Transmission frame construction method and device, computer device, readable storage medium and program product

Abstract

This application relates to a method, apparatus, computer device, readable storage medium, and program product for constructing a transmission frame. The method includes: obtaining a preset total frame length, a preset number of subframes, and the length of each subframe; obtaining a first ratio between the length of a first portion of the obstructed area of ​​the preset transmission frame and the total frame length; for at least one subframe in the preset transmission frame with missing information, sorting the subframes along the intra-frame field parsing direction of the preset transmission frame, and obtaining a second length of the obstructed portion of the frame header of the last subframe in the sorting result; determining a data extraction ratio for the preset transmission frame based on the first ratio, the number of subframes, the second length, and the subframe length; further selecting interleaving parameters and coding rate based on the data extraction ratio and transmission efficiency; obtaining a spreading factor based on interference tolerance; and finally determining the target transmission frame. The method provided in this application can maximize the reliable transmission of signals.

Description

Technical Field

[0001] This application relates to the field of satellite communication technology, and in particular to a method, apparatus, computer device, readable storage medium, and program product for constructing transmission frames. Background Technology

[0002] With the rapid development of sensor technology, automated navigation systems, and artificial intelligence, USVs (Unmanned Surface Vehicles) are entering a phase of accelerated development. USVs are considered a core component of future naval unmanned combat systems, capable of performing various tasks such as intelligence surveillance, reconnaissance, and oceanographic surveys. As the complexity of the maritime combat environment increases, the crucial role of communication systems in unmanned combat systems becomes increasingly prominent, serving as the core hub for system operation. USVs primarily rely on satellite communication and UHF / VHF radio communication for signal transmission, with satellite communication offering significant advantages in terms of wide coverage and high transmission rates.

[0003] However, due to the constraints of space in the hull, the antenna layout is limited and the installation position is relatively low. This results in severe signal attenuation caused by the periodic obstruction of USVs by waves in rough sea conditions, making normal communication virtually impossible. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, apparatus, computer device, readable storage medium, and program product for constructing transmission frames that can effectively alleviate the degree of signal attenuation, in order to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides a method for constructing a transmission frame, the method comprising:

[0006] For any one of a variety of preset transmission frames, during the process of receiving the preset transmission frame sent by the sending terminal, the total frame length of the preset transmission frame, the number of subframes in the preset transmission frame, and the subframe length of any one subframe are obtained. For the portion of the preset transmission frame that is blocked by an obstacle during transmission, a first ratio between the first length of the blocked portion and the total frame length is obtained. The total frame length is the same for different types of preset transmission frames, but the number of subframes is different.

[0007] For at least one information-deficient subframe in the preset transmission frame, the at least one information-deficient subframe is sorted along the intra-frame field parsing direction of the preset transmission frame, and for the frame header of the last subframe in the sorting result, the second length of the occluded portion of the frame header that is obscured by the obstacle is obtained.

[0008] Based on the first ratio, the number of subframes, the second length, and the subframe length, the data extraction ratio of the preset transmission frame is determined; wherein, the data extraction ratio represents the second ratio between the first data amount and the second data amount, the first data amount is the amount of data contained in the preset transmission frame when the preset transmission frame is received, and the second data amount is the amount of data contained in the preset transmission frame when the sending terminal sends the preset transmission frame.

[0009] Determine the encoding interleaving scheme and the transmission efficiency of any preset transmission frame. Based on the transmission efficiency and the data extraction ratio, determine the target transmission frame structure and combine the encoding interleaving scheme and the target transmission frame structure to determine the target transmission frame.

[0010] In one embodiment, determining the data extraction ratio of the preset transmission frame based on the first ratio, the number of subframes, the second length, and the subframe length includes:

[0011] If the second length is less than a preset length threshold, the data extraction ratio is determined based on the first ratio.

[0012] If the second length is not less than a preset length threshold, the data extraction ratio is determined based on the first ratio, the number of subframes, the second length, and the subframe length.

[0013] In one embodiment, determining the coding interleaving scheme includes:

[0014] Obtain multiple inter-frame interleaving parameters, target coding bitrate, and the number of multiple subframes of the various preset transmission frames;

[0015] For an initial combination formed by any number of subframes and any interleaving parameters between subframes, Monte Carlo simulation is performed based on the initial combination and the target coding rate to obtain the bit error rate curve under the initial combination;

[0016] Based on the bit error rate curve, a target combination is determined from all initial combinations, and the product of the number of subframes in the target combination and the inter-subframe interleaving parameter is determined as the interleaving width of the target transmission frame.

[0017] In one embodiment, obtaining the target coding bitrate includes:

[0018] During the transmission of the preset transmission frame, for any one of the uplink and downlink, the data transmission distance, operating frequency, atmospheric power loss, and feeder power loss of the link are obtained, and the power loss value of the link is obtained based on the data transmission distance, the operating frequency, the atmospheric power loss, and the feeder power loss.

[0019] Obtain the carrier bandwidth, and determine the carrier-to-noise ratio of the link based on the power loss value and the carrier bandwidth; wherein, the carrier-to-noise ratio characterizes the ratio between the carrier signal power and the channel noise power density;

[0020] The target ground demodulation threshold is obtained based on the carrier-to-noise ratio and the carrier bandwidth, and the target coding rate is determined based on the principle that the decoding performance meets the target ground demodulation threshold.

[0021] In one embodiment, obtaining the carrier bandwidth includes:

[0022] Obtain the preset ground demodulation threshold, interference tolerance, and the minimum information rate allowed by the physical layer of the communication system;

[0023] The spreading factor is obtained based on the preset ground demodulation threshold and the anti-interference tolerance.

[0024] Based on the spreading factor, the minimum information rate, and the transmission efficiency, the chip transmission rate is obtained;

[0025] The root raised cosine parameter is determined, and the carrier bandwidth is determined based on the chip transmission rate and the root raised cosine parameter.

[0026] In one embodiment, any subframe includes a frame header, an information identifier, and a frame body arranged in sequence. The frame body consists of multiple information blocks and multiple pilot symbols, and the information blocks and the pilot symbols are alternately distributed in the frame body.

[0027] Secondly, this application also provides a transmission frame construction apparatus, the apparatus comprising:

[0028] The acquisition module is used to acquire, during the process of receiving the preset transmission frame sent by the sending terminal, the total frame length of the preset transmission frame, the number of subframes in the preset transmission frame, and the subframe length of any one of the preset transmission frames, and to acquire, for the occluded portion of the preset transmission frame that is blocked by an obstacle during transmission, a first ratio between the first length of the occluded portion and the total frame length; wherein, the total frame length is the same for different types of preset transmission frames, but the number of subframes is different.

[0029] The sorting module is used to sort at least one information-deficient subframe in the preset transmission frame along the intra-frame field parsing direction of the preset transmission frame, and to obtain the second length of the occluded portion of the frame header of the last subframe in the sorting result, which is obscured by the obstacle.

[0030] The first determining module is used to determine the data extraction ratio of the preset transmission frame based on the first ratio, the number of subframes, the second length, and the subframe length; wherein the data extraction ratio represents the second ratio between the first data amount and the second data amount, the first data amount is the amount of data contained in the preset transmission frame when the preset transmission frame is received, and the second data amount is the amount of data contained in the preset transmission frame when the sending terminal sends the preset transmission frame;

[0031] The second determining module is used to determine the encoding interleaving scheme and the transmission efficiency of any preset transmission frame, determine the target transmission frame structure based on the transmission efficiency and the data extraction ratio, and determine the target transmission frame in combination with the encoding interleaving scheme and the target transmission frame structure.

[0032] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the methods in any of the above embodiments.

[0033] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the steps of the methods in any of the above embodiments.

[0034] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the steps of the methods in any of the above embodiments.

[0035] The aforementioned transmission frame construction method, apparatus, computer device, computer-readable storage medium, and computer program product, for any one of a variety of preset transmission frames, during the process of receiving a preset transmission frame sent by a transmitting terminal, obtain the total frame length of the preset transmission frame, the number of subframes in the preset transmission frame, and the subframe length of any one subframe, and for the obstructed portion of the preset transmission frame that is blocked by an obstacle during transmission, obtain a first ratio between the first length of the obstructed portion and the total frame length; wherein, different types of preset transmission frames have the same total frame length but different numbers of subframes; for at least one information-deficient subframe in the preset transmission frame, along the intra-frame field parsing direction of the preset transmission frame, the at least one information-deficient subframe is parsed. The data extraction ratio of a preset transmission frame is determined based on the following steps: The data extraction ratio represents the second ratio between the first data quantity and the second data quantity. The first data quantity is the amount of data contained in the preset transmission frame when it is received, and the second data quantity is the amount of data contained in the preset transmission frame when it is sent by the transmitting terminal. The method also determines the coding interleaving scheme and the transmission efficiency of any preset transmission frame. Based on the transmission efficiency and the data extraction ratio, the target transmission frame structure is determined, and the target transmission frame is determined by combining the coding interleaving scheme and the target transmission frame structure. This method, for preset transmission frames with different numbers of subframes, selects the target transmission frame structure by comparing the data extraction ratio and the transmission efficiency. This minimizes signal loss while maintaining transmission efficiency during the transmission of a signal composed of the target transmission frame. Further experimental analysis based on the data extraction ratio and transmission efficiency is used to select interleaving parameters and coding rate, ultimately determining the target transmission frame. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is an application environment diagram of the transmission frame construction method in one embodiment;

[0038] Figure 2 This is a flowchart illustrating a transmission frame construction method in one embodiment;

[0039] Figure 3 This is a diagram of a wave-blocking waveform transmission frame structure in one embodiment.

[0040] Figure 4 This is a diagram showing the actual discarded information under different numbers of subframes due to wave occlusion in one embodiment.

[0041] Figure 5 This is a flowchart illustrating a method for determining the data extraction ratio in one embodiment;

[0042] Figure 6 This is a schematic diagram of the bit error rate curves under different bit interleaving widths for a subframe number of 64 in one embodiment.

[0043] Figure 7 This is a schematic diagram of the bit error rate curves under different bit interleaving widths for a subframe number of 128;

[0044] Figure 8 This is a schematic diagram of the bit error rate curves under different bit interleaving widths for a subframe number of 256;

[0045] Figure 9 This is a schematic diagram illustrating the inter-frame interleaving frame order change in one embodiment;

[0046] Figure 10 This is a schematic diagram of the performance curves of different numbers of subframes as a function of inter-subframe interleaving parameters in one embodiment;

[0047] Figure 11 This is a schematic diagram of performance curves under various interleaving parameters in one embodiment;

[0048] Figure 12 This is a schematic diagram of the bit error rate curves under different numbers of subframes with a fixed number of coding blocks in one embodiment.

[0049] Figure 13 This is a schematic diagram of a satellite communication link in one embodiment;

[0050] Figure 14 and Figure 15 This is a decoding performance curve at different code rates in one embodiment;

[0051] Figure 16 This is a structural block diagram of a transmission frame construction apparatus in one embodiment;

[0052] Figure 17 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0054] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0055] The transmission frame construction method provided in this application embodiment can be applied to, for example, Figure 1 The application environment shown is a satellite communication system comprised of a communication satellite 101, a transmitting terminal 102, and a receiving terminal 103. The link from the transmitting terminal 102 to the communication satellite 101 is the uplink, and the link from the communication satellite 101 to the receiving terminal 103 is the downlink. The satellite communication system can be, but is not limited to, a high-throughput satellite communication system or a transparent satellite communication system. In the case of a high-throughput satellite communication system, one of the transmitting terminal 102 and the receiving terminal 103 is a gateway station, and the other is a small station. If the small station is a USV, the telemetry and control channel from the gateway station to the small station uses a general anti-interference waveform and an anti-wave obstruction anti-interference waveform, while the service channel uses a general low-multiplication spread spectrum waveform and an anti-wave obstruction anti-interference waveform. The small station autonomously selects whether to receive the anti-wave obstruction anti-interference waveform based on real-time sea conditions. The link from the small station to the gateway station uses a general low-multiplication spread spectrum waveform, and the small station uses a time-slot communication mode when sea conditions are good, based on its own sea condition detection results. In the case of a transparent satellite communication system, one of the transmitting terminal 102 and the receiving terminal 103 is a shore base station / large ship (master station), and the other terminal is a small station. The telemetry and control channel from the master station to the small station adopts a general anti-interference waveform and an anti-wave blockage anti-interference waveform, while the service channel adopts a general low-multiplication spread spectrum waveform and an anti-wave blockage anti-interference waveform. The small station autonomously selects whether to receive the anti-wave blockage anti-interference waveform based on the real-time sea conditions. The link from the small station to the master station adopts a general low-multiplication spread spectrum waveform. When the sea conditions are good, the small station adopts a time-slot communication mode based on its own sea condition detection results.

[0056] In one exemplary embodiment, such as Figure 2 As shown, a method for constructing a transmission frame is provided, which can be applied to... Figure 1 Taking the receiving terminal as an example, the explanation includes the following steps 202 to 208. Wherein:

[0057] S202. For any one of the multiple preset transmission frames, during the process of receiving the preset transmission frame sent by the sending terminal, the total frame length of the preset transmission frame, the number of subframes in the preset transmission frame, and the subframe length of any one subframe are obtained. For the occluded part of the preset transmission frame that is blocked by an obstacle during transmission, the first ratio between the first length of the occluded part and the total frame length is obtained. Among them, the total frame length of different types of preset transmission frames is the same, but the number of subframes is different.

[0058] Optionally, the obstacle may be, but is not limited to, ocean waves.

[0059] Optionally, the total frame length of the preset transmission frame can be determined, but is not limited to, based on the preset occlusion period of the obstacle.

[0060] Optionally, since the starting position of wave obstruction of the transmission frame is random, obstruction of the frame header may lead to the loss of the entire transmission frame data. Therefore, the preset transmission frame is divided into multiple independent subframes with the same structure, such as... Figure 3 As shown, each subframe is the same size and includes a frame header (synchronization header), an information identifier, and a frame body arranged sequentially. The frame body consists of multiple information blocks and multiple pilot symbols, which are alternately distributed within the frame body. Each subframe, through its included synchronization header and pilot symbols, ensures independent time-frequency synchronization. The information identifier identifies the subframe waveform parameters and its position within the transmission frame. Pilot symbols are inserted at equal intervals into the subframe payload to support carrier frequency offset, phase estimation, and compensation by the receiving terminal.

[0061] Optionally, since the anti-interference waveform frame body has a high spreading factor, it will lead to a decrease in the overall signal-to-noise ratio of the frame. The frame header needs to be set with an appropriate spreading factor to obtain a certain spreading gain. At the same time, since it is necessary to ensure that the waveforms at the same chip rate have the same frame header, when designing the frame header, priority should be given to designing the frame header for the waveform with a high spreading frame body. The length of the basic frame header can be appropriately increased to reduce the complexity of the receiver.

[0062] Optionally, since the information frame body has a high spreading factor, if RM encoding, BCH code, etc. are used, high-multiplication spreading is also required, the overall length is long, and accurate decoding is required, resulting in a low fault tolerance rate. Under each symbol rate condition, multiple PN codes can be selected to identify the waveform at each symbol rate. During the signal reception process, it is only necessary to use the local PN code to perform alignment correlation with the corresponding part extracted from the received signal, and the received waveform type is obtained according to the PN code that maximizes the correlation value.

[0063] S204. For at least one information-deficient subframe in the preset transmission frame, sort the at least one information-deficient subframe along the intra-frame field parsing direction of the preset transmission frame, and for the frame header of the last subframe in the sorting result, obtain the second length of the occluded part of the frame header that is blocked by an obstacle.

[0064] The parsing direction of intra-frame fields is from the frame header to the frame body.

[0065] Optionally, the second length of the occluded portion of the frame header that is obscured by an obstacle is random.

[0066] Optionally, during the transmission of a preset transmission frame, if a subframe is obstructed by an obstacle, causing partial or complete loss of information within that subframe, then that subframe is considered an information-missing subframe. If the frame header of a subframe is obstructed, all data contained in that subframe may be completely lost, and the longer the obstructed portion of the frame header, the greater the likelihood of complete data loss. For example, if... Figure 4 As shown, Figure 4 SF1 to SF16 are all subframes, from Figure 4 As shown in the topmost image, if the frame header of subframe SF4 is obscured, there is a possibility that the entire SF4 information may be lost. Figure 4 As shown in the middle image, if the frame header of subframe SF7 is obscured, then there is a possibility that the entire information of SF7 may be lost. Figure 4 As shown in the bottommost diagram, if the frame header of subframe SF13 is obscured, then there is a possibility that the information of the entire SF13 may be lost.

[0067] S206. Based on the first ratio, the number of subframes, the second length, and the subframe length, determine the data extraction ratio of the preset transmission frame; wherein, the data extraction ratio represents the second ratio between the first data amount and the second data amount, the first data amount is the amount of data contained in the preset transmission frame when the preset transmission frame is received, and the second data amount is the amount of data contained in the preset transmission frame when the sending terminal sends the preset transmission frame.

[0068] Alternatively, the data extraction ratio can be obtained by the following formula:

[0069]

[0070]

[0071] In the formula, For the data extraction ratio, The first ratio is given, and N is the number of subframes. For the subframe length, Total frame length A is the second length, and A is the preset length threshold.

[0072] Optionally, if If A is greater than or equal to A, it cannot be captured correctly. The subframe containing the corresponding frame header; in a given In the case of a certain value, increasing the number of subframes N can improve the data extraction ratio, and... At that time, the data extraction ratio was the lowest.

[0073] Optionally, such as Figure 4 As shown, if the first ratio The percentage is 50%, meaning that the first length of the transmitted frame that is blocked accounts for 50% of the total frame length. However, since the frame header is blocked, the information of the entire subframe may be lost, which results in the proportion of information extracted from the received transmitted frame being less than 50%. By comparing the actual information lost under different numbers of subframes, it can be seen that increasing the number of subframes can effectively alleviate the additional information loss caused by the blockage of the frame header by the waves.

[0074] S208. Determine the coding interleaving scheme and the transmission efficiency of any preset transmission frame. Based on the transmission efficiency and data extraction ratio, determine the target transmission frame structure and combine the coding interleaving scheme and the target transmission frame structure to determine the target transmission frame.

[0075] Optionally, a higher data extraction ratio indicates that using the corresponding preset transmission frame as the transmission frame can minimize the information loss caused by obstacles blocking the transmission frame; transmission efficiency refers to the ratio of the actual transmission speed of effective data to the total transmission speed, which is used to measure the utilization of transmission resources.

[0076] In the aforementioned transmission frame construction method, for any one of a variety of preset transmission frames, during the process of receiving a preset transmission frame sent by the transmitting terminal, the total frame length of the preset transmission frame, the number of subframes in the preset transmission frame, and the subframe length of any one subframe are obtained. Furthermore, for the occluded portion of the preset transmission frame that is blocked by an obstacle during transmission, a first ratio between the first length of the occluded portion and the total frame length is obtained. The total frame length is the same for different types of preset transmission frames, but the number of subframes is different. For at least one information-deficient subframe in the preset transmission frame, the at least one information-deficient subframe is sorted along the intra-frame field parsing direction of the preset transmission frame, and the sorting results are then... The method for the last subframe header obtains the second length of the portion of the header obscured by an obstacle; based on a first ratio, the number of subframes, the second length, and the subframe length, a data extraction ratio for a preset transmission frame is determined; wherein, the data extraction ratio represents the second ratio between the first data amount and the second data amount, the first data amount being the amount of data contained in the preset transmission frame when the preset transmission frame is received, and the second data amount being the amount of data contained in the preset transmission frame when the transmitting terminal sends the preset transmission frame; the method determines the coding interleaving scheme and the transmission efficiency of any preset transmission frame; based on the transmission efficiency and the data extraction ratio, the target transmission frame structure is determined; and the target transmission frame is determined by combining the coding interleaving scheme and the target transmission frame structure. The method provided in this application, for preset transmission frames containing different numbers of subframes, selects target transmission frames by comparing the data extraction ratio and the transmission efficiency. This ensures that during the transmission of a signal composed of target transmission frames, signal loss is minimized while maximizing the data transmission capacity of the target transmission frame.

[0077] In some embodiments, such as Figure 5 As shown, based on the first ratio, the number of subframes, the second length, and the subframe length, the data extraction ratio of the preset transmission frame is determined, including:

[0078] S502, if the second length is less than the preset length threshold, determine the data extraction ratio based on the first ratio.

[0079] S504. If the second length is not less than the preset length threshold, determine the data extraction ratio based on the first ratio, the number of subframes, the second length, and the subframe length.

[0080] Optionally, under a fixed information payload, increasing the number of subframes N will improve the data extraction ratio. Based on the content of this embodiment, the formula for calculating the data extraction ratio can be further refined as follows:

[0081]

[0082]

[0083] In this embodiment, by comparing the second length with a preset length threshold, the data extraction ratio is determined, thereby maximizing the data extraction ratio.

[0084] In some embodiments, determining the coding interleaving scheme includes: acquiring multiple inter-frame interleaving parameters, a target coding rate, and multiple subframe numbers for multiple preset transmission frames; performing Monte Carlo simulation based on the initial combination and the target coding rate for any initial combination formed by any number of subframes and any inter-frame interleaving parameter to obtain the bit error rate curve under the initial combination; and determining a target combination from all initial combinations based on the bit error rate curve, and determining the interleaving width of the target transmission frame as the product between the number of subframes and the inter-frame interleaving parameter in the target combination.

[0085] Among them, the inter-frame interleaving parameters are used to define the data permutation rules between different subframes (such as interleaving depth, data block permutation order, etc.). The core function is to distribute continuous data across multiple subframes for transmission to combat burst errors in the channel. The coding rate refers to the ratio of the number of useful information bits in the channel coding to the total number of bits after coding (such as 1 / 3, 5 / 6), which is a key parameter for measuring coding efficiency and anti-interference capability. Monte Carlo simulation simulates the actual channel environment (such as random noise, burst blockage) through a large number of random experiments, and performs tens of thousands of transmission simulations for each combination of "number of subframes + interleaving parameters", statistically analyzes the bit error rate under different signal-to-noise ratios, and finally generates a statistically significant performance curve. The bit error rate refers to the ratio of the number of erroneous bits after decoding at the receiver to the total number of transmitted bits, which is a core indicator for measuring communication reliability. The interleaving width is used to quantify the data range covered by the interleaving operation, representing the total number of units to which the data is distributed during the interleaving operation. The larger the width, the stronger the ability to resist long burst errors.

[0086] Optionally, assuming a 1 / 4 (2560, 10240) LDPC is used, the wave blocking period is 1.28s, the information rate is 128kbps, and each subframe contains one coded block, the bit error rate curves under different subframe numbers N and different interleaving widths are as follows: Figure 6 , Figure 7 , Figure 8As shown, with the same interleaving width, an interleaving width that is an integer multiple of the number of coding blocks ensures that all coding blocks undergo essentially consistent interleaving processing. This allows burst errors caused by wave blockage to be distributed more evenly across the coding blocks, preventing some coding blocks from deteriorating further due to uneven interleaving during wave blockage. In "1 / 4 (2560, 10240) LDPC", 1 / 4 represents the target coding rate, 2560 represents the number of useful information bits, 10240 represents the total bit length after coding, LDPC (Low-Density Parity-Check Code) is a high-performance channel coding technique. Its core function is to add "redundant check bits" to the "useful information bits," enabling the receiver to detect and correct errors generated during transmission (such as wave blockage or noise interference). It is a key technology for ensuring communication reliability, and ber represents the bit error rate.

[0087] Optionally, considering information transmission efficiency, the number of selectable subframes is limited; assuming the total length of the synchronization header and information identifier in each subframe is 80 symbols, and a pilot symbol is inserted every 64 information symbols in the subframe body; Table 1 shows the frame efficiency when the number of subframes is 64, 128, 256, and 512 respectively:

[0088] Table 1

[0089]

[0090] Optionally, the total number of frame header symbols in Table 1 is the total length of the frame header; the number of subframes N, the total number of frame header symbols, the total number of pilots, and the frame efficiency in Table 1 are all for the entire transmission frame.

[0091] Optionally, a frame rate reduction of up to 5% is achieved when the number of subframes is 512 compared to 256. The optimal inter-subframe interleaving parameters will be investigated for subframe numbers of 64, 128, and 256. The inter-subframe interleaving frame order variation is as follows: Figure 9 As shown, I represents the inter-frame interleaving parameter.

[0092] Optionally, Table 2 shows the possible interleaving parameters I for different numbers of subframes N. Different inter-frame interleaving parameters will also affect the interleaving effect. By performing Monte Carlo simulations under different interleaving conditions, suitable inter-frame interleaving parameters can be obtained. Figure 10 The graph shows the performance curves of different inter-frame interleaving parameters for each selected number of subframes. Here, ES / N0 is 3.8 dB, and the bit interleaving width is the same as the number of subframes. ES is the average energy carried by a single modulation symbol, and N0 is the noise power spectral density. The reasonable combination of inter-frame interleaving parameters can be obtained from the graph as shown in the following formula:

[0093]

[0094] Table 2

[0095]

[0096] Optionally, Figure 11 For different Below is the curve showing the change in bit error rate (BER) with signal-to-noise ratio (SNR); Table 3 shows the Monte Carlo simulation parameters at this point. By comparing the performance curves, the selected... The product of the two parameters yields the interleaving width for one deep interleaving. .

[0097] Table 3

[0098]

[0099] Optionally, in the foregoing discussion, it was assumed that the number of coded blocks was the same as the number of subframes. Under this assumption, the number of coded blocks would change with the number of subframes; as the number of subframes increased, the code length would decrease, the encoding and decoding complexity would decrease, and the occlusion effect would decrease. However, to a certain extent, the reduction in occlusion effect brought about by the increase in the number of subframes could not compensate for the impact of the decrease in code length.

[0100] Optionally, the interleaving scheme is further analyzed with a fixed number of coding blocks of 64. In order to highlight the impact of different subframe numbers on decoding performance, eight cases with subframe numbers of 4, 8, 16, 32, 64, 128, 256, and 512 are considered. In the simulation analysis, the number of waves blocking frames is set to the number of subframes × the blocking probability + 1.

[0101] Optionally, Monte Carlo experiments were conducted under different subframe numbers, with the experimental conditions being the same as those in Table 3.

[0102] Optionally, such as Figure 12 As shown, when the number of subframes is small, increasing the number of subframes can significantly improve the occlusion effect. However, after the number of subframes exceeds a certain value, the improvement in the occlusion effect decreases with increasing the number of subframes. When ES / N0 is 4.2dB, the bit error rate is basically the same when the number of subframes is 128, 256, and 512, all below 10⁻⁶. Therefore, considering both performance and frame efficiency, the following coding interleaving scheme can be selected: (2560, 10240)LDPC, with 128 subframes and an interleaving width of 256.

[0103] In this embodiment, the interleaving width of the target transmission frame is determined based on multiple interleaving parameters between subframes, the target coding rate, and the number of multiple subframes of multiple preset transmission frames. This can more effectively alleviate the occlusion effect of ocean waves and significantly improve communication reliability.

[0104] In some embodiments, obtaining the target coding rate includes: during the transmission of a preset transmission frame, for any one of the uplink and downlink links, obtaining the data transmission distance, operating frequency, atmospheric power loss, and feeder power loss of the link, and obtaining the power loss value of the link based on the data transmission distance, operating frequency, atmospheric power loss, and feeder power loss; obtaining the carrier bandwidth, and determining the carrier-to-noise ratio of the link based on the power loss value and the carrier bandwidth; wherein, the carrier-to-noise ratio characterizes the ratio between the carrier signal power and the channel noise power density; obtaining the target ground demodulation threshold based on the carrier-to-noise ratio and the carrier bandwidth, and determining the target coding rate based on the principle that the decoding performance meets the target ground demodulation threshold.

[0105] Among them, feeder loss refers to the signal power attenuation that occurs when a signal is transmitted through a transmission line (feeder) from the output port of the high-frequency equipment at the transmitting end to the antenna feed source, and from the antenna feed source to the input port of the receiving equipment at the receiving end; operating frequency refers to the frequency of the radio waves used by the communication system to transmit signals.

[0106] Optionally, Figure 13 This represents a satellite communication link, and the gain and loss are marked. (See diagram.) , The uplink and downlink propagation losses are respectively, as shown in the following formula:

[0107]

[0108] In the formula, for or d is the data transmission distance, f is the operating frequency, A is the atmospheric power loss, and F is the feeder power loss.

[0109] Optionally, the uplink and downlink carrier noise ratios are as follows:

[0110]

[0111] In the formula, EIRP is the product of the antenna transmit power and the antenna gain; G / T is the quality factor, which is the ratio of the antenna gain to the equivalent noise temperature of the receiving system. , Where B is the Boltzmann constant and B is the carrier bandwidth. This represents the number of subcarriers.

[0112] Optionally, ground demodulation threshold As shown in the following formula:

[0113]

[0114] In the formula, This refers to the bit rate.

[0115] Alternatively, the link parameters can be as shown in Table 4:

[0116] Table 4

[0117]

[0118] Optionally, the link budget at different bit rates can be obtained from Table 4, as shown in Table 5:

[0119] Table 5

[0120]

[0121] Optionally, to ensure at least one times the link margin, the ground demodulation threshold is therefore... It should be less than 5.8dB; by studying the decoding performance of different coding interleaving schemes, and giving a bit error rate of 10... -6 Work threshold.

[0122] Optionally, the Monte Carlo experimental parameters are shown in Table 6, derived from... Figure 14 It can be seen that even with a code rate of 1 / 2, there is still a high error rate under extremely high Eb / N0 conditions;

[0123] Optionally, from Table 7, Figure 15 It can be seen that when the code rate is 1 / 3, the decoding performance cannot meet the link-to-ground demodulation threshold requirements. In contrast, the decoding performance at code rates of 1 / 4 and 1 / 5 can both meet the link-to-ground demodulation threshold. The performance at a code rate of 1 / 5 is improved compared to 1 / 4, but its information transmission efficiency is 20% lower than that at a code rate of 1 / 4. In actual engineering projects, the code rate can be selected according to actual needs. This embodiment uses the 1 / 4 LDPC coding scheme. Table 7 shows the demodulation threshold values ​​at different code rates.

[0124] Table 6

[0125]

[0126] Table 7

[0127]

[0128] In this embodiment, by determining the target decoding bitrate, the ground demodulation performance can be accurately guaranteed, and the communication reliability can be improved.

[0129] In some embodiments, obtaining the carrier bandwidth includes: obtaining a preset ground demodulation threshold, an anti-interference tolerance, and the minimum information rate allowed by the physical layer of the communication system; obtaining a spreading factor based on the preset ground demodulation threshold and the anti-interference tolerance; obtaining a chip transmission rate based on the spreading factor, the minimum information rate, and the transmission efficiency; determining a root-raised cosine parameter, and determining the carrier bandwidth based on the chip transmission rate and the root-raised cosine parameter.

[0130] Among them, the spreading factor is used to describe the extent to which the spreading operation expands the signal bandwidth or chip rate; the root raised cosine (RRC) parameter is a key parameter used in digital communication systems to describe the characteristics of the RRC filter, and it has an important impact on signal shaping, spectral characteristics, and the bit error rate performance of the system; the interference tolerance refers to the maximum interference signal strength that a device or system can withstand while maintaining normal operation, and it is a key indicator for measuring its interference resistance.

[0131] Optionally, assuming the lowest physical layer information rate is 16kbps, using LDPC coding with a preset coding rate of 1 / 2, QPSK (Quadrature Phase Shift Keying) modulation, a demodulation threshold of 5dB, and an interference tolerance of 25dB, then the spreading factor should be at least:

[0132]

[0133] Optionally, if the spreading factor is set to a power of 2, the frame body spreading ratio can be set to 1024. At this time, the information chip transmission rate is 16.384 Mcps. In order to leave space for the frame header, information identifier, pilot, etc., the chip transmission rate is set to 19.2 Mcps. If the root raised cosine parameter is selected as 0.25, the required bandwidth is 24MHz.

[0134] Optionally, the spread spectrum ratio can be reduced to increase the information rate, and the waveform can be applied to the link between the gateway station and the main station in a high-throughput satellite communication system.

[0135] In this embodiment, by determining the carrier bandwidth based on the chip transmission rate and the root raised cosine parameter, the anti-interference and demodulation requirements can be accurately balanced, thereby improving the reliability in complex scenarios.

[0136] Based on the above wave-resistant and interference-resistant waveform design method, the following waveforms were actually designed: interference-resistant measurement and control waveform 1, wave-resistant service waveform 2, and wave-resistant interference-resistant measurement and control waveform 3. The waveform structures are shown in Tables 8 and 9 below:

[0137] Table 8

[0138]

[0139] Table 9

[0140]

[0141] In one exemplary embodiment, another method for constructing transport frames is proposed, including the following:

[0142] To address the anti-interference requirements of the telemetry and control channel from the master station to the small station, a high spreading ratio waveform is designed, and the spreading ratio is designed according to the anti-interference tolerance. The information chip rate is obtained based on the required information bit rate and the spreading ratio, and the required bandwidth is obtained after adding the frame header, identifier, and pilot.

[0143] To address the need for wave-blocking resistance, the multi-subframe structure characteristics of the wave-blocking waveform are determined. Each subframe includes a frame header and an identifier. Low-rate LDPC coding is designed based on the maximum wave blockage probability. Long-period deep interleaving is designed with a fixed interleaving width and the interleaving depth is determined by the transmission frame length.

[0144] The transmission frame length is variable; the worse the sea conditions, the longer the transmission frame is required.

[0145] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0146] Based on the same inventive concept, this application also provides a transmission frame construction apparatus for implementing the transmission frame construction method described above. The solution provided by this apparatus is similar to the implementation described in the above method; therefore, the specific limitations in one or more transmission frame construction apparatus embodiments provided below can be found in the limitations of the transmission frame construction method described above, and will not be repeated here.

[0147] In one exemplary embodiment, such as Figure 16 As shown, a transmission frame construction apparatus 1600 is provided, including: an acquisition module 1601, a sorting module 1602, a first determination module 1603, and a second determination module 1604, wherein:

[0148] The acquisition module 1601 is used to acquire, during the process of receiving the preset transmission frame sent by the sending terminal, the total frame length of the preset transmission frame, the number of subframes in the preset transmission frame, and the subframe length of any one of the preset transmission frames, and to acquire, for the occluded part of the preset transmission frame that is blocked by an obstacle during transmission, the first ratio between the first length of the occluded part and the total frame length; wherein, the total frame length of different types of preset transmission frames is the same, but the number of subframes is different.

[0149] The sorting module 1602 is used to sort at least one information-deficient subframe in the preset transmission frame along the intra-frame field parsing direction of the preset transmission frame, and to obtain the second length of the occluded portion of the frame header of the last subframe in the sorting result, which is obscured by the obstacle.

[0150] The first determining module 1603 is used to determine the data extraction ratio of the preset transmission frame based on the first ratio, the number of subframes, the second length, and the subframe length; wherein the data extraction ratio represents the second ratio between the first data amount and the second data amount, the first data amount is the amount of data contained in the preset transmission frame when the preset transmission frame is received, and the second data amount is the amount of data contained in the preset transmission frame when the sending terminal sends the preset transmission frame.

[0151] The second determining module 1604 is used to determine the encoding interleaving scheme and the transmission efficiency of any preset transmission frame, determine the target transmission frame structure based on the transmission efficiency and the data extraction ratio, and determine the target transmission frame in combination with the encoding interleaving scheme and the target transmission frame structure.

[0152] In some embodiments, the first determining module 1603 is further configured to determine the data extraction ratio based on the first ratio when the second length is less than a preset length threshold; and to determine the data extraction ratio based on the first ratio, the number of subframes, the second length, and the subframe length when the second length is not less than the preset length threshold.

[0153] In some embodiments, the second determining module 1604 is further configured to acquire multiple inter-frame interleaving parameters, a target coding rate, and multiple subframe numbers of the multiple preset transmission frames; for an initial combination formed by any number of subframes and any inter-frame interleaving parameter, perform Monte Carlo simulation based on the initial combination and the target coding rate to obtain the bit error rate curve under the initial combination; based on the bit error rate curve, determine a target combination from all initial combinations, and determine the interleaving width of the target transmission frame as the product between the number of subframes and the inter-frame interleaving parameter in the target combination.

[0154] In some embodiments, the second determining module 1604 is further configured to, during the transmission of the preset transmission frame, for any one of the uplink and downlink links, obtain the data transmission distance, operating frequency, atmospheric power loss, and feeder power loss of the link, and obtain the power loss value of the link based on the data transmission distance, the operating frequency, the atmospheric power loss, and the feeder power loss; obtain the carrier bandwidth, and determine the carrier-to-noise ratio of the link based on the power loss value and the carrier bandwidth; wherein the carrier-to-noise ratio characterizes the ratio between the carrier signal power and the channel noise power density; obtain the target ground demodulation threshold based on the carrier-to-noise ratio and the carrier bandwidth, and determine the target coding rate based on the principle that the decoding performance meets the target ground demodulation threshold.

[0155] In some embodiments, the second determining module 1604 is further configured to obtain a preset ground demodulation threshold, an anti-interference tolerance, and the minimum information rate allowed by the physical layer of the communication system; obtain a spreading factor based on the preset ground demodulation threshold and the anti-interference tolerance; determine a root raised cosine parameter based on the spreading factor, the minimum information rate, and the transmission efficiency; and determine the carrier bandwidth based on the chip transmission rate and the root raised cosine parameter.

[0156] In some embodiments, the transmission frame construction apparatus 1600 is further configured to include a frame header, an information identifier, and a frame body arranged sequentially in any subframe, wherein the frame body is composed of a plurality of information blocks and a plurality of pilot symbols, and the information blocks and the pilot symbols are alternately distributed in the frame body.

[0157] Each module in the aforementioned transmission frame construction device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0158] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 17 As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores and transmits data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network connection. When executed by the processor, the computer program implements a method for constructing transmission frames.

[0159] Those skilled in the art will understand that Figure 17 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0160] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0161] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0162] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0163] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0164] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0165] 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 application.

[0166] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for constructing a transmission frame, characterized in that, The method includes: For any one of a variety of preset transmission frames, during the process of receiving the preset transmission frame sent by the sending terminal, the total frame length of the preset transmission frame, the number of subframes in the preset transmission frame, and the subframe length of any one subframe are obtained. For the portion of the preset transmission frame that is blocked by an obstacle during transmission, a first ratio between the first length of the blocked portion and the total frame length is obtained. The total frame length is the same for different types of preset transmission frames, but the number of subframes is different. For at least one information-deficient subframe in the preset transmission frame, the at least one information-deficient subframe is sorted along the intra-frame field parsing direction of the preset transmission frame, and for the frame header of the last subframe in the sorting result, the second length of the occluded portion of the frame header that is obscured by the obstacle is obtained. Based on the first ratio, the number of subframes, the second length, and the subframe length, the data extraction ratio of the preset transmission frame is determined; wherein, the data extraction ratio represents the second ratio between the first data amount and the second data amount, the first data amount is the amount of data contained in the preset transmission frame when the preset transmission frame is received, and the second data amount is the amount of data contained in the preset transmission frame when the sending terminal sends the preset transmission frame. Determine the encoding interleaving scheme and the transmission efficiency of any preset transmission frame. Based on the transmission efficiency and the data extraction ratio, determine the target transmission frame structure and combine the encoding interleaving scheme and the target transmission frame structure to determine the target transmission frame.

2. The method according to claim 1, characterized in that, Based on the first ratio, the number of subframes, the second length, and the subframe length, the data extraction ratio of the preset transmission frame is determined, including: If the second length is less than a preset length threshold, the data extraction ratio is determined based on the first ratio. If the second length is not less than a preset length threshold, the data extraction ratio is determined based on the first ratio, the number of subframes, the second length, and the subframe length.

3. The method according to claim 1, characterized in that, The determination of the coding interleaving scheme includes: Obtain multiple inter-frame interleaving parameters, target coding bitrate, and the number of multiple subframes of the various preset transmission frames; For an initial combination formed by any number of subframes and any interleaving parameters between subframes, Monte Carlo simulation is performed based on the initial combination and the target coding rate to obtain the bit error rate curve under the initial combination; Based on the bit error rate curve, a target combination is determined from all initial combinations, and the product of the number of subframes in the target combination and the inter-subframe interleaving parameter is determined as the interleaving width of the target transmission frame.

4. The method according to claim 3, characterized in that, The process of obtaining the target encoding bitrate includes: During the transmission of the preset transmission frame, for any one of the uplink and downlink, the data transmission distance, operating frequency, atmospheric power loss, and feeder power loss of the link are obtained, and the power loss value of the link is obtained based on the data transmission distance, the operating frequency, the atmospheric power loss, and the feeder power loss. Obtain the carrier bandwidth, and determine the carrier-to-noise ratio of the link based on the power loss value and the carrier bandwidth; wherein, the carrier-to-noise ratio characterizes the ratio between the carrier signal power and the channel noise power density; The target ground demodulation threshold is obtained based on the carrier-to-noise ratio and the carrier bandwidth, and the target coding rate is determined based on the principle that the decoding performance meets the target ground demodulation threshold.

5. The method according to claim 4, characterized in that, The acquisition of carrier bandwidth includes: Obtain the preset ground demodulation threshold, interference tolerance, and the minimum information rate allowed by the physical layer of the communication system; The spreading factor is obtained based on the preset ground demodulation threshold and the anti-interference tolerance. Based on the spreading factor, the minimum information rate, and the transmission efficiency, the chip transmission rate is obtained; The root raised cosine parameter is determined, and the carrier bandwidth is determined based on the chip transmission rate and the root raised cosine parameter.

6. The method according to claim 1, characterized in that, Any subframe includes a frame header, an information identifier, and a frame body arranged in sequence. The frame body consists of multiple information blocks and multiple pilot symbols, and the information blocks and the pilot symbols are distributed alternately in the frame body.

7. A transmission frame construction apparatus, characterized in that, The device includes: The acquisition module is used to acquire, during the process of receiving the preset transmission frame sent by the sending terminal, the total frame length of the preset transmission frame, the number of subframes in the preset transmission frame, and the subframe length of any one of the preset transmission frames, and to acquire, for the occluded portion of the preset transmission frame that is blocked by an obstacle during transmission, a first ratio between the first length of the occluded portion and the total frame length; wherein, the total frame length is the same for different types of preset transmission frames, but the number of subframes is different. The sorting module is used to sort at least one information-deficient subframe in the preset transmission frame along the intra-frame field parsing direction of the preset transmission frame, and to obtain the second length of the occluded portion of the frame header of the last subframe in the sorting result, which is obscured by the obstacle. The first determining module is used to determine the data extraction ratio of the preset transmission frame based on the first ratio, the number of subframes, the second length, and the subframe length; wherein the data extraction ratio represents the second ratio between the first data amount and the second data amount, the first data amount is the amount of data contained in the preset transmission frame when the preset transmission frame is received, and the second data amount is the amount of data contained in the preset transmission frame when the sending terminal sends the preset transmission frame; The second determining module is used to determine the encoding interleaving scheme and the transmission efficiency of any preset transmission frame, determine the target transmission frame structure based on the transmission efficiency and the data extraction ratio, and determine the target transmission frame in combination with the encoding interleaving scheme and the target transmission frame structure.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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