention aims to overcome the above-mentioned shortcomings of the prior art and provide a signaling interaction method and device for adaptive coding modulation of UAVs. By defining a feedback format for multi-dimensional state information, the transmitter can obtain richer channel information to support Q-table decision-making, while maintaining compatibility with existing communication protocols.

[0006] The technical solution adopted by this invention to solve its technical problem is: A signaling interaction method for adaptive coding modulation of unmanned aerial vehicles (UAVs), applicable to communication systems including transmitters and receivers, includes the following steps: The receiving end performs channel measurement on the received signal to obtain the instantaneous signal-to-noise ratio estimate and line-of-sight / non-line-of-sight status of the current frame; The receiving end maintains a signal-to-noise ratio (SNR) historical buffer and a confirmed / unconfirmed identification result historical buffer. It calculates the SNR change trend based on the SNR historical buffer and calculates the recent block error rate based on the confirmed / unconfirmed identification result historical buffer, compares it with the target block error rate, and generates a recent block error rate exceeding the standard flag. The receiving end combines the quantized level of the instantaneous signal-to-noise ratio estimate, the indicator of the signal-to-noise ratio change trend, the indicator of the line-of-sight / non-line-of-sight state, and the indicator of the recent block error rate exceeding the standard into multi-dimensional state information. The receiving end encapsulates the multi-dimensional state information into uplink feedback signaling and sends it to the transmitting end through a preset uplink feedback channel; The transmitting end receives the uplink feedback signaling and parses it to obtain the multi-dimensional state information; The transmitter uses the multidimensional state information as an index to query the locally stored Q table to obtain the corresponding modulation and coding scheme index; The transmitting end encapsulates the modulation and coding scheme into downlink control signaling and sends it to the receiving end through a preset downlink control channel; The receiving end receives data according to the modulation and coding scheme index.

[0007] Furthermore, the indicator of the signal-to-noise ratio change trend is determined by comparing the slope of the linear fitting of the signal-to-noise ratio of the most recent L frames with a preset positive and negative threshold, corresponding to three states: rising, falling, or stable. The indicator of the recent block error rate exceeding the standard is determined by comparing the block error rate of the confirmed / unconfirmed identification results of the most recent W frames with the target block error rate. If it exceeds the target, it is set to 1; otherwise, it is set to 0.

[0008] Furthermore, the uplink feedback signaling uses the same physical layer channel transmission as the channel quality indicator in the 3GPP standard, but the information fields are redefined as the components of the multidimensional state information; the multidimensional state information is jointly encoded and transmitted in multiple consecutive subframes to reduce feedback overhead.

[0009] A receiver device for adaptive coding modulation of unmanned aerial vehicles includes: The control signaling receiving module is used to receive downlink control signaling and parse it to obtain the modulation and coding scheme index; The data receiving module, connected to the control signaling receiving module, is used to receive data according to the modulation and coding scheme index; generate an acknowledgment / unacknowledgment identification result based on the downlink data reception result, and feed the acknowledgment / unacknowledgment identification result back to the historical storage module; The historical storage module is used to store historical signal-to-noise ratio estimates and historical confirmed / unconfirmed identification results; The channel measurement module is used to perform channel measurements on the received signal to obtain the instantaneous signal-to-noise ratio estimate and line-of-sight / non-line-of-sight status of the current frame. The state calculation module, connected to the channel measurement module and the historical storage module, is used to calculate the signal-to-noise ratio change trend based on the historical signal-to-noise ratio estimate, calculate the recent block error rate based on the historical confirmed / unconfirmed identification results and compare it with the target block error rate to generate a recent block error rate exceeding the standard flag, and quantify the level of the instantaneous signal-to-noise ratio estimate. The information generation module, connected to the state calculation module, is used to combine the level of the instantaneous signal-to-noise ratio estimate, the indicator of the signal-to-noise ratio change trend, the indicator of line-of-sight / non-line-of-sight state, and the indicator of recent block error rate exceeding the standard into multi-dimensional state information. The feedback sending module, connected to the information generation module, is used to encapsulate the multi-dimensional status information into uplink feedback signaling and send it through a preset feedback channel;

[0010] A transmitter device for adaptive coding modulation of unmanned aerial vehicles, comprising: The feedback receiving module is used to receive uplink feedback signaling and parse it to obtain multi-dimensional status information, which includes instantaneous signal-to-noise ratio level, signal-to-noise ratio change trend indicator, line-of-sight / non-line-of-sight status indicator, and recent block error rate exceeding standard indicator. The signaling parsing module, connected to the feedback receiving module, is used to verify and format the multi-dimensional status information; The Q-table storage module is used to store the trained state-action value function table; The decision module connects the signaling parsing module and the Q-table storage module, and is used to query the Q-table using the multi-dimensional state information as an index to obtain the corresponding modulation and coding scheme index. The control transmission module, connected to the decision module, is used to encapsulate the modulation and coding scheme index into downlink control signaling and transmit it through a preset control channel.

[0011] An adaptive coding modulation communication system for unmanned aerial vehicles (UAVs) includes a receiver device as described above and a transmitter device as described above.

[0012] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described above.

[0013] The beneficial effects of this invention are: 1. By defining a feedback format for multi-dimensional state information, the transmitter can acquire richer channel information, including dynamic trends, line-of-sight status, and reliability statistics, providing sufficient basis for Q-table decisions. Compared with existing CQI feedback, this invention combines SNR trends, LOS status, and recent BLER exceedance flags in the feedback, thereby enhancing the dimensionality of the channel state description.

[0014] 2. It reuses the physical layer channels defined by existing standards, only redefining the information fields, and has good backward compatibility.

[0015] 3. Quantify the SNR trend and BLER overshoot flag into binary / triple flags to reduce feedback overhead, making it suitable for scenarios where UAV uplink resources are limited.

[0016] 4. By clarifying the signaling interaction process between the receiver and transmitter, a complete closed-loop link adaptive system is formed. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of the signaling interaction process of the present invention, which shows the external data flow and internal module division between the transmitter and receiver.

[0019] Figure 2 This is a structural block diagram of the receiving end device of the present invention.

[0020] Figure 3 This is a structural block diagram of the transmitter device of the present invention. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0022] Example 1: Signaling Interaction Method like Figure 1 As shown, this embodiment provides a signaling interaction method for adaptive coding modulation of unmanned aerial vehicles (UAVs), which is applicable to communication systems including transmitters and receivers.

[0023] The receiving end includes: 201 control signaling receiving module, 202 data receiving module, 203 historical storage module, 204 channel measurement module, 205 status calculation module, 206 information generation module, and 207 feedback transmission module.

[0024] The transmitter includes: 301 Q-table storage module, 302 decision module, 303 control transmission module, 304 feedback reception module, and 305 signaling parsing module.

[0025] Figure 1 Solid arrows indicate the main data flow, while dashed arrows indicate auxiliary feedback information. The specific interaction steps are as follows: Step 101: The receiver performs channel measurements on the received signal to obtain the instantaneous signal-to-noise ratio estimate and line-of-sight / non-line-of-sight status of the current frame. (0 / 1 bits represent this). This step is performed by the 204-channel measurement module.

[0026] Step 102: The receiver maintains a historical SNR buffer of length 5, storing the estimated SNR of the most recent 5 frames. A linear fit is performed on the SNR within the buffer, and the slope k is calculated. If k > 0.3, it is determined to be an upward trend; if k < 0.3, it is determined to be a downward trend; otherwise, it is determined to be a stable trend. A SNR change trend indicator is generated. This can be encoded using 2 bits (00: falling, 01: stable, 10: rising). This step is performed by the 205 state calculation module.

[0027] Step 103: The receiver maintains an ACK / NACK history buffer of length 5, and calculates the proportion of NACKs in the most recent 5 frames as the recent block error rate. If the recent block error rate is greater than 0.01 (the target block error rate is 0.01), a recent block error rate exceeding the limit flag is generated. ,otherwise The receiver quantizes the instantaneous signal-to-noise ratio estimate into four levels (e.g., level 0: <5 dB, level 1: 5-10 dB, level 2: 10-15 dB, level 3: >15 dB), and the quantization result is... (2 bits). This step is performed by the 205 state calculation module.

[0028] Step 104: [The text appears to be incomplete and contains several grammatical errors. A more accurate translation would require (2 bits) (2 bits) (1 bit) (1 bit) is combined into 6 bits of multidimensional state information. This step is performed by the 206 information generation module.

[0029] Step 105: The receiving end encapsulates the 6-bit multidimensional state information into uplink feedback signaling. In this embodiment, PUCCH format 2 or PUSCH resource transmission is used, or two consecutive subframes are used for joint transmission (3 bits per subframe). This step is performed by the 207 feedback transmission module and sent to the transmitting end through the uplink.

[0030] Step 106: The transmitting end receives the uplink feedback signaling through the 304 feedback receiving module, and the 305 signaling parsing module parses it to obtain the multi-dimensional status information. .

[0031] Step 107: The transmitter uses the multi-dimensional state information as an index to query the Q table stored in the 301 Q table storage module. The Q table dimension is the size of the state space (in this embodiment, SNR level 4 × trend 3 × LOS state 2 × BLER flag 2 = 48) multiplied by the number of MCSs (24). The corresponding MCS index is obtained by querying, and this step is executed by the 302 decision module.

[0032] Step 108: The transmitter encapsulates the MCS index into downlink control signaling via the 303 control transmission module and sends it to the receiver via the downlink (303→201). In this embodiment, the MCS index occupies 5 bits and reuses the modulation and coding scheme field in the DCI format.

[0033] Step 109: The receiving end receives the downlink control signaling through the 201 downlink control signaling receiving module, parses it to obtain the MCS index, and passes it to the 202 data receiving module. 202 receives data according to the MCS index.

[0034] Step 110: The 202 data receiving module generates ACK / NACK based on the transmission result and feeds it back to the 203 historical storage module to update the recent block error rate statistics.

[0035] Example 2: Receiving device like Figure 2 As shown, this embodiment provides a receiver device for adaptive coding modulation of unmanned aerial vehicles, including the following modules: 201 Control Signaling Receiver Module: Used to receive downlink control signaling from the transmitter, parse it to obtain the modulation and coding scheme index, and pass the MCS index to the data receiving module.

[0036] 202 Data Receiving Module: Connects to the control signaling receiving module and is used to receive data according to the modulation and coding scheme index. This module also transmits the received signal to the channel measurement module and feeds back the ACK / NACK results generated by demodulation and decoding to the historical storage module.

[0037] 203 Historical Storage Module: Used to store historical signal-to-noise ratio estimates and historical ACK / NACK results, and to pass historical data to the status calculation module.

[0038] 204 Channel Measurement Module: Performs channel measurements on the received signal to obtain the instantaneous signal-to-noise ratio estimate and line-of-sight / non-line-of-sight status of the current frame, and simultaneously transmits the instantaneous SNR and LOS status to the status calculation module.

[0039] 205. State Calculation Module: Connects the channel measurement module and the historical storage module. It calculates the SNR change trend based on historical SNR estimates, calculates the recent block error rate (BER) based on historical ACK / NACK results and compares it with the target BER to generate a recent BER exceeding the limit flag. It also quantifies the level of the instantaneous SNR estimate. The quantized level of the instantaneous SNR estimate, the SNR trend flag, the LOS status flag, and the recent BLER exceeding the limit flag are then passed to the information generation module.

[0040] 206 Information Generation Module: Connects to the status calculation module, combines the quantized level of the instantaneous SNR estimate, SNR trend indicator, LOS status indicator, and recent BLER exceedance indicator into multi-dimensional status information, and transmits it to the feedback sending module.

[0041] 207 Feedback Transmission Module: Encapsulates multi-dimensional status information into uplink feedback signaling and sends it to the transmitter through the uplink feedback channel.

[0042] Example 3: Transmitter Equipment like Figure 3 As shown, this embodiment provides a transmitter device for adaptive coding modulation of unmanned aerial vehicles, including the following modules: 301 Q-table storage module: Stores the trained state-action value function table. The Q-table is obtained through offline training.

[0043] 302 Decision Module: Connects the signaling parsing module and the Q-table storage module, queries the Q-table using multi-dimensional status information as an index to obtain the corresponding modulation and coding scheme index, and passes the MCS index to the control transmission module.

[0044] 303 Control Transmission Module: Encapsulates the modulation and coding scheme index into downlink control signaling and transmits it to the receiving end via the downlink control channel (corresponding to...). Figure 2 (Module 201 in the middle).

[0045] 304 Feedback Receiving Module: Receives uplink feedback signaling from the receiving end, extracts the raw signaling data, and passes it to the signaling parsing module.

[0046] 305 Signaling Parsing Module: Parses the original signaling, recovers the multi-dimensional state information, and passes the parsed multi-dimensional state information to the decision module for MCS query of the current frame.

[0047] Example 4: Standard Compatibility Implementation This embodiment provides an implementation compatible with 3GPP standards. For 5G NR systems, uplink feedback signaling can reuse PUCCH format 2 or PUSCH resources. If the number of multidimensional state information bits exceeds 4 bits, one of the following methods can be used: Use PUCCH format 3 / 4 to transmit larger payloads.

[0048] Multidimensional state information is jointly encoded and transmitted in multiple subframes, with each subframe transmitting a portion of the bits.

[0049] Redefine the CQI table to map multidimensional state information to the existing 4-bit CQI index.

[0050] Downlink control signaling can reuse the modulation and coding scheme field (5 bits) in DCI format to directly carry the MCS index.

[0051] Example 5: Synergy with Reinforcement Learning Schemes The signaling interaction method of this invention can work in conjunction with the reinforcement learning-based adaptive coding and modulation decision method to form a complete closed-loop link adaptive system. In this collaborative system, the transmitter queries the Q-table based on the multi-dimensional state information fed back from the receiver to make MCS decisions, and notifies the receiver of the decision results through downlink control signaling. The signaling interaction mechanism of this invention provides the necessary state information transmission channel and decision result feedback channel for the above-mentioned decision method, enabling the receiver to report channel state information to the transmitter and transmit the decision results back to the receiver, thereby achieving efficient adaptive coding and modulation closed-loop control.

[0052] The signaling interaction method and device provided by this invention can be applied to scenarios such as UAV communication, cellular mobile communication, and satellite communication, especially low-altitude UAV links that require high reliability and efficient spectrum utilization. By reusing existing standard channels, this invention has good backward compatibility and can be quickly deployed in existing networks.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A signaling interaction method for adaptive coding modulation of unmanned aerial vehicles, characterized in that, Applicable to communication systems that include a transmitter and a receiver, comprising the following steps: The receiving end performs channel measurement on the received signal to obtain the instantaneous signal-to-noise ratio estimate and line-of-sight / non-line-of-sight status of the current frame; The receiving end maintains a signal-to-noise ratio (SNR) historical buffer and a confirmed / unconfirmed identification result historical buffer. It calculates the SNR change trend based on the SNR historical buffer and calculates the recent block error rate based on the confirmed / unconfirmed identification result historical buffer, compares it with the target block error rate, and generates a recent block error rate exceeding the standard flag. The receiving end combines the quantized level of the instantaneous signal-to-noise ratio estimate, the indicator of the signal-to-noise ratio change trend, the indicator of the line-of-sight / non-line-of-sight state, and the indicator of the recent block error rate exceeding the standard into multi-dimensional state information. The receiving end encapsulates the multi-dimensional state information into uplink feedback signaling and sends it to the transmitting end through a preset uplink feedback channel; The transmitting end receives the uplink feedback signaling and parses it to obtain the multi-dimensional state information; The transmitter uses the multi-dimensional state information as an index to query a preset state-action value function table to obtain the corresponding modulation and coding scheme index. The transmitting end encapsulates the modulation and coding scheme into downlink control signaling and sends it to the receiving end through a preset downlink control channel; The receiving end receives data according to the modulation and coding scheme index.

2. The method according to claim 1, characterized in that, The signal-to-noise ratio (SNR) change trend indicator is determined by comparing the slope of the linear fitting of the SNR of the most recent L frames with a preset positive or negative threshold, corresponding to three states: rising, falling, or stable. The recent block error rate exceeding the standard indicator is determined by comparing the block error rate statistically obtained from the confirmed / unconfirmed identification results of the most recent W frames with the target block error rate. If it exceeds the target, it is set to 1; otherwise, it is set to 0.

3. The method according to claim 1, characterized in that, The uplink feedback signaling uses the same physical layer channel transmission as the channel quality indicator in the 3GPP standard, but the information fields are redefined as the components of the multidimensional state information; the multidimensional state information is jointly encoded and transmitted in multiple consecutive subframes to reduce feedback overhead.

4. A receiver device for adaptive coding modulation of unmanned aerial vehicles, characterized in that, include: The control signaling receiving module is used to receive downlink control signaling and parse it to obtain the modulation and coding scheme index; The data receiving module, connected to the control signaling receiving module, is used to receive data according to the modulation and coding scheme index, generate an acknowledgment / unacknowledgment identification result based on the downlink data reception result, and feed the acknowledgment / unacknowledgment identification result back to the historical storage module; The historical storage module is used to store historical signal-to-noise ratio estimates and historical confirmed / unconfirmed identification results; The channel measurement module is used to perform channel measurements on the received signal to obtain the instantaneous signal-to-noise ratio estimate and line-of-sight / non-line-of-sight status of the current frame. The state calculation module, connected to the channel measurement module and the historical storage module, is used to calculate the signal-to-noise ratio change trend based on the historical signal-to-noise ratio estimate, calculate the recent block error rate based on the historical confirmed / unconfirmed identification results and compare it with the target block error rate to generate a recent block error rate exceeding the standard flag, and quantify the level of the instantaneous signal-to-noise ratio estimate. The information generation module, connected to the state calculation module, is used to combine the level of the instantaneous signal-to-noise ratio estimate, the indicator of the signal-to-noise ratio change trend, the indicator of line-of-sight / non-line-of-sight state, and the indicator of recent block error rate exceeding the standard into multi-dimensional state information. The feedback sending module, connected to the information generation module, is used to encapsulate the multi-dimensional status information into uplink feedback signaling and send it through a preset feedback channel; The data receiving module is also used to feed back the confirmation / unconfirmation identification results generated by the received data to the historical storage module for updating the recent error block rate statistics.

5. A transmitter device for adaptive coding modulation of unmanned aerial vehicles, characterized in that, include: The feedback receiving module is used to receive uplink feedback signaling and parse it to obtain multi-dimensional status information, which includes instantaneous signal-to-noise ratio level, signal-to-noise ratio change trend indicator, line-of-sight / non-line-of-sight status indicator, and recent block error rate exceeding standard indicator. The signaling parsing module, connected to the feedback receiving module, is used to verify and format the multi-dimensional status information; The Q-table storage module is used to store the trained state-action value function table; The decision module connects the signaling parsing module and the Q-table storage module, and is used to query the Q-table using the multi-dimensional state information as an index to obtain the corresponding modulation and coding scheme index. The control transmission module, connected to the decision module, is used to encapsulate the modulation and coding scheme index into downlink control signaling and transmit it through a preset control channel.

6. An adaptive coding modulation communication system for unmanned aerial vehicles (UAVs), characterized in that, It includes the receiving device as described in claim 4 and the transmitting device as described in claim 5.

7. A computer-readable storage medium having a computer program stored thereon, the program being executed by a processor to implement the method as claimed in any one of claims 1 to 3.

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