Lightweight scattering communication-in-motion modulation and demodulation device

Abstract

The invention discloses a light-weight scattering communication-in-motion modulation and demodulation device, and relates to the technical field of wireless communication. The system comprises a service processing module, a coding and decoding module, a modulation unit, a demodulation unit, a modulation and demodulation control module, a monitoring software module and an AD / DA module. Through a frequency domain FFT frequency offset analysis method, the frequency offset of a received signal is calculated in real time, and the frequency offset compensation of the received signal is carried out per second, so that the device can adapt to Doppler frequency offset change in a communication-in-moving environment; the channel quality is evaluated in real time through a received signal-to-noise ratio, and a signal rate fast-increasing and fast-decreasing strategy is adopted according to the evaluated channel quality, so that the device can adapt to a time-varying channel in a communication-in-moving environment; through a special broken link processing function, the device can adapt to a blocked channel condition in a communication-in-moving environment; and all software modules are integrated on two pieces of XC7Z045-2FFG900I, so that the hardware integration degree is high, and the lightweight requirement of the device is met.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communication, and in particular to a lightweight scattering communication-in-motion modulation and demodulation device. Background Art

[0002] Tropospheric scatter communication is a beyond-line-of-sight communication method that uses the forward scattering effect of radio waves by scatterers in the troposphere's atmospheric medium. It has the advantages of large communication capacity and can be used all day. However, since tropospheric scattering communication is directional beam communication and the beam is transmitted parallel to the ground, in the mobile communication scenario, it is affected by the uncertain channels in motion, and uncertain channel obstructions are prone to occur during the communication process, which will lead to a decrease in the available rate or even link disconnection. In the mobile communication scenario, the Doppler frequency deviation changes in real time and the rate and range of change are large, requiring the demodulator to have a strong real-time frequency deviation calculation and compensation capability. In addition, the application scenario of mobile communication determines that the equipment needs to have certain lightweight requirements to facilitate the equipment to be equipped on mobile vehicles and ships. Summary of the invention

[0003] In view of this, the present invention proposes a lightweight scattering communication-in-motion modulation and demodulation device. The method can effectively cope with the environment where the channel conditions change rapidly and there is a time-varying Doppler frequency deviation in the scattering communication-in-motion scenario, and has the characteristics of simple structure, high degree of integration, and lightweight.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A lightweight scattering communication-in-motion modulation and demodulation device comprises a service processing module 1, a coding module 2, a modulation unit 3, a demodulation unit 4, a modulation and demodulation control module 5, a monitoring software module 6 and an AD / DA module 7;

[0006] When sending data, the service processing module 1 frames the service data and sends it to the coding module 2. The coding module 2 receives the framed data sent by the service processing module 1, encodes it and sends it to the modulation unit 3. The modulation unit 3 is responsible for the timing control of sending the intermediate frequency signal, baseband signal modulation and shaping, and up-conversion of the intermediate frequency signal according to the control of the modulation and demodulation control module 5, and sends the up-converted intermediate frequency signal to the AD / DA module 7. The AD / DA module 7 converts the intermediate frequency signal into digital-to-analog format and sends it.

[0007] When receiving data, the AD / DA module 7 performs analog-to-digital conversion on the received external signal to obtain a digital intermediate frequency signal, and sends it to the demodulation unit 4. The demodulation unit 4 receives the digital intermediate frequency signal sent by the AD / DA module 7, demodulates and demaps it, and then sends it to the encoding and decoding module 2. The encoding and decoding module 2 receives the demapped data sent by the demodulation unit 4, decodes it, and then sends it to the service processing module 1. The service processing module 1 receives the decoded data sent by the encoding and decoding module 2, deframes it and parses it to obtain service data, wherein the service data includes the signal-to-noise ratio estimation value of the lightweight scattering mobile communication modem device of the opposite end;

[0008] The demodulation unit 4 includes a timing control module, a digital down-conversion module, a low-pass filtering module, a ping-pong RAM storage and read-write control module, a timing module, a frequency deviation calculation and compensation module, a signal-to-noise ratio estimation module, an equalization and channel estimation module, and a demapping module;

[0009] The digital down-conversion module receives the digital intermediate frequency signal sent by the AD / DA module 7, down-converts it into a baseband signal and then sends it to the low-pass filtering module. The low-pass filtering module receives the baseband signal sent by the digital down-conversion module, performs low-pass filtering on it and then sends it to the ping-pong RAM storage and read-write control module. The ping-pong RAM storage and read-write control module performs ping-pong storage on the baseband signal sent by the low-pass filtering module according to each frame as a unit. The timing module calculates the timing deviation according to each frame of the stored signal, and sends the timing error to the timing control module for timing error processing. The frequency deviation calculation and compensation module estimates the frequency deviation of each frame of the signal, and sends the frame signal after the frequency deviation compensation. The signal is stored in the ping-pong RAM storage and read-write control module. The signal-to-noise ratio estimation module estimates the signal-to-noise ratio of each frame signal after the frequency offset compensation, and sends the estimated signal-to-noise ratio value to the equalization and channel estimation module and the modulation and demodulation control module 5. The equalization and channel estimation module performs channel estimation and equalization on each frame signal after the frequency offset compensation according to the estimated signal-to-noise ratio value, and then sends the frame signal to the demapping module. The demapping module performs demapping processing on the signal sent by the equalization and channel estimation module. The timing control module is responsible for the reception timing of the demodulation unit 4, the statistical reception second starting position, and the reception signal time control according to the control of the modulation and demodulation control module 5 and the timing error sent by the timing module;

[0010] The modulation and demodulation control module 5 receives the signal-to-noise ratio estimation value sent by the signal-to-noise ratio estimation module, and controls the communication rate according to the local signal-to-noise ratio estimation value and the peer signal-to-noise ratio estimation value. In addition, the modulation and demodulation control module 5 also interacts with the monitoring software module 6 to complete the control of the modulation unit 3 and the demodulation unit 4, and reports the current working status;

[0011] The monitoring software module 6 transmits the information sent by the host computer monitoring to the modem control module 5. In addition, it also collects the status information reported by the modem control module 5 and feeds it back to the host computer monitoring.

[0012] Further, the modulation and demodulation control module 5 receives the signal-to-noise ratio estimation value sent by the signal-to-noise ratio estimation module, and controls the communication rate according to the local signal-to-noise ratio estimation value and the peer signal-to-noise ratio estimation value, including a rate adaptive fast speed increase / deceleration strategy and a rate processing strategy after link disconnection, specifically including the following processes:

[0013] For the rate-adaptive rapid speed-up and speed-down strategy, multiple communication rate gears are set, and the signal-to-noise ratio corresponding to each communication rate is calculated to obtain the signal-to-noise ratio threshold of each communication rate gear, wherein the signal-to-noise ratio threshold difference corresponding to two adjacent communication rate gears is 3db; when the current communication rate is stable for t1s, the average signal-to-noise ratio estimation value of the devices at both ends within t1s is calculated respectively, and the smaller average signal-to-noise ratio estimation value is compared with the signal-to-noise ratio threshold to determine the gear change of the communication rate up or down. If the gear change is greater than 3, the communication rate is up or downgraded according to the gear change of 3 gears, otherwise the communication rate is directly up or downgraded according to the gear change;

[0014] If no signal is received from the other end, the link is considered broken and the post-break rate processing strategy is executed. Specifically:

[0015] First, the current communication rate is forced to be stable for t2s to send and receive, and wait for communication to be restored. If communication cannot be restored after t2s, the communication rate is reduced to the minimum communication rate and wait for t3s. If communication is restored at the current communication rate or the minimum communication rate, the devices at both ends wait for t4s. After that, the average signal-to-noise ratio estimation value of the devices at both ends within t4s is calculated respectively, and the maximum communication rate that can be supported by the devices at both ends is obtained. Communication is carried out at a lower rate of the smaller maximum communication rate. If communication is still not restored at the minimum communication rate, it falls back to the synchronization stage and resynchronizes.

[0016] Furthermore, the frequency offset calculation and compensation module estimates the frequency offset of each frame signal, which specifically includes the following processes:

[0017] The frequency deviation calculation and compensation module first squares the received single-frame signal, and then obtains the frequency domain data of the squared frame signal by calculating FFT. Centered on the point with a frequency of 0 in the frequency domain, a window is opened in the range of ±600Hz, and the maximum value of the absolute value of the FFT calculation result is found within the window range. The 1 / 2 of the frequency corresponding to the maximum value is the frequency deviation estimate of the current frame signal.

[0018] Due to the adoption of the above technical solution, the beneficial effects of the present invention compared with the prior art are:

[0019] 1. The modem control module in the present invention is related to the adaptive rate control method in the mobile communication scenario, so that the communication rate of the device can change in time with the change of channel quality, and the appropriate communication rate can be changed in time with the change of channel quality. In addition, a separate processing strategy for the case of link disconnection is added, which can maintain the communication rate in the case of short-term occlusion and quickly restore the communication rate after occlusion. This device is more in line with the use requirements in the mobile communication scenario and ensures the communication quality in the mobile communication application scenario.

[0020] 2. The demodulation unit in the present invention has a method for real-time frequency offset compensation. In the frequency hopping system, each frequency hopping offset is calculated and compensated in real time to ensure that the demodulation end can compensate for the frequency offset within the range of ±600Hz in real time. The demodulation end frequency offset compensation capability in the scattered moving communication scenario is enhanced, which is more in line with the application scenario of real-time change of channel Doppler frequency offset in the scattered moving communication scenario.

[0021] 3. The present invention uses two FPGAs: XC7Z045-2FFG900I to realize the construction of software modules, with a high degree of integration, so the size is small, the weight is light, the maintenance is convenient, the equipment is highly lightweight, the equipment maneuverability is significantly improved, and the equipment lightweight requirements in the mobile communication scenario are better met. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of a lightweight scattering communication-in-motion modulation and demodulation device in an embodiment of the present invention.

[0023] Figure 2 Schematic diagram of the structure of a demodulation unit in an embodiment of the present invention.

[0024] Figure 3 The present invention is a schematic diagram of a process flow of a rate-adaptive rapid rate-up and rate-down strategy in a mobile communication scenario according to an embodiment of the present invention.

[0025] Figure 4 The figure is a schematic diagram of the flow of rate processing strategy after link disconnection in a mobile communication scenario according to an embodiment of the present invention.

[0026] Figure 5 The figure is a schematic diagram of the process of real-time frequency offset compensation at the demodulation end in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0028] A lightweight scattering in-motion modulation and demodulation device, such as Figure 1 As shown, it includes a service processing module 1, a coding module 2, a modulation unit 3, a demodulation unit 4, a modulation and demodulation control module 5, a monitoring software module 6 and an AD / DA module 7;

[0029] Specifically, in this embodiment, two FPGAs: XC7Z045-2FFG900I are used to implement a lightweight scattered mobile communication modem device, the business processing module 1 and the encoding and decoding module 2 are implemented based on one of the XC7Z045-2FFG900I, the modulation unit 3, the demodulation unit 4, the modulation and demodulation control module 5 and the monitoring software module 6 are implemented based on the other XC7Z045-2FFG900I; the AD / DA module 7 is implemented using AD9434 and AD9154 chips.

[0030] When sending data, the service processing module 1 frames the service data and sends it to the coding module 2. The coding module 2 receives the framed data sent by the service processing module 1, encodes it and sends it to the modulation unit 3. The modulation unit 3 is responsible for the timing control of sending the intermediate frequency signal, baseband signal modulation and shaping, and up-conversion of the intermediate frequency signal according to the control of the modulation and demodulation control module 5, and sends the up-converted intermediate frequency signal to the AD / DA module 7. The AD / DA module 7 converts the intermediate frequency signal into digital-to-analog format and sends it.

[0031] Specifically, the modulation unit 3 receives the communication rate, modulation mode and other information sent by the modulation and demodulation control module 5, selects the corresponding shaping mode and timing control mode based on the information, and sends the working status to the modulation and demodulation control module 5;

[0032] When receiving data, the AD / DA module 7 performs analog-to-digital conversion on the received external signal to obtain a digital intermediate frequency signal, and sends it to the demodulation unit 4. The demodulation unit 4 receives the digital intermediate frequency signal sent by the AD / DA module 7, demodulates and demaps it, and then sends it to the encoding and decoding module 2. The encoding and decoding module 2 receives the demapped data sent by the demodulation unit 4, decodes it, and then sends it to the service processing module 1. The service processing module 1 receives the decoded data sent by the encoding and decoding module 2, deframes it and parses it to obtain service data, wherein the service data includes the signal-to-noise ratio estimation value of the lightweight scattering mobile communication modem device of the opposite end;

[0033] like Figure 2 As shown, the demodulation unit 4 includes a timing control module, a digital down-conversion module, a low-pass filtering module, a ping-pong RAM storage and read-write control module, a timing module, a frequency offset calculation and compensation module, a signal-to-noise ratio estimation module, an equalization and channel estimation module, and a demapping module;

[0034] The digital down-conversion module receives the digital intermediate frequency signal sent by the AD / DA module 7, down-converts it into a baseband signal and then sends it to the low-pass filtering module. The low-pass filtering module receives the baseband signal sent by the digital down-conversion module, performs low-pass filtering on it and then sends it to the ping-pong RAM storage and read-write control module. The ping-pong RAM storage and read-write control module performs ping-pong storage on the baseband signal sent by the low-pass filtering module according to each frame as a unit. The timing module calculates the timing deviation according to each frame of the stored signal, and sends the timing error to the timing control module for timing error processing. The frequency deviation calculation and compensation module estimates the frequency deviation of each frame of the signal, and sends the frame signal after the frequency deviation compensation. The signal is stored in the ping-pong RAM storage and read-write control module. The signal-to-noise ratio estimation module estimates the signal-to-noise ratio of each frame signal after the frequency offset compensation, and sends the estimated signal-to-noise ratio value to the equalization and channel estimation module and the modulation and demodulation control module 5. The equalization and channel estimation module performs channel estimation and equalization on each frame signal after the frequency offset compensation according to the estimated signal-to-noise ratio value, and then sends the frame signal to the demapping module. The demapping module performs demapping processing on the signal sent by the equalization and channel estimation module. The timing control module is responsible for the reception timing of the demodulation unit 4, the statistical reception second starting position, and the reception signal time control according to the control of the modulation and demodulation control module 5 and the timing error sent by the timing module;

[0035] Specifically, the demodulation unit 4 performs down-conversion processing according to the demodulation rate sent by the modulation and demodulation control module 5;

[0036] The modulation and demodulation control module 5 receives the signal-to-noise ratio estimation value sent by the signal-to-noise ratio estimation module, and controls the communication rate according to the local signal-to-noise ratio estimation value and the peer signal-to-noise ratio estimation value. In addition, the modulation and demodulation control module 5 also interacts with the monitoring software module 6 to complete the control of the modulation unit 3 and the demodulation unit 4, and reports the current working status;

[0037] Specifically, controlling the communication rate is part of the timing control of the modulation and demodulation process;

[0038] Specifically, in this embodiment, the modem control module 5 exchanges information with the monitoring software module 6 by sharing memory on the XC7Z045-2FFG900I, collects the monitoring information of the local end once per second, and puts the monitoring information on the inter-core shared memory address of the XC7Z045-2FFG900I, and informs the monitoring to fetch the latest monitoring data from the address through an interrupt, thereby completing the reporting of the monitoring data. When the monitoring software module 6 sends data, the monitoring information is also put on the shared memory address and an interrupt is sent. When the modem control module 5 receives the interrupt of the monitoring software module 6, it fetches data from the shared memory address, thereby completing the sending of a monitoring. Thus, the interaction of monitoring information is completed.

[0039] The monitoring software module 6 transmits the information sent by the host computer monitoring to the modem control module 5. In addition, it also collects the status information reported by the modem control module 5 and feeds it back to the host computer monitoring.

[0040] Further, the modulation and demodulation control module 5 receives the signal-to-noise ratio estimation value sent by the signal-to-noise ratio estimation module, and controls the communication rate according to the local signal-to-noise ratio estimation value and the peer signal-to-noise ratio estimation value, including a rate adaptive fast speed increase / deceleration strategy and a rate processing strategy after link disconnection, specifically including the following processes:

[0041] For the rate-adaptive rapid speed-up and speed-down strategy, multiple communication rate gears are set, and the signal-to-noise ratio corresponding to each communication rate is calculated to obtain the signal-to-noise ratio threshold of each communication rate gear, wherein the signal-to-noise ratio threshold difference corresponding to two adjacent communication rate gears is 3db; when the current communication rate is stable for t1s, the average signal-to-noise ratio estimation value of the devices at both ends within t1s is calculated respectively, and the smaller average signal-to-noise ratio estimation value is compared with the signal-to-noise ratio threshold to determine the gear change of the communication rate up or down. If the gear change is greater than 3, the communication rate is up or downgraded according to the gear change of 3 gears, otherwise the communication rate is directly up or downgraded according to the gear change;

[0042] If no signal is received from the other end, the link is considered broken and the post-break rate processing strategy is executed. Specifically:

[0043] First, the current communication rate is forced to be stable for t2s to send and receive, and wait for communication to be restored. If communication cannot be restored after t2s, the communication rate is reduced to the minimum communication rate and wait for t3s. If communication is restored at the current communication rate or the minimum communication rate, the devices at both ends wait for t4s. After that, the average signal-to-noise ratio estimation value of the devices at both ends within t4s is calculated respectively, and the maximum communication rate that can be supported by the devices at both ends is obtained. Communication is carried out at a lower rate of the smaller maximum communication rate. If communication is still not restored at the minimum communication rate, it falls back to the synchronization stage and resynchronizes.

[0044] Specifically, in this embodiment, Figure 3 As shown, for the rate-adaptive rapid speed-up and speed-down strategy, multiple communication rate gears are set, and the signal-to-noise ratio corresponding to each communication rate is calculated to obtain the signal-to-noise ratio threshold of each communication rate gear, wherein the signal-to-noise ratio threshold difference corresponding to two adjacent communication rate gears is 3db; when the current communication rate is stable for 3s, the average signal-to-noise ratio estimation value of the devices at both ends within 3s is calculated respectively, and the smaller average signal-to-noise ratio estimation value is compared with the signal-to-noise ratio threshold to determine the gear change of the communication rate up or down. If the gear change is greater than 3, the communication rate is up or down according to the gear change of 3 gears, otherwise the communication rate is directly up or down according to the gear change;

[0045] like Figure 4 As shown, if the peer signal is not received, it is determined to be a link break, and the post-link break rate processing strategy is executed, specifically:

[0046] First, the current communication rate is forced to be stable for 15 seconds, and the communication is waited for to be restored. If the communication cannot be restored after 15 seconds, the communication rate is reduced to the minimum communication rate and then waits for 20 seconds. If the communication is restored at the current communication rate or the minimum communication rate, the devices at both ends wait for another 5 seconds. After that, the average signal-to-noise ratio estimation value of the devices at both ends within 5 seconds is calculated respectively, and the maximum communication rate that can be supported by the devices at both ends is obtained. The devices at both ends communicate at a lower rate of the smaller maximum communication rate. If the communication is still not restored at the minimum communication rate, the device returns to the synchronization stage and resynchronizes.

[0047] Furthermore, if Figure 5 As shown, the frequency offset calculation and compensation module estimates the frequency offset of each frame signal, which specifically includes the following processes:

[0048] The frequency deviation calculation and compensation module first squares the received single-frame signal, and then obtains the frequency domain data of the squared frame signal by calculating FFT. Centered on the point with a frequency of 0 in the frequency domain, a window is opened in the range of ±600Hz, and the maximum value of the absolute value of the FFT calculation result is found within the window range. The 1 / 2 of the frequency corresponding to the maximum value is the frequency deviation estimate of the current frame signal.

[0049] In summary, the present invention can effectively cope with the environment where the channel conditions change rapidly and there is a time-varying Doppler frequency deviation in the scattered moving communication scenario, and it has the characteristics of simple structure, high degree of integration and lightweight.

[0050] Those skilled in the art will appreciate that the embodiments described are intended to help readers understand the principles of the present invention, and should be understood that the scope of protection of the present invention is not limited to the embodiments described. For those skilled in the art, the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A lightweight scattering in-motion modulation and demodulation device, characterized in that: It comprises a service processing module (1), a coding module (2), a modulation unit (3), a demodulation unit (4), a modulation and demodulation control module (5), a monitoring software module (6) and an AD / DA module (7); When sending data, the service processing module (1) frames the service data and sends it to the coding module (2). The coding module (2) receives the framed data sent by the service processing module (1), encodes it, and sends it to the modulation unit (3). The modulation unit (3) is responsible for the timing control of sending the intermediate frequency signal, baseband signal modulation and shaping, and up-conversion of the intermediate frequency signal according to the control of the modulation and demodulation control module (5), and sends the up-converted intermediate frequency signal to the AD / DA module (7). The AD / DA module (7) converts the intermediate frequency signal into digital-to-analog format before sending it. When receiving data, the AD / DA module (7) performs analog-to-digital conversion on the received external signal to obtain a digital intermediate frequency signal, and sends the signal to the demodulation unit (4); the demodulation unit (4) receives the digital intermediate frequency signal sent by the AD / DA module (7), performs demodulation and demapping processing on the signal, and sends the signal to the encoding and decoding module (2); the encoding and decoding module (2) receives the demapped data sent by the demodulation unit (4), decodes the signal, and sends the signal to the service processing module (1); the service processing module (1) receives the decoded data sent by the encoding and decoding module (2), deframes the signal, and parses the signal to obtain service data, wherein the service data includes a signal-to-noise ratio estimation value of the lightweight scattering communication-in-motion modulation and demodulation device at the opposite end; The demodulation unit (4) comprises a timing control module, a digital down-conversion module, a low-pass filtering module, a ping-pong RAM storage and read-write control module, a timing module, a frequency deviation calculation and compensation module, a signal-to-noise ratio estimation module, an equalization and channel estimation module and a demapping module; The digital down-conversion module receives the digital intermediate frequency signal sent by the AD / DA module (7), down-converts the digital intermediate frequency signal into a baseband signal, and then sends it to the low-pass filtering module; the low-pass filtering module receives the baseband signal sent by the digital down-conversion module, performs low-pass filtering on the baseband signal, and then sends it to the ping-pong RAM storage and read-write control module; the ping-pong RAM storage and read-write control module performs ping-pong storage on the baseband signal sent by the low-pass filtering module according to each frame as a unit; the timing module calculates the timing deviation according to each frame of the stored signal, and sends the timing error to the timing control module for timing error processing; the frequency deviation calculation and compensation module estimates the frequency deviation of each frame of the signal, and stores the frame signal after the frequency deviation compensation. to the ping-pong RAM storage and read-write control module, the signal-to-noise ratio estimation module estimates the signal-to-noise ratio of each frame signal after frequency offset compensation, and sends the signal-to-noise ratio estimation value to the equalization and channel estimation module and the modulation and demodulation control module (5), the equalization and channel estimation module performs channel estimation and equalization on each frame signal after frequency offset compensation according to the signal-to-noise ratio estimation value, and then sends the frame signal to the demapping module, the demapping module performs demapping processing on the signal sent by the equalization and channel estimation module, and the timing control module is responsible for the reception timing of the demodulation unit (4), statistics on the start position of the reception second, and the reception signal time control according to the control of the modulation and demodulation control module (5) and the timing error sent by the timing module; The modulation and demodulation control module (5) receives the signal-to-noise ratio estimation value sent by the signal-to-noise ratio estimation module, and controls the communication rate according to the local signal-to-noise ratio estimation value and the opposite signal-to-noise ratio estimation value. In addition, the modulation and demodulation control module (5) also exchanges information with the monitoring software module (6) to complete the control of the modulation unit (3) and the demodulation unit (4), and reports the current working status; The monitoring software module (6) transmits the information sent by the host computer monitoring to the modulation and demodulation control module (5), and further collects the status information reported by the modulation and demodulation control module (5) and feeds it back to the host computer monitoring.

2. A lightweight scattering in-motion modulation and demodulation device according to claim 1, characterized in that: The modulation and demodulation control module (5) receives the signal-to-noise ratio estimation value sent by the signal-to-noise ratio estimation module, and controls the communication rate according to the local signal-to-noise ratio estimation value and the peer signal-to-noise ratio estimation value, including a rate adaptive fast speed increase / deceleration strategy and a rate processing strategy after link disconnection, specifically including the following processes: For the rate-adaptive rapid speed-up and speed-down strategy, multiple communication rate gears are set, and the signal-to-noise ratio corresponding to each communication rate is calculated to obtain the signal-to-noise ratio threshold of each communication rate gear, wherein the signal-to-noise ratio threshold difference corresponding to two adjacent communication rate gears is 3db; when the current communication rate is stable for t1s, the average signal-to-noise ratio estimation value of the devices at both ends within t1s is calculated respectively, and the smaller average signal-to-noise ratio estimation value is compared with the signal-to-noise ratio threshold to determine the gear change of the communication rate up or down. If the gear change is greater than 3, the communication rate is up or downgraded according to the gear change of 3 gears, otherwise the communication rate is directly up or downgraded according to the gear change; If no signal is received from the other end, the link is considered broken and the post-break rate processing strategy is executed. Specifically: First, the current communication rate is forced to be stable for t2s to send and receive, and wait for communication to be restored. If communication cannot be restored after t2s, the communication rate is reduced to the minimum communication rate and wait for t3s. If communication is restored at the current communication rate or the minimum communication rate, the devices at both ends wait for t4s. After that, the average signal-to-noise ratio estimation value of the devices at both ends within t4s is calculated respectively, and the maximum communication rate that can be supported by the devices at both ends is obtained. Communication is carried out at a lower rate of the smaller maximum communication rate. If communication is still not restored at the minimum communication rate, it falls back to the synchronization stage and resynchronizes.

3. A lightweight scattering in-motion modulation and demodulation device according to claim 1, characterized in that: The frequency deviation calculation and compensation module estimates the frequency deviation of each frame signal. The process includes: The frequency deviation calculation and compensation module first squares the received single-frame signal, and then obtains the frequency domain data of the squared frame signal by calculating FFT. Centered on the point with a frequency of 0 in the frequency domain, a window is opened in the range of ±600Hz, and the maximum value of the absolute value of the FFT calculation result is found within the window range. The 1 / 2 of the frequency corresponding to the maximum value is the frequency deviation estimate of the current frame signal.

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