Short-wave asymmetric link establishment communication method, device and equipment

Abstract

The invention discloses a short-wave asymmetric link establishment communication method, device and equipment. The short-wave asymmetric link establishment communication method comprises the following steps: a calling party and a called party appoint a synchronous or asynchronous link establishment mode and a frequency set; the calling party sends a link establishment request of a robust waveform; the called party receives the link establishment request, and selects a robust waveform or a fast waveform to send a link establishment response according to the signal-to-noise ratio and Doppler spread of a received signal; the calling party receives the link establishment response and sends data; the called party receives the data and sends a data response; the calling party sends an interaction inquiry of which the waveform is consistent with the link establishment response waveform; and the called party receives the interaction inquiry and sends an interaction response of which the waveform is consistent with that of the interaction inquiry. According to the method, the anti-interference capability of link establishment is improved and the link establishment process is accelerated by adopting an asymmetric waveform link establishment technology, and the anti-interference capability is reflected by different leader sequences of a robust waveform and a fast waveform; the asymmetric waveform link establishment technology can also be applied to relay networking, the anti-interference performance of link establishment of the relay networking is enhanced, and the asymmetric waveform link establishment technology can also be compatible with a traditional link establishment mode.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and more specifically, to a shortwave asymmetric link establishment communication method, device and equipment. Background Art

[0002] The shortwave skywave communication window changes with the change of the ionosphere (time), so the dynamic evaluation of the communication effect before data transmission and the link establishment technology that automatically selects the optimal frequency point to establish a link have become the standard of shortwave radio stations, and the link establishment (Automatic Link Establishment, ALE) performance also approximately determines the efficiency of shortwave communication. In order to cope with the complex time-varying dispersion channel and various interferences in skywave transmission, shortwave communication experts at home and abroad have carried out a lot of research work on the waveform performance, anti-interference, and coordinated data transmission efficiency of shortwave communication. In 1988, the U.S. military released the second-generation shortwave automatic link establishment technology (2G-ALE) standard MIL-STD-188-141A, which effectively solved the demand for voice communication and low data communication requirements in the 1980s and 1990s. However, 2G-ALE uses an asynchronous link establishment method with 8FSK modulation, which takes a long time to establish a link and has weak anti-interference ability. Secondly, the signal-to-noise ratio of 2G-ALE link establishment is higher than that of low-speed data transmission waveform, resulting in problems such as failure to establish a link when low-speed data transmission is available. In 1999, the U.S. military released the third-generation shortwave automatic link establishment technology (3G-ALE) standard MIL-STD-188-141B, which has two modes: robust link establishment and fast link establishment, and adds a synchronization mechanism to speed up the link establishment speed and reduce the link establishment signal-to-noise ratio requirements. In 2017, the U.S. military released the fourth-generation shortwave automatic link establishment technology (4G-ALE) standard MIL-STD-188-141D that supports broadband communications. It still uses robust link establishment and fast link establishment, with both synchronous and asynchronous mechanisms, and adds spectrum sensing technology for variable channels and signal bandwidth at preferred frequencies.

[0003] However, the prior art adopts a synchronous or asynchronous link establishment mode in the shortwave link establishment process. Regardless of whether it is a robust waveform or a fast waveform, they are used in pairs on the same channel, that is, when a robust waveform is used to inquire, a robust waveform is used to answer on the same frequency, and when a fast waveform is used to inquire, a fast waveform is used to answer on the same frequency. Since the link establishment process lasts for a long time, the probability of being identified and intercepted is high, and the two waveforms are the same, the probability of being interfered is high. In view of the inadaptability of the synchronous / asynchronous and robust / fast pairing methods in the shortwave link establishment process in actual use environments, there is an urgent need for an asynchronous fast link establishment method that can support variable channels and signal bandwidths on the preferred frequency, avoid spectrum conflicts, and reduce network establishment time, thereby achieving a low detection probability and improving the anti-interference effect. Summary of the invention

[0004] The present invention aims to overcome at least one defect in the prior art and provide a shortwave asymmetric link establishment communication method, device and equipment for solving the problem of identifying low delay spread channels and compensating for leaked energy and correcting the delay spread estimation value in this case.

[0005] The technical method adopted by the present invention is a short-wave asymmetric link establishment communication method, comprising the following steps: Step S100: The calling party and the called party agree on a synchronous or asynchronous link establishment mode and frequency set; Step S200: The calling party sends a link establishment request of a robust waveform; Step S300: the called party receives the link establishment request and selects a robust waveform or a fast waveform to send a link establishment response according to the signal-to-noise ratio and Doppler spread of the received signal; Step S400: The calling party receives a link establishment response and sends data; Step S500: the called party receives the data and sends a data response; Step S600: the calling party sends an interactive inquiry whose waveform is consistent with the link establishment response waveform; Step S700: The called party receives the interactive inquiry and sends an interactive response whose waveform is consistent with the interactive inquiry waveform.

[0006] Synchronous link establishment means that the sender and receiver always maintain the same change on a set of agreed frequency sets, and asynchronous link establishment means that the sender and receiver send and receive on a set of agreed frequency sets. The link establishment request is usually a robust waveform because the robust waveform has better anti-interference ability than the fast waveform, making the signal more stable and improving the success rate of link establishment. According to the signal-to-noise ratio and Doppler spread of the received signal, the robust waveform or fast waveform is independently selected to send the link establishment response. The use of fast waveform response can increase the transmission rate and reduce the interaction time. The use of robust waveform can better resist interference when the channel environment is poor, and the signal is more stable.

[0007] During the synchronous link establishment process, the frame structure of the robust waveform and the fast waveform consists of a start-up control level, a leading sequence and several segments. The duration of the robust waveform is 1100ms~1300ms, and the duration of the fast waveform is about 400ms~600ms. The start-up control level is used to ensure the stable start of the signal, the leading sequence is used for synchronization and channel estimation, and multiple data segments carry the actual communication information. Due to its longer duration, the robust waveform can provide better anti-interference performance and a longer communication distance, and is suitable for communication scenarios that require high reliability and stability; the fast waveform, with its shorter duration, can establish a communication link faster and reduce latency, and is suitable for communication scenarios with high real-time requirements.

[0008] In order to reasonably allocate the preamble sequence, during the asynchronous link establishment process, the frame structure of the robust waveform and the fast waveform consists of a starting control level, multiple preamble sequences and a number of segments. During the link establishment inquiry, the number of preamble sequences is calculated as follows:

[0009] N represents the number of preamble sequences, T is the duration of the waveform, F is the number of frequency sets, and r is the preamble sequence; during link establishment response, the number of preamble sequences is 1. This ensures that the number of preamble sequences can be reasonably and effectively allocated under different waveform durations and frequency set numbers. In the link establishment response phase, in order to simplify the communication process and improve the response speed, the number of preamble sequences is fixed to 1.

[0010] In addition to sending a robust waveform, sending a link establishment request in step S200 also includes sending a link establishment request using a fast waveform when the link connectivity and location information are known. For example, if it is known in advance that the locations of the sender and receiver are in sea surface ground wave communication, a fast waveform link establishment inquiry is used. When the link connectivity is stable and the location information is clear, the use of a fast waveform can significantly reduce the delay of the link establishment request and improve communication efficiency.

[0011] In step S300, according to the signal-to-noise ratio and Doppler spread of the received signal, autonomously selecting a robust waveform or a fast waveform to send a link establishment response is specifically as follows: (1) When the signal-to-noise ratio is greater than 3dB, use fast waveform response; (2) When the signal-to-noise ratio is less than 0 dB, use a robust waveform response; (3) When 0≤SNR≤3dB, if Doppler spread DS≤0.1, use fast waveform response; (4) When 0≤SNR≤3dB, if Doppler spread DS>0.1, use robust waveform response.

[0012] When the signal-to-noise ratio of the received signal is higher than 3dB, it indicates that the channel condition is good and a fast waveform is selected for response, because the fast waveform has the characteristics of high-speed transmission and can improve communication efficiency; when the signal-to-noise ratio of the received signal is lower than 0dB, the channel condition is poor and a robust waveform is selected for response to ensure the reliability and stability of communication; for medium channel conditions with a signal-to-noise ratio between 0dB and 3dB, Doppler spread is added as a selection condition. If the Doppler spread DS is less than or equal to 0.1, it indicates that the channel is relatively stable, so the system chooses to use a fast waveform for response to balance communication efficiency and reliability; if the Doppler spread DS is greater than 0.1, it indicates that there are large dynamic changes in the channel, and the system chooses to use a robust waveform for response to cope with the instability of the channel and ensure the successful establishment of communication.

[0013] In the step S300, when the waveform of the link establishment response is a fast waveform, the subsequent data interaction process without disconnecting the link adopts the fast waveform to send inquiries and responses; when the waveform of the link establishment response is a robust waveform, the subsequent data interaction process without disconnecting the link adopts the robust waveform to send inquiries and responses. When the channel conditions are good, the fast waveform is selected as the link establishment response waveform, which can quickly and accurately transmit data. In the subsequent data interaction process, if the link is not disconnected, the fast waveform is used for data interaction, making full use of its high-speed transmission characteristics to improve communication efficiency and real-time performance; if the channel conditions are more complex or there is interference, a more reliable robust waveform is used to ensure the integrity of the data. Therefore, in the subsequent data interaction process without disconnecting the link, the robust waveform is used for data interaction to cope with possible channel instability and interference, and ensure the reliability and stability of communication.

[0014] In a harsh electromagnetic environment, even if a robust waveform cannot be used to establish a link, a relay network link is also included. The relay network link establishment includes source node link establishment and relay node link establishment. The source node link establishment is to establish a link from the source node to the relay node, and the relay node link establishment is to establish a link from the relay node to the destination node. Before the relay node link is established, spectrum sensing is required to obtain the link establishment frequency of the relay node. Since the source node cannot establish a link with the destination node even if a robust link is used, the relay node link establishment inquiry and the source node link establishment inquiry use different frequency points, and fast calling is used to achieve a low detection probability of the signal.

[0015] The link establishment process of the relay network is specifically as follows: a link establishment request of a robust waveform is sent from the source node to the relay node, and the relay node sends a link establishment response of a fast waveform to the source node. After the source node successfully establishes the link, the link establishment frequency of the relay node is found through spectrum sensing, and the relay node sends a link establishment request of a fast waveform to the destination node, and the destination node sends a link establishment response of a fast waveform to the relay node. Since the robust waveform has strong anti-interference ability and stability in a complex channel environment, in the case of a known poor channel environment, the use of a robust waveform to send a link establishment request can increase the success rate of the link establishment request being delivered to the relay node. After receiving the link establishment request from the source node, the relay node will immediately send a link establishment response of a fast waveform to the source node. The fast waveform has a fast transmission speed and a small delay, which can improve the real-time performance of the link establishment response and speed up the progress of the entire link establishment process. After the source node successfully establishes a communication link with the relay node, the relay node will perform spectrum sensing. Spectrum sensing is a key link in the relay network link building process. It is used to obtain the current channel usage in real time, and then select the best link building frequency to avoid frequency conflicts with other communication systems and ensure the stability and security of communication. Finally, after successfully obtaining the link building frequency, the relay node will send a link building request using a fast waveform to the destination node. After receiving the link building request from the relay node, the destination node will immediately send a link building response to the relay node using the same fast waveform. At this point, the relay network link building process is complete, and stable data transmission is achieved between the source node and the destination node through the relay node.

[0016] A shortwave asymmetric link establishment communication device is constructed based on the above-mentioned shortwave asymmetric link establishment communication method, and includes the following modules: An agreement module, in which the calling party and the called party agree on a synchronous or asynchronous link establishment mode and frequency set; In the link establishment module, the calling party sends a link establishment request using a robust waveform; the called party receives the link establishment request and autonomously selects a robust waveform or a fast waveform to send a link establishment response based on the signal-to-noise ratio and Doppler spread of the received signal; Data transceiver module: the calling party receives the link establishment response and sends data; the called party receives the data and sends a data response; In the interactive module, the calling party sends an interactive inquiry with a waveform consistent with the waveform of the link establishment response; the called party receives the interactive inquiry and sends an interactive response with a waveform consistent with the interactive inquiry waveform.

[0017] A communication device comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the above-mentioned short-wave asymmetric link establishment communication method.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. Asymmetric waveform link building technology When the robust waveform inquiry is used for synchronous / asynchronous link establishment, the called party can use the robust waveform response or the fast waveform response according to the quality of the received signal. To resist malicious interference, the leading sequences of the robust waveform and the fast waveform are inconsistent, that is, the interferer cannot use recording and playback attacks only after detecting the link establishment inquiry of the initiator, resulting in the inability to correctly identify and receive the link establishment response; 2. Enhance the anti-interference capability of relay cooperative networking Usually, relay cooperative networking is carried out in a harsh electromagnetic environment, that is, the source node cannot establish a link with the destination node using robust link establishment. Compared with the relay cooperative networking based on symmetric link establishment, which only uses the method of changing the link establishment frequency, the asymmetric networking method of the present invention enhances the anti-interference ability of the network; 3. Compatibility with traditional chain building methods The design of the robust waveform is the same as the preamble sequence and encoding and decoding method of the traditional 3G ALE and 4G ALE link establishment waveforms. During the receiving process, it only needs to decode messages of different lengths twice, and the waveform is judged by verifying the CRC check bit. Therefore, it can be directly compatible with the traditional waveform. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings of the present invention are only used for illustrative purposes and cannot be understood as limiting the present invention. In order to more clearly illustrate the technical methods of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a flow chart of the present invention.

[0021] Figure 2 It is a fast waveform frame structure in the synchronous mode of the present invention. Figure 3 This is the robust waveform frame structure in the synchronous mode of the present invention.

[0022] Figure 4 It is a schematic diagram of quick response interaction in the synchronous mode of the present invention.

[0023] Figure 5 It is a schematic diagram of robust response interaction in the synchronous mode of the present invention.

[0024] Figure 6 This is the query frame structure in the asynchronous mode of the present invention.

[0025] Figure 7 This is the response frame structure in the asynchronous mode of the present invention.

[0026] Figure 8This is a schematic diagram of the quick response interaction in the asynchronous mode of the present invention.

[0027] Fig. 9 It is a schematic diagram of robust response interaction in asynchronous mode of the present invention.

[0028] Fig.10 It is a schematic diagram of the relay collaborative networking and link building process of the present invention.

[0029] Fig.11 It is a structural diagram of the shortwave asymmetric link building communication device of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical methods in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Example 1 Shortwave link establishment includes synchronous link establishment and asynchronous link establishment. The link establishment waveform includes robust waveform and fast waveform. In the process of synchronous link establishment or asynchronous link establishment, robust waveform or fast waveform can be used to establish the link. Synchronous link establishment means that the sender and receiver always maintain the same change on a set of agreed frequency sets, that is, they change to the same frequency at the same time, and change to the next frequency at the same time after the same time. This usually requires the sender and receiver to have the same time of day (TOD); asynchronous link establishment means that the sender and receiver have the same frequency change time period on a set of agreed frequency sets, and change according to their different starting times, that is, they change to frequencies that are not necessarily the same at different times, but each changes to its next frequency after the same time. It is not necessary for the sender and receiver to have the same time of day (TOD). Synchronous link establishment or asynchronous link establishment is the consistency of time between the sender and receiver. The effect is that the synchronous link establishment speed is faster than the asynchronous link establishment speed, but the synchronous link establishment requires both parties to have a time mechanism.

[0032] The robust waveform usually uses a data rate of 75bps, while the fast waveform uses 300bps. The condition for robust link establishment is that the signal-to-noise ratio (SNR) is around -6dB~0dB, and the condition for fast link establishment is that the signal-to-noise ratio (SNR) is around 0dB~6dB. Usually, the message used for link establishment is about 50 bits, and the robust waveform is about 1s, and the fast waveform is about 200ms. The waiting interval is 200ms~700ms, which is estimated to be 500ms. If synchronous link establishment is used, including transmission and reception and interval, it is usually waveform time + waiting interval + waveform time. The robust waveform is about 2.5s, and the fast link establishment is about 1s; if asynchronous link establishment is used, including transmission and reception and interval, the total number of frequencies N needs to be considered, which is usually (N-1)*waveform time + waiting interval + waveform time.

[0033] The existing shortwave link establishment technology, whether it is a robust waveform or a fast waveform link establishment, is used in pairs under the same channel, that is, when a robust waveform is used for inquiry, a robust waveform is used for response on the same frequency, and when a fast waveform is used for inquiry, a fast waveform is used for response on the same frequency. Since the link establishment process lasts for a long time, the probability of being identified and intercepted is high, and the two waveforms sent and received are the same, the probability of being interfered is high. Therefore, the present invention proposes a shortwave asymmetric link establishment communication method, which is based on asynchronous inquiry of a robust waveform and synchronous response of a fast waveform, and supports variable channels and signal bandwidths on preferred frequencies, which can avoid spectrum conflicts and reduce network establishment time, and achieve low detection probability and anti-interference effects.

[0034] like Figure 1 As shown, this embodiment provides a shortwave asymmetric link establishment communication method, including: Step S100: The calling party and the called party agree on a synchronous or asynchronous link establishment mode and frequency set; Step S200: the calling party sends a link establishment request of a robust waveform; Step S300: the called party receives the link establishment request and autonomously selects a robust waveform or a fast waveform to send a link establishment response according to the signal-to-noise ratio and Doppler spread of the received signal; Step S400: The calling party receives a link establishment response and sends data; Step S500: the called party receives the data and sends a data response; Step S600: the calling party sends an interactive inquiry whose waveform is consistent with the link establishment response waveform; Step S700: The called party receives the interactive inquiry and sends an interactive response whose waveform is consistent with the interactive inquiry waveform.

[0035] In step S200, in addition to using a robust waveform, the link establishment request can also be sent using a fast waveform to establish a link. According to the link connectivity and location information, a fast waveform link establishment query is used. For example, if it is known that the locations of the sender and the receiver are in sea surface ground wave communication, the sender and the receiver can use a fast link establishment query.

[0036] In this embodiment, as shown in the following table, both the robust waveform and the fast waveform adopt PSK modulation, a symbol rate of 2400, and a spread spectrum method is adopted in the data segment.

[0037]

[0038] In this embodiment, combined with Figures 2 to 5 As shown in the figure, in synchronous mode, the fast waveform and the robust waveform only insert a leading sequence between the starting control level and the data segment. The fast waveform lasts for about 500ms; the robust waveform lasts for about 1200ms. The robust waveform has a longer duration and better anti-interference performance. Therefore, the calling party usually uses the robust waveform to inquire first to increase the success rate of the link establishment request. The called party receives the signal-to-noise ratio (SNR) and selects different waveform responses. The judgment is based on the following: (1) When the signal-to-noise ratio is greater than 3dB, use fast waveform response; (2) When the signal-to-noise ratio is less than 0 dB, use a robust waveform response; (3) When 0≤SNR≤3dB, if Doppler spread (DS)≤0.1, use fast waveform response; (4) When 0≤SNR≤3dB, if Doppler spread (DS)>0.1, use robust waveform response.

[0039] If the called party uses fast waveform response to establish a link, the interaction between the calling party and the called party during the data transmission process (without disconnecting the link) shall use fast waveform interaction; if the called party uses robust waveform response to establish a link, the interaction between the initiator and the called party during the data transmission process (without disconnecting the link) shall use robust waveform interaction.

[0040] In this embodiment, combined with Figures 6 to 9 As shown, in asynchronous mode, N preamble sequences are inserted between the start control level and the data segment during the link establishment inquiry of the fast waveform and the robust waveform. The setting of the N value is proportional to the number of frequency sets.

[0041] T is the waveform time, F is the frequency set number, and r is the leading sequence.

[0042] The link establishment response of the fast waveform and the robust waveform inserts a preamble sequence between the starting control level and the data segment. The usage method is the same as the synchronous mode. The calling party first uses the robust waveform to inquire, and the called party independently selects the robust waveform or the fast waveform to reply according to the quality of the received signal. If the called party uses the fast waveform to answer the link, the interaction between the initiator and the called party during the data transmission process (without disconnecting the link) will use the fast waveform interaction; if the called party uses the robust waveform to answer the link, the interaction between the initiator and the called party during the data transmission process (without disconnecting the link) will use the robust waveform interaction.

[0043] In this embodiment, if Fig.10 As shown in the figure, in a harsh electromagnetic environment, even if the robust link establishment cannot be successful, the relay network link establishment method is usually adopted. The relay network still continues the inquiry and response method. Both link establishments can adopt the synchronous / asynchronous link establishment method. Regardless of whether the synchronous / asynchronous link establishment is used, the two link establishments are the source node link establishment and the relay node link establishment. The source node link establishment is a link establishment request with a robust waveform sent by the source node, and the relay node receives the link establishment request and sends a link establishment response with a fast waveform to the source node; the relay node link establishment is a link establishment request with a fast waveform sent by the relay node to the destination node, and the destination node receives the link establishment request and sends a link establishment response with a fast waveform to the relay node. The link establishment inquiry of the relay node and the link establishment inquiry of the source node use different frequency points, and a fast call is used to achieve a low detection probability of the signal, which can improve the success rate of link establishment and strengthen the stability of the relay network link establishment.

[0044] Example 2 like Fig.11 As shown, a shortwave asymmetric link establishment communication device provided in this embodiment is constructed based on the shortwave asymmetric link establishment communication method in embodiment 1, and includes the following modules: An agreement module, in which the calling party and the called party agree on a synchronous or asynchronous link establishment mode and frequency set; In the link establishment module, the calling party sends a link establishment request using a robust waveform; the called party receives the link establishment request and autonomously selects a robust waveform or a fast waveform to send a link establishment response based on the signal-to-noise ratio and Doppler spread of the received signal; Data transceiver module: the calling party receives the link establishment response and sends data; the called party receives the data and sends a data response; In the interactive module, the calling party sends an interactive inquiry with a waveform consistent with the waveform of the link establishment response; the called party receives the interactive inquiry and sends an interactive response with a waveform consistent with the interactive inquiry waveform.

[0045] Example 3 Another embodiment of the present invention is a communication device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the above-mentioned shortwave asymmetric link establishment communication method.

[0046] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A shortwave asymmetric link establishment communication method, characterized in that: The following steps are involved: Step S100: The calling party and the called party agree on a synchronous or asynchronous link establishment mode and frequency set; Step S200: the calling party sends a link establishment request of a robust waveform; Step S300: the called party receives the link establishment request and selects a robust waveform or a fast waveform to send a link establishment response according to the signal-to-noise ratio and Doppler spread of the received signal; Step S400: The calling party receives a link establishment response and sends data; Step S500: the called party receives the data and sends a data response; Step S600: the calling party sends an interactive inquiry whose waveform is consistent with the link establishment response waveform; Step S700: The called party receives the interactive inquiry and sends an interactive response whose waveform is consistent with the interactive inquiry waveform.

2. The shortwave asymmetric link establishment communication method according to claim 1, characterized in that: During the synchronous link establishment process, the frame structure of the robust waveform and the fast waveform consists of a starting control level, a leading sequence and several segments. The duration of the robust waveform is 1100ms~1300ms, and the duration of the fast waveform is about 400ms~600ms.

3. The shortwave asymmetric link establishment communication method according to claim 1, characterized in that: During the asynchronous link establishment process, the frame structure of the robust waveform and the fast waveform consists of a starting control level, multiple preamble sequences and a number of segments. During the link establishment inquiry, the number of preamble sequences is calculated as follows: N represents the number of preamble sequences, T is the duration of the waveform, F is the number of frequency sets, and r is the preamble sequence; when establishing a link response, the number of preamble sequences is 1.

4. The shortwave asymmetric link establishment communication method according to claim 3, characterized in that: In step S200, when the link connectivity and location information are known, a fast waveform is used to replace a robust waveform to send a link establishment request.

5. The shortwave asymmetric link establishment communication method according to claim 4, characterized in that: In step S300, according to the signal-to-noise ratio and Doppler spread of the received signal, autonomously selecting a robust waveform or a fast waveform to send a link establishment response is specifically as follows: (1) When the signal-to-noise ratio is greater than 3dB, use fast waveform response; (2) When the signal-to-noise ratio is less than 0 dB, use a robust waveform response; (3) When 0≤SNR≤3dB, if Doppler spread DS≤0.1, use fast waveform response; (4) When 0≤SNR≤3dB, if Doppler spread DS>0.1, use robust waveform response.

6. The shortwave asymmetric link establishment communication method according to claim 5, characterized in that: In the sending of the link establishment response in step S300, when the waveform of the link establishment response is a fast waveform, subsequent data interaction processes that have not disconnected the link all use the fast waveform to send inquiries and responses; when the waveform of the link establishment response is a robust waveform, subsequent data interaction processes that have not disconnected the link all use the robust waveform to send inquiries and responses.

7. The shortwave asymmetric link establishment communication method according to claim 6, characterized in that: It also includes relay network chain establishment, which includes source node chain establishment and relay node chain establishment. The source node chain establishment is to establish a chain from the source node to the relay node, and the relay node chain establishment is to establish a chain from the relay node to the destination node. Before the relay node chain is established, spectrum sensing is required to obtain the chain establishment frequency of the relay node.

8. The shortwave asymmetric link establishment communication method according to claim 7, characterized in that: The link establishment process of the relay network is specifically as follows: a link establishment request with a robust waveform is sent from the source node to the relay node, and the relay node sends a link establishment response with a fast waveform to the source node. After the source node successfully establishes the link, the link establishment frequency of the relay node is found through spectrum sensing, and the relay node sends a link establishment request with a fast waveform to the destination node, and the destination node sends a link establishment response with a fast waveform to the relay node.

9. A shortwave asymmetric link communication device, characterized in that: The short-wave asymmetric link establishment communication method according to claims 1 to 8 is constructed, and includes the following modules: An agreement module, in which the calling party and the called party agree on a synchronous or asynchronous link establishment mode and frequency set; In the link establishment module, the calling party sends a link establishment request using a robust waveform; the called party receives the link establishment request and autonomously selects a robust waveform or a fast waveform to send a link establishment response based on the signal-to-noise ratio and Doppler spread of the received signal; Data transceiver module: the calling party receives the link establishment response and sends data; The called party receives data and sends a data response; In the interactive module, the calling party sends an interactive inquiry with a waveform consistent with the waveform of the link establishment response; the called party receives the interactive inquiry and sends an interactive response with a waveform consistent with the interactive inquiry waveform.

10. A communication device, characterized in that: The invention comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the short-wave asymmetric link establishment communication method as claimed in any one of claims 1 to 8.

Images