Satellite network data transmission method

Abstract

The embodiment of the application discloses a satellite network data sending method. The method comprises the following steps: acquiring satellite payload data packets; establishing data frames corresponding to the satellite payload data packets, wherein the data frames comprise first signal-to-noise ratio data frames, second signal-to-noise ratio data frames and third signal-to-noise ratio data frames; sending the data frames to a receiving end; and processing the data frames to obtain the satellite payload data packets. The working point ranges of the first signal-to-noise ratio data frames, the second signal-to-noise ratio data frames and the third signal-to-noise ratio data frames are greater than or equal to-15 dB and less than-10 dB, greater than or equal to-10 dB and less than 0 dB, and greater than or equal to 0 dB and less than 20 dB. The first signal-to-noise ratio data frames comprise a plurality of sub-first signal-to-noise ratio data frames, and the frame length of the sub-first signal-to-noise ratio data frames is the same as that of the second signal-to-noise ratio data frames and the third signal-to-noise ratio data frames. The unique code field of the frame header of the first signal-to-noise ratio data frames, the unique code field of the frame header of the second signal-to-noise ratio data frames and the unique code field of the frame header of the third signal-to-noise ratio data frames are selected from a pseudo-random sequence set.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite network communication. More particularly, it relates to a satellite network data transmission method. BACKGROUND

[0002] In a conventional satellite communication system, such as DVB-S2X, the range of the working point of the ratio of the per-symbol energy to the noise power spectral density (Es / No) is -10dB~20dB. With the change of the working point, the frame structure and the frame length are also dynamically adjusted accordingly. Although this dynamic adjustment can adapt to different communication conditions, the satellite communication system needs to send different waveforms to support different apertures and different capabilities of the receiving end, which leads to additional overhead of system resources.

[0003] In a conventional satellite communication system, the physical frame with a shorter frame structure is used for transmission under high signal-to-noise ratio channel conditions, and the physical frame with a longer frame structure is used for transmission under low signal-to-noise ratio channel conditions. The working point of high signal-to-noise ratio is 0dB~20dB, and a shorter frame header is used. The working point of low signal-to-noise ratio is 0dB~-10dB, and a longer frame header is used. The working point range of high and low signal-to-noise ratio is not convenient to mix. For example, using a high signal-to-noise ratio frame at 5dB, a sudden rain fade causes a 10dB signal loss, so the transmitter and receiver need to change the transmission mode and the receiving mode respectively.

[0004] In addition, with the increase of the modulation order, the overhead of the frame header of the high signal-to-noise ratio frame gradually increases.

[0005] In addition, when a larger fading is encountered on the signal transmission path or the antenna form of the receiving end is smaller, the signal-to-noise ratio of the working point may be lower than -10dB. In this case, the existing low signal-to-noise ratio frame cannot meet the working point condition, and a lower signal-to-noise ratio frame structure needs to be introduced to support the working point of signal-to-noise ratio -15dB~-10dB. SUMMARY

[0006] The present application aims to provide a satellite network data transmission method to solve at least one of the problems in the prior art.

[0007] To achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0008] The first aspect of the present application provides a satellite network data transmission method, which comprises:

[0009] obtaining a satellite payload data packet;

[0010] establishing a data frame corresponding to the satellite payload data packet, the data frame comprising a plurality of first signal-to-noise ratio data frames, a plurality of second signal-to-noise ratio data frames and a plurality of third signal-to-noise ratio data frames;

[0011] The data frame is transmitted by a transmitting end to a receiving end, so that the receiving end processes the data frame to obtain the satellite payload data packet.

[0012] The working point of the first signal-to-noise ratio data frame ranges from greater than or equal to -15 dB to less than -10 dB, the working point of the second signal-to-noise ratio data frame ranges from greater than or equal to -10 dB to less than 0 dB, and the working point of the third signal-to-noise ratio data frame ranges from greater than or equal to 0 dB to less than 20 dB.

[0013] The first signal-to-noise ratio data frame includes a plurality of sub-first signal-to-noise ratio data frames, the frame length of the sub-first signal-to-noise ratio data frame is the same as the frame length of the second signal-to-noise ratio data frame, and the frame length of the second signal-to-noise ratio data frame is the same as the frame length of the third signal-to-noise ratio data frame.

[0014] The unique code field of the frame header of the first signal-to-noise ratio data frame is selected from a pseudo-random sequence set, and the unique code field of the frame header of the second signal-to-noise ratio data frame and the unique code field of the frame header of the third signal-to-noise ratio data frame are also selected from the pseudo-random sequence set.

[0015] Optionally, the establishing of the data frame corresponding to the satellite payload data packet comprises:

[0016] A plurality of first signal-to-noise ratio data frames corresponding to the satellite payload data packet are established.

[0017] The establishing of one first signal-to-noise ratio data frame corresponding to the satellite payload data packet comprises:

[0018] A plurality of first frame bodies corresponding to the satellite payload data packet are established.

[0019] A plurality of first frame headers corresponding to the plurality of first frame bodies are established, the first frame header comprising a first unique code field, a physical layer signaling field and a second unique code field.

[0020] A plurality of first sub-first signal-to-noise ratio data frames corresponding to the satellite payload data packet are established, the first sub-first signal-to-noise ratio data frame comprising a first frame header and a first frame body.

[0021] A plurality of second frame headers corresponding to the plurality of first frame bodies are established, the second frame header comprising a third unique code field, a physical layer signaling field and a fourth unique code field.

[0022] A plurality of second sub-first signal-to-noise ratio data frames corresponding to the satellite payload data packet are established, the second sub-first signal-to-noise ratio data frame comprising a second frame header and a first frame body.

[0023] The first signal-to-noise ratio data frame is established according to the plurality of first sub-first signal-to-noise ratio data frames and the plurality of second sub-first signal-to-noise ratio data frames.

[0024] wherein the first frame header and the second frame header are different from each other.

[0025] Optionally, the set of pseudo-random sequences comprises a first set of pseudo-random sequences and a second set of pseudo-random sequences.

[0026] The first set of pseudo-random sequences comprises a first pseudo-random sequence and a second pseudo-random sequence.

[0027] The first pseudo-random sequence is:

[0028] 05EA4AE105EA5F198AE11F19B4ABDB5EDB5EE1344AE105EA528F,

[0029] The 896 bits in the second pseudo-random sequence are:

[0030] 7C667C667C664A3CD2AF17A97C662B8484D12B8484D1D2AF17A9D2AF6D7B6D7B4A3C84D17C66D2AF2B847C66D2AFD2AF4A3C84D184D14A3C84D184D16D7B2B8417A984D14A3C7C666D7B84D117A9D2AF6D7B2B84D2AF17A917A97C664A3C17A92B846D7B6D7B4A3C4A3C4A3CD2AF6D7B;

[0031] The second set of pseudo-random sequences comprises a third pseudo-random sequence and a fourth pseudo-random sequence; the third pseudo-random sequence is:

[0032] 19D1C04C19D1F3D2FA18BA18891E6725C91E73D2FA1899D1C04C,

[0033] The 896 bits in the fourth pseudo-random sequence are:

[0034] 0130CF4B24799C976747D2BB01302479CF4BE8629C97CF4BE862D2BBCF4B6747E8620130E8629C976747E862CF4BD2BBD2BBD2BB9C972479 247967470130D2BB674767476747D2BB9C97E8620130D2BBCF4B0130CF4B9C97E86224799C9701309C979C97247924790130CF4B2479D2BB.

[0035] Optionally, establishing a data frame corresponding to the satellite payload data packet includes:

[0036] Establish multiple first signal-to-noise ratio data frames corresponding to the satellite payload data packets;

[0037] Establishing a first signal-to-noise ratio data frame corresponding to the satellite payload data packet includes:

[0038] Establish multiple first frame bodies corresponding to the satellite payload data packets;

[0039] Establish multiple first frame headers corresponding to the multiple first frame bodies, wherein the first frame header includes a first unique code field, a physical layer signaling field, and a second unique code field;

[0040] Multiple first sub-first signal-to-noise ratio data frames are established corresponding to the satellite payload data packets. Each first sub-first signal-to-noise ratio data frame includes a first frame header and a first frame body.

[0041] Establish multiple second frame headers corresponding to the multiple first frame bodies, wherein the second frame header includes a third unique code field, a physical layer signaling field, and a fourth unique code field;

[0042] Multiple second sub-first signal-to-noise ratio data frames are established corresponding to the satellite payload data packets. Each second sub-first signal-to-noise ratio data frame includes a second frame header and a first frame body.

[0043] Establish multiple third frame headers corresponding to the multiple first frame bodies, wherein the third frame header includes a fifth unique code field, a physical layer signaling field, and a sixth unique code field;

[0044] Multiple third sub-first signal-to-noise ratio data frames are established corresponding to the satellite payload data packets. Each third sub-first signal-to-noise ratio data frame includes a third frame header and a first frame body.

[0045] The first signal-to-noise ratio data frame is established based on the plurality of first sub-first signal-to-noise ratio data frames, the plurality of second sub-first signal-to-noise ratio data frames, and the plurality of third sub-first signal-to-noise ratio data frames;

[0046] The first frame header, the second frame header and the third frame header are different from each other.

[0047] Optionally, the set of pseudo-random sequences comprises a first set of pseudo-random sequences, a second set of pseudo-random sequences, a third set of pseudo-random sequences, a fourth set of pseudo-random sequences.

[0048] The first set of pseudo-random sequences comprises a first pseudo-random sequence and a second pseudo-random sequence.

[0049] The first pseudo-random sequence is:

[0050] 05EA4AE105EA5F198AE11F19B4ABDB5EDB5EE1344AE105EA528F,

[0051] The 896 bits in the second pseudo-random sequence are:

[0052] 7C667C667C664A3CD2AF17A97C662B8484D12B8484D1D2AF17A9D2AF6D7B6D7B4A3C84D17C66D2AF2B847C66D2AFD2AF4A3C84D184D14A3C84D184D16D7B2B8417A984D14A3C7C666D7B84D117A9D2AF6D7B2B84D2AF17A917A97C664A3C17A92B846D7B6D7B4A3C4A3C4A3CD2AF6D7B;

[0053] The second set of pseudo-random sequences comprises a third pseudo-random sequence and a fourth pseudo-random sequence.

[0054] The third pseudo-random sequence is:

[0055] 19D1C04C19D1F3D2FA18BA18891E6725C91E73D2FA1899D1C04C,

[0056] The 896 bits in the fourth pseudo-random sequence are:

[0057] 0130CF4B24799C976747D2BB01302479CF4BE8629C97CF4BE862D2BBCF4B6747E8620130E8629C976747E862CF4BD2BBD2BBD2BB9C972479 247967470130D2BB674767476747D2BB9C97E8620130D2BBCF4B0130CF4B9C97E86224799C9701309C979C97247924790130CF4B2479D2BB;

[0058] The third set of pseudo-random sequences includes the fifth pseudo-random sequence and the sixth pseudo-random sequence;

[0059] The fifth pseudo-random sequence is:

[0060] 3D42ABA709B03263C78947897D4287897D42B739F263C9B009B0;

[0061] The 896 bits in the sixth pseudo-random sequence are:

[0062] 26C01E25DCE726C04758DCE7AE9C4758AE9CF50AF50ADCE7AE9CC98F26C0DCE74758F50AAE9C1E2547581E25C98FDCE747581E25F50A4758 C98FAE9CF50ADCE726C01E254758AE9C1E25AE9CC98FAE9CF50AC98FC98F47584758C98FDCE7475826C0F50A26C01E25DCE7AE9CC98FDCE7;

[0063] The fourth set of pseudo-random sequences includes the seventh pseudo-random sequence and the eighth pseudo-random sequence;

[0064] The seventh pseudo-random sequence is:

[0065] 209D6AC85E97C6A21963E1D4E09D6AC8609D5963E09D46A2327F;

[0066] The 896 bits in the eighth pseudo-random sequence are:

[0067] 7A5F1A8882751A88658F7A5F7A5F7A5F1A881A88AB21AB211A8887538753AB21658FC9FC8275C9FC658F8753658F1A88C9FC9FC8753C9FC8275658F7A5F87538753C9FC8753AB21AB21AB217A5F82757A5F1A88C9FC658FC9FCC9FC8275AB211A88AB218753658F658F82757A5F8753.

[0068] Optionally, the establishing the data frame corresponding to the satellite payload data packet further comprises:

[0069] establishing a plurality of second signal-to-noise ratio data frames corresponding to the satellite payload data packet;

[0070] wherein the establishing one second signal-to-noise ratio data frame corresponding to the satellite payload data packet comprises:

[0071] establishing a second frame body corresponding to the satellite payload data packet;

[0072] establishing a first frame header corresponding to the second frame body, the first frame header comprising a first unique code field, a physical layer signaling field and a second unique code field;

[0073] establishing the second signal-to-noise ratio data frame according to the first frame header and the second frame body;

[0074] the establishing the data frame corresponding to the satellite payload data packet further comprises:

[0075] establishing a plurality of third signal-to-noise ratio data frames corresponding to the satellite payload data packet;

[0076] wherein the establishing one third signal-to-noise ratio data frame corresponding to the satellite payload data packet comprises:

[0077] establishing a third frame body corresponding to the satellite payload data packet, the third frame body comprising a plurality of encoding frames;

[0078] establishing a second frame header corresponding to the third frame body, the second frame header comprising a third unique code field, a physical layer signaling field and a fourth unique code field;

[0079] establishing the third signal-to-noise ratio data frame according to the second frame header and the third frame body.

[0080] Optionally, the first frame body has a first length, the first frame body is modulated by BPSK, the first frame body has a spreading factor of 2, and the first frame body supports one encoding frame.

[0081] or the length of the second frame body is a first length, the second frame body adopts BPSK modulation, the spreading factor of the second frame body is 2, and the second frame body supports 1 coded frame;

[0082] or the length of the third frame body is a first length,

[0083] if the third frame body adopts QPSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 4 coded frames;

[0084] if the third frame body adopts 8PSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 6 coded frames;

[0085] if the third frame body adopts 16APSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 8 coded frames;

[0086] if the third frame body adopts 32APSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 10 coded frames;

[0087] if the third frame body adopts 64APSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 12 coded frames.

[0088] Optionally, the length of the first frame body is a second length, the first frame body adopts BPSK modulation, the spreading factor of the first frame body is 1, and the first frame body supports 1 coded frame;

[0089] or the length of the second frame body is a second length,

[0090] the second frame body adopts BPSK modulation, the spreading factor of the second frame body is 1, and the second frame body supports 1 coded frame;

[0091] or the length of the third frame body is a second length,

[0092] if the third frame body adopts QPSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 2 coded frames;

[0093] if the third frame body adopts 8PSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 3 coded frames;

[0094] if the third frame body adopts 16APSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 4 coded frames;

[0095] If the third frame body adopts 32APSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 5 coded frames.

[0096] If the third frame body adopts 64APSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 6 coded frames.

[0097] Optionally, the first bit of the physical layer signaling of the physical layer signaling field is 0, indicating that the frame body is a long frame, and the frame length of the long frame is a first length; and the first bit is 1, indicating that the frame body is a short frame, and the frame length of the short frame is a second length.

[0098] The second bit of the physical layer signaling is 0, indicating that the frame body adopts modulation order of 32APSK and below; and the second bit is 1, indicating that the frame body adopts modulation order of 64APSK and above.

[0099] The combination of the third bit, the fourth bit, the fifth bit, the sixth bit and the seventh bit of the physical layer signaling indicates the corresponding modulation and coding format.

[0100] Optionally, the transmitting the data frame to the receiving end by the transmitting end, so that the receiving end processes the data frame to obtain the satellite payload data packet comprises:

[0101] Encoding the transmitted information bits into coded frames by the transmitting end, and repeating mapping the coded frames into a plurality of sub-first signal-to-noise ratio data frames in the same first signal-to-noise ratio data frame;

[0102] Combining and decoding the soft information bits of the plurality of sub-first signal-to-noise ratio data frames in the same first signal-to-noise ratio data frame by the receiving end to obtain corresponding information bits.

[0103] The beneficial effects of the present application are as follows:

[0104] The technical solution of the present application can work in the range of Es / No of-15dB~20dB by adopting the composite waveform of the fixed frame structure, and supports multiple modulation modes. This design not only improves the adaptability and flexibility of the method, but also significantly reduces the resource overhead, and provides an efficient and reliable solution for satellite communication. BRIEF DESCRIPTION OF DRAWINGS

[0105] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0106] Figure 1 A flowchart of a satellite network data transmission method provided by an embodiment of the present application is shown.

[0107] Figure 2A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0108] Figure 3 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0109] Figure 4 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0110] Figure 5 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0111] Figure 6 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0112] Figure 7 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0113] Figure 8 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0114] Figure 9 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0115] Figure 10 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0116] Figure 11 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0117] Figure 12 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0118] Figure 13 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0119] Figure 14 A structure diagram of a data frame of the satellite network data sending method provided by the embodiment of the present application is shown.

[0120] Figure 15 The autocorrelation diagram of the pseudo-random sequence in the second example of the satellite network data sending method provided by the embodiment of the application is shown.

[0121] Figure 16 The cross-correlation diagram of the pseudo-random sequence in the first example and the second example of the satellite network data sending method provided by the embodiment of the application is shown.

[0122] Figure 17 The autocorrelation diagram of the pseudo-random sequence in the third example of the satellite network data sending method provided by the embodiment of the application is shown.

[0123] Figure 18 The cross-correlation diagram of the pseudo-random sequence in the first example and the third example of the satellite network data sending method provided by the embodiment of the application is shown.

[0124] Figure 19 The autocorrelation diagram of the pseudo-random sequence in the fourth example of the satellite network data sending method provided by the embodiment of the application is shown.

[0125] Figure 20 The cross-correlation diagram of the pseudo-random sequence in the first example and the fourth example of the satellite network data sending method provided by the embodiment of the application is shown. DETAILED DESCRIPTION

[0126] In order to more clearly illustrate the application, the application will be further described below with reference to the embodiments and the accompanying drawings. Like components are denoted by the same reference signs in the accompanying drawings. Those skilled in the art should understand that the specific description below is illustrative rather than limiting, and should not limit the protection scope of the application.

[0127] When a larger fading is encountered on the signal transmission path or the antenna form of the receiving end is smaller, the signal-to-noise ratio of the working point can be lower than -10dB. In this case, the existing low signal-to-noise ratio data frame cannot meet the working point condition, and a lower signal-to-noise ratio data frame needs to be introduced to support the working point with a signal-to-noise ratio of -15dB~ -10dB.

[0128] Therefore, one embodiment of the application provides a satellite network data sending method, which comprises the following steps: Figure 1As shown, the method includes: acquiring a satellite payload data packet; establishing a data frame corresponding to the satellite payload data packet, the data frame including multiple first signal-to-noise ratio (SNR) data frames (i.e., extremely low SNR data frames), multiple second SNR data frames (i.e., ultra-low SNR data frames), and multiple third SNR data frames (ordinary SNR data frames); transmitting the data frame to a receiving end using a transmitting end, so that the receiving end processes the data frame to obtain the satellite payload data packet; wherein, the operating point range of the extremely low SNR data frame is greater than or equal to -15dB and less than -10dB, and the operating point range of the ultra-low SNR data frame is... The operating point range is greater than or equal to -10dB and less than 0dB; the operating point range of the ordinary signal-to-noise ratio (SNR) data frame is greater than or equal to 0dB and less than 20dB. The extremely low SNR data frame includes multiple sub-extremely low SNR data frames, the frame length of which is the same as that of the ultra-low SNR data frame, and the frame length of which is the same as that of the ordinary SNR data frame. The unique code field of the frame header of the first SNR data frame, the unique code field of the frame header of the second SNR data frame, and the unique code field of the frame header of the third SNR data frame are all selected from a set of pseudo-random sequences.

[0129] This embodiment, by employing a composite waveform with a fixed frame structure, can operate within an Es / No range of -15dB to 20dB and supports multiple modulation modes. This design not only improves the adaptability and flexibility of the method but also significantly reduces resource consumption, providing an efficient and reliable solution for satellite communication.

[0130] In a specific example, such as Figure 2 As shown, the frame consists of a frame header 10 and a frame body 11. The frame header 10 contains a unique word 1 (UW1) 101, a physical layer signaling field (PLSC) 102, and a unique word 2 (UW2) 103. The frame body 11 consists of multiple coded frames (XFECFRAME) 111 mapped to symbols, with pilot symbols 113 inserted at equal intervals within the data symbols 112.

[0131] Furthermore, UW1 can be used for acquisition at a normal aperture receiver, while PLSC can be used for physical layer signaling indication of normal signal-to-noise ratio (SNR) data frames. The combination of UW1 and UW2 can be used for frame header acquisition of extremely low SNR data frames (operating point SNR less than -10dB) and ultra-low SNR data frames (operating point SNR of -10dB to -2dB), supporting small aperture receivers.

[0132] Furthermore, ultra-low signal-to-noise ratio (SNR) data frames (operating point SNR of -10dB to -2dB) are indicated by UW2 Walsh sequence signaling.

[0133] Further, the extremely low signal-to-noise ratio data frame (operating point signal-to-noise ratio less than -10 dB) is composed of multiple frames, and the frame format is indicated by combination between frame headers.

[0134] In one specific example, the extremely low signal-to-noise ratio data frame is composed of multiple frames, and each frame transmits repeatedly encoded information.

[0135] Further, as shown in FIG. 1, for example, the extremely low signal-to-noise ratio data frame is composed of a first frame header 21, a second frame header 22, and a first frame body 23. Figure 3 The extremely low signal-to-noise ratio data frame is composed of a first frame header 21, a second frame header 22, and a first frame body 23. The extremely low signal-to-noise ratio data frame is composed of a composite frame header composed of multiple pseudo-random sequences, that is, there are multiple pseudo-random sequences composed of combinations of UW1 and UW2. The composite frame header composed of one pseudo-random sequence indicates the start of the extremely low signal-to-noise ratio data frame.

[0136] Further, as shown in FIG. 1, for example, the extremely low signal-to-noise ratio data frame is composed of a first frame header 21, a second frame header 22, and a first frame body 23. Figure 4 The extremely low signal-to-noise ratio data frame is composed of a first frame header 21, a second frame header 22, and a first frame body 23. The extremely low signal-to-noise ratio data frame is composed of a composite frame header composed of multiple pseudo-random sequences, that is, there are multiple pseudo-random sequences composed of combinations of UW1 and UW2. The composite frame header composed of one pseudo-random sequence indicates the start of the extremely low signal-to-noise ratio data frame.

[0137] In one possible implementation, the length of the first frame body is a first length, the first frame body adopts BPSK modulation, the spreading factor of the first frame body is 2, and the first frame body supports 1 encoded frame.

[0138] Or the length of the second frame body is a first length, the second frame body adopts BPSK modulation, the spreading factor of the second frame body is 2, and the second frame body supports 1 encoded frame.

[0139] Or the length of the third frame body is a first length, if the third frame body adopts QPSK modulation, the spreading factor of the third frame body is 1, the third frame body supports 4 encoded frames; if the third frame body adopts 8PSK modulation, the spreading factor of the third frame body is 1, the third frame body supports 6 encoded frames; if the third frame body adopts 16APSK modulation, the spreading factor of the third frame body is 1, the third frame body supports 8 encoded frames; if the third frame body adopts 32APSK modulation, the spreading factor of the third frame body is 1, the third frame body supports 10 encoded frames; and if the third frame body adopts 64APSK modulation, the spreading factor of the third frame body is 1, the third frame body supports 12 encoded frames.

[0140] In one specific example, the first length is 34020 symbols.

[0141] In one specific example, as shown in Figure 5 Fig. 4, a long frame with non-inserted pilot generated based on a composite frame has an LDPC code length of 16200.

[0142] Further, as shown in Figure 5 Fig. 5, A is a frame structure when BPSK modulation is adopted, including a frame header 41 and a data symbol block 42; B is a frame structure when QPSK modulation is adopted, including a frame header 41 and a data symbol block 43; C is a frame structure when 8PSK modulation is adopted, including a frame header 41 and a data symbol block 44; D is a frame structure when 16APSK modulation is adopted, including a frame header 41 and a data symbol block 45; E is a frame structure when 32APSK modulation is adopted, including a frame header 41 and a data symbol block 46; F is a frame structure when 64APSK modulation is adopted, including a frame header 41 and a data symbol block 47.

[0143] Further, when BPSK modulation is adopted, the spreading (repetition) factor is 2, supporting 1 code word; when QPSK modulation is adopted, the spreading factor is 1, supporting 4 code words; when 8PSK modulation is adopted, the spreading factor is 1, supporting 6 code words; when 16APSK modulation is adopted, the spreading factor is 1, supporting 8 code words; when 32APSK modulation is adopted, the spreading factor is 1, supporting 10 code words; when 64APSK modulation is adopted, the spreading factor is 1, supporting 12 code words.

[0144] In one specific example, as shown in Figure 6 Fig. 6, a physical frame format of a long frame with inserted pilot generated based on a composite frame includes a frame header 51 and a frame body 52, the frame header 51 includes a unique code field 511, a physical layer signaling field 512 and a unique code field 513; the frame body 52 includes a data symbol block 521 and a pilot symbol block 522.

[0145] Further, the unique code field 511 is a pseudo-random sequence with a length of 206 bits, adopting pi / 2 BPSK modulation; the physical layer signaling field 512 has a length of 64 bits, the physical layer signaling field 512 supports normal signal-to-noise ratio data frame, super low signal-to-noise ratio data frame indication, adopting pi / 2 BPSK modulation; the unique code field 513 is a pseudo-random sequence with a length of 900 bits, adopting pi / 2 BPSK modulation;

[0146] Further, the frame body part carries data symbols generated by constellation modulation of the payload data packets; in the frame body 52, a pilot symbol block 522 with a length of 36 symbols is inserted every 8 time slots, and each time slot contains 90 data symbols, i.e. the length of a data symbol block 521 is 720 symbols. Meanwhile, a pilot symbol block 522 is additionally added at the end of each frame. In total, there are 45 data symbol blocks 521 and 45 pilot symbol blocks 522. Meanwhile, the length of the frame header 51 is 1170 symbols, and the length of the frame is 35190 symbols.

[0147] In a possible implementation, the length of the first frame body is a second length, the first frame body adopts BPSK modulation, the spreading factor of the first frame body is 1, and the first frame body supports 1 coded frame;

[0148] or the length of the second frame body is the second length, the second frame body adopts BPSK modulation, the spreading factor of the second frame body is 1, and the second frame body supports 1 coded frame;

[0149] or the length of the third frame body is the second length, if the third frame body adopts QPSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 2 coded frames; if the third frame body adopts 8PSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 3 coded frames; if the third frame body adopts 16APSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 4 coded frames; if the third frame body adopts 32APSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 5 coded frames; if the third frame body adopts 64APSK modulation, the spreading factor of the third frame body is 1, and the third frame body supports 6 coded frames.

[0150] In a specific example, the second length is 17028 symbols.

[0151] In a specific example, as shown in Figure 7 the LDPC code length of the short frame without inserted pilot generated based on the composite frame is 16200.

[0152] Further, as shown in Figure 7As shown, A is the frame structure when BPSK modulation is adopted, including frame header 61 and data symbol block 62; B is the frame structure when QPSK modulation is adopted, including frame header 61 and data symbol block 63; C is the frame structure when 8PSK modulation is adopted, including frame header 61 and data symbol block 64; D is the frame structure when 16APSK modulation is adopted, including frame header 61 and data symbol block 65; E is the frame structure when 32APSK modulation is adopted, including frame header 61 and data symbol block 66; F is the frame structure when 64APSK modulation is adopted, including frame header 61 and data symbol block 67.

[0153] Further, when BPSK modulation is adopted, the spreading factor is 1, supporting 1 code word; when QPSK modulation is adopted, the spreading factor is 1, supporting 2 code words; when 8PSK modulation is adopted, the spreading factor is 1, supporting 3 code words; when 16APSK modulation is adopted, the spreading factor is 1, supporting 4 code words; when 32APSK modulation is adopted, the spreading factor is 1, supporting 5 code words; when 64APSK modulation is adopted, the spreading factor is 1, supporting 6 code words.

[0154] In a specific example, as shown in Figure 8 A physical frame format of a short frame with inserted pilot based on a composite frame, including frame header 71 and frame body 72, the frame header 71 includes unique code field 711, physical layer signaling field 712 and unique code field 713; the frame body 72 includes data symbol block 721 and pilot symbol block 722.

[0155] Further, the unique code field 711 is a pseudo-random sequence with a length of 206 bits, adopting pi / 2 BPSK modulation; the length of the physical layer signaling field 712 is 64 bits, the physical layer signaling field 712 supports normal frame, super low signal-to-noise ratio frame indication, adopting pi / 2 BPSK modulation; the unique code field 713 is a pseudo-random sequence with a length of 900 bits, adopting pi / 2 BPSK modulation;

[0156] Further, the frame body part carries data symbols generated by constellation modulation of payload data packets; in the frame body 72, a pilot symbol block 722 with a length of 36 symbols is inserted every 8 time slots, and each time slot contains 90 data symbols, i.e. the length of the data symbol block 721 is 720 symbols. At the same time, an additional pilot symbol block 722 is added at the tail of each frame. A total of 22 data symbol blocks 721 and 22 pilot symbol blocks 72. At the same time, the length of the frame header 71 is 1170 symbols, and the frame length is 18198 symbols.

[0157] In one possible implementation, when the first bit of the physical layer signaling in the physical layer signaling field is 0, it indicates that the frame body is a long frame with a first length; when the first bit is 1, it indicates that the frame body is a short frame with a second length. When the second bit of the physical layer signaling is 0, it indicates that the frame body uses a modulation order of 32 APSK or less; when the second bit is 1, it indicates that the frame body uses a modulation order of 64 APSK or more. The combination of the third, fourth, fifth, sixth, and seventh bits of the physical layer signaling represents the corresponding modulation and coding format.

[0158] In a specific example, PLSC is designed with two transmission modes, transmitting 7-bit physical layer signaling and 8-bit physical layer signaling respectively.

[0159] Furthermore, such as Figure 9 As shown, the 7-bit physical layer signaling code PLSC includes the seventh bit (b1) 81, the sixth bit (b2) 82, the fifth bit (b3) 83, the fourth bit (b4) 84, the third bit (b5) 85, the second bit (b6) 86, and the first bit (b7) 87.

[0160] Furthermore, the seventh bit 81, the sixth bit 82, the fifth bit 83, the fourth bit 84, and the third bit 85 together represent the MODCOD code.

[0161] Furthermore, the second bit 86 represents the extended MODCOD flag. When the second bit 86 is 0, it represents a non-high-order (BPSK, QPSK, 8PSK, 16APSK and 32APSK) MODCOD. When the second bit 86 is 1, it represents a high-order modulation (64APSK, 128APSK and 256APSK) MODCOD.

[0162] Furthermore, the first bit 87 indicates the frame length type. When the first bit 87 is 0, it indicates a long frame (35190 symbols), and when the first bit 87 is 1, it indicates a short frame (18198 symbols).

[0163] Furthermore, the MODCOD field signaling indication when the second bit 86 is 0 is shown in Table 1.

[0164] Table 1 MODCOD Domain Signaling Indicator Table when the Second Bit is 0

[0165]

[0166] Further, the b1b2b3b4b5 of 29 and the b1b2b3b4b5 of 30 correspond to the encoding modulation mode used by the super low signal-to-noise ratio receiver; in this way, the super low signal-to-noise ratio data frame can also be recognized by the ordinary signal-to-noise ratio receiver, and the ordinary signal-to-noise ratio receiver will skip the current super low signal-to-noise ratio data frame and find the b1b2b3b4b5 of 1~28 data frame for demodulation.

[0167] Further, the MODCOD field signaling when the second bit 86 is 1 is shown in Table 2.

[0168] Table 2 MODCOD field signaling when the second bit is 1

[0169]

[0170] Further, when the second bit 86 is 1, the modulation order of 64APSK or above is supported.

[0171] In a specific example, as shown in Figure 10 The 8bits physical layer signaling code PLSC includes the eighth bit (b0) 90, the seventh bit (b1) 91, the sixth bit (b2) 92, the fifth bit (b3) 93, the fourth bit (b4) 94, the third bit (b5) 95, the second bit (b6) 96 and the first bit (b7) 97.

[0172] Further, the eighth bit 90 represents the frame type, and the eighth bit 90 is 0 when representing the traditional ordinary frame structure, and the eighth bit 90 is 1 when representing the composite frame structure, such as the ordinary signal-to-noise ratio data frame, the super low signal-to-noise ratio data frame, and the extremely low signal-to-noise ratio data frame based on the composite frame structure.

[0173] Further, the seventh bit 91 to the first bit 97 of the composite frame structure defines the same as the 7bits physical layer signaling code.

[0174] Further, the seventh bit (b1) 91, the sixth bit (b2) 92, the fifth bit (b3) 93, the fourth bit (b4) 94, and the third bit (b5) 95 represent the MODCOD code.

[0175] Further, the second bit 96 represents the extended MODCOD flag bit, and the second bit 96 is 0 when representing the non-high order (BPSK, QPSK, 8PSK, 16APSK and 32APSK) MODCOD, and the second bit 96 is 1 when representing the high order modulation (64APSK, 128APSK and 256APSK) MODCOD.

[0176] Further, the first bit 97 represents a frame length type, and the first bit 87 is 0 to represent a long frame (35190 symbols) and the first bit 97 is 1 to represent a short frame (18198 symbols).

[0177] In one specific example, as shown in FIG. 1, the UW2 sequence includes a first sequence 1001, a second sequence (PN2-1) 1002, a third sequence (PN2-2) 1003, a fourth sequence (PN2-3) 1004, a fifth sequence (PN2-4) 1005, a sixth sequence (PN2-5) 1006, a seventh sequence (PN2-6) 1007, an eighth sequence (PN2-7) 1008, a ninth sequence (PN2-8) 1009, and a tenth sequence 1010. Figure 11

[0178] Further, the first sequence 1001 of the UW2 sequence includes 2 bits, which are all 0 bits, and the tenth sequence 1010 includes 2 bits, which are all 0 bits; the second sequence 1002 to the ninth sequence 1009 include 896 bits, which are superimposed by 8 short PN sequences and Walsh sequences, and the Walsh sequence has a length of 8 chips (chip), which are a first chip (w0) 1021, a second chip (w1) 1022, a third chip (w2) 1023, a fourth chip (w3) 1024, a fifth chip (w4) 1025, a sixth chip (w5) 1026, a seventh chip (w6) 1027, and an eighth chip (w7) 1028.

[0179] Further, the superimposition rule of the PN sequence and the Walsh sequence is as follows: the PN sequence is equally divided into 8 parts, each part is a short PN sequence with a length of 112 bits, and each part is subjected to an exclusive or operation with the corresponding chip of the Walsh sequence.

[0180] Further, there is a corresponding relationship between the Walsh sequence and the code rate and the spreading factor of the LDPC code, and the corresponding relationship between the Walsh sequence and the code rate and the spreading factor is shown in Table 3.

[0181] Table 3 Corresponding relationship table of Walsh sequence and code rate and spreading factor

[0182]

[0183] ​In a possible implementation, the establishing the data frame corresponding to the satellite payload data packet further includes: establishing a plurality of ultra-low signal-to-noise ratio data frames corresponding to the satellite payload data packet; wherein the establishing one ultra-low signal-to-noise ratio data frame corresponding to the satellite payload data packet includes: establishing a second frame body corresponding to the satellite payload data packet; establishing a first frame header corresponding to the second frame body, the first frame header including a first unique code field, a physical layer signaling field, and a second unique code field; and establishing the ultra-low signal-to-noise ratio data frame according to the first frame header and the second frame body; and the establishing the data frame corresponding to the satellite payload data packet further includes: establishing a plurality of normal signal-to-noise ratio data frames corresponding to the satellite payload data packet; wherein the establishing one normal signal-to-noise ratio data frame corresponding to the satellite payload data packet includes: establishing a third frame body corresponding to the satellite payload data packet, the third frame body including a plurality of encoded frames; establishing a second frame header corresponding to the third frame body, the second frame header including a third unique code field, a physical layer signaling field, and a fourth unique code field; and establishing the normal signal-to-noise ratio data frame according to the second frame header and the third frame body.

[0184] In a specific example, when the system works in an ultra-low signal-to-noise ratio mode, one ultra-low signal-to-noise ratio data frame is composed of a plurality of ultra-low signal-to-noise ratio sub-frames, that is, based on a plurality of sub-ultra-low signal-to-noise ratio data frames carrying the same encoded information, the frame format is indicated by the combination between the sub-ultra-low signal-to-noise ratio data frame headers, and the demodulation gain is provided by the repetition between the frames during reception.

[0185] Further, the ultra-low signal-to-noise ratio data frame is constituted in mode 1, including the sub-ultra-low signal-to-noise ratio data frame headers composed of two pseudo-random sequences, that is, there are two pseudo-random sequences composed of the combination of UW1 and UW2, wherein the first sub-ultra-low signal-to-noise ratio data frame header composed of the pseudo-random sequence indicates the starting sub-frame of the ultra-low signal-to-noise ratio data frame, and the subsequent sub-frames are composed of a plurality of first sub-ultra-low signal-to-noise ratio data frames and second sub-ultra-low signal-to-noise ratio data frames.

[0186] Further, the ultra-low signal-to-noise ratio data frame is constituted in mode 2, including the sub-ultra-low signal-to-noise ratio data frame headers composed of a plurality of pseudo-random sequences, that is, there are a plurality of pseudo-random sequences composed of the combination of UW1 and UW2, wherein the first sub-ultra-low signal-to-noise ratio data frame header indicates the starting sub-frame of the ultra-low signal-to-noise ratio data frame, and the third sub-ultra-low signal-to-noise ratio data frame header indicates the last sub-ultra-low signal-to-noise ratio frame.

[0187] In a specific example, a satellite communication system can choose either Extremely Low Signal-to-Noise Ratio (SNR) data frame configuration mode 1 or Extremely Low SNR data frame configuration mode 2 for communication in extremely low SNR mode. For frame header capture using Extremely Low SNR data frame configuration mode 1, two pseudo-random sequences need to be correlated, each including UW1 and UW2. For frame header capture using Extremely Low SNR data frame configuration mode 2, more than two pseudo-random sequences need to be correlated, each including UW1 and UW2.

[0188] Furthermore, such as Figure 12 As shown, it includes an extremely low signal-to-noise ratio (SNR) data frame 1110 and a normal SNR data frame 1120; the extremely low SNR data frame 1110 includes a frame header 1111, a frame header 1112, and a frame body 1113; the normal SNR data frame includes a frame header 1112 and a frame body 1114.

[0189] Furthermore, for data frames with extremely low signal-to-noise ratios, capturing only the first frame header and performing correlation on two pseudo-random sequences each time results in relatively low computational overhead. For example... Figure 12 As shown, extremely low signal-to-noise ratio (SNR) data frames are constructed in mode 1, and ordinary SNR data frames are transmitted together. The extremely low SNR receiver can distinguish between them using signaling indications based on the SNR data frame construction mode 1. This is achieved by combining the header of the first sub-extremely low SNR data frame with the headers of other sub-extremely low SNR data frames for signaling indication. When the header 1111 of the first sub-extremely low SNR data frame is detected, it marks the start of an extremely low SNR data frame; when the header 1112 of the second sub-extremely low SNR data frame is detected, it marks the last sub-frame of the current extremely low SNR frame. The ordinary SNR receiver can skip the extremely low SNR data frame construction mode 1 using PLS detection and directly demodulate the mixed ordinary SNR frames.

[0190] In a specific example, extremely low signal-to-noise ratio (SNR) data frames of configuration 2 and ordinary SNR data frames are transmitted together. They can be distinguished by the signaling indication of the extremely low SNR data frame configuration 2. By combining two or more sub-extremely low SNR data frame headers, the start and end of the extremely low SNR data frame configuration 2 frame are indicated, thereby separating it from the ordinary SNR data frame.

[0191] Furthermore, such as Figure 13 As shown, it includes an extremely low signal-to-noise ratio (SNR) data frame 1210 and a normal SNR data frame 1220; the extremely low SNR data frame 1210 includes a frame header 1211, a frame header 1212, a frame header 1213, and a frame body 1214; the normal SNR data frame includes a frame header 1212 and a frame body 1215.

[0192] Furthermore, such as Figure 13As shown, the extremely low SNR data frame includes 3 sub extremely low SNR data frames. For the extremely low SNR data frame formation mode 2 frame header capture, including more than two sub extremely low SNR data frame headers, more than 2 pseudo-random sequence correlations need to be performed each time, and the calculation overhead is relatively large. The extremely low SNR receiver can be distinguished by the signaling indication of the extremely low SNR data frame formation mode 2, and the first sub extremely low SNR data frame header and the other sub extremely low SNR data frame headers are combined for signaling indication. When the first sub extremely low SNR data frame header 1211 is detected, the beginning of the extremely low SNR data frame is marked; when the third sub extremely low SNR data frame header 1213 is detected, the last sub frame of the current extremely low SNR frame is marked. Similarly, the normal SNR receiver can skip the extremely low SNR data frame formation mode 2 by PLS detection, and directly demodulate the mixed normal SNR frame.

[0193] Further, when the extremely low SNR data frame formation mode 1 or the extremely low SNR data frame formation mode 2 is adopted, in the extremely low SNR data frame, the same Walsh sequence needs to be adopted in the UW2 of the frame header 1111, the frame header 1112, the frame header 1211, the frame header 1212, and the frame header 1213, and the default is 00000000.

[0194] In a possible implementation, the establishing the data frame corresponding to the satellite payload data packet comprises: establishing a plurality of extremely low SNR data frames corresponding to the satellite payload data packet; wherein the establishing one extremely low SNR data frame corresponding to the satellite payload data packet comprises: establishing a plurality of first frame bodies corresponding to the satellite payload data packet; establishing a plurality of first frame headers corresponding to the plurality of first frame bodies, the first frame header comprising a first unique code field, a physical layer signaling field, and a second unique code field; establishing a plurality of first sub extremely low SNR data frames corresponding to the plurality of first frame bodies, the first sub extremely low SNR data frame comprising a first frame header and a first frame body; establishing a plurality of second frame headers corresponding to the plurality of first frame bodies, the second frame header comprising a third unique code field, a physical layer signaling field, and a fourth unique code field; establishing a plurality of second sub extremely low SNR data frames corresponding to the plurality of first frame bodies, the second sub extremely low SNR data frame comprising a second frame header and a first frame body; and establishing the extremely low SNR data frame according to the plurality of first sub extremely low SNR data frames and the plurality of second sub extremely low SNR data frames; wherein the first frame header and the second frame header are different from each other.

[0195] In a possible implementation, the pseudo-random sequence set comprises a first pseudo-random sequence set and a second pseudo-random sequence set.

[0196] The first pseudo-random sequence set comprises a first pseudo-random sequence and a second pseudo-random sequence; the first pseudo-random sequence is:

[0197] 05 EA4A E105 EA5F198 AE11F19B4ABDB5EDB5EE1344AE105EA528F,

[0198] The 896 bits in the second pseudo-random sequence are:

[0199] 7C66 7C66 7C66 4A3C D2AF 17A9 7C66 2B84 84D1 2B84 84D1 D2AF 17A9 D2AF 6D7B 6D7B 4A3C 84D1 7C66 D2AF 2B84 7C66 D2AF D2AF 4A3C 84D1 84D1 4A3C 84D1 84D1 6D7B 2B84 17A9 84D1 4A3C 7C66 6D7B 84D1 17A9 D2AF 6D7B 2B84 D2AF 17A9 17A9 7C66 4A3C 17A9 2B84 6D7B 6D7B 4A3C 4A3C 4A3C D2AF 6D7B ;

[0200] The second set of pseudo-random sequences includes a third pseudo-random sequence and a fourth pseudo-random sequence; the third pseudo-random sequence is:

[0201] 19D1C04C19D1F3D2FA18BA18891E6725C91E73D2FA1899D1C04C,

[0202] The 896 bits in the fourth pseudo-random sequence are:

[0203] 0130CF4B24799C976747D2BB01302479CF4BE8629C97CF4BE862D2BBCF4B6747E8620130E8629C976747E862CF4BD2BBD2BBD2BB9C972479247967470130D2BB674767476747D2BB9C97E8620130D2BBCF4B0130CF4B9C97E86224799C9701309C979C97247924790130CF4B2479D2BB.

[0204] In a possible implementation, the establishing the data frame corresponding to the satellite payload data packet comprises: establishing a plurality of extremely low signal-to-noise ratio data frames corresponding to the satellite payload data packet; wherein establishing one extremely low signal-to-noise ratio data frame corresponding to the satellite payload data packet comprises: establishing a plurality of first frame bodies corresponding to the satellite payload data packet; establishing a plurality of first frame headers corresponding to the plurality of first frame bodies, the first frame header comprising a first unique code field, a physical layer signaling field and a second unique code field; establishing a plurality of first sub-extremely low signal-to-noise ratio data frames corresponding to the satellite payload data packet, the first sub-extremely low signal-to-noise ratio data frame comprising a first frame header and a first frame body; establishing a plurality of second frame headers corresponding to the plurality of first frame bodies, the second frame header comprising a third unique code field, a physical layer signaling field and a fourth unique code field; establishing a plurality of second sub-extremely low signal-to-noise ratio data frames corresponding to the satellite payload data packet, the second sub-extremely low signal-to-noise ratio data frame comprising a second frame header and a first frame body; establishing a plurality of third frame headers corresponding to the plurality of first frame bodies, the third frame header comprising a fifth unique code field, a physical layer signaling field and a sixth unique code field; establishing a plurality of third sub-extremely low signal-to-noise ratio data frames corresponding to the satellite payload data packet, the third sub-extremely low signal-to-noise ratio data frame comprising a third frame header and a first frame body; and establishing the extremely low signal-to-noise ratio data frame according to the plurality of first sub-extremely low signal-to-noise ratio data frames, the plurality of second sub-extremely low signal-to-noise ratio data frames and the plurality of third sub-extremely low signal-to-noise ratio data frames; wherein the first frame header, the second frame header and the third frame header are different from each other.

[0205] In a possible implementation, the set of pseudo-random sequences comprises a first set of pseudo-random sequences, a second set of pseudo-random sequences, a third set of pseudo-random sequences and a fourth set of pseudo-random sequences.

[0206] The first set of pseudo-random sequences comprises a first pseudo-random sequence and a second pseudo-random sequence; the first pseudo-random sequence is:

[0207] 05EA4AE105EA5F198AE11F19B4ABDB5EDB5EE1344AE105EA528F,

[0208] The 896 bits in the second pseudo-random sequence are:

[0209] 7 C667 C667 C664 A3 CD2AF17 A97 C662 B8484D12 B8484D1 D2AF17 A9 D2AF6 D7B6 D7B4 A3 C84D17 C66 D2AF2 B847 C66 D2AF D2AF4 A3 C84D18 4D14 A3 C84D18 4D16 D7B2 B8417 A984D14 A3 C7 C666 D7B84D117 A9 D2AF6 D7B2 B84D2AF17 A917 A97 C664 A3 C17 A92 B846 D7B6 D7B4 A3 C4 A3 C4 A3 CD2AF6 D7B;

[0210] The second set of pseudo-random sequences includes a third pseudo-random sequence and a fourth pseudo-random sequence; the third pseudo-random sequence is:

[0211] 19 D1C04C19 D1F3D2FA18 BA18891 E6725C91 E73D2FA18 9D1C04C,

[0212] The 896 bits in the fourth pseudo-random sequence are:

[0213] 0130CF4B24799C976747D2BB01302479CF4BE8629C97CF4BE862D2BBCF4B6747E8620130E8629C976747E862CF4BD2BBD2BBD2BB9C972479247967470130D2BB674767476747D2BB9C97E8620130D2BBCF4B0130CF4B9C97E86224799C9701309C979C97247924790130CF4B2479D2BB;

[0214] The third set of pseudo-random sequences includes a fifth pseudo-random sequence and a sixth pseudo-random sequence; the fifth pseudo-random sequence is:

[0215] 3D42ABA709B03263C78947897D4287897D42B739F263C9B009B0;

[0216] The 896 bits in the sixth pseudo-random sequence are:

[0217] 26C01E25DCE726C04758DCE7AE9C4758AE9CF50AF50ADCE7AE9CC98F26C0DCE74758F50AAE9C1E2547581E25C98FDCE747581E25F50A4758C98FAE9CF50ADCE726C01E254758AE9C1E25AE9CC98FAE9CF50AC98FC98F47584758C98FDCE7475826C0F50A26C01E25DCE7AE9CC98FDCE7;

[0218] The fourth set of pseudo-random sequences comprises a seventh pseudo-random sequence and an eighth pseudo-random sequence; the seventh pseudo-random sequence is:

[0219] 209D6AC85E97C6A21963E1D4E09D6AC8609D5963E09D46A2327F;

[0220] The 896 bits in the eighth pseudo-random sequence are:

[0221] 7A5F1A8882751A88658F7A5F7A5F7A5F1A881A88AB21AB211A8887538753AB21658F C9FC8275C9FC658F8753658F1A88C9FC658FC9FCC9FC8275AB211A88AB218753658F 658F82757A5F8753.

[0222] In a possible implementation, the transmitting, by the transmitting end, of the data frame to the receiving end so that the receiving end processes the data frame to obtain the satellite payload data packet comprises: encoding, by the transmitting end, the transmitted information bits to form an encoded frame, and repeatedly mapping the encoded frame to a plurality of sub-ELSNR data frames in the same ELSNR data frame; and combining, by the receiving end, soft information bits of the plurality of sub-ELSNR data frames in the same ELSNR data frame and performing decoding to obtain corresponding information bits.

[0223] In one specific example, there are two kinds of base composite frames in the very low SNR data frame, corresponding to a long frame with length of 35190 and a short frame with length of 18198. When the long frame is used, the format of 1 / 5 code rate, spreading factor of 2 and BPSK modulation is selected; when the short frame is used, the format of 1 / 5 code rate, spreading factor of 1 and BPSK modulation is selected. The very low SNR data frame can be selected to repeat on the basis of the long frame or the short frame. If the frame is repeated on the basis of the long frame, the spreading factor is denoted as SF2; if the frame is repeated on the basis of the short frame, the spreading factor is denoted as SF1. When the SNR is in the range of -15B~ -10dB, the selected several combinations and the corresponding working points are listed as follows in Table 4, in which ELSNR is the very low SNR, VLSNR is the ultra low SNR, and Normal is the normal SNR.

[0224] Table 4 Modulation mode and demodulation threshold of very low SNR frame

[0225]

[0226] Further, the same encoded information is transmitted through multiple sub-frames under the same very low SNR frame to resist the deeper fading of the signal under the very low SNR. After receiving and demodulating, the repeated soft information bits are combined to obtain the spreading gain. For example, when the spreading factor SF2 of the base composite frame is 1, the corresponding Es / No demodulation threshold is -9.5dB; when SF2 is 2, the same encoded information is transmitted by continuously transmitting two base composite frames with SF2 of 1, and the corresponding Es / No demodulation threshold is -12.5dB; when SF2 is 4, the same encoded information is transmitted by continuously transmitting four base composite frames with SF2 of 1, and the corresponding Es / No demodulation threshold is -15.5dB; on this basis, when SF2 is 8, the corresponding Es / No demodulation threshold is -18.5dB.

[0227] Further, for a group of demodulated spreading frames, the soft information bits of the group of spreading frames are combined as follows:

[0228] The log-likelihood ratio (LLR) corresponding to the input bits of the first SF2 base composite frame code word can be expressed as ; wherein, is the log-likelihood ratio corresponding to the 1st bit of the first SF2 base composite frame code word; is the log-likelihood ratio corresponding to the 2nd bit of the first SF2 base composite frame code word; is the log-likelihood ratio corresponding to the 16200th bit of the first SF2 base composite frame code word.

[0229] The log-likelihood ratio (LLR) corresponding to the input bits of the second SF2 base composite frame code word can be expressed as ; wherein, the log-likelihood ratio corresponding to the 1st bit of the 2nd SF2 base composite frame code word; the log-likelihood ratio corresponding to the 2nd bit of the 2nd SF2 base composite frame code word, the log-likelihood ratio corresponding to the 16200th bit of the 2nd SF2 base composite frame code word.

[0230] omitted,

[0231] the log-likelihood ratio corresponding to the Mth SF2 base composite frame code word bit can be expressed as: ; wherein, the log-likelihood ratio corresponding to the 1st bit of the Mth SF2 base composite frame code word; the log-likelihood ratio corresponding to the 2nd bit of the Mth SF2 base composite frame code word; the log-likelihood ratio corresponding to the 16200th bit of the Mth SF2 base composite frame code word.

[0232] the merged soft information bit is:

[0233]

[0234] wherein, the log-likelihood ratio corresponding to the n bit of the (i+1)th SF2 base composite frame code word.

[0235] Then the merged soft information bit is decoded.

[0236] In the embodiment, the soft information bit of the group of repeated frames is merged to obtain additional spread spectrum processing gain, and deep fading of a signal in an extremely low signal-to-noise ratio condition is resisted.

[0237] In a specific example, the antenna aperture of a satellite receiving end is different, the conditions of channels are different, and the receiving capability is different. When working in a normal signal-to-noise ratio or an ultra-low signal-to-noise ratio condition, a normal composite frame structure is adopted. According to the receiving end capability, working in a normal signal-to-noise ratio, an ultra-low signal-to-noise ratio, or an extremely low signal-to-noise ratio mode can be configured, and the receiving end can work in a large signal-to-noise ratio range (-15 dB to 20 dB).

[0238] Further, under the common SNR condition, the received air interface signal SNR is relatively high, and the frame header is detected by the UWI sequence, so that all frames are visible, that is, when it receives a data frame, 5-bit MODCOD is obtained by decoding the physical layer signaling field, if the corresponding data bit range is within 0-28, it is determined that it is a common frame, and common SNR demodulation is performed; and if the corresponding 5-bit MODCOD obtained by decoding the physical layer signaling field is 29 or 30, it is determined that the frame is a super low SNR data frame, at this time, the frame boundary of the next frame can also be calculated, and the processing of the current frame is skipped; in this way, even if there is a mixed situation of super low SNR frames and very low SNR frames, the chain search can still be used when receiving the common frame.

[0239] Further, when the satellite communication system of the application works in the super low SNR mode, the receiving end in the system detects the UWI and UW2 sequences in the composite frame header (that is, the correlation values of UWI and UW2 are combined, and it is detected whether a correlation peak appears, if yes, it is a super low SNR data frame), at this time, the Walsh sequence carried on UW2 needs to be obtained to obtain the frame format information (that is, the autocorrelation detection of UW2 and each Walsh sequence is performed, and the code rate and the spreading factor corresponding to the Walsh sequence with the highest autocorrelation are taken as the frame format information of the received data frame), at this time, the capture and identification of the super low SNR frame can be completed.

[0240] Further, when the system works in the very low SNR mode, the receiving end determines the number of sub-frames included in a very low SNR data frame by detecting the combination relationship between the first sub-very low SNR data frame header, the second sub-very low SNR data frame header or the third sub-very low SNR data frame header, and resists the working environment of the very low SNR through the coding frame repetition gain between the sub-frames.

[0241] Further, it is assumed that the sequence composed of the unique code domain UWI and the unique code domain UW2 in one sub-very low SNR data frame header can be denoted as ; wherein, is the 1st element of the sequence; is the 2nd element of the sequence; is the 1106th element of the sequence. The corresponding pi / 2 BPSK modulation symbol is Z, therefore, the autocorrelation function of the two is defined as:

[0242]

[0243] In the formula, is the autocorrelation function, is the i-th symbol after modulation of the sequence composed of the unique code domain UWI and the unique code domain UW2 in the sub-very low SNR data frame header; is the autocorrelation delay, is a conjugate operation.

[0244] Further, the calculation formula of the maximum normalized sidelobe of the autocorrelation function is:

[0245]

[0246] wherein, is the maximum normalized sidelobe of the autocorrelation function; is the value of the autocorrelation function when k is 0.

[0247] Further, the pi / 2 BPSK modulated symbol corresponding to the sequence composed of the unique word field UW1 and the unique word field UW2 in the frame header of another sub-very low signal-to-noise ratio data frame is X, and the cross-correlation function Z is defined as:

[0248]

[0249] wherein, is the cross-correlation function; is the (i+k)th symbol after modulation of the sequence composed of the unique word field UW1 and the unique word field UW2 in the frame header of another sub-very low signal-to-noise ratio data frame, is the cross-correlation delay, is a conjugate operation.

[0250] Further, the calculation formula of the maximum normalized sidelobe of the cross-correlation function is:

[0251]

[0252] wherein, is the maximum normalized sidelobe of the cross-correlation function.

[0253] In one specific example, a first instance corresponding to the unique word field UW1 and the unique word field UW2 is given (i.e., when the unique word field UW1 is a 206-bit pseudo-random sequence), the unique word field UW1 of the instance 1 is:

[0254] 3D42ABA709B03263C78947897D4287897D42B739F263C9B009B0,

[0255] The unique word field UW2 of the instance 1 is:

[0256] 26C01E25DCE726C04758DCE7AE9C4758AE9CF50AF50ADCE7AE9CC98F26C0DCE74758F50AAE9C1E2547581E25C98FDCE747581E25F50A4758C98FAE9CF50ADCE726C01E254758AE9C1E25AE9CC98FAE9CF50AC98FC98F47584758C98FDCE7475826C0F50A26C01E25DCE7AE9CC98FDCE7.

[0257] Further, as shown in Figure 14 Figure 14 The coordinates of a certain point 1301 are (497, 0.1067). The autocorrelation of the pseudo-random sequence of the unique code field UW1 and the unique code field UW2 in the composite frame header has a maximum normalized sidelobe less than 0.15, and has good autocorrelation.

[0258] In a specific example, the embodiment gives a second example of the unique code field UW1 and the unique code field UW2, the unique code field UW1 of example 2 is:

[0259] 209D6AC85E97C6A21963E1D4E09D6AC8609D5963E09D46A2327F,

[0260] The unique code field UW2 of example 2 is:

[0261] 7A5F1A8882751A88658F7A5F7A5F7A5F1A881A88AB21AB211A8887538753AB21658F C9FC8275C9FC658F8753658F1A88C9FCC9FC8753C9FC8275658F7A5F87538753C9 FC8753AB21AB21AB217A5F82757A5F1A88C9FC658FC9FCC9FC8275AB211A88AB21 8753658F658F82757A5F8753.

[0262] Further, as shown in Figure 15 The autocorrelation of the pseudo-random sequence of example 2 of the unique code field UW1 and the unique code field UW2 in the composite frame header has a maximum normalized sidelobe less than 0.15, and has good autocorrelation.

[0263] Figure 16 ​​As shown, the maximum normalized cross-correlation value between Instance 2 and Instance 1 of unique code fields UW1 and UW2 in the composite frame header is less than 0.15, and they also have good cross-correlation.

[0264] In a specific example, this embodiment provides a third instance corresponding to unique code fields UW1 and UW2. The unique code field UW1 in instance 3 is:

[0265] 05EA4AE105EA5F198AE11F19B4ABDB5EDB5EE1344AE105EA528F,

[0266] The unique code field UW2 in Example 3 is:

[0267] 7C667C667C664A3CD2AF17A97C662B8484D12B8484D1D2AF17A9D2AF6D7B6D7B4A3C84D17C66D2AF2B847C66D2AFD2AF4A3C84D184D14A3C 84D184D16D7B2B8417A984D14A3C7C666D7B84D117A9D2AF6D7B2B84D2AF17A917A97C664A3C17A92B846D7B6D7B4A3C4A3C4A3CD2AF6D7B.

[0268] Furthermore, such as Figure 17 As shown, the autocorrelation of the pseudo-random sequences of unique code fields UW1 and UW2 in the composite frame header has a maximum normalized sidelobe of less than 0.15, indicating good autocorrelation.

[0269] Furthermore, such as Figure 18 As shown, the maximum normalized cross-correlation value between Instance 3 and Instance 1 of the unique code fields UW1 and UW2 in the composite frame header is less than 0.15, and they also have good cross-correlation.

[0270] In a specific example, this embodiment provides a fourth instance corresponding to unique code fields UW1 and UW2. The unique code field UW1 in instance 4 is:

[0271] 19D1C04C19D1F3D2FA18BA18891E6725C91E73D2FA1899D1C04C,

[0272] The unique code field UW2 in Example 4 is:

[0273] 0130 CF4B 2479 C976747D2BB 0130 2479 CF4B E8629C97 CF4B E862D2BB CF4B 6747 E862 0130 E8629C976747E862 CF4B D2BBD2BBD2BB9C9724792479 6747 130 D2BB 6747 6747 747D2BB9C97 E862 0130 D2BBCF4B 0130 CF4B9C97 E862 2479 C970 1309C979C9724792479 0130 CF4B 2479 D2BB.

[0274] Further, as shown in Figure 19 the autocorrelation of the pseudo-random sequence of instance 4 of the unique word field UW1 and the unique word field UW2 in the composite frame header has a maximum normalized side lobe less than 0.15, which has good autocorrelation.

[0275] Further, as shown in Figure 20 the cross-correlation normalized maximum value between instance 4 and instance 1 of the unique word field UW1 and the unique word field UW2 in the composite frame header is less than 0.15, while having good cross-correlation.

[0276] In summary, the embodiment has the following advantages: Fixed frame structure: The new waveform adopts a fixed frame structure, which means that the basic structure of the frame remains unchanged regardless of the change in signal-to-noise ratio. This design simplifies the complexity of the system and reduces resource consumption. Support for very low signal-to-noise ratio: The new waveform can work at very low signal-to-noise ratio, which enables it to maintain stable performance in harsh communication environments. Multiple modulation modes: The new waveform supports various modulation modes from BPSK to 64APSK. This flexibility enables the system to select the appropriate modulation mode according to the communication requirements, thereby optimizing transmission efficiency and reliability. Reducing system resource overhead: Since a fixed frame structure is adopted, the system no longer needs to send different waveforms for different path losses and different capabilities of the receiving end. This not only simplifies the design and implementation of the system, but also reduces resource consumption and improves the overall efficiency of the system.

Claims

1. A method of transmitting data in a satellite network, characterized by, The method comprises: acquiring a satellite payload data packet; establishing a data frame corresponding to the satellite payload data packet, the data frame comprising a plurality of first signal-to-noise ratio data frames, a plurality of second signal-to-noise ratio data frames and a plurality of third signal-to-noise ratio data frames; transmitting the data frame to a receiving end by a transmitting end, so that the receiving end processes the data frame to obtain the satellite payload data packet; wherein the operating point of the first signal-to-noise ratio data frame ranges from greater than or equal to -15 dB to less than -10 dB, the operating point of the second signal-to-noise ratio data frame ranges from greater than or equal to -10 dB to less than 0 dB, and the operating point of the third signal-to-noise ratio data frame ranges from greater than or equal to 0 dB to less than 20 dB; the first signal-to-noise ratio data frame comprises a plurality of sub-first signal-to-noise ratio data frames, the frame length of the sub-first signal-to-noise ratio data frame is the same as that of the second signal-to-noise ratio data frame, and the frame length of the second signal-to-noise ratio data frame is the same as that of the third signal-to-noise ratio data frame; the unique code field of the frame header of the first signal-to-noise ratio data frame is selected from a pseudo-random sequence set, and the unique code field of the frame header of the second signal-to-noise ratio data frame and the unique code field of the frame header of the third signal-to-noise ratio data frame are also selected from the pseudo-random sequence set; the establishing of the data frame corresponding to the satellite payload data packet comprises: establishing a plurality of first signal-to-noise ratio data frames corresponding to the satellite payload data packet; wherein the establishing of one first signal-to-noise ratio data frame corresponding to the satellite payload data packet comprises: establishing a plurality of first frame bodies corresponding to the satellite payload data packet; establishing a plurality of first frame headers corresponding to the plurality of first frame bodies, the first frame header comprising a first unique code field, a physical layer signaling field and a second unique code field; establishing a plurality of first sub-first signal-to-noise ratio data frames corresponding to the satellite payload data packet, the first sub-first signal-to-noise ratio data frame comprising a first frame header and a first frame body; establishing a plurality of second frame headers corresponding to the plurality of first frame bodies, the second frame header comprising a third unique code field, a physical layer signaling field and a fourth unique code field; establishing a plurality of second sub-first signal-to-noise ratio data frames corresponding to the satellite payload data packet, the second sub-first signal-to-noise ratio data frame comprising a second frame header and a first frame body; establishing the first signal-to-noise ratio data frame according to the plurality of first sub-first signal-to-noise ratio data frames and the plurality of second sub-first signal-to-noise ratio data frames; wherein the first frame header and the second frame header are different from each other; or the establishing of the data frame corresponding to the satellite payload data packet comprises: establishing a plurality of first signal-to-noise ratio data frames corresponding to the satellite payload data packet; wherein the establishing of one first signal-to-noise ratio data frame corresponding to the satellite payload data packet comprises: establishing a plurality of first frame bodies corresponding to the satellite payload data packet; establishing a plurality of first frame headers corresponding to the plurality of first frame bodies, the first frame header comprising a first unique code field, a physical layer signaling field and a second unique code field; establishing a plurality of first sub-first signal-to-noise ratio data frames corresponding to the satellite payload data packet, the first sub-first signal-to-noise ratio data frame comprising a first frame header and a first frame body; establish a plurality of second frame headers corresponding to the plurality of first frame bodies, the second frame header comprising a third unique code field, a physical layer signaling field and a fourth unique code field; establish a plurality of second sub-first signal-to-noise ratio data frames corresponding to the satellite payload data packet, the second sub-first signal-to-noise ratio data frame comprising a second frame header and a first frame body; establish a plurality of third frame headers corresponding to the plurality of first frame bodies, the third frame header comprising a fifth unique code field, a physical layer signaling field and a sixth unique code field; establish a plurality of third sub-first signal-to-noise ratio data frames corresponding to the satellite payload data packet, the third sub-first signal-to-noise ratio data frame comprising a third frame header and a first frame body; establish the first signal-to-noise ratio data frame according to the plurality of first sub-first signal-to-noise ratio data frames, the plurality of second sub-first signal-to-noise ratio data frames and the plurality of third sub-first signal-to-noise ratio data frames; wherein the first frame header, the second frame header and the third frame header are different from each other.

2. The satellite network data transmission method according to claim 1, wherein the set of pseudo-random sequences comprises a first set of pseudo-random sequences and a second set of pseudo-random sequences; the first set of pseudo-random sequences comprises a first pseudo-random sequence and a second pseudo-random sequence; the first pseudo-random sequence is: 05EA4AE105EA5F198AE11F19B4ABDB5EDB5EE1344AE105EA528F, the 896 bits in the second pseudo-random sequence are: 7C667C667C664A3CD2AF17A97C662B8484D12B8484D1D2AF17A9D2AF6D7B6D7B4A3C84D17C66D2AF2B847C66D2AFD2AF4A3C84D184D14A3C84D184D16D7B2B8417A984D14A3C7C666D7B84D117A9D2AF6D7B2B84D2AF17A917A97C664A3C17A92B846D7B6D7B4A3C4A3C4A3CD2AF6D7B; the second set of pseudo-random sequences comprises a third pseudo-random sequence and a fourth pseudo-random sequence; the third pseudo-random sequence is: 19D1C04C19D1F3D2FA18BA18891E6725C91E73D2FA1899D1C04C, the 896 bits in the fourth pseudo-random sequence are: 0130 CF4B 2479 9C97 6747 D2BB 0130 2479 CF4B E862 9C97 CF4B E862 D2BB CF4B 6747 E862 0130 E862 9C97 6747 E862 CF4B D2BB D2BB D2BB B9C97 2479 2479 6747 0130 D2BB 6747 6747 6747 D2BB B9C97 E862 0130 D2BB CF4B 0130 CF4B 9C97 E862 2479 9C97 0130 9C97 9C97 2479 2479 0130 CF4B 2479 D2BB.

3. The satellite network data sending method of claim 1, wherein the set of pseudo-random sequences comprises a first set of pseudo-random sequences, a second set of pseudo-random sequences, a third set of pseudo-random sequences, and a fourth set of pseudo-random sequences; the first set of pseudo-random sequences comprises a first pseudo-random sequence and a second pseudo-random sequence; the first pseudo-random sequence is: 05EA 4AE105EA 5F198AE11F19B4ABDB5EDB5EE1344AE105EA528F, 896 bits in the second pseudo-random sequence are: 7C66 7C66 7C66 4A3CD2AF17A9 7C66 2B84 84D12B84 84D1D2AF17A9 D2AF6D7B6D7B4A3C84D17C66D2AF2B84 7C66D2AFD2AF4A3C84D184D14A3C84D184D16D7B2B84 17A9 84D14A3C7C666D7B84D117A9D2AF6D7B2B84D2AF17A9 17A9 7C664A3C17A92B846D7B6D7B4A3C4A3C4A3CD2AF6D7B; the second set of pseudo-random sequences comprises a third pseudo-random sequence and a fourth pseudo-random sequence; the third pseudo-random sequence is: 19D1C04C19D1F3D2FA18BA18891E6725C91E73D2FA18 99D1C04C, 896 bits in the fourth pseudo-random sequence are: 0130 CF4B 2479 9C97 6747 D2BB 0130 2479 CF4B E862 9C97 CF4B E862 D2BB CF4B 6747 E862 0130 E862 9C97 6747 E862 CF4B D2BB D2BB D2BB B9C97 2479 2479 6747 0130 D2BB 6747 6747 6747 D2BB B9C97 E862 0130 D2BB CF4B 0130 CF4B 9C97 E862 2479 9C97 0130 9C97 9C97 2479 2479 0130 CF4B 2479 D2BB. The third pseudo-random sequence set includes a fifth pseudo-random sequence and a sixth pseudo-random sequence; The fifth pseudo-random sequence is: 3D42ABA709B03263C78947897D4287897D42B739F263C9B009B0; The 896 bits in the sixth pseudo-random sequence are: 26C01E25DCE726C04758DCE7AE9C4758AE9CF50AF50ADCE7AE9CC98F26C0DCE74758F50AAE9C1E2547581E25C98FDCE747581E25F50A4758C98FAE9CF50ADCE726C01E254758AE9C1E25AE9CC98FAE9CF50AC98FC98F47584758C98FDCE7475826C0F50A26C01E25DCE7AE9CC98FDCE7; The fourth pseudo-random sequence set includes a seventh pseudo-random sequence and an eighth pseudo-random sequence; The seventh pseudo-random sequence is: 209D6AC85E97C6A21963E1D4E09D6AC8609D5963E09D46A2327F; The 896 bits in the eighth pseudo-random sequence are: 7A5F1A8882751A88658F7A5F7A5F7A5F1A881A88AB21AB211A8887538753AB21658FC9FC8275C9FC658F8753658F1A88C9FC658FC9FCC9FC8275AB211A88AB218753658F658F82757A5F8753.

4. The satellite network data transmission method of claim 1, wherein The establishing of the data frame corresponding to the satellite payload data packet further comprises: establishing a plurality of second signal-to-noise ratio data frames corresponding to the satellite payload data packet; The establishing of one second signal-to-noise ratio data frame corresponding to the satellite payload data packet comprises: establishing a second frame body corresponding to the satellite payload data packet; establishing a first frame header corresponding to the second frame body, the first frame header comprising a first unique code field, a physical layer signaling field and a second unique code field; establishing the second signal-to-noise ratio data frame according to the first frame header and the second frame body; The establishing of the data frame corresponding to the satellite payload data packet further comprises: establishing a plurality of third signal-to-noise ratio data frames corresponding to the satellite payload data packet; The establishing of one third signal-to-noise ratio data frame corresponding to the satellite payload data packet comprises: establishing a third frame body corresponding to the satellite payload data packet, the third frame body comprising a plurality of encoding frames; establish a second frame header corresponding to the third frame body, the second frame header comprising a third unique code field, a physical layer signaling field and a fourth unique code field; establish the third signal-to-noise ratio data frame according to the second frame header and the third frame body.

5. The satellite network data transmission method according to claim 4, wherein the length of the first frame body is a first length, the first frame body is modulated by BPSK, the spreading factor of the first frame body is 2, and the first frame body supports one coded frame; or the length of the second frame body is the first length, the second frame body is modulated by BPSK, the spreading factor of the second frame body is 2, and the second frame body supports one coded frame; or the length of the third frame body is the first length, if the third frame body is modulated by QPSK, the spreading factor of the third frame body is 1, and the third frame body supports four coded frames; if the third frame body is modulated by 8PSK, the spreading factor of the third frame body is 1, and the third frame body supports six coded frames; if the third frame body is modulated by 16APSK, the spreading factor of the third frame body is 1, and the third frame body supports eight coded frames; if the third frame body is modulated by 32APSK, the spreading factor of the third frame body is 1, and the third frame body supports ten coded frames; if the third frame body is modulated by 64APSK, the spreading factor of the third frame body is 1, and the third frame body supports twelve coded frames.

6. The satellite network data transmission method according to claim 4, wherein the length of the first frame body is a second length, the first frame body is modulated by BPSK, the spreading factor of the first frame body is 1, and the first frame body supports one coded frame; or the length of the second frame body is the second length, the second frame body is modulated by BPSK, the spreading factor of the second frame body is 1, and the second frame body supports one coded frame; or the length of the third frame body is the second length, if the third frame body is modulated by QPSK, the spreading factor of the third frame body is 1, and the third frame body supports two coded frames; if the third frame body is modulated by 8PSK, the spreading factor of the third frame body is 1, and the third frame body supports three coded frames; if the third frame body is modulated by 16APSK, the spreading factor of the third frame body is 1, and the third frame body supports four coded frames; if the third frame body is modulated by 32APSK, the spreading factor of the third frame body is 1, and the third frame body supports five coded frames; if the third frame body is modulated by 64APSK, the spreading factor of the third frame body is 1, and the third frame body supports six coded frames.

7. The satellite network data transmission method according to claim 5 or 6, wherein the first bit of the physical layer signaling of the physical layer signaling field is 0, indicating that the frame body is a long frame, and the frame length of the long frame is the first length; or the first bit is 1, indicating that the frame body is a short frame, and the frame length of the short frame is the second length. ​ ​ ​ The second bit of the physical layer signaling is 0, indicating that the frame body adopts modulation order of 32APSK and below, and the second bit is 1, indicating that the frame body adopts modulation order of 64APSK and above; The combination of the third bit, the fourth bit, the fifth bit, the sixth bit and the seventh bit of the physical layer signaling indicates the corresponding modulation and coding format.

8. The satellite network data transmission method according to claim 7, characterized in that, The transmitting of the data frame from the transmitting end to the receiving end for processing of the data frame by the receiving end to obtain the satellite payload data packet comprises: The transmitting end encodes the transmitted information bits to form a coded frame, and repeatedly maps the coded frame to a plurality of sub-first SNR data frames in the same first SNR data frame; The receiving end combines and decodes the soft information bits of the plurality of sub-first SNR data frames in the same first SNR data frame to obtain the corresponding information bits.

Images