Underwater communication method, electronic device, and storage medium

Abstract

The application provides an underwater communication method, an electronic device and a storage medium, and relates to the technical field of underwater communication. The signals of multiple frequency points in the synchronization area in the data frame are configured in a time domain in a set order or simultaneously. When the data frame is applied to underwater communication, the synchronization area carrying the synchronization signal is set, a linear frequency modulation signal is not required as the synchronization signal, the calculation amount is reduced, the combination of the signals of different frequency points in the synchronization area and the time sequence are set, and the anti-interference capability can be greatly improved. Therefore, the underwater communication signal has high anti-interference capability and small calculation amount, and the underwater communication reliability is further improved.

Description

Technical Field

[0001] This application relates to the field of underwater communication technology, and in particular to an underwater communication method, electronic device and storage medium. Background Technology

[0002] Currently, in underwater communication and positioning, sound waves are typically used for long-distance data transmission because they are unaffected by the conductivity and color of water. However, the widely used underwater communication and positioning sonar is limited by environmental changes when transmitting signals. For example, when applied in environments such as swimming pools and shallow seas, multipath reflections and strong noise signals can lead to unsatisfactory communication and positioning results and high packet loss rates.

[0003] The existing frame synchronization methods used in underwater communication typically use a single-frequency signal as a preamble and a linear frequency modulated (LFM) signal as a synchronization code. However, the single-frequency signal has poor resistance to co-channel interference, and the LFM signal requires a large amount of computation during processing at the receiving end, resulting in high cost and poor anti-interference capability. Summary of the Invention

[0004] In view of this, embodiments of this application provide an underwater communication method, electronic device, and storage medium to solve the problems of poor signal anti-interference capability and large computational load in existing underwater communication methods.

[0005] To address the above problems, this application provides the following technical solutions:

[0006] A first aspect of this application discloses a data frame for underwater communication, the data frame comprising at least:

[0007] A synchronization zone for carrying synchronization signals, the synchronization zone is located at the beginning of the data frame, the synchronization zone includes signals at N frequency points, the signals at the N frequency points appear in a set order or simultaneously in the time domain; the value of N is greater than or equal to 2;

[0008] The data area used to carry valid data.

[0009] Preferably, the frequency points used by the synchronization zone are a set or subset of the frequency points used by other zones in the data frame besides the synchronization zone.

[0010] Preferably, among the N frequency points, the time interval between the first occurrence of two adjacent frequency points in the time domain is greater than or equal to 1ms.

[0011] Preferably, the data frame further includes: a symbol reference area disposed before or after the data area;

[0012] The reference signal carried by each symbol in the symbol reference area is used to set the judgment conditions or preprocessing methods corresponding to different modulation modes for the valid data in the data area.

[0013] The reference signal in the symbol reference area corresponds to the valid data in the data area. The correspondence means that for each symbol, frequency point, or equivalent signal of the valid data in the data area, a corresponding reference signal appears at least once in the symbol reference area.

[0014] Preferably, the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area are set based on preset conditions;

[0015] The preset condition is that the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area are fixed.

[0016] or,

[0017] The preset condition is that when one or more symbols in the region before the symbol reference area remain unchanged, the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area remain unchanged.

[0018] or,

[0019] The preset condition is that the order and time interval of the occurrence of each symbol, frequency point or equivalent signal in the symbol reference area change with the changes of one or more symbols in the area preceding the symbol reference area.

[0020] Preferably, the time interval between each symbol, frequency point, or equivalent signal in the symbol reference area is the same as the time interval between each symbol, frequency point, or equivalent signal in the data area.

[0021] Alternatively, under the same frame type, the minimum time interval of each symbol, frequency point, or equivalent signal in the symbol reference area is not less than the time interval of the symbols in the data area at the lowest communication rate.

[0022] Alternatively, under the same frame type, the communication rate of each symbol in the symbol reference area is not higher than the minimum communication rate used by the data area.

[0023] Preferably, the data frame further includes:

[0024] This is used to set the communication rate of different regions within the same data frame, so that the communication rates of different regions are all the same or partially the same; wherein, the communication rate includes the transmission rate of symbols or the time interval between symbols.

[0025] Preferably, the communication rate indicated by at least one earlier symbol in the rate zone is used to determine the transmission rate of at least one later symbol in the rate zone or the time interval between symbols.

[0026] A second aspect of this application discloses an underwater communication method applied at a transmitting end, the method comprising:

[0027] Based on the parameter information of the data frame to be transmitted at the sending end, each region in the data frame as disclosed in the first aspect of the embodiments of this application is configured, wherein the signals of N frequency points in the synchronization region of the data frame are configured to appear in a set order or simultaneously in the time domain, and the value of N is greater than or equal to 2.

[0028] The data frame is transmitted so that the receiving end can determine whether the frame is synchronized based on the detection result of the synchronization area of ​​the data frame. If the frame is synchronized, the data area of ​​the data frame is demodulated to obtain the underwater communication data.

[0029] Preferably, the method further includes:

[0030] Configure the reference signal in the symbol reference area of ​​the data frame, and use the reference signal to set the judgment conditions or preprocessing methods corresponding to different modulation schemes for the valid data in the data area of ​​the data frame.

[0031] Preferably, the method further includes:

[0032] At least the rate zone of the data frame is configured such that the communication rates of different regions in the same transmitted data frame are all or partially the same; wherein the communication rate includes the transmission rate of symbols or the time interval between symbols.

[0033] A third aspect of this application discloses an underwater communication method applied at a receiving end, the method comprising:

[0034] The system receives a data frame as disclosed in the first aspect of the embodiments of this application, detects the synchronization area of ​​the received data frame, and demodulates the data area to obtain underwater communication data when the frame is synchronized.

[0035] The detection of the synchronization zone in the received data frame includes:

[0036] The order of the signals at N frequency points in the synchronization zone of the received data frame in the time domain is the same as the order of the signals at N frequency points in the time domain in the synchronization zone of the data frame transmitted by the transmitting end; the value of N is greater than or equal to 2;

[0037] If they are the same, then frame synchronization is determined.

[0038] Preferably, the process of detecting the synchronization zone of the received data frame further includes:

[0039] The duration of the signal at each frequency point in the synchronization zone of the received data frame is not less than the duration of the corresponding frequency point transmitted in the synchronization zone of the data frame transmitted by the transmitting end.

[0040] If the signals of N frequency points in the synchronization zone of the data frame transmitted by the transmitting end appear in the same order in the time domain, and the duration of the signal of each frequency point is not less than the duration of the corresponding frequency point transmitted in the synchronization zone of the data frame transmitted by the transmitting end, then frame synchronization is determined.

[0041] Preferably, the demodulation of the data area includes:

[0042] The reference signal in the symbol reference area of ​​the received data frame is parsed to determine the preprocessing method corresponding to the current frequency shift keying modulation mode of the reference signal, and the preprocessing method is executed.

[0043] The preprocessing method includes:

[0044] Obtain the frequency point f corresponding to each symbol in the symbol reference area, and the signal strength Vf of the reference signal it carries; The value of n is the total number of frequency points minus 1. ;

[0045] The signal at each frequency point in the data area of ​​the received data frame is multiplied by an attenuation correction coefficient, with each frequency point corresponding to an attenuation correction coefficient Kf. The value of Vc is either the maximum value of the signal strength Vf, or a non-zero value.

[0046] Preferably, demodulating the data area includes:

[0047] The reference signal in the symbol reference area of ​​the received data frame is parsed, and the amplitude threshold is determined based on the characteristics of the reference signal and the current amplitude modulation method adopted by the receiving end. The amplitude threshold required for demodulation is adjusted according to the amplitude of the reference signal, and the data area of ​​the data frame is demodulated based on the adjusted amplitude threshold.

[0048] The fourth aspect of this application discloses an electronic device, which includes at least one processor and at least one memory and bus connected to the processor; wherein the processor and the memory communicate with each other through the bus; the processor is used to call program instructions in the memory to construct a data frame as disclosed in the first aspect of this application; or to execute an underwater communication method as disclosed in the second or third aspect of this application.

[0049] The fifth aspect of this application discloses a storage medium storing a program that, when executed by a processor, constructs a data frame as disclosed in the first aspect of this application; or implements an underwater communication method as disclosed in the second or third aspect of this application.

[0050] Based on the above embodiments of this application, an underwater communication data frame, method, electronic device, and storage medium are provided. The data frame includes at least a synchronization region for carrying synchronization signals and a data region for carrying valid data. The synchronization region is located at the beginning of the data frame and includes signals at N frequency points. These N frequency points appear in a predetermined order or simultaneously in the time domain; the value of N is greater than or equal to 2. In this embodiment, by configuring the signals at multiple frequency points within the synchronization region of the data frame to appear in a predetermined order or simultaneously in the time domain, when the data frame is applied to underwater communication, by setting a synchronization region carrying synchronization signals, it is not necessary to use a linear frequency modulated signal as the synchronization signal, reducing the computational load. Furthermore, by setting the combination and timing of different frequency signals within the synchronization region, the anti-interference capability can be significantly improved. This achieves the goal of strong anti-interference capability and low computational load in underwater communication, further improving the reliability of underwater communication. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0052] Figure 1 This is a schematic diagram of the structure of a data frame disclosed in an embodiment of this application;

[0053] Figure 2A This is an example diagram of a synchronization signal composed of continuous transmissions at two frequency points f0 and f1 as disclosed in the embodiments of this application;

[0054] Figure 2B This is an example diagram of a synchronization signal composed of intermittent transmissions at two frequencies, f0 and f1, as disclosed in an embodiment of this application.

[0055] Figures 3A to 3D This is a schematic diagram illustrating different transmission methods of partial synchronization signals when using two frequency points, as disclosed in an embodiment of this application.

[0056] Figure 4 This is a schematic diagram of another data frame structure disclosed in an embodiment of this application;

[0057] Figure 5 This is a schematic diagram of another data frame structure disclosed in an embodiment of this application;

[0058] Figures 6A to 6D This is an example diagram illustrating the relationship between the value of the rate region and the rate as disclosed in the embodiments of this application;

[0059] Figures 7A to 7B This is an example diagram illustrating the variable spacing of symbols in the rate region disclosed in this application.

[0060] Figure 8 This is a schematic diagram of the 2FSK symbol reference area disclosed in the embodiments of this application;

[0061] Figures 9A to 9D This is a schematic diagram of demodulation based on the symbol reference area signal when f1 attenuation is severe, as disclosed in the embodiments of this application.

[0062] Figure 10 This is a flowchart illustrating an underwater communication method provided in an embodiment of this application. Detailed Implementation

[0063] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0064] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product or device.

[0065] The following is an explanation of some of the technical terms that appear in this application:

[0066] Frequency point: A specific frequency value or a very narrow frequency range that is assigned to a particular communication within a continuous frequency range (spectrum).

[0067] Frequency: The number of times a signal completes a periodic change per unit of time.

[0068] Symbol: The basic unit of signal that carries information. Symbols are modulated onto a carrier wave with a specific frequency and transmitted as a signal at a specified frequency.

[0069] As can be seen from the background technology, the existing frame synchronization methods used in underwater communication typically use a single-frequency signal as a preamble and a linear frequency modulated signal as a synchronization code. However, the single-frequency signal has poor resistance to co-channel interference, and the linear frequency modulated signal requires a large amount of computation during processing at the receiving end, resulting in high cost and poor reliability.

[0070] Therefore, this application discloses a data frame for underwater communication, an underwater communication method based on the data frame, and related apparatus. In this application embodiment, signals at multiple frequency points in the synchronization zone of the data frame are configured in the time domain to appear in a predetermined order or simultaneously. When this data frame is applied to underwater communication, by setting a synchronization zone carrying the synchronization signal, it is not necessary to use a linear frequency modulated signal as the synchronization signal, reducing the computational load. Simultaneously, setting the combination and timing of different frequency signals in the synchronization zone can significantly improve anti-interference capability. This achieves the goal of ensuring strong anti-interference capability and low computational load during underwater communication, further enhancing the reliability of underwater communication.

[0071] like Figure 1 The diagram shown is a schematic diagram of the structure of a data frame disclosed in an embodiment of this application; the data frame is used for underwater communication and includes at least a synchronization area 11 and a data area 12.

[0072] The synchronization area 11 is located at the beginning of the data frame. This synchronization area 11 carries synchronization signals. It is used for frame synchronization and symbol synchronization, among other things.

[0073] The synchronization zone includes signals at N frequency points, which appear in a predetermined order or simultaneously in the time domain; the value of N is greater than or equal to 2. In this embodiment, the synchronization zone, through the combination of different frequency signals and the setting of the timing sequence, can significantly improve the anti-interference capability of the signal when applied to underwater communication. In this embodiment, linear frequency modulation (LFM) signals are not used as synchronization signals, further reducing the computational load.

[0074] In one embodiment of this application, among the N frequency points, the time interval between the first occurrence of two adjacent frequency points in the time domain is greater than or equal to 1ms.

[0075] In one embodiment of this application, among the N frequency points, the time interval between the first occurrence of two adjacent frequency points in the time domain and the duration of the signal are greater than or equal to 1ms.

[0076] In this embodiment, by increasing the time interval between different signals and the duration of each signal when configuring the synchronization zone of the data frame, the anti-interference capability of the signal can be further improved. When the data frame is used for underwater communication, the receiving end can determine whether the currently received signal is a valid frame synchronization signal by detecting the time interval and duration of adjacent frequency points.

[0077] like Figure 2A As shown, taking the synchronization signal composed of two frequency points f0 and f1 continuously transmitted as an example, this illustrates the situation when the data frame disclosed in the embodiments of this application is applied to underwater communication.

[0078] For the transmitting end, a signal with frequency f0 is transmitted at time t1 in the synchronization zone and lasts for a certain period of time (t2-t1). At time t2, a signal with frequency f1 is transmitted and lasts for a certain period of time (t3-t2). The receiving end determines whether it is a valid frame synchronization signal by judging the first occurrence times of f0 and f1, and the duration of the signals at each frequency. If the receiving end detects the f0 signal and its duration is not less than t2-t1, and then detects the f1 signal, with the first occurrence time interval between f0 and f1 being t2-t1, and the duration of f1 not less than t3-t2, then it is a valid synchronization signal; otherwise, it is not. Each symbol after the synchronization zone is delayed by a fixed time relative to t1. Detecting the synchronization zone allows the determination of the start time of each symbol, thus achieving symbol synchronization. Subsequent underwater communication can then continue.

[0079] It should be noted that in specific underwater communication applications, the timing and interval of the first occurrence of signals at different frequencies, as well as the minimum duration of signals at different frequencies, are considered valid as long as they deviate from the set values ​​within a certain error range. Additionally, a certain degree of frequency error is permissible, such as... Figure 2A In the process, if the frequency of the transmitted signal is f0 or near f0 during the time period t1~t2, it is also effective; after filtering, it is sufficient as long as f0 and f1 can be distinguished.

[0080] In practical applications, the duration of the signal received by the receiver may be greater than the set value. For example, at the transmitting end, the duration of the signal with frequency f0 is t2-t1. The duration of the signal received by the receiver may be greater than t2-t1. Therefore, the principle for the receiver to judge is that the duration of f0 is not less than the specified value (t2-t1).

[0081] Signals at the same frequency point in the synchronization zone can be transmitted continuously or intermittently. Intermittent transmission can reduce power consumption. Figure 2A This is a schematic diagram of continuous launch. Figure 2BThis is a schematic diagram of intermittent transmission; the signal at each frequency point can be transmitted continuously or intermittently. Specifically, for the transmitting end, at time t1 in the synchronization zone, a signal with frequency f0 is transmitted once, and during the period (t2-t1), f0 is transmitted again at preset time intervals, that is, f0 is transmitted intermittently during the period (t2-t1); at time t2, a signal with frequency f1 is transmitted once, and during the period (t3-t2), f0 is transmitted again at preset time intervals, that is, f1 is transmitted intermittently during the period (t3-t2).

[0082] In practical applications, Figure 2A The synchronization zones shown can be synchronized, with f0 and f1 transmitting simultaneously, their transmission intervals overlapping, or they can be transmitted at intervals. Specifically, as shown... Figures 3A to 3D The diagram shows different transmission methods for partial synchronization signals when using two frequency points. It should be noted that, for... Figure 2B That also applies.

[0083] in, Figure 3A Simultaneous firing of f0 and f1; Figure 3B The firing order is f1 to fire first, followed by f0. Figure 3C For overlapping emission of f0 and f1; Figure 3D F0 is paused for a period of time before F1 is launched.

[0084] The frequency of the signal used in the synchronization zone can be the same as or different from the frequency of the signal after the synchronization zone, that is, the frequency that does not appear after the synchronization zone is used.

[0085] In one embodiment of this application, the frequency points used by the synchronization zone are a set or subset of the frequency points used by other zones in the data frame besides the synchronization zone. That is, the frequency points of the signal used in the synchronization zone can be the same as the frequency points of the signal following the synchronization zone, or only a portion of the frequency points of the signal following the synchronization zone can be used. For example, if there are a total of four frequency points of the signal following the synchronization zone, the synchronization zone can use all four frequency points, or only two of them. This setting avoids adding other new frequency points, thereby improving the utilization rate of the bandwidth.

[0086] In one embodiment of this application, the synchronization zone may also include signals from three or more frequency points. By adjusting the order of appearance of different frequency points, the duration of each frequency point signal, and the interval between the first appearance times of different frequency points, more permutations and combinations can be achieved, which will not be listed here. Different permutations and combinations can represent different meanings, such as different rates, data lengths, frame types, etc. Taking the use of two frequency points f0 and f1 as an example, it can be used... Figure 2A In this context, f0 preceding f1 indicates a speed. Figure 3B In the case of f1 first and f0 second, it indicates another type of rate.

[0087] This data area 12 is located after the synchronization area 11, and it is used to carry valid data. This valid data includes the data required for underwater communication.

[0088] The valid data portion in data area 12 is the smallest subset that can represent a frame of data, without redundant information; it may not include fixed data, padding data, or error correction and check bits.

[0089] In one embodiment of this application, the data area 12 also includes a carrier of invalid data.

[0090] In one embodiment of this application, the data area 12 also includes an error correction and verification area, that is, the data area 12 contains a data sub-area and an error correction and verification area.

[0091] The data frames for underwater communication disclosed in this application significantly improve anti-interference capabilities by combining and timing signals at different frequencies within the synchronization zone. This anti-interference capability is primarily reflected in the fact that although noise signals have a wide spectrum, they are unlikely to conform to or cover the timing used in the synchronization zone, i.e., the order, duration, and time interval of different frequencies. In underwater communication, there is generally a certain interval between symbols. By setting the timing, duration, and time interval of signals at different frequencies within the synchronization zone, the probability of off-synchronization zone signals and their multipath reflections being misidentified as synchronization zone signals in a data frame can be significantly reduced, thereby improving the signal's anti-interference capability.

[0092] like Figure 4 The diagram shown is a schematic diagram of another data frame for underwater communication disclosed in an embodiment of this application. The data frame includes a synchronization area 11, a data area 12, and a symbol reference area 13.

[0093] exist Figure 4 In this context, the reference area 13 is set before the data area 12 and after the synchronization area 11.

[0094] Figure 4 The specific settings and applications of the synchronization area 11 and data area 12 shown are as follows: Figure 1 The synchronization area 11 and data area 12 are the same, see below.

[0095] The reference signals carried by each symbol in the symbol reference area 13 are used to set the judgment conditions or preprocessing methods corresponding to different modulation schemes for the valid data in the data area 12.

[0096] The modulation methods include, but are not limited to, frequency modulation, phase modulation, amplitude modulation, and linear frequency modulation.

[0097] This determination condition is a method for distinguishing different symbols during demodulation. For example, when the modulation method used by the receiver is amplitude modulation, the amplitude threshold is used as the determination condition. The amplitude threshold can be adjusted according to the magnitude of the reference signal amplitude.

[0098] The preprocessing method includes parsing the reference signal in the symbol reference area 13 of the data frame, determining the preprocessing method corresponding to the features of the reference signal, and executing the preprocessing method.

[0099] Specifically, the reference signal in the symbol reference area 13 corresponds to the valid data in the data area 12. This correspondence means that for each symbol, frequency point, or equivalent signal of the valid data in the data area 12, a corresponding reference signal appears at least once in the symbol reference area 13. An equivalent signal is a signal that has the same characteristics as a symbol.

[0100] The order and interval of the symbols or their equivalent signals in the symbol reference area 13 are predetermined, or they can be constant, or they can change only with the changes in the data before the symbol reference area 13; that is, based on the data received before the symbol reference area 13, the order and time interval of each symbol in the symbol reference area 13 can be uniquely determined; for example, the time interval of different symbols in the symbol reference area can be adjusted according to the order of the different frequency points in the synchronization area 11.

[0101] In one embodiment of this application, the time interval of each symbol, frequency point or equivalent signal in the symbol reference area 13 is the same as the time interval of each symbol, frequency point or equivalent signal in the data area 12.

[0102] In one embodiment of this application, under the same frame type, the minimum time interval between each symbol, frequency point, or equivalent signal in the symbol reference area 13 is not less than the time interval between symbols in the data area 12 at the lowest communication rate. Based on this, the bit error rate can be reduced.

[0103] In one embodiment of this application, under the same frame type, the communication rate of each symbol in the symbol reference area 13 is no higher than the minimum communication rate used by the data area 12. Based on this, the bit error rate can be reduced.

[0104] In one embodiment of this application, the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area 13 are set based on preset conditions. The preset conditions are: the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area 13 are fixed and fixed.

[0105] In one embodiment of this application, the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area 13 are set based on a preset condition. The preset condition is that when one or more symbols in the area before the symbol reference area 13 remain unchanged, the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area 13 remain unchanged.

[0106] In one embodiment of this application, the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area 13 are set based on a preset condition. The preset condition is that the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area 13 change with the change of one or more symbols in the area preceding the symbol reference area 13.

[0107] In one embodiment of this application, the symbol reference area 13 may also be located after the data area 12. In specific applications, the symbol reference area 13 is located after the data area 12. After the receiving end buffers the signal received from the data area, it performs corresponding processing on the valid data in the data area, such as demodulation, after receiving the signal from the symbol reference area 12.

[0108] The data frame for underwater communication disclosed in this application, by setting reference signals carried by each symbol in the symbol reference area, addresses the variations in signal strength and multipath interference caused by individual differences in different transducers, different signal attenuation at different positions during movement, and differences in the surrounding environment. It sets judgment conditions or preprocessing methods corresponding to different modulation schemes for the effective data in the data area. By setting these judgment conditions or preprocessing methods for different modulation schemes, the bit error rate can be significantly reduced during demodulation at the receiving end, thereby improving the reliability of underwater communication. Simultaneously, setting the combination and timing of different frequency signals in the synchronization area can significantly improve anti-interference capability. This achieves the goal of strong anti-interference capability and low computational load in underwater communication, further improving the reliability of underwater communication.

[0109] In one embodiment of this application, the underwater communication data frame includes at least the following: Figure 4 The data area 12 and the symbol reference area 13 are defined in the data area. By setting the reference signal carried by each symbol in the symbol reference area, when faced with individual differences between different transducers, different signal attenuation at different positions during movement, and differences in the surrounding environment, which lead to changes in signal strength and multipath interference, the data area sets judgment conditions or preprocessing methods corresponding to different modulation schemes for the effective data. During demodulation at the receiving end, the bit error rate can be significantly reduced, thereby improving the reliability of underwater communication.

[0110] like Figure 5The diagram shown is a structural schematic of another data frame disclosed in an embodiment of this application; the data frame is used for underwater communication and includes at least a synchronization area 11, a data area 12, a symbol reference area 13, and a rate area 14.

[0111] Figure 5 The specific settings and applications of the synchronization area 11, data area 12, and symbol reference area 13 shown are as follows: Figure 4 The synchronization area 11, data area 12 and symbol reference area 13 are consistent, as can be seen in the figure.

[0112] The rate zone 14 is used to set the communication rate of different regions in the same data frame, so that the communication rates of different regions are all the same or partially the same; wherein, the communication rate includes the transmission rate of symbols or the time interval between symbols.

[0113] The communication rate indicated by at least one earlier symbol in the rate zone 14 is used to determine the transmission rate of at least one later symbol in the rate zone 14 or the time interval between symbols.

[0114] like Figures 6A to 6D The example shown illustrates the relationship between the values ​​of the rate zone and the rate, using 2FSK modulation and a rate zone 14 data with 2 bits as an example. The rate zone 14 data has 2 bits, with a value range of 0 to 3. Different values ​​in rate zone 14 correspond to different rates.

[0115] like Figure 6A As shown, when the value of the rate zone is 0 (0B00), the rate after the rate zone is 125bps; Figure 6B As shown, when the value of the rate zone is 1 (0B01), the rate after the rate zone is 250bps; Figure 6C As shown, when the value of the rate zone is 2 (0B10), the rate after the rate zone is 500bps; Figure 6D As shown, when the value of the rate zone is 3 (0B11), the data rate after the rate zone is 1kbps. Multiple rate zone values ​​can also correspond to a single rate; for example, when the rate zone value is 2 or 3, the data rate after the rate zone is 500bps. When the rate zone has multiple bits, there can be more rate combinations.

[0116] The interval between symbols in the rate zone can be fixed or variable. To shorten communication time, different symbols in the rate zone can have different intervals. For example... Figure 7A and Figure 7B As shown, taking 2FSK modulation and 4 bits of data in the rate zone as an example, it illustrates that the symbol interval in the rate zone is variable.

[0117] like Figure 7A and Figure 7BAs shown, the rule for the spacing of symbols in the rate region is: when the value of the previous symbol is 0, the spacing between the current symbol and the next symbol remains unchanged; when the value of the previous symbol is 1, the spacing between the current symbol and the next symbol is halved. Specifically, in Figure 7A In the middle, the value of the rate zone is 0B0000, and the symbol interval after the rate zone remains unchanged; in Figure 7B In the middle, the value of the rate zone is 0B1111, and the symbol interval in the rate zone is halved sequentially, that is... Figure 7B In this case, T2-T1=(T1-T0) / 2, T3-T2=(T2-T1) / 2. This method can shorten the transmission time of the rate zone, making the communication time of the entire frame data shorter.

[0118] This application sets a rate zone 14 in the data frame so that different positions in a data frame have different rates. The communication rate of some or all symbols in the rate zone 14 depends on the value of the rate zone 14. Since the symbols after the rate zone 14 account for a relatively high proportion in a data frame, this part of the rate can also be considered as the rate of this data frame.

[0119] When this data frame is used for underwater communication, if communication fails, the sending end can reduce the rate and retry. Since the data frame contains a rate zone, when the sending end transmits a data frame at any rate, the receiving end can determine the communication rate based on the value of the rate zone and demodulate the subsequent signal. That is, the sending end does not need to notify the receiving end in advance when changing the rate, and the sending end can change the rate in real time.

[0120] Therefore, when the packet loss rate is high, the sender can modify the rate zone value to reduce the communication rate and increase the probability of successful reception at the receiver; when the packet loss rate is low, the communication rate can be appropriately increased, shortening the communication time while maintaining a low packet loss rate. This further improves the reliability of underwater communication.

[0121] In one embodiment of this application, the underwater communication data frame includes at least the following: Figure 5 The data area 12 and the rate area 14 are defined within the same data frame. By using the rate area to set the communication rate of different regions within the same data frame, the communication rates of different regions can be made all or partially the same, enabling the rate to be adjusted according to environmental requirements during underwater communication, thereby improving the reliability of underwater communication.

[0122] Based on the data frames for underwater communication disclosed in the above embodiments of this application, this application also discloses a method for underwater communication using the aforementioned data frames, which is applied at the transmitting end. The underwater communication method includes the following steps:

[0123] S11: Configure each region in the data frame according to the parameter information of the data frame to be transmitted by the sending end.

[0124] In S11, the data frame is the data frame disclosed in the aforementioned embodiments of this application.

[0125] When configuring the data frame in S11, the signals of N frequency points in the synchronization area of ​​the configuration data frame appear in the time domain in a set order or simultaneously.

[0126] Where N is greater than or equal to 2.

[0127] S12: Transmit a data frame so that the receiver can determine whether the frame is synchronized based on the detection result of the synchronization area of ​​the data frame, and if the frame is synchronized, demodulate the data area of ​​the data frame to obtain the underwater communication data.

[0128] During the specific execution of S12, this data frame is sent based on the configuration, such as... Figure 2A The configuration shown is such that the transmitting end transmits a signal with frequency f0 at time t1 in the synchronization zone and continues for a certain period of time (t2-t1), and transmits a signal with frequency f1 at time t2 and continues for a certain period of time (t3-t2).

[0129] In one embodiment of this application, during the execution of S11 to configure the data frame, the reference signal in the symbol reference area of ​​the data frame is configured, and the reference signal is used to set the judgment conditions or preprocessing methods corresponding to different modulation schemes for the valid data in the data area of ​​the data frame.

[0130] Depending on the modulation method, the judgment conditions or preprocessing content will also be different, and may include signal strength, frequency shift, or phase shift.

[0131] Execute S12 to send the configured data frame, so that the receiving end can demodulate it based on the modulation scheme determination conditions or preprocessing methods set by the valid data in the data area of ​​the data frame in the symbol reference area.

[0132] In one embodiment of this application, during the execution of S11, the rate zone of the data frame is configured so that the communication rates of different regions in the same transmitted data frame are all the same or partially the same; wherein, the communication rate includes the transmission rate of symbols or the time interval between symbols.

[0133] Based on the data frames for underwater communication disclosed in the above embodiments of this application, and the underwater communication method applied at the transmitting end, the embodiments of this application also disclose a corresponding underwater communication method applied at the receiving end, which includes:

[0134] S21: Receive the data frame sent in S12 above, detect the synchronization area of ​​the received data frame, and demodulate the data area to obtain underwater communication data when the frame is synchronized.

[0135] The specific execution of S21, which involves detecting the synchronization zone of the received data frame, includes:

[0136] The system checks whether the order of the signals at N frequency points in the synchronization zone of the received data frame in the time domain is the same as the order of the signals at N frequency points in the time domain in the synchronization zone of the transmitted data frame. If they are the same, the frame is synchronized; otherwise, it is not synchronized. Here, N is greater than or equal to 2.

[0137] In one embodiment of this application, during the process of performing S21 to detect the synchronization region of the received data frame, the method further includes:

[0138] The duration of the signal at each frequency point in the synchronization zone of the received data frame is not less than the duration of the corresponding frequency point transmitted in the synchronization zone of the data frame transmitted by the transmitting end.

[0139] If the signals of N frequency points in the synchronization zone of the data frame transmitted by the transmitting end appear in the same order in the time domain, and the duration of the signal of each frequency point is not less than the duration of the corresponding frequency point in the synchronization zone of the data frame transmitted by the transmitting end, then frame synchronization is determined.

[0140] In combination with the above Figure 2A The configuration involves the receiver determining whether a signal is a valid frame synchronization signal by judging the first occurrence times of f0 and f1, and the duration of signals at each frequency. If the receiver detects signal f0 with a duration no less than t2-t1, and then detects signal f1 with a first occurrence time interval of t2-t1 and f1's duration no less than t3-t2, then it is considered a valid synchronization signal, achieving frame synchronization. Otherwise, it is not. Under frame synchronization, the receiver demodulates the data area of ​​the data frame to obtain the underwater communication data.

[0141] In one embodiment of this application, the specific execution of S22 to demodulate the data area includes:

[0142] The receiving end parses the reference signal in the symbol reference area of ​​the received data frame, determines the judgment condition or preprocessing method corresponding to the characteristics of the reference signal, and demodulates the data area of ​​the data frame based on the judgment condition or preprocessing method.

[0143] In one embodiment of this application, the receiving end parses the reference signal in the symbol reference area of ​​the received data frame, determines the amplitude threshold based on the characteristics of the reference signal, and specifically executes S22 to demodulate the data area.

[0144] The receiver parses the reference signal in the symbol reference area of ​​the received data frame, determines the amplitude threshold based on the characteristics of the reference signal, and adjusts the amplitude threshold required for demodulation according to the amplitude of the reference signal, and demodulates the data area of ​​the data frame based on the adjusted amplitude threshold.

[0145] In one embodiment of this application, the receiving end parses the reference signal in the symbol reference area of ​​the received data frame and determines that the characteristics of the reference signal correspond to the preprocessing method of frequency shift keying modulation currently used by the receiving end. Specifically, the process of demodulating the data area in step S22 includes:

[0146] If the current receiver uses frequency shift keying (FSK) modulation, the receiver analyzes the reference signal in the symbol reference area of ​​the received data frame, determines the preprocessing method that can be used when using FSK modulation (i.e., frequency modulation, 2FSK or MFSK) based on the characteristics of the reference signal, and then executes the preprocessing method:

[0147] Obtain the frequency point f corresponding to each symbol in the symbol reference area, and the signal strength Vf of the reference signal it carries; The value of n is the total number of frequency points minus 1. .

[0148] The signal at each frequency point in the data area of ​​the received data frame is multiplied by an attenuation correction coefficient, with each frequency point corresponding to an attenuation correction coefficient Kf. The value of Vc is either the maximum value of the signal strength Vf, or a non-zero value.

[0149] It should be noted that different modulation methods correspond to different preprocessing methods.

[0150] like Figure 8 As shown, the symbol reference area in the data frame is located before the data area, the configured modulation scheme is 2FSK, and the data area has only two frequency points, f0 and f1, both of which must appear in the symbol reference area. The receiver demodulates the data area signal using a preprocessing method based on the characteristics of the symbol reference areas f0 and f1, and then performs demodulation to extract the data area content. This improves the demodulation success rate and enhances the reliability of underwater communication.

[0151] like Figures 9A to 9D As shown, the explanation will continue with the example of the f1 signal being severely attenuated and the data area taking 3 bits of data.

[0152] Figure 9A The signal represents the symbol reference area of ​​the transmitting end. The f0 signal is transmitted at time Ts0, and the f1 signal is transmitted at time Ts1. Figure 9BThe signal in the symbol reference area of ​​the receiver when f1 is severely attenuated is Ts0 of the transmitter at time Tr0 of the receiver and Ts1 of the transmitter at time Tr1 of the receiver. At time Tr1, the signal strength of f1 is lower than that of f0. Figure 9C The received 3-bit raw signal from the data area has significant attenuation due to f1. At this point, the receiver preprocesses the data area signal based on the characteristics of the reference signal in the symbol reference area. Because f1 attenuates significantly in the symbol reference area, the f1 signal in the data area is amplified during preprocessing. The amplification factor is K = Vr0 / Vr1, where Vr0 is the signal strength of f0 at time Tr0, and Vr1 is the signal strength of f1 at time Tr1. Multiplying all f1 signals in the data area by K yields the preprocessed signal, at which point f1 has recovered from an attenuated signal to a normal signal. All f0 signals in the data area remain unchanged, equivalent to being multiplied by 1. The preprocessed signal is as follows: Figure 9D As shown, the data can be successfully demodulated at this point, and the demodulated 3-bit data is 0B010. This avoids demodulation errors.

[0153] like Figure 10 The image shows an underwater communication method disclosed in an embodiment of this application. The underwater communication method includes:

[0154] S101: The sending end configures each region in the data frame according to the parameter information of the data frame to be transmitted.

[0155] During the execution of S101, one or more of the following configurations may be executed:

[0156] The signals of N frequency points in the synchronization zone of the configuration data frame appear in the time domain in a set order or simultaneously;

[0157] The reference signals carried by each symbol in the symbol reference area of ​​the configuration data frame are used to set the judgment conditions or preprocessing methods corresponding to different modulation schemes for the valid data in the data area of ​​the data frame.

[0158] Configure the rate zone of the data frame so that the communication rates of different regions in the same transmitted data frame are all the same or partially the same; wherein, the communication rate includes the transmission rate of symbols or the time interval between symbols.

[0159] S102: The sending end sends the configured data frame.

[0160] S103: The receiving end receives the data frame.

[0161] S104: The receiving end processes each region of the data frame, and demodulates the data region of the data frame under frame synchronization to obtain underwater communication data.

[0162] In the specific implementation of S104, the processing of other areas includes:

[0163] If the data frame has a synchronization zone, the receiving end checks whether the order of the signals at N frequency points in the synchronization zone of the received data frame in the time domain is the same as the order of the signals at N frequency points in the time domain in the synchronization zone of the data frame transmitted by the sending end; the value of N is greater than or equal to 2; if they are the same, the frame synchronization is determined.

[0164] If the data frame has a synchronization zone, the receiver checks whether the duration of the signal at each frequency point in the synchronization zone of the received data frame is not less than the duration of the corresponding frequency point transmitted in the synchronization zone of the data frame transmitted by the transmitter; and checks whether the order in which the signals at N frequency points in the synchronization zone of the received data frame appear in the time domain is the same as the order in which the signals at N frequency points in the synchronization zone of the data frame transmitted by the transmitter appear in the time domain.

[0165] If the signals of N frequency points in the synchronization zone of the data frame transmitted by the transmitting end appear in the same order in the time domain, and the duration of the signal of each frequency point is not less than the duration of the corresponding frequency point in the synchronization zone of the data frame transmitted by the transmitting end, then frame synchronization is determined.

[0166] If the data frame has a symbol reference area and the receiver uses frequency shift keying modulation, during the demodulation of the data area of ​​the data frame, the receiver analyzes the characteristics of the reference signal in the symbol reference area of ​​the received data frame, determines the preprocessing method corresponding to the frequency shift keying modulation method based on the characteristics of the reference signal, and executes the preprocessing method including:

[0167] Obtain the frequency point f corresponding to each symbol in the symbol reference area, and the signal strength Vf of the reference signal it carries; The value of n is the total number of frequency points minus 1. The signal at each frequency point in the data area of ​​the received data frame is multiplied by an attenuation correction factor, with each frequency point corresponding to an attenuation correction factor Kf. The value of Vc is either the maximum value of the signal strength Vf, or a non-zero value.

[0168] If the data frame has a symbol reference area, during the demodulation of the data area of ​​the data frame, the receiving end parses the characteristics of the reference signal in the symbol reference area of ​​the received data frame, determines the amplitude threshold corresponding to the current amplitude modulation method adopted by the receiving end based on the characteristics of the reference signal, adjusts the amplitude threshold required for demodulation according to the amplitude of the reference signal, and demodulates the data area of ​​the data frame based on the adjusted amplitude threshold.

[0169] If the data frame has a rate zone, the receiving end determines the communication rate based on the value set in the rate zone and demodulates the subsequent signals.

[0170] The underwater communication disclosed in this application involves the sending end configuring various regions of a data frame based on requirements, and sending the data frame to the receiving end. This configuration significantly improves anti-interference capabilities, reduces computational load, and enhances the reliability of underwater communication. After receiving the configured data frame, the receiving end performs underwater communication by parsing the content obtained from each region of the data frame, thus ensuring the reliability of underwater communication.

[0171] Based on the data frames for underwater communication disclosed in the above embodiments of this application, and the underwater communication method applied to the sending end and receiving end, this application also discloses an electronic device, which includes at least one processor and at least one memory and bus connected to the processor; wherein the processor and the memory communicate with each other through the bus; the processor is used to call program instructions in the memory to construct the data frames for underwater communication as disclosed in the above embodiments of this application; or to execute the underwater communication method disclosed in the above embodiments of this application.

[0172] This application also discloses a storage medium storing a program that, when executed by a processor, constructs a data frame for underwater communication as disclosed in the foregoing embodiments of this application; or implements an underwater communication method as disclosed in the foregoing embodiments of this application.

[0173] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An underwater communication method, characterized in that, Applied to the sending end, the method includes: Based on the parameter information of the data frame to be transmitted at the transmitting end, each region in the data frame is configured. The data frame includes at least: a synchronization region for carrying synchronization signals, a data region for carrying valid data, and a symbol reference region set before or after the data region. The synchronization region is located at the beginning of the data frame and includes signals at N frequency points. The signals at the N frequency points in the synchronization region of the data frame are configured to appear in a set order or simultaneously in the time domain, and the value of N is greater than or equal to 2. The reference signals in the symbol reference region of the data frame are configured, and the reference signals are used to set judgment conditions or preprocessing methods corresponding to different modulation schemes for the valid data in the data region of the data frame. The data frame is transmitted so that the receiving end can determine whether the frame is synchronized based on the detection result of the synchronization area of ​​the data frame. If the frame is synchronized, the data area of ​​the data frame is demodulated to obtain the underwater communication data.

2. The method according to claim 1, characterized in that, The frequency points used by the synchronization zone are the set or subset of frequency points used by other zones in the data frame besides the synchronization zone.

3. The method according to claim 1, characterized in that, Among the N frequency points, the time interval between the first occurrence of two adjacent frequency points in the time domain is greater than or equal to 1ms.

4. The method according to any one of claims 1 to 3, characterized in that, The reference signal in the symbol reference area has a corresponding relationship with the valid data in the data area. The corresponding relationship means that for each symbol, frequency point, or equivalent signal of the valid data in the data area, a corresponding reference signal appears at least once in the symbol reference area.

5. The method according to claim 4, characterized in that, The order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area are set based on preset conditions. The preset condition is that the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area are fixed. or, The preset condition is that when one or more symbols in the region before the symbol reference area remain unchanged, the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area remain unchanged. or, The preset condition is that the order and time interval of the occurrence of each symbol, frequency point or equivalent signal in the symbol reference area change with the changes of one or more symbols in the area preceding the symbol reference area.

6. The method according to claim 4, characterized in that, The time interval between each symbol, frequency point, or equivalent signal in the symbol reference area is the same as the time interval between each symbol, frequency point, or equivalent signal in the data area. Alternatively, under the same frame type, the minimum time interval of each symbol, frequency point, or equivalent signal in the symbol reference area is not less than the time interval of the symbols in the data area at the lowest communication rate. Alternatively, under the same frame type, the communication rate of each symbol in the symbol reference area is not higher than the minimum communication rate used by the data area.

7. The method according to any one of claims 1 to 3, characterized in that, The data frame further includes: a rate zone for setting the communication rate of different regions within the same data frame; the method further includes: At least the rate zone of the data frame is configured such that the communication rates of different regions in the same transmitted data frame are all or partially the same; wherein the communication rate includes the transmission rate of symbols or the time interval between symbols.

8. The method according to claim 7, characterized in that, The communication rate indicated by at least one earlier symbol in the rate zone is used to determine the transmission rate of at least one later symbol in the rate zone or the time interval between symbols.

9. An underwater communication method, characterized in that, Applied to the receiving end, the method includes: The system receives data frames, detects the synchronization region of the received data frames, and demodulates the data region to obtain underwater communication data when the frames are synchronized. The data frame includes at least: a synchronization region for carrying synchronization signals, a data region for carrying valid data, and a symbol reference region located before or after the data region. The synchronization region is located at the beginning of the data frame and includes signals at N frequency points. The reference signals carried by each symbol in the symbol reference region are used to set judgment conditions or preprocessing methods corresponding to different modulation schemes for the valid data in the data region. The detection of the synchronization zone in the received data frame includes: The order of the signals at N frequency points in the synchronization zone of the received data frame in the time domain is the same as the order of the signals at N frequency points in the time domain in the synchronization zone of the data frame transmitted by the transmitting end; the value of N is greater than or equal to 2; If they are the same, then frame synchronization is determined.

10. The method according to claim 9, characterized in that, The process of detecting the synchronization zone of the received data frame also includes: The duration of the signal at each frequency point in the synchronization zone of the received data frame is not less than the duration of the corresponding frequency point transmitted in the synchronization zone of the data frame transmitted by the transmitting end. If the signals of N frequency points in the synchronization zone of the data frame transmitted by the transmitting end appear in the same order in the time domain, and the duration of the signal of each frequency point is not less than the duration of the corresponding frequency point transmitted in the synchronization zone of the data frame transmitted by the transmitting end, then frame synchronization is determined.

11. The method according to claim 9, characterized in that, The reference signal in the symbol reference area has a corresponding relationship with the valid data in the data area. The corresponding relationship means that for each symbol, frequency point, or equivalent signal of the valid data in the data area, a corresponding reference signal appears at least once in the symbol reference area.

12. The method according to claim 11, characterized in that, The order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area are set based on preset conditions. The preset condition is that the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area are fixed. or, The preset condition is that when one or more symbols in the region before the symbol reference area remain unchanged, the order and time interval of each symbol, frequency point or equivalent signal in the symbol reference area remain unchanged. or, The preset condition is that the order and time interval of the occurrence of each symbol, frequency point or equivalent signal in the symbol reference area change with the changes of one or more symbols in the area preceding the symbol reference area.

13. The method according to claim 11 or 12, characterized in that, The time interval between each symbol, frequency point, or equivalent signal in the symbol reference area is the same as the time interval between each symbol, frequency point, or equivalent signal in the data area. Alternatively, under the same frame type, the minimum time interval of each symbol, frequency point, or equivalent signal in the symbol reference area is not less than the time interval of the symbols in the data area at the lowest communication rate. Alternatively, under the same frame type, the communication rate of each symbol in the symbol reference area is not higher than the minimum communication rate used by the data area.

14. The method according to claim 11 or 12, characterized in that, Demodulating the data area includes: The reference signal in the symbol reference area of ​​the received data frame is parsed, and a preprocessing method corresponding to the frequency shift keying modulation mode currently used by the receiving end is determined based on the characteristics of the reference signal, and the preprocessing method is executed. The preprocessing method includes: Obtain the frequency point f corresponding to each symbol in the symbol reference area, and the signal strength Vf of the reference signal it carries; The value of n is the total number of frequency points minus 1, V ; The signal at each frequency point in the data area of ​​the received data frame is multiplied by an attenuation correction factor, with each frequency point corresponding to an attenuation correction factor Kf. The value of Vc is either the maximum value of the signal strength Vf or a non-zero value.

15. The method according to claim 11 or 12, characterized in that, Demodulating the data area includes: The reference signal in the symbol reference area of ​​the received data frame is parsed, and the amplitude threshold is determined based on the characteristics of the reference signal and the current amplitude modulation method adopted by the receiving end. The amplitude threshold required for demodulation is adjusted according to the amplitude of the reference signal, and the data area of ​​the data frame is demodulated based on the adjusted amplitude threshold.

16. The method according to any one of claims 9 to 12, characterized in that, The data frame also includes: This is used to set the communication rate of different regions within the same data frame, so that the communication rates of different regions are all the same or partially the same; wherein, the communication rate includes the transmission rate of symbols or the time interval between symbols.

17. The method according to claim 16, characterized in that, The communication rate indicated by at least one earlier symbol in the rate zone is used to determine the transmission rate of at least one later symbol in the rate zone or the time interval between symbols.

18. An electronic device, characterized in that, The electronic device includes at least one processor, and at least one memory and bus connected to the processor; wherein the processor and the memory communicate with each other through the bus; the processor is used to call program instructions in the memory to execute the underwater communication method as described in any one of claims 1 to 17.

19. A storage medium, characterized in that, It stores a program that, when executed by a processor, implements the underwater communication method as described in any one of claims 1 to 17.

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