A TDMA-based TDCS anti-jamming communication system and communication method
By combining TDMA technology and TDCS system, a multi-user networking protocol was designed, which solved the problem of the limited use of TDCS system in multi-user networking, and realized a stable and efficient communication system with adaptive capability to complex environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TIANFU JIANGXI LAB
- Filing Date
- 2025-05-07
- Publication Date
- 2026-07-21
AI Technical Summary
The TDCS system is limited in use in multi-user networks and is incompatible with commonly used protocols such as CSMA and CA, which leads to a decline in communication system performance.
Combining TDMA technology, a TDMA-based TDCS anti-interference communication system is designed. By integrating the application layer, data link layer, physical layer, and sensing decision module, multi-user networking is realized. Time slots are allocated and channels are switched using beacon frames. Combining CCSK, BPSK, QPSK, and 16QAM modulation methods, the network status is adjusted according to the spectrum sensing results and network conditions.
Maintaining stability and efficiency of multi-user communication in complex communication environments, improving communication efficiency, reducing energy consumption, optimizing resource allocation, and enhancing adaptability.
Smart Images
Figure CN120454882B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of wireless communication technology, and more specifically, to a TDMA-based TDCS anti-interference communication system and communication method. Background Technology
[0002] With the widespread use of wireless communication services in both military and civilian fields, spectrum resources suitable for electromagnetic wave transmission under current communication technology conditions are becoming increasingly precious. Due to the openness of electromagnetic space, mutual interference between wireless communication devices is inevitable, making it difficult to implement communication services.
[0003] As jamming techniques have evolved from traditional narrowband jamming to broadband and agile jamming, anti-jamming techniques such as spread spectrum, frequency hopping, and time hopping have been applied in anti-jamming communication systems. However, because they lack the ability to actively acquire information such as the time-frequency distribution of jamming signals, the use of these anti-jamming techniques has also led to a decline in communication system performance. Cognitive radio technology, which aims to improve spectrum utilization, is one approach to solving this problem. Its core idea is to interact with the surrounding environment to sense and utilize idle spectrum in physical space, thereby limiting the occurrence of communication conflicts.
[0004] Building upon this foundation, Transform Domain Communication Systems (TDCS) utilize spectrum sensing and spectrum decision-making techniques from cognitive radio to actively locate the frequency range of interfering signals, determine idle spectrum, and avoid interfered frequency bands by jointly designing signal waveforms at both the transmitting and receiving ends, demonstrating significant development potential. However, due to the flexible and variable signal waveforms and the need for frequent spectrum sensing, TDCS systems have lacked a corresponding multi-user networking protocol, which limits their application. Summary of the Invention
[0005] The embodiments of this application provide a TDMA-based TDCS anti-interference communication system and communication method to solve the technical problem that the TDCS system is limited in use in multi-user networks in the prior art.
[0006] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.
[0007] According to a first aspect of the embodiments of this application, a TDMA-based TDCS anti-interference communication system is provided, applied to network communication between a TDCS transmitter and receiver with spectrum sensing and spectrum decision capabilities, including:
[0008] It integrates the application layer, data link layer, physical layer, and perception and decision-making module;
[0009] The integrated application layer is connected to the data link layer, the data link layer is connected to the physical layer, and the perception and decision module is connected to the integrated application layer, the data link layer, and the physical layer respectively.
[0010] In the data transmission process, the integrated application layer packages message data into application layer frames and transmits them to the data link layer; the data link layer assembles the application layer frames into physical layer service data units and transmits them to the physical layer; the physical layer generates transmission signals from the physical layer service data units for transmission.
[0011] In the data receiving process, the physical layer is used to demodulate the received data to extract the physical layer service data unit and pass it to the data link layer; the data link layer is used to determine whether the receiving address of the received data is correct, and if correct, it is transmitted to the integrated application layer; the integrated application layer is used to verify whether the data is correct and store the correct data.
[0012] The perception and decision-making module is used to collect user communication information from the integrated application layer, the data link layer, and the physical layer during the data transmission and reception processes to make network behavior decisions, and to transmit decision parameters to the integrated application layer, the data link layer, and the physical layer.
[0013] In some embodiments of this application, based on the foregoing scheme, the communication system allocates time slots to users in the network via beacon frames.
[0014] In some embodiments of this application, based on the aforementioned scheme, the physical layer is configured with four modulation schemes: CCSK, BPSK, QPSK, and 16QAM.
[0015] In some embodiments of this application, based on the aforementioned scheme, the application layer frame includes a frame sequence number field, a frame ACK number field, an error control field, a data type field, and a data length field.
[0016] In some embodiments of this application, based on the foregoing scheme, the physical layer service data unit includes: a frame control field, a duration field, an address field, a frame sequence number field, a data field, and an error detection field.
[0017] In some embodiments of this application, based on the aforementioned scheme, the physical layer adds a preamble training sequence and header for synchronization before modulating the physical layer service data unit.
[0018] According to a second aspect of the embodiments of this application, a communication method based on the all-night system as described in the first aspect is provided, comprising:
[0019] During communication, the physical layer acquires spectrum sensing data and transmits it to the sensing decision module. The sensing decision module performs modulation control and channel control on the physical layer based on the spectrum sensing data.
[0020] During communication, the data link layer acquires the beacon reception status and transmits it to the perception and decision module. The perception and decision module then controls the beacon transmission of the data link layer based on the beacon reception status.
[0021] During the communication process, the integrated application layer acquires communication success rate data and transmits it to the perception and decision module. The perception and decision module controls the network to switch working channels based on the communication success rate data.
[0022] In some embodiments of this application, based on the foregoing scheme, the physical layer acquires spectrum sensing data and transmits it to the sensing decision module. The sensing decision module performs modulation control and channel control on the physical layer based on the spectrum sensing data, including:
[0023] The physical layer determines whether a primary user signal has been received based on prior information about the data. If a primary user signal is detected, the physical layer reports the primary user identifier to the perception and decision module, and the perception and decision module switches the channel.
[0024] If no primary user signal is detected, the power spectrum amplitude is used to determine whether there are other interference signals on the current working channel. If interference exists, the interference flag is reported to the perception and decision module, which then controls the physical layer to gradually reduce the modulation order. If no interference exists, the perception and decision module controls the physical layer to gradually increase the modulation order.
[0025] In some embodiments of this application, based on the foregoing scheme, the data link layer acquires beacon reception information and transmits it to the perception and decision module. The perception and decision module then performs beacon transmission control on the data link layer based on the beacon reception information, including:
[0026] If the data link layer does not receive a beacon frame within a set time, it reports a beacon loss flag to the perception and decision module.
[0027] After the perception and decision-making module detects the beacon loss flag, it controls the communication system to switch channels.
[0028] In some embodiments of this application, based on the foregoing scheme, the integrated application layer acquires communication success rate data and transmits it to the perception and decision module. The perception and decision module controls the network to switch working channels based on the communication success rate data, including:
[0029] The integrated application layer continuously calculates the signal reception success rate within a set time period based on the received confirmation number and error verification.
[0030] If the signal reception success rate is lower than the set threshold within the set time period, a low communication success rate flag will be reported to the perception and decision module.
[0031] After the perception and decision-making module detects a low communication success rate flag, it controls the network to switch working channels.
[0032] The technical solution of this application rationally designs a multi-user TDCS communication system based on TDMA according to the technical characteristics of the TDCS communication system, which makes up for the shortcomings of the TDCS system in that it cannot form a multi-user network for communication.
[0033] The technical solution of this application uses TDMA technology and beacon frames to complete the task of allocating time slots and switching channels for multiple users, thus maintaining the smooth operation of the network in the case of multi-user, multi-channel communication.
[0034] The technical solution of this application can make comprehensive decisions based on TDCS spectrum sensing results and current network operating parameters, and flexibly adjust the network operating status according to real-time communication conditions, thereby improving communication efficiency, reducing energy consumption and optimizing resource allocation, thus ensuring efficient and stable communication transmission, and significantly improving the adaptive capability of the communication system in the face of complex environments.
[0035] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description
[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:
[0037] Figure 1 A schematic diagram of the structure of a TDMA-based TDCS anti-jamming communication system according to an embodiment of this application is shown;
[0038] Figure 2 A schematic diagram of network time slot allocation according to an embodiment of this application is shown;
[0039] Figure 3 A schematic diagram of channel allocation according to an embodiment of this application is shown;
[0040] Figure 4 A schematic diagram of a Markov process for modulation mode switching according to an embodiment of this application is shown;
[0041] Figure 5A schematic diagram of a physical layer service data unit according to an embodiment of this application is shown;
[0042] Figure 6 A schematic diagram of the physical layer transmission frame structure according to an embodiment of this application is shown;
[0043] Figure 7 A schematic diagram of an application layer frame structure according to an embodiment of this application is shown;
[0044] Figure 8 A schematic flowchart of a communication method according to an embodiment of this application is shown. Detailed Implementation
[0045] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.
[0046] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.
[0047] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.
[0048] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.
[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0050] The following detailed description of some embodiments of this application will be provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0051] The TDCS cognitive communication system possesses spectrum sensing capabilities, enabling it to modify signal waveforms based on the current spectrum state and exhibiting strong anti-interference characteristics. However, it is incompatible with commonly used protocols such as CSMA and CA. This application combines TDMA time-division multiplexing technology with the TDCS system to propose a TDMA-based TDCS anti-interference communication system. By comprehensively designing the physical layer, data link layer, and application layer, and integrating a sensing and decision-making module, a multi-user cognitive network is built, maintaining a relatively stable multi-user communication state in complex communication environments.
[0052] The communication system described in this application is used for network communication between a TDCS transmitter and receiver with spectrum sensing and spectrum decision capabilities. This communication system requires that the users in the network be TDCS cognitive wireless communication devices with spectrum sensing capabilities. The transmitter includes a spectrum sensing module, a spectrum decision module, a communication parameter selection module, a convolutional coding module, an interleaving module, a CCSK modulator, and a PSK / QAM modulator. The receiver includes a channel synchronization module, a channel estimation module, a spectrum sensing module, a spectrum decision module, a decoder, a deinterleaving unit, a CCSK demodulator, and a PSK / QAM demodulator.
[0053] The TDCS cognitive wireless communication device can detect the current spectrum status and report the detection results to the network's perception decision module. Furthermore, the TDCS cognitive wireless device can change its current signal waveform and modulation mode according to the instructions of the perception decision module. It can send and receive signals with CCSK, BPSK, QPSK and 16QAM modulation modes. Thus, when the channel conditions are good, it can choose a signal waveform with a fast communication rate but poor anti-interference performance, and when the channel is interfered with, it can choose a signal waveform with good anti-interference performance but slower communication rate.
[0054] For details, see Figure 1 The diagram shows a schematic of the structure of a TDMA-based TDCS anti-interference communication system according to an embodiment of the present application.
[0055] like Figure 1As shown, this communication system specifically includes:
[0056] It integrates the application layer, data link layer, physical layer, and perception and decision-making module;
[0057] The integrated application layer is connected to the data link layer, the data link layer is connected to the physical layer, and the perception and decision module is connected to the integrated application layer, the data link layer, and the physical layer respectively.
[0058] In the data transmission process, the integrated application layer packages message data into application layer frames and transmits them to the data link layer; the data link layer assembles the application layer frames into physical layer service data units and transmits them to the physical layer; the physical layer generates transmission signals from the physical layer service data units for transmission.
[0059] In the data receiving process, the physical layer is used to demodulate the received data to extract the physical layer service data unit and pass it to the data link layer; the data link layer is used to determine whether the receiving address of the received data is correct, and if correct, it is transmitted to the integrated application layer; the integrated application layer is used to verify whether the data is correct and store the correct data.
[0060] The perception and decision-making module is used to collect user communication information from the integrated application layer, the data link layer, and the physical layer during the data transmission and reception processes to make network behavior decisions, and to transmit decision parameters to the integrated application layer, the data link layer, and the physical layer.
[0061] like Figure 1 As shown, the perception and decision module obtains spectrum sensing data from the physical layer and sends modulation control and channel control to the physical layer; the perception and decision module obtains beacon reception information from the data link layer and sends control to the downlink beacon; the perception and decision module also obtains communication success rate data from the integrated application layer and controls the channel based on the communication success rate data.
[0062] For example, the data transmission process of this communication system is as follows:
[0063] 1. The application layer packages the message data into application layer frames and passes them to the data link layer;
[0064] 2. The data link layer assembles application layer frames into physical layer service data units and transmits them to the physical layer;
[0065] 3. The physical layer assembles the PSDU into a physical layer transmission frame, and after encoding, interleaving and modulation, generates a transmission signal for transmission.
[0066] The data receiving process is as follows:
[0067] 1. After the physical layer detects the transmission frame through the synchronization symbol, it demodulates the PSDU based on the packet header information and passes it to the data link layer;
[0068] 2. The data link layer first determines whether the data receiving address is its own; if so, it passes the data to the integrated application layer; otherwise, it discards the data.
[0069] 3. After the application layer verifies that the data is correct based on the confirmation number and check digit, it receives the data and stores it locally.
[0070] The perception and decision-making module interacts with the integrated application layer, data link layer, and physical layer. It collects communication information from each layer of the network and transmits decision parameters to each layer.
[0071] In some feasible embodiments, based on the aforementioned scheme, the communication system allocates time slots to users in the network via beacon frames.
[0072] For example, the network time slot allocation diagram is shown in the figure. Figure 2 As shown.
[0073] There are n users in the network, numbered from 1 to n. Each user is allocated 25ms of transmission time, during which they can choose any transmission time. A 5ms user protection interval is reserved. After receiving the beacon frame, each user begins transmission after a delay of (n-1)*30ms according to their user number. A 10ms sensing time slot is reserved at the end of each transmission cycle. During this sensing time slot, there are no user signals, allowing all users to use it for electromagnetic spectrum sensing and to locate spectral holes for communication.
[0074] The channel allocation of this communication system is shown in the diagram. Figure 3 As shown, a total of 6 channels are divided from 552.5MHz to 642.5MHz, with center frequencies at 560MHz, 575MHz, 590MHz, 605MHz, 620MHz, and 635MHz respectively. Each channel has a bandwidth of 15MHz, of which 10MHz is occupied by the signal. The physical layer divides the 10MHz occupied bandwidth into a total of 64 subcarriers for loading OFDM symbols. An OFDM symbol contains 52 subcarriers, of which 48 are data subcarriers, and subcarriers -21, -7, 7, and 21 are pilot subcarriers loaded with pilot symbols for channel equalization. The center subcarrier 0 is not used.
[0075] In some feasible embodiments, based on the aforementioned scheme, the physical layer is configured with four modulation methods: CCSK, BPSK, QPSK, and 16QAM.
[0076] It should be noted that in this embodiment, the physical layer can perform four modulation schemes: CCSK, BPSK, QPSK, and 16QAM, and can switch the modulation scheme according to the instructions of the perception decision module. To achieve a certain degree of anti-interference function and avoid the easy acquisition of the switching strategy, a Markov process is used to model the switching strategy to realize the switching of communication parameters. In actual communication, the external electromagnetic environment is divided into two situations: with interference and without interference. Under interference, the modulation scheme is switched from a higher order to a lower order to reduce the bit error rate and improve anti-interference performance; under interference-free environment, the modulation scheme is switched from a lower order to a higher order to increase the communication rate. The Markov process for modulation scheme switching is illustrated in the diagram. Figure 4 As shown.
[0077] In some feasible embodiments, based on the aforementioned scheme, the physical layer adds a preamble training sequence and header for synchronization before modulating the physical layer service data unit.
[0078] For example, such as Figure 5 As shown, the preamble training sequence includes 10 short training symbols for automatic gain control, diversity selection, timing acquisition, and coarse frequency offset estimation, and 2 long training symbols for channel estimation and fine frequency offset estimation. The header (SIGNAL) field contains the following fields: data rate bit, reserved bit, packet length bit, and parity bit, which constitute a single OFDM symbol using BPSK modulation.
[0079] In some feasible embodiments, based on the aforementioned scheme, the physical layer service data unit includes: a frame control field, a duration field, an address field, a frame sequence number field, a data field, and an error detection field.
[0080] It should be noted that in this embodiment, the data link layer is responsible for controlling the data transmission of users in the network. The data link layer of user 1 in the network will periodically send beacon frames. All users, when not receiving a beacon frame, will store the frames sent by the application layer into a queue. After receiving a beacon frame, they will wait for their allocated time slot and then send the frames sequentially. After receiving the application layer frame, the data link layer assembles it into a physical layer service data unit. The structure of the physical layer service data unit is shown in the diagram. Figure 6 As shown. The Frame Control field indicates the type and function of the frame, the Duration field stores the duration of the frame, the three Address fields store the destination address, source address, and broadcast address of the frame, the Sequence Control field stores the frame sequence number, the Frame Body field stores the data sent from the application layer (maximum 1500 bytes), and finally, there is a 4-byte error detection field.
[0081] The structure of a beacon frame is the same as that of a regular data frame. The difference lies in the frame control field, which is used to distinguish beacon frames. In addition, the frame body stores an 8-byte timestamp for timed synchronization by various users.
[0082] In some feasible embodiments, based on the aforementioned scheme, the application layer frame includes a frame sequence number field, a frame ACK number field, an error control field, a data type field, and a data length field.
[0083] It should be noted that in this embodiment, the integrated application layer first determines whether the data needs to be sent in packets based on the size of the data selected by the user. If the data to be sent by the user exceeds the preset maximum frame length, it will be split into multiple data frames and sent sequentially.
[0084] The integrated application layer frame structure is shown in the diagram. Figure 7 As shown. The sequence number is used to uniquely identify the data packet in this connection. The acknowledgment number (ACK Num) is the expected sequence number of the next data packet from the communicating party, mainly used for checksum and error control. The data type (Data Type) is used to identify the type of the original data to which the data packet belongs. The data length (DataLength) is used to identify the length of the remaining data in the data packet after removing the header.
[0085] The receiving end checks the acknowledgment number in the data packet. If ACK = M, it indicates that it has correctly received all data packets up to sequence number M. Simultaneously, during transmission, it embeds the expected sequence number of the next frame into the frame body. If the receiving end detects a checksum error in the frame header, the frame is considered an erroneous frame and is discarded, triggering an error retransmission mechanism. When an error occurs, the receiving party immediately sends a retransmission request to the other party, which then retransmits the previous frame upon receiving the retransmission request.
[0086] During communication, data packets may be lost for various reasons. When neither party has received any data, both enter a state of waiting for the other to transmit, resulting in a deadlock. A timeout retransmission mechanism can break the deadlock. If the data packet sender does not receive a corresponding ACK within the timeout period, it will retransmit the previous data packet.
[0087] Based on the same inventive concept, this application also provides a communication method, which is implemented based on the communication system described in any of the above embodiments. Specifically, the method includes:
[0088] During communication, the physical layer acquires spectrum sensing data and transmits it to the sensing decision module. The sensing decision module performs modulation control and channel control on the physical layer based on the spectrum sensing data.
[0089] During communication, the data link layer acquires the beacon reception status and transmits it to the perception and decision module. The perception and decision module then controls the beacon transmission of the data link layer based on the beacon reception status.
[0090] During the communication process, the integrated application layer acquires communication success rate data and transmits it to the perception and decision module. The perception and decision module controls the network to switch working channels based on the communication success rate data.
[0091] In some feasible embodiments, based on the foregoing scheme, the physical layer acquires spectrum sensing data and transmits it to the sensing decision module. The sensing decision module performs modulation control and channel control on the physical layer based on the spectrum sensing data, including:
[0092] The physical layer determines whether a primary user signal has been received based on prior information about the data. If a primary user signal is detected, the physical layer reports the primary user identifier to the perception and decision module, and the perception and decision module switches the channel.
[0093] If no primary user signal is detected, the power spectrum amplitude is used to determine whether there are other interference signals on the current working channel. If interference exists, the interference flag is reported to the perception and decision module, which then controls the physical layer to gradually reduce the modulation order. If no interference exists, the perception and decision module controls the physical layer to gradually increase the modulation order.
[0094] In some feasible embodiments, based on the foregoing scheme, the data link layer acquires beacon reception information and transmits it to the perception and decision module. The perception and decision module then controls beacon transmission of the data link layer based on the beacon reception information, including:
[0095] If the data link layer does not receive a beacon frame within a set time, it reports a beacon loss flag to the perception and decision module.
[0096] After the perception and decision-making module detects the beacon loss flag, it controls the communication system to switch channels.
[0097] In some feasible embodiments, based on the aforementioned scheme, the integrated application layer acquires communication success rate data and transmits it to the perception and decision module. The perception and decision module controls the network to switch working channels based on the communication success rate data, including:
[0098] The integrated application layer continuously calculates the signal reception success rate within a set time period based on the received confirmation number and error verification.
[0099] If the signal reception success rate is lower than the set threshold within the set time period, a low communication success rate flag will be reported to the perception and decision module.
[0100] After the perception and decision-making module detects a low communication success rate flag, it controls the network to switch working channels.
[0101] For example, see Figure 8 This provides a specific example of a communication method.
[0102] 1. When the system starts up, the network operates on the preset modulation mode and channel, waiting for information to be reported by each layer module;
[0103] 2. The physical layer first determines whether the master user signal has been received based on prior information. Since the master user has the highest network privileges, if the master user signal is detected, the physical layer reports the master user identifier to the perception and decision module, notifies the network to immediately stop sending beacon frames, thereby cutting off communication, and restarts communication after switching channels to avoid the problem.
[0104] 3. When the physical layer does not detect the primary user signal, it will determine whether there are other interference signals on the current working channel based on the power spectrum amplitude. If interference exists, it will report the interference flag to the perception and decision module. The perception and decision module will control the physical layer to gradually reduce the modulation order until CCSK. If the perception and decision module does not detect the interference flag, it will gradually increase the modulation order until 16QAM.
[0105] 4. If the data link layer does not receive a beacon frame for a certain period of time, it will report a beacon loss flag to the perception and decision module, indicating that the network may no longer be working on the current channel or that there is too much interference on the current channel. After the perception and decision module detects the beacon loss flag, it will control the communication system to switch channels.
[0106] 5. The integrated application layer will continuously calculate the signal reception success rate over a certain period of time based on the received confirmation number and error check. If the communication success rate is lower than 30% within the time period, it will report the low communication success rate flag to the perception and decision module, indicating that the channel is not suitable for long-term communication. The perception and decision module will then control the network to switch the working channel.
[0107] Other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. It should be understood that this application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.
Claims
1. A TDMA-based TDCS anti-interference communication system, applied to network communication between a TDCS transmitter and receiver with spectrum sensing and spectrum decision capabilities, characterized in that, include: It integrates the application layer, data link layer, physical layer, and perception and decision-making module; The integrated application layer is connected to the data link layer, the data link layer is connected to the physical layer, and the perception and decision module is connected to the integrated application layer, the data link layer, and the physical layer respectively. In the data transmission process, the integrated application layer packages message data into application layer frames and transmits them to the data link layer; the data link layer assembles the application layer frames into physical layer service data units and transmits them to the physical layer; the physical layer generates transmission signals from the physical layer service data units for transmission. In the data receiving process, the physical layer is used to demodulate the received data to extract the physical layer service data unit and pass it to the data link layer; the data link layer is used to determine whether the receiving address of the received data is correct, and if correct, it is transmitted to the integrated application layer; the integrated application layer is used to verify whether the data is correct and store the correct data. The perception and decision-making module is used to collect user communication information from the integrated application layer, the data link layer, and the physical layer during the data transmission and data reception processes to make network behavior decisions, and to transmit decision parameters to the integrated application layer, the data link layer, and the physical layer. Specifically, the perception and decision module obtains spectrum sensing data from the physical layer and sends modulation control and channel control to the physical layer; the perception and decision module obtains beacon reception status from the data link layer and sends beacon transmission control to the data link layer; the perception and decision module obtains communication success rate data from the integrated application layer and controls the channel based on the communication success rate data.
2. The communication system according to claim 1, characterized in that, The communication system allocates time slots to users in the network through beacon frames.
3. The communication system according to claim 1, characterized in that, The physical layer is configured with four modulation schemes: CCSK, BPSK, QPSK, and 16QAM.
4. The communication system according to claim 1, characterized in that, The application layer frame includes a frame sequence number field, a frame ACK number field, an error control field, a data type field, and a data length field.
5. The communication system according to claim 1, characterized in that, The physical layer service data unit includes: a frame control field, a duration field, an address field, a frame sequence number field, a data field, and an error detection field.
6. The communication system according to claim 1, characterized in that, Before modulating the physical layer service data unit, the physical layer adds a preamble training sequence and header for synchronization.
7. A communication method based on the communication system as described in any one of claims 1-6, characterized in that, include: During communication, the physical layer acquires spectrum sensing data and transmits it to the sensing decision module. The sensing decision module performs modulation control and channel control on the physical layer based on the spectrum sensing data. During communication, the data link layer acquires the beacon reception status and transmits it to the perception and decision module. The perception and decision module then controls the beacon transmission of the data link layer based on the beacon reception status. During the communication process, the integrated application layer acquires communication success rate data and transmits it to the perception and decision module. The perception and decision module controls the network to switch working channels based on the communication success rate data.
8. The method according to claim 7, characterized in that, The physical layer acquires spectrum sensing data and transmits it to the sensing decision module. The sensing decision module performs modulation control and channel control on the physical layer based on the spectrum sensing data, including: The physical layer determines whether a primary user signal has been received based on prior information about the data. If a primary user signal is detected, the physical layer reports the primary user identifier to the perception and decision module, and the perception and decision module switches the channel. If no primary user signal is detected, the power spectrum amplitude is used to determine whether there are other interference signals on the current working channel. If interference exists, the interference flag is reported to the perception and decision module, which then controls the physical layer to gradually reduce the modulation order. If no interference exists, the perception and decision module controls the physical layer to gradually increase the modulation order.
9. The method according to claim 7, characterized in that, The data link layer acquires beacon reception information and transmits it to the perception and decision module. Based on the beacon reception information, the perception and decision module controls beacon transmission at the data link layer, including: If the data link layer does not receive a beacon frame within a set time, it reports a beacon loss flag to the perception and decision module. After the perception and decision-making module detects the beacon loss flag, it controls the communication system to switch channels.
10. The method according to claim 7, characterized in that, The integrated application layer acquires communication success rate data and transmits it to the perception and decision module. The perception and decision module controls the network to switch operating channels based on the communication success rate data, including: The integrated application layer continuously calculates the signal reception success rate within a set time period based on the received confirmation number and error verification. If the signal reception success rate is lower than the set threshold within the set time period, a low communication success rate flag will be reported to the perception and decision module. After the perception and decision-making module detects a low communication success rate flag, it controls the network to switch working channels.