Signal processing method for cross-medium communication
By processing the signal at the transmitting end and demodulating it at the receiving end, the problem of reduced signal-to-noise ratio in communication between air and water is solved, achieving efficient and reliable cross-medium communication.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 崂山国家实验室
- Filing Date
- 2023-11-09
- Publication Date
- 2026-07-10
AI Technical Summary
In cross-medium communication between air and water, reduced energy of the communication wave and external interference lead to a decrease in the signal-to-noise ratio and reduced communication efficiency.
By employing steps such as m-sequence scrambling, channel coding, LFM modulation, and synchronization information addition at the transmitting end, and synchronization detection, LFM demodulation, channel decoding, and m-sequence descrambling at the receiving end, the reliability and anti-interference capability of the signal are improved.
It improves the communication efficiency and signal quality of cross-media communication, and enhances the reliability and security of communication.
Smart Images
Figure CN117650869B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of cross-medium communication technology, and particularly relates to a signal processing method for cross-medium communication. Background Technology
[0002] Research on communication technologies between air and water is of great scientific and strategic significance, including downlink communication from air to water and uplink communication from water to air. Among these, cross-medium communication between water and air is an important means for underwater information to access commercial networks on land and in the air, and has significant application value in the fields of marine exploration and marine communication.
[0003] When communication waves are used for cross-medium communication, the waveform energy at the physical layer is reduced, resulting in a decrease in the signal-to-noise ratio during the receiving process. Furthermore, the receiving process is susceptible to external interference, generating interference waves unrelated to communication. Moreover, the amplitude of the interference waves is often greater than the intensity of the communication waves, which can easily overwhelm the communication waves, leading to a decrease in communication efficiency.
[0004] Therefore, how to provide a signal processing method with high communication efficiency for cross-media communication is a technical problem that urgently needs to be solved. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention provides a signal processing method for cross-medium communication. By modulating the information to be transmitted at the transmitting end and demodulating the signal at the receiving end, the reliability and anti-interference capability of the signal are improved, thereby increasing the communication efficiency of cross-medium communication.
[0006] This invention provides a signal processing method for cross-medium communication, including a transmitter modulating information to be transmitted to obtain a transmitted signal; the modulation includes the following steps: the transmitter performs m-sequence scrambling and channel coding on the information to be transmitted to obtain information to be modulated; the information to be modulated is subjected to LFM modulation to obtain modulated information, wherein the modulation order of LFM modulation is N; synchronization information is added to the modulated information to obtain a transmitted signal.
[0007] This technical solution can improve signal reliability and anti-interference ability, and improve the communication efficiency of cross-media communication.
[0008] In some embodiments, during the modulation step, before the information to be transmitted is scrambled with an m-sequence, the transmitting end performs bit-based processing on the information to be transmitted to obtain the bit-based information to be transmitted. This technical solution reduces signal distortion and noise by converting the information to be transmitted into a binary bit stream, thereby improving signal reliability.
[0009] In some embodiments, during the modulation step, before LFM modulation of the information to be modulated, the transmitting end groups the information to be modulated according to a set modulation order; the grouped information to be modulated is then LFM modulated according to the group number. This technical solution can realize frequency division multiplexing of LFM signals, improving the spectral utilization and data transmission rate of the signal.
[0010] In some embodiments, during the modulation step, the optimal fractional order of the base signal in the modulated information is calculated, and the optimal order is obtained based on the maximum value of the fractional-order transformation.
[0011] In some embodiments, the signal processing method for cross-medium communication further includes a step of demodulating the received signal at the receiving end to recover the information to be transmitted. Demodulation includes the following steps: the receiving end performs synchronization detection on the received signal and extracts the information to be demodulated; LFM demodulation is performed on the information to be demodulated to obtain a demodulation result, wherein the modulation order of the demodulation is N; channel decoding and m-sequence descrambling are performed on the demodulation result sequentially to obtain the recovered information to be transmitted. This technical solution can correct errors and decrypt the demodulation result according to the encoding and scrambling method of the transmitting end, thereby improving the security and quality of cross-medium communication.
[0012] In some embodiments, during the demodulation step, before synchronization detection of the received signal, the receiving end performs a first filtering process on the received signal to filter out interference signals; after synchronization detection of the received signal, the information to be demodulated is grouped, and the grouped information to be demodulated is sequentially subjected to a first transformation process, a second filtering process, and a second transformation process to enhance the signal strength of the information to be demodulated. This technical solution can improve signal quality and demodulation capability.
[0013] In some embodiments, the first filtering process includes: the receiver performing bandpass filtering on the received signal to filter out low-frequency interference signals. This technical solution can filter out low-frequency interference signals such as water surface fluctuations, while retaining the effective frequency range of the received signal, thereby reducing noise levels and improving the signal-to-noise ratio.
[0014] In some embodiments, the first transformation process includes: copying the grouped demodulated information into N channels and performing the optimal order fractional Fourier transform on the N channels.
[0015] In some embodiments, the second filtering process includes: calculating an upper and lower limit for filtering based on the transmission frequency of the transmitter and the sampling frequency of the receiver; and applying the calculated upper and lower limits to the N channels of demodulated information after the first transformation. This technical solution removes unwanted frequency components and retains useful frequency components through the second filtering process, thereby enhancing the signal strength and quality.
[0016] In some embodiments, the second transformation process includes performing an optimal-order fractional Fourier inverse transform on the N channels of demodulated information after the second filtering process.
[0017] Based on the above scheme, the signal processing method for cross-medium communication in this embodiment of the invention improves the reliability and anti-interference capability of the signal and increases the communication efficiency of cross-medium communication by processing and modulating the information to be transmitted at the transmitting end; improves the security and quality of cross-medium communication by correcting and decrypting the received signal at the receiving end; and achieves efficient and high-quality cross-medium communication through the cooperation of the transmitting end and the receiving end.
[0018] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description
[0019] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:
[0020] Figure 1 This is a flowchart of how the transmitting end modulates the information to be transmitted to obtain the transmitted signal;
[0021] Figure 2 A flowchart illustrating how the receiving end demodulates the received signal to obtain the recovered information to be transmitted;
[0022] Figure 3 This is a block diagram of an acoustic transducer.
[0023] Figure 4 Block diagram of the laser detector
[0024] Figure 5 This is a schematic diagram illustrating the principle of scrambling the m-sequence in Example 1;
[0025] Figure 6 The waveform diagram of the acoustic signal in Example 1 is shown below;
[0026] Figure 7 This is a waveform diagram of the received signal in Example 1;
[0027] Figure 8 This is a waveform diagram of the information to be transmitted recovered in Example 1.
[0028] In the picture:
[0029] 1. Acoustic transducer; 2. Laser detector;
[0030] 101. Scrambling module; 102. Encoding module; 103. LFM modulation module; 104. First synchronization module; 105. Bit conversion module; 106. Grouping module; 107. Calculation module; 108. Analog-to-digital conversion module;
[0031] 201. Synchronization detection module; 202. LFM demodulation module; 203. Decoding module; 204. Descrambling module; 205. Filtering module; 206. Transformation module; 207. Synchronization processing module. Detailed Implementation
[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0033] In the description of this invention, it should be understood that the terms "center", "lateral", "longitudinal", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0034] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.
[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0036] The terms “system,” “unit,” and “module” used in this article are methods for distinguishing different components, elements, parts, sections, or assemblies at different levels. These terms may be replaced by other expressions that achieve the same purpose.
[0037] like Figures 1-2As shown, in one embodiment of the signal processing method for cross-medium communication of the present invention, the signal processing method for cross-medium communication includes a transmitting end modulating information to be transmitted to obtain a transmitted signal; the modulation includes the following steps: the transmitting end performs m-sequence scrambling and channel coding on the information to be transmitted to obtain information to be modulated; the information to be modulated is subjected to LFM modulation to obtain modulated information, wherein the modulation order of LFM modulation is N; synchronization information is added to the modulated information to obtain a transmitted signal.
[0038] In the above illustrative embodiments, the signal processing method for cross-medium communication effectively resists noise and multipath interference by using m-sequence scrambling and channel coding, improving signal correlation and error correction capabilities, thereby enhancing the reliability and anti-interference capability of cross-medium communication. By using LFM modulation with an N-order modulation scheme, N-ary data transmission is achieved, increasing the data transmission rate. By adding synchronization information to the modulated information, time and frequency synchronization in cross-medium communication is achieved, improving the synchronization performance of cross-medium communication. Simultaneously, the LFM-modulated information has good distance resolution, which is beneficial for achieving precise positioning in cross-medium communication. In summary, the signal processing method for cross-medium communication provided in this embodiment can improve signal reliability and anti-interference capability, and increase the communication efficiency of cross-medium communication.
[0039] In some embodiments, such as Figure 1 As shown, in the modulation step, before the information to be transmitted is scrambled with an m-sequence, the transmitting end performs bit-based processing on the information to be transmitted to obtain the bit-based information to be transmitted. By converting the information to be transmitted into a binary bit stream, the influence of signal distortion and noise is reduced, and the reliability of the signal is improved.
[0040] Furthermore, such as Figure 1 As shown, in the modulation step, before the information to be modulated is subjected to LFM modulation, the transmitting end groups the information to be modulated into groups according to the set modulation order; the grouped information to be modulated is then subjected to LFM modulation according to the group number. It should be noted that each group corresponds to a different frequency change rate of the LFM signal, i.e., the slope, which enables frequency division multiplexing of the LFM signal, improving the spectral efficiency and data transmission rate of the signal.
[0041] It should also be noted that in some embodiments, LFM modulation is performed according to the group number, which can make the LFM signal of each group have different phases, thereby realizing phase encoding of the LFM signal and improving the synchronization performance and positioning accuracy of the signal.
[0042] In some embodiments, such as Figure 1As shown, in the modulation step, the optimal fractional order is calculated for the base signal in the modulated information, and the optimal order is obtained based on the maximum value of the fractional transform. It should be noted that the transmitting end stores the optimal order after obtaining it. It can be understood that the base signal refers to the LFM signal modulated by the base signal, and the fractional transform is a generalized Fourier transform that can achieve adaptive modulation and enhancement of the signal. By calculating the optimal fractional order for the base signal in the modulated information, the optimal order can be obtained based on the maximum value of the fractional transform, making the angle at which the base signal is most concentrated in the time-frequency plane, thereby improving the resolution and detection performance of the modulated information and achieving optimal focusing of the modulated information.
[0043] It should be noted that the signal obtained after the information to be transmitted is bit-divided is a digital signal, and the signal obtained after adding synchronization information is also a digital signal, such as... Figure 1 As shown, after adding synchronization information to the modulated information, the process also includes an analog-to-digital conversion of the digital signal to obtain the transmitted signal.
[0044] In some embodiments, such as Figure 2 As shown, the signal processing method for cross-medium communication further includes a step of demodulating the received signal at the receiving end to recover the information to be transmitted; the demodulation includes the following steps: the receiving end performs synchronization detection on the received signal and extracts the information to be demodulated; the information to be demodulated is LFM demodulated to obtain the demodulation result, wherein the modulation order of the demodulation is N; the demodulation result is sequentially subjected to channel decoding and m-sequence descrambling to obtain the recovered information to be transmitted.
[0045] In the above illustrative embodiments, the receiving end performs synchronization detection on the received signal, and can achieve time and frequency synchronization for cross-medium communication based on the synchronization information added by the transmitting end. Through LFM demodulation, the received signal can be processed in reverse according to the modulation method of the transmitting end, thereby recovering the transmitted information and achieving information recovery in cross-medium communication, improving the reliability and accuracy of cross-medium communication. By sequentially performing channel decoding and m-sequence descrambling on the demodulation result, error correction and decryption can be performed on the demodulation result according to the encoding and scrambling method of the transmitting end, thereby improving the security and quality of cross-medium communication. Through the cooperation of the transmitting and receiving ends, efficient and high-quality cross-medium communication is achieved.
[0046] In some embodiments, such as Figure 2 As shown, in the demodulation step, before the received signal undergoes synchronization detection, the receiving end performs a first filtering process on the received signal to remove interference signals. After the received signal undergoes synchronization detection, the information to be demodulated is grouped, and the grouped information to be demodulated undergoes a first transformation process, a second filtering process, and a second transformation process in sequence to enhance the signal strength of the information to be demodulated. Through the above filtering and transformation processes, the signal quality and demodulation capability are improved.
[0047] In some embodiments, such as Figure 2 As shown, the first filtering process includes: the receiving end performs bandpass filtering on the received signal to filter out low-frequency interference signals. It should be noted that in water-to-air cross-medium communication, water surface fluctuations can interfere with the acoustic signal. By performing bandpass filtering on the received signal to filter out low-frequency interference signals such as water surface fluctuations, the effective frequency range of the received signal is preserved, thereby reducing noise levels, improving the signal-to-noise ratio, and enhancing the reliability and stability of the received signal.
[0048] In some embodiments, such as Figure 2 As shown, the first transformation process includes: copying the grouped demodulated information into N channels and performing the optimal order fractional Fourier transform on the N channels.
[0049] In some embodiments, such as Figure 2 As shown, the second filtering process includes: calculating the upper and lower limits of the filtering based on the transmission frequency of the transmitter and the sampling frequency of the receiver; and applying the calculated upper and lower limits to the N channels of information to be demodulated after the first transformation. It should be noted that when the transmission frequency range of the transmitter is [F1, F2] and the sampling frequency of the receiver is F... s When, the upper limit of the filter F high It is obtained by calculation using equation (1), and the expression of equation (1) is:
[0050]
[0051] Filter lower limit F low The result is obtained by calculation using equation (2), and the expression for equation (2) is:
[0052]
[0053] In the above embodiments, by calculating the upper and lower limits of the second filtering process, the effective frequency range of the information to be demodulated can be determined, thereby selecting appropriate filter parameters to achieve optimal processing of the information to be demodulated, improving signal transmission efficiency and processing speed; through the second filtering process, unwanted frequency components are removed, useful frequency components are retained, and the signal strength and quality are enhanced, thereby improving signal resolution and detection performance.
[0054] In some embodiments, such as Figure 2 As shown, the second transformation process includes performing N-channel optimal-order fractional Fourier inverse transforms on the N channels of demodulated information after the second filtering process. It should be noted that by using N-channel optimal-order fractional Fourier transforms, the trade-off between the time and frequency domains of the signal is altered, making signal processing more flexible to adapt to different application requirements.
[0055] In some embodiments, such as Figure 2 As shown, in the LFM demodulation step, the N signals are synchronized with their corresponding base signals, and the maximum value of the N signal outputs is taken as the demodulation result. Synchronization processing refers to the process of processing synchronization information using a matched filter, specifically including the following steps: the receiver convolves the time-domain information of the received signal with the synchronization information of the transmitted signal; according to the principle of the matched filter, the synchronization information of the transmitted signal has a maximum value at the corresponding position of the received signal, and the position where the matched filter result is maximum is the start position of the signal; based on the user-defined signal synchronization and signal interval parameters, the signal to be modulated is extracted.
[0056] like Figure 3 As shown, this embodiment also provides a cross-medium communication device. This device employs the signal processing method for cross-medium communication described in the above embodiments, and includes a transmitting end and a receiving end. The transmitting end includes an acoustic transducer 1, which comprises:
[0057] Scrambling module 101 is used to scramble the information to be transmitted using an m-sequence.
[0058] The encoding module 102 is communicatively connected to the scrambling module 101 and is used to perform channel coding on the information to be transmitted to obtain the information to be modulated.
[0059] LFM modulation module 103 is communicatively connected to encoding module 102 and is used to perform LFM modulation on the information to be modulated to obtain modulated information, where N is the modulation order;
[0060] The first synchronization module 104 is communicatively connected to the LFM modulation module 103 and is used to add synchronization information to the modulated information to obtain the transmission signal.
[0061] In the above illustrative embodiment, convolutional coding is used for channel coding. The acoustic transducer 1 in this embodiment processes the information to be transmitted to obtain the transmitted signal. The beneficial effects of the transmitting end's processing of the information to be transmitted in the aforementioned signal processing method for cross-medium communication also apply to this embodiment, and will not be repeated here.
[0062] In some embodiments, such as Figure 3 As shown, the acoustic transducer 1 also includes a bitening module 105, which is communicatively connected to the scrambling module 101 and is used to perform bitening processing on the information to be transmitted.
[0063] In some embodiments, such as Figure 3As shown, the acoustic transducer 1 also includes a grouping module 106, which is communicatively connected to the encoding module 102 and the LFM modulation module 103, and is used to group the information to be modulated according to the set modulation order.
[0064] In some embodiments, such as Figure 3 As shown, the acoustic transducer 1 also includes a calculation module 107, which is communicatively connected to the LFM modulation module 103 and the first synchronization module 104, respectively. The calculation module 107 is used to perform fractional-order optimal order calculation on the base signal in the modulated information and obtain the optimal order based on the maximum value of the fractional-order transformation.
[0065] In some embodiments, such as Figure 3 As shown, the acoustic transducer 1 also includes an analog-to-digital converter module 108, which is communicatively connected to the first synchronization module 104 and is used to perform analog-to-digital conversion on the modulated information after adding synchronization information to obtain the transmitted signal.
[0066] In some embodiments, such as Figure 4 As shown, the receiving end includes a laser detector 2, which includes:
[0067] The synchronization detection module 201 is used to perform synchronization detection on the received signal and extract the information to be demodulated.
[0068] LFM demodulation module 202 is communicatively connected to synchronization detection module 201 and is used to perform LFM demodulation on the information to be demodulated to obtain the demodulation result;
[0069] Decoding module 203 is communicatively connected to LFM demodulation module 202 and is used to decode the demodulation result channel.
[0070] The descrambling module 204, which is communicatively connected to the decoding module 203, is used to descramble the demodulation result using an m-sequence to obtain the recovered information to be transmitted.
[0071] In the above illustrative embodiment, convolutional code decoding is used for channel decoding. The laser detector 2 in this embodiment processes the received signal to recover the information to be transmitted. The beneficial effects of the receiving end's processing of the received signal in the aforementioned signal processing method for cross-medium communication also apply to this embodiment, and will not be repeated here.
[0072] In some embodiments, such as Figure 4As shown, the laser detector 2 also includes a filtering module 205 and a conversion module 206. The filtering module 205 is communicatively connected to the conversion module 206. The filtering module 205 is also communicatively connected to the synchronous detection module 201 and the LFM demodulation module 202, respectively, for performing first filtering and second filtering. The conversion module 206 is also communicatively connected to the LFM demodulation module 202, and the conversion module 206 is used for performing first conversion and second conversion.
[0073] In some embodiments, such as Figure 4 As shown, the laser detector 2 also includes a synchronization processing module 207, which is communicatively connected to the conversion module 206 and is used to process the synchronization information through a matched filter.
[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0075] To facilitate understanding of the signal processing method for cross-medium communication proposed in this invention, a detailed description is provided through Example 1.
[0076] Example 1
[0077] Example 1 uses an acoustic transducer 1 as the transmitter and a laser detector 2 as the receiver. The acoustic transducer 1 is located underwater and the laser detector 2 is located above the water to perform cross-medium communication from water to air.
[0078] After the acoustic transducer 1 digitizes the information to be transmitted, it performs m-sequence scrambling on the digitized information. The schematic diagram of m-sequence scrambling is shown below. Figure 5 As shown, C0-C n Indicates a connecting line, C n =1 indicates a connection, C n =0 indicates disconnection. In this scheme, an m-sequence of length 31 is selected, and the binary values of octal 45 and decimal 37 are chosen as the feedback coefficient connection state. After binary conversion of 37, it becomes 100101. Since C0, C n Since a connection is necessary, 00101 is input into the m-sequence scrambling module 101 to generate the final scrambling sequence. The input bit information and the scrambling sequence are subjected to modulo-2 operation to generate the scrambled signal. The operation rule is shown in equation (3).
[0079] Output information = mod(input information + m sequence, 2) (3);
[0080] After scrambling, bit information with the same distribution as the noise is obtained. The scrambled information is then encoded using convolutional coding, with a (2,1,3) convolutional code chosen. The code rate is 1 / 2, and the state word uses g1=111, g2=101. The encoded state transition and output state transition tables are shown in Table 1.
[0081] Table 1(2,1,3) Convolutional Code State Transition and Output State Transition Table
[0082]
[0083]
[0084] After the convolutional code encoding is completed, the output encoded data enters the modulation unit. The modulation unit uses the LFM signal as the base modulation frequency waveform. Based on the modulation order and transducer transmission parameters selected by the user, the slope of the LFM signal is set. In this embodiment, the transmission frequency range of the transmitting transducer is 10-13kHz, and a 4-LFM modulation depth is selected, i.e., the modulation order is 4. The final 4-LFM transmission signal parameters are shown in Table 2.
[0085]
[0086]
[0087] In this embodiment, the optimal order calculation range is selected as -2 to 2, with a resolution of 0.1. After the optimal order calculation is completed, the optimal order is stored, and the input information to be modulated is grouped according to modulation order 4, with each group consisting of two bits. Based on the group calculation number, the transmit waveform is selected, the information modulation is completed, and synchronization information is added. Subsequently, analog-to-digital conversion is performed, and finally, the acoustic signal is output through acoustic transducer 1. The waveform of the acoustic signal is shown in the figure. Figure 6 As shown, Figure 6 The horizontal axis represents time, and the vertical axis represents frequency.
[0088] Laser detector 2 detected the received signal, and the waveform of the received signal is shown below. Figure 7 As shown, Figure 7The horizontal axis represents time, and the vertical axis represents frequency. The received signal undergoes a first filtering process to remove low-frequency interference. Synchronization detection is then performed to extract the information to be demodulated. This information is grouped, and the grouped information is then subjected to a first transformation, a second filtering process, and a second transformation. In the first transformation, the information to be demodulated is divided into four paths. Each of the four received signals undergoes an optimal-order fractional Fourier transform and a second filtering process in the 10-13kHz transmission band. Then, based on the stored optimal order, an optimal-order inverse fractional Fourier transform (the second transformation) is performed. This second transformation converts the information to be demodulated into a time-domain signal. The time-domain signal is synchronized with the corresponding base LFM signal, and the maximum synchronization value is output. The four demodulation results are compared, and the maximum value is selected as the demodulation result. The demodulation result is then subjected to channel decoding and m-sequence descrambling to obtain the recovered transmit information, completing cross-medium communication. The waveform of the recovered transmit information is shown in the figure below. Figure 8 As shown, Figure 8 The horizontal axis represents time, and the vertical axis represents frequency.
[0089] By comparing the waveform diagrams of the acoustic signal, the received signal, and the recovered information to be transmitted in Example 1, it can be seen that the recovered information to be transmitted can be well restored to the acoustic signal. This example can improve the signal-to-noise ratio of cross-medium communication and improve communication quality and efficiency.
[0090] Through the description of several embodiments of the signal processing method for cross-medium communication of the present invention, it can be seen that the embodiments of the signal processing method for cross-medium communication of the present invention have at least one or more of the following advantages:
[0091] 1. The signal processing method for cross-medium communication provided by the present invention improves the reliability and anti-interference capability of the signal and improves the communication efficiency of cross-medium communication by processing and modulating the information to be transmitted at the transmitting end.
[0092] 2. The signal processing method for cross-medium communication provided by the present invention improves the security and quality of cross-medium communication by correcting and decrypting the received signal at the receiving end;
[0093] 3. The signal processing method for cross-medium communication provided by the present invention achieves efficient and high-quality cross-medium communication through the cooperation of the transmitting end and the receiving end.
[0094] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0095] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.
Claims
1. A signal processing method for cross-medium communication, characterized in that, This includes the transmitting end modulating the information to be transmitted to obtain the transmission signal; The modulation includes the following steps: The transmitting end performs m-sequence scrambling and channel coding on the information to be transmitted to obtain the information to be modulated; The transmitting end groups the information to be modulated according to a set modulation order; the grouped information to be modulated is then LFM modulated according to the group number to obtain modulated information, wherein the modulation order of LFM modulation is N; The optimal fractional order is calculated for the base signal in the modulated information, and the optimal order is obtained based on the maximum value of the fractional transform. Synchronization information is added to the modulated information to obtain the transmitted signal.
2. The signal processing method for cross-medium communication according to claim 1, characterized in that, In the modulation step, before the information to be transmitted is scrambled with an m-sequence, the transmitting end performs bit-firing processing on the information to be transmitted to obtain bit-firing information to be transmitted.
3. The signal processing method for cross-medium communication according to any one of claims 1-2, characterized in that, It also includes a step of demodulating the received signal at the receiving end to recover the information to be transmitted; The demodulation includes the following steps: the receiving end performs synchronization detection on the received signal and extracts the information to be demodulated; the information to be demodulated is subjected to LFM demodulation to obtain a demodulation result, wherein the modulation order of the demodulation is N; the demodulation result is subjected to channel decoding and m-sequence descrambling in sequence to obtain the recovered information to be transmitted.
4. The signal processing method for cross-medium communication according to claim 3, characterized in that, In the demodulation step, before the received signal is synchronized, the receiving end performs a first filtering process on the received signal to filter out interference signals; after the received signal is synchronized, the information to be demodulated is grouped, and the grouped information to be demodulated is sequentially subjected to a first transformation process, a second filtering process, and a second transformation process to enhance the signal strength of the information to be demodulated.
5. The signal processing method for cross-medium communication according to claim 4, characterized in that, The first filtering process includes: the receiving end performs bandpass filtering on the received signal to filter out low-frequency interference signals.
6. The signal processing method for cross-medium communication according to claim 4, characterized in that, The first transformation process includes: copying the grouped demodulated information into N channels and performing the optimal order fractional Fourier transform on the N channels.
7. The signal processing method for cross-medium communication according to claim 6, characterized in that, The second filtering process includes: calculating the upper and lower limits of the filtering process based on the transmission frequency of the transmitter and the sampling frequency of the receiver; and performing the second filtering process on the N channels of demodulated information after the first transformation based on the calculated upper and lower limits of the filtering process.
8. The signal processing method for cross-medium communication according to claim 7, characterized in that, The second transformation process includes performing an optimal-order fractional Fourier inverse transform on the N channels of demodulated information after the second filtering process.