Satellite demodulation equipment frame synchronization method

Abstract

The invention discloses a satellite demodulation equipment frame synchronization method, which comprises a frame synchronization step used for acquiring and guiding demodulation equipment to receive a TDMA (Time Division Multiple Access) burst and detecting TDMA burst time T'of the TDMA burst. According to the synchronization method, the frame plan and the initial TDMA burst decoding data are acquired, the satellite demodulation equipment can receive the DVB signal and the TDMA signal, and frame synchronization can be realized without interaction with the main small station; the synchronization method is also configured with a synchronization result verification step and a synchronization time following step, so that the receiving correctness probability is improved, and the false alarm and missed detection probability is reduced.

Description

Technical Field

[0001] The invention belongs to the field of communications, and in particular relates to a satellite demodulation equipment frame synchronization method. Background Art

[0002] In the satellite signal receiving system, the burst guidance reception of TDMA carrier has strict requirements on the burst start time. Since the burst time indicated by the network control signaling in the DVB main carrier is time-deviated from the actual sending time of the TDMA small station burst, the burst signaling marking time and the actual receiving time of the TDMA small station burst by the satellite may not be aligned, and the satellite signal reception and demodulation cannot be guided according to the network control signaling.

[0003] In addition, even if the burst time indicated by the signaling of each superframe is aligned with the actual burst time of the superframe on the satellite, after passing through the demodulation device, the detected time may also be non-aligned due to the different delays of the demodulation device in performing DVB carrier detection and TDMA carrier detection, so the frame synchronization process is a necessary process.

[0004] In the forward VSAT network design, the correction process is completed by the master station and the small station in the system. The demodulation equipment, as a third-party receiver, does not interact with the master station. If the TDMA burst is to be received correctly, time synchronization needs to be achieved in the demodulation equipment. Summary of the invention

[0005] The purpose of the present invention is to provide a satellite demodulation device frame synchronization method, which can achieve frame synchronization on the basis that the demodulation device does not interact with a main station.

[0006] The method includes a frame synchronization step for obtaining a TDMA burst time T′ for guiding a demodulation device to receive a TDMA burst and detect the TDMA burst. The specific steps are as follows:

[0007] Step SA1: Obtain frame plan and initial TDMA burst decoding data;

[0008] Step SA2: Determine the TDMA burst search time range by the following method

[0009] [A 起始时间 , A 结束时间 ]:

[0010] A 起始时间 =A1-A τ

[0011] A 结束时间 =A1+A2+A τ

[0012] Where: A1 is the start time of a frame in the frame plan, A2 is the length of a frame in the frame plan, A τ is the time offset;

[0013] Step SA3: Search the time range A of the TDMA burst determined in step SA2. 起始时间 Start acquiring TDMA bursts until A of TDMA burst search time range A 结束时间 ;

[0014] Step SA4: Taking the first TDMA burst in the TDMA burst search time range A as a reference, take the length of a frame, and take the first TDMA burst in the taken frame as a reference to perform a graphic match with the burst allocation in the frame plan. If the match is successful, execute SA5; if the match is unsuccessful, execute SA8:

[0015] Step SA5: Calculate the time difference Δτ according to the following method:

[0016] Δτ=T i -T j

[0017] Where: T i is the start time of the first TDMA burst in the TDMA burst search time range A; T j is the allocation start time of the TDMA burst in the frame plan that matches the first TDMA burst pattern within the TDMA burst search time range A;

[0018] Step SA6: Calculate the TDMA burst time T′ according to the following method:

[0019] T′=T″+Δτ

[0020] Where: T″ is the burst start time of the target TDMA burst configured in the frame plan; Δτ is the time difference obtained in step SA5;

[0021] Step SA7: using the TDMA burst time T′ obtained in step SA6 to guide the demodulation device to start detecting and receiving TDMA bursts, thereby achieving frame synchronization of the satellite demodulation device;

[0022] Step SA8: If the match is unsuccessful, take the second TDMA burst within the TDMA burst search time range A as the reference to take the length of one frame, and take the first TDMA burst in the taken frame as the reference to perform graphic matching with the burst allocation in the frame plan. If the match is successful, execute step SA5; if the match is unsuccessful, continue to move back one burst, and take the third TDMA burst within the TDMA burst search time range A as the reference to take the length of one frame for graphic matching, and so on, until the match is successful. If the current TDMA burst search time range A cannot complete the match, repeat steps SA2-SA8 with the start time and frame length of the remaining frames in the frame plan until the match is successful.

[0023] Furthermore, the synchronization method further includes a synchronization result verification step, the specific steps are as follows:

[0024] Step SB1: Determine the TDMA burst search time range A′ of the current superframe;

[0025] Step SB2: acquiring the TDMA burst of the current frame from the start time of the TDMA burst search time range A′ determined in step SB1 until the end time of the TDMA burst search time range A′;

[0026] Step SB3: Graphically match the TDMA burst within the TDMA burst search time range A′ with the current superframe in the frame plan. If the match is successful, it means that the time difference obtained in step SA5 can be applied to the current superframe;

[0027] Step SB4: Repeat steps SB1-SB3 for a specified number of times. When the number of successful matches is greater than or equal to the specified threshold, the time difference Δτ obtained in step SA5 is correct; otherwise, it means that the time difference Δτ obtained in step SA5 is wrong. Re-execute steps SA1-SA5 to obtain the time difference Δτ.

[0028] Furthermore, the TDMA burst search time range A′ is [t1+Δτ, t1+Δτ+T], where t1 is the start time of the current superframe, Δτ is the time difference obtained in step SA5, and T is the frame period of the current superframe.

[0029] Furthermore, the synchronization method further includes a synchronization time following step, which specifically includes: guiding the demodulation device to receive and detect the superframe according to the sum of the burst start time in each superframe, the time difference Δτ obtained in step SA5, and the link delay, obtaining the TDMA burst in the superframe for matching with the corresponding TDMA burst in the frame plan, and if the match is successful, the superframe verification is successful, and calculating the average error of each pair of burst times that can correspond to the superframe, which is the time difference generated during the operation, and compensating this value to the time difference Δτ obtained in step SA5 to obtain the updated time difference Δτ;

[0030] If the match fails, the current superframe check fails. When the check failure ratio exceeds the specified threshold, the frame synchronization step is re-executed.

[0031] Furthermore, the frame plan and TDMA decoded data are obtained by the following steps:

[0032] Step SA11: The satellite demodulation device frame locks the DVB master station signal and outputs the DVB master station decoded data;

[0033] Step SA12: Analyze the frame plan according to the DVB decoded data;

[0034] Step SA13: Decode the TDMA burst according to the decoded parameters issued by the parsed frame plan to obtain TDMA burst decoded data.

[0035] Furthermore, the satellite demodulation equipment uses the same clock source to receive the master station signal and the TDMA burst signal, performs demodulation and decoding, and obtains DVB decoded data and TDMA burst decoded data.

[0036] The present invention also provides a satellite demodulation device, which is configured with:

[0037] A first receiving channel, used for receiving a master station signal;

[0038] A second receiving channel for receiving TDMA bursts;

[0039] The frame synchronization module is used to obtain the TDMA burst time T′ for guiding the demodulation device to receive the TDMA burst and detect the TDMA burst. The frame synchronization steps are as follows:

[0040] Step SA1: Obtain frame plan and initial TDMA burst decoding data;

[0041] Step SA2: Determine the TDMA burst search time range by the following method

[0042] [A 起始时间 , A 结束时间 ]:

[0043] A 起始时间 =A1-A τ

[0044] A 结束时间 =A1+A2+A τ

[0045] Where: A1 is the start time of a frame in the frame plan, A2 is the length of a frame in the frame plan, A τ is the time offset;

[0046] Step SA3: Search the time range A of the TDMA burst determined in step SA2.起始时间 Start acquiring TDMA bursts until A of TDMA burst search time range A 结束时间 ;

[0047] Step SA4: Taking the first TDMA burst in the TDMA burst search time range A as a reference, take the length of a frame, and take the first TDMA burst in the taken frame as a reference to perform a graphic match with the burst allocation in the frame plan. If the match is successful, execute SA5; if the match is unsuccessful, execute SA8:

[0048] Step SA5: Calculate the time difference Δτ according to the following method:

[0049] Δτ=T i -T j

[0050] Where: T i is the start time of the first TDMA burst in the TDMA burst search time range A; T j is the allocation start time of the TDMA burst in the frame plan that matches the first TDMA burst pattern within the TDMA burst search time range A;

[0051] Step SA6: Calculate the TDMA burst time T′ according to the following method:

[0052] T′=T″+Δτ

[0053] Where: T″ is the burst start time of the target TDMA burst configured in the frame plan; Δτ is the time difference obtained in step SA5;

[0054] Step SA7: using the TDMA burst time T′ obtained in step SA6 to guide the demodulation device to start detecting and receiving TDMA bursts, thereby achieving frame synchronization of the satellite demodulation device;

[0055] Step SA8: If the match is unsuccessful, take the second TDMA burst within the TDMA burst search time range A as the reference to take the length of one frame, and take the first TDMA burst in the taken frame as the reference to perform graphic matching with the burst allocation in the frame plan. If the match is successful, execute step SA5; if the match is unsuccessful, continue to move back one burst, and take the third TDMA burst within the TDMA burst search time range A as the reference to take the length of one frame for graphic matching, and so on, until the match is successful. If the current TDMA burst search time range A cannot complete the match, repeat steps SA2-SA8 with the start time and frame length of the remaining frames in the frame plan until the match is successful.

[0056] Furthermore, the device is also configured with a synchronization result verification module, which performs the following steps:

[0057] Step SB1: Determine the TDMA burst search time range A′ of the current superframe;

[0058] Step SB2: acquiring the TDMA burst of the current frame from the start time of the TDMA burst search time range A′ determined in step SB1 until the end time of the TDMA burst search time range A′;

[0059] Step SB3: Graphically match the TDMA burst within the TDMA burst search time range A′ with the current superframe in the frame plan. If the match is successful, it means that the time difference obtained in step SA5 can be applied to the current superframe;

[0060] Step SB4: Repeat steps SB1-SB3 for a specified number of times. When the number of successful matches is greater than or equal to the specified threshold, the time difference Δτ obtained in step SA5 is correct; otherwise, it means that the time difference Δτ obtained in step SA5 is wrong. Re-execute steps SA1-SA5 to obtain the time difference Δτ.

[0061] Furthermore, the device is also configured with a synchronous time following module, which performs the following steps: guiding the demodulation device to receive and detect the superframe according to the sum of the burst start time in each superframe, the time difference Δτ obtained in step SA5 and the link delay, obtaining the TDMA burst in the superframe for matching with the corresponding TDMA burst in the frame plan, and if the match is successful, the superframe verification is successful, calculating the average error of each pair of burst times that can correspond to this superframe, and this error is the time difference generated during the operation, and compensating this value to the time difference Δτ obtained in step SA5 to obtain the updated time difference Δτ;

[0062] If the match fails, the current superframe check fails. When the check failure ratio exceeds the specified threshold, the frame synchronization step is re-executed.

[0063] The present invention also provides a computer device, comprising a memory, a processor and a computer program stored in the memory, wherein the computer program is executed by the processor to implement the steps of the method of the present invention.

[0064] The beneficial effects of the present invention are:

[0065] 1) This synchronization method obtains the frame plan and initial TDMA burst decoding data. The satellite demodulation equipment can receive DVB signals and TDMA signals and can achieve frame synchronization without interacting with the main station.

[0066] 2) The synchronization method is also configured with a synchronization result verification step and a synchronization time following step, which improves the probability of correct reception and reduces the probability of false alarm and missed detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to more clearly illustrate the embodiments of the present application, the following briefly introduces the drawings required for use or involved in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Without paying creative work, other drawings can be obtained based on these drawings:

[0068] Figure 1 This is a diagram of the sliding matching process;

[0069] Figure 2 The relative time status diagram of DVB and TDMA bursts in various processing nodes. DETAILED DESCRIPTION

[0070] This section describes the present invention more fully with reference to the accompanying drawings, in which illustrative embodiments of the present invention are shown. However, the present invention may also be embodied in many different forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided so that the disclosure is full and complete and fully conveys the scope of the present invention to those skilled in the art.

[0071] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the present invention. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "include" and "comprise" when used herein specify the presence of the illustrated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof.

[0072] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted according to an idealized or very formal meaning unless specifically defined herein.

[0073] There are three main steps in guiding satellite signal reception with network control signaling: 1) parsing network control signaling to obtain the frame plan of each TDMA frame indicated in the network control signaling. The frame plan contains key parameters such as the start time of the burst in each frame, modulation mode, symbol rate, code length, code rate and encoding mode; 2) achieving frame synchronization, aligning the start time of each frame burst indicated by the network control signaling in the frame plan with the TDMA frame in the satellite signal in time; 3) completing burst demodulation reception, configuring the receiving demodulation processing parameters according to each burst parameter indicated by the network control signaling in the frame plan, and realizing demodulation, decoding and clearing of each burst of the satellite signal. Among the three steps of guiding satellite signal reception with network control signaling, frame synchronization is the key step. Due to the complex and changeable air propagation conditions of satellite signals, the delay of the signal reaching the receiving device is constantly changing. The burst start time indicated by the network control signaling needs to be dynamically adjusted according to the signal reception delay to achieve continuous guidance of reception demodulation by network control signaling.

[0074] After the demodulation device locks the DVB signal, it outputs DVB decoding data. After signaling analysis, the frame plan is obtained, which includes the frame number of the current frame, the frame start time, each carrier information, and the burst allocation information of each carrier. After the demodulation device is configured according to the L frequency, symbol rate, modulation mode, code rate and other information of each carrier, the demodulation device can output TDMA decoding data. The decoding data contains each burst detection information of a certain carrier, such as detection time, modulation mode, code rate, etc.

[0075] The frame plan and initial TDMA burst decoding data are passed into the frame synchronization module. After frame synchronization processing, the time difference between the signaling time marked in the DVB and the actual TDMA burst time is obtained; based on this time difference, the TDMA burst time T′ of each frame TDMA burst can be calculated, and the demodulation equipment can be guided to receive and detect TDMA bursts according to the TDMA burst time T′ and the parsed burst configuration to achieve frame synchronization.

[0076] The frame synchronization module performs the following steps:

[0077] Step SA1: Obtain frame plan and initial TDMA burst decoding data;

[0078] Step SA2: Determine the TDMA burst search time range by the following method

[0079] [A 起始时间 , A 结束时间 ]:

[0080] A 起始时间 =A1-A τ

[0081] A 结束时间 =A1+A2+A τ

[0082] Where: A1 is the start time of a frame in the frame plan, A2 is the length of a frame in the frame plan, A τ is the time offset; the time offset is based on the device configuration of the synchronization method being applied, such as ±20ms, or, in order to speed up the frame synchronization speed, the time offset range can be narrowed, such as ±5ms, ±10ms, or ±15ms.

[0083] Step SA3: acquiring TDMA bursts from the start time of the TDMA burst search time range A determined in step SA2 until the end time of the TDMA burst search time range A;

[0084] Step SA4: Taking the first TDMA burst in the TDMA burst search time range A as a reference, take the length of a frame, and take the first TDMA burst in the taken frame as a reference to perform a graphic match with the burst allocation in the frame plan. If the match is successful, execute SA5; if the match is unsuccessful, execute SA8:

[0085] Step SA5: Calculate the time difference Δτ according to the following method:

[0086] Δτ=T i -T j

[0087] Where: T i is the start time of the first TDMA burst in the TDMA burst search time range A; T j is the allocation start time of the TDMA burst in the frame plan that matches the first TDMA burst pattern within the TDMA burst search time range A;

[0088] Step SA6: Calculate the TDMA burst time T′ according to the following method:

[0089] T′=T″+Δτ

[0090] Where: T″ is the burst start time of the target TDMA burst configured in the frame plan; Δτ is the time difference obtained in step SA5;

[0091] Step SA7: using the TDMA burst time T′ obtained in step SA6 to guide the demodulation device to start receiving and detecting the TDMA burst, thereby achieving frame synchronization of the satellite demodulation device;

[0092] Step SA8: If the match is unsuccessful, take the second TDMA burst within the TDMA burst search time range A as the reference to take the length of one frame, and take the first TDMA burst in the taken frame as the reference to perform graphic matching with the burst allocation in the frame plan. If the match is successful, execute step SA5; if the match is unsuccessful, continue to move back one burst, take the third TDMA burst within the TDMA burst search time range A as the reference to take the length of one frame for graphic matching, and so on, until the match is successful; if the current TDMA burst search time range A cannot complete the match, repeat steps SA2-SA8 with the start time and frame length of the remaining frames in the frame plan until the match is successful.

[0093] The matching process performed by the frame synchronization module is sliding matching, and its principle is as follows Figure 1 As shown, a successful TDMA burst pattern match means that the two matching TDMA bursts are as follows Figure 2 shown.

[0094] Since TDMA burst time (reception, detection) may have false detection and the burst duration is short, the result of a sliding match cannot be guaranteed to be correct. To ensure that the time difference Δτ calculated by the sliding match is the correct frame plan and TDMA burst time difference, the correctness of the time difference Δτ result needs to be verified; if this result is correct, the burst detection time within the search range can correspond one-to-one with the burst time in the frame plan.

[0095] Therefore, the synchronization method also has a synchronization result verification step, including:

[0096] Step SB1: Determine the TDMA burst search time range A′[t1+Δτ, t1+Δτ+T] of the current superframe, where t1 is the start time of the current superframe, Δτ is the time difference obtained in step SA5, and T is the frame period of the current superframe;

[0097] Step SB2: acquiring the TDMA burst of the current frame from the start time of the TDMA burst search time range A′ determined in step SB1 until the end time of the TDMA burst search time range A′;

[0098] Step SB3: Graphically match the TDMA burst within the TDMA burst search time range A′ with the current superframe in the frame plan. If the match is successful, it means that the time difference obtained in step SA5 can be applied to the current superframe;

[0099] Step SB4: Repeat steps SB1-SB3 for a specified number of times. When the number of successful matches is greater than or equal to the specified threshold, the time difference Δτ obtained in step SA5 is correct; otherwise, it means that the time difference Δτ obtained in step SA5 is wrong. Re-execute steps SA1-SA5 to obtain the time difference Δτ.

[0100] After the frame synchronization is successful, the TDMA burst time T′ is used to guide the TDMA carrier reception. However, due to the slow movement of the satellite position and the accumulated deviation of the local clock, the initial synchronization result (TDMA burst time T′) cannot always be successfully guided. Therefore, it is necessary to perform synchronization time correction all the time so that the synchronization time can follow the frame plan and TDMA deviation.

[0101] Therefore, the synchronization method also has a synchronization time following step, which is specifically: according to the burst start time in each superframe, the time difference Δτ obtained in step SA5 and the sum of the link delay, the demodulation device is guided to receive and detect the superframe, and the TDMA burst in the superframe is obtained for matching with the corresponding TDMA burst in the frame plan. If the match is successful, the superframe verification is successful, and the average error of each pair of corresponding burst times of this superframe is calculated. This error is the time difference generated during the operation process, and this value is compensated to the time difference Δτ obtained in step SA5 to obtain an updated time difference Δτ; if the match is unsuccessful, the current superframe verification fails; after the verification failure ratio exceeds the specified threshold, the frame synchronization step is re-executed, and the sliding matching is re-performed to calculate the time difference.

[0102] In this method, the frame plan and TDMA decoding data are obtained by the following steps:

[0103] 1) Lock the DVB master station signal, and the DVB decoder outputs the DVB master station decoded data;

[0104] 2) Configure the signal satellite differential and LNB;

[0105] 3) DVB and TDMA use the same clock source and synchronize the clocks;

[0106] 4) Analyze the frame plan based on DVB decoding data;

[0107] 5) Obtain all carriers in the signal according to the frame plan, including carrier uplink frequency, symbol rate, modulation mode, code rate, frame length and time slot allocation information;

[0108] 6) Send decoding parameters according to the parsed frame plan information and output TDMA decoding data.

[0109] This method can obtain the time difference between the DVB frame plan and the TDMA frame. It is necessary to find the graphic position that matches the burst allocation graphic in the DVB frame plan from the continuous TDMA detection burst. Figure 2 As shown), the time offset between the initial DVB signal and the TDMA signal is also different. Some signals will indicate the relative time deviation between DVB and TDMA in the DVB signaling, and some signals have no time difference indication, and the approximate time difference needs to be obtained based on signal analysis.

[0110] Before synchronization, since the demodulation device does not know when and with which specification to perform burst detection, the demodulation device can only detect TDMA bursts blindly. At this time, detection needs to be performed at each time position. Due to noise interference, a burst may be detected at a time position where there is no burst, resulting in a false alarm; or a burst may not be detected at the burst position, resulting in missed detection. After the method is successfully synchronized, the TDMA burst time T′ is used to guide the demodulation device to receive and receive the TDMA burst at the TDMA burst time T′, and then the received and detected TDMA burst is demodulated and decoded according to the modulation mode, code rate, frame length, type, assigned small station ID and other specific information of the TDMA burst configured in the frame plan; solve the following problems: a) determine the ACM (Adaptive Coding and Modulation) burst reception demodulation parameters in the carrier; b) solve the problem of inaccurate burst classification (the small station to which the burst belongs and its burst type); c) reduce the probability of false alarm and missed detection, and increase the probability of correct reception.

[0111] The synchronization method can be implemented by a satellite demodulation device, which is configured with:

[0112] A first receiving channel, used for receiving a master station signal;

[0113] A second receiving channel for receiving TDMA bursts;

[0114] A frame synchronization module, executing the aforementioned frame synchronization steps;

[0115] A synchronization result verification module, which executes the aforementioned synchronization result verification step;

[0116] The synchronous time following module executes the aforementioned synchronous time following steps.

[0117] The present synchronization method can also be implemented by a computer device, which includes a memory, a processor, and a computer program stored in the memory, wherein the program is written in computer-readable code and has been successfully debugged; the processor and the memory are connected via a data bus or a signal line, so that the processor can read the computer program stored in the memory and run the computer program to implement the present synchronization method.

[0118] The memory in the device can be any memory capable of storing computer programs, such as readable memory, random access memory, serial access memory, cache memory, semiconductor memory, magnetic surface memory, magnetic core memory, optical disk memory, etc. The processor can be constructed by any single-chip microcomputer, digital processor, ARM, or other hardware capable of running computer programs.

[0119] In addition, the processor may also have a storage function, and the computer program / instruction is directly stored in the processor, and the processor is started through the peripheral circuit of the processor to execute the computer program / instruction to implement the method. The computer program is written in machine language, such as C language, assembly language, C++ language, JAVA language, etc.

[0120] The present disclosure has been described by the above-mentioned relevant embodiments, but the above-mentioned embodiments are only examples for implementing the present disclosure. It must be pointed out that the disclosed embodiments do not limit the scope of the present disclosure. On the contrary, changes and modifications made without departing from the spirit and scope of the present disclosure are all within the scope of patent protection of the present disclosure.

Claims

1. A satellite demodulation device frame synchronization method, characterized in that: The method includes a frame synchronization step for obtaining a TDMA burst time T′ for guiding a demodulation device to receive a TDMA burst and detect the TDMA burst. The specific steps are as follows: Step SA1: Obtain frame plan and initial TDMA burst decoding data; Step SA2: Determine the TDMA burst search time range [A 起始时间 , A 结束时间 ]: A 起始时间 Time=A1-A τ <h2 style=";text-align:left;direction:ltr">A<h2 style=";text-align:left;direction:ltr"> 结束时间 <h2 style=";text-align:left;direction:ltr"> (A1+A2+A)<h2 style=";text-align:left;direction:ltr"> τ Where: A1 is the start time of a frame in the frame plan, A2 is the length of a frame in the frame plan, A τ is the time offset; Step SA3: Search the TDMA burst time range A from the TDMA burst time range A determined in step SA2. 起始时间 Start acquiring TDMA bursts until A of TDMA burst search time range A 结束时间 ; Step SA4: Taking the first TDMA burst in the TDMA burst search time range A as a reference, take the length of a frame, and take the first TDMA burst in the taken frame as a reference to perform a graphic match with the burst allocation in the frame plan. If the match is successful, execute SA5; if the match is unsuccessful, execute SA8: Step SA5: Calculate the time difference Δτ according to the following method: Δτ=T i -T j Where: T i The start time of the first TDMA burst in the TDMA burst search time range A; T j is the allocation start time of the TDMA burst in the frame plan that matches the first TDMA burst pattern within the TDMA burst search time range A; Step SA6: Calculate the TDMA burst time T′ according to the following method: T′=T″+Δτ Where: T″ is the burst start time of the target TDMA burst configured in the frame plan; Δτ is the time difference obtained in step SA5; Step SA7: using the TDMA burst time T′ obtained in step SA6 to guide the demodulation device to start detecting and receiving TDMA bursts, thereby achieving frame synchronization of the satellite demodulation device; Step SA8: If the match is unsuccessful, take the second TDMA burst within the TDMA burst search time range A as the reference to take the length of one frame, and take the first TDMA burst in the taken frame as the reference to perform graphic matching with the burst allocation in the frame plan. If the match is successful, execute step SA5; if the match is unsuccessful, continue to move back one burst, and take the third TDMA burst within the TDMA burst search time range A as the reference to take the length of one frame for graphic matching, and so on, until the match is successful. If the current TDMA burst search time range A cannot complete the match, repeat steps SA2-SA8 with the start time and frame length of the remaining frames in the frame plan until the match is successful.

2. The satellite demodulation device frame synchronization method according to claim 1, characterized in that: It also includes the synchronization result verification step, the specific steps are as follows: Step SB1: Determine the TDMA burst search time range A′ of the current superframe; Step SB2: acquiring the TDMA burst of the current frame from the start time of the TDMA burst search time range A′ determined in step SB1 until the end time of the TDMA burst search time range A′; Step SB3: Graphically match the TDMA burst within the TDMA burst search time range A′ with the current superframe in the frame plan. If the match is successful, it means that the time difference obtained in step SA5 can be applied to the current superframe; Step SB4: Repeat steps SB1-SB3 for a specified number of times. When the number of successful matches is greater than or equal to the specified threshold, the time difference Δτ obtained in step SA5 is correct; otherwise, it means that the time difference Δτ obtained in step SA5 is wrong. Re-execute steps SA1-SA5 to obtain the time difference Δτ.

3. The satellite demodulation device frame synchronization method according to claim 2, characterized in that: The TDMA burst search time range A′ is [t1+Δτ, t1+Δτ+T], where t1 is the start time of the current superframe, Δτ is the time difference obtained in step SA5, and T is the frame period of the current superframe.

4. The satellite demodulation device frame synchronization method according to claim 1, characterized in that: It also includes a synchronization time following step, which specifically includes: guiding the demodulation device to receive and detect the superframe according to the sum of the burst start time in each superframe, the time difference Δτ obtained in step SA5 and the link delay, obtaining the TDMA burst in the superframe for matching with the corresponding TDMA burst in the frame plan, if the match is successful, then the superframe verification is successful, calculating the average error of each pair of burst times that can correspond to this superframe, and this error is the time difference generated during the operation, and compensating this value to the time difference Δτ obtained in step SA5 to obtain the updated time difference Δτ; If the match fails, the current superframe check fails. When the check failure ratio exceeds the specified threshold, the frame synchronization step is re-executed.

5. The satellite demodulation device frame synchronization method according to claim 1, characterized in that: The frame plan and TDMA decoded data are obtained by the following steps: Step SA11: The satellite demodulation device frame locks the DVB master station signal and outputs the DVB master station decoded data; Step SA12: Analyze the frame plan according to the DVB decoded data; Step SA13: Decode the TDMA burst according to the decoded parameters issued by the parsed frame plan to obtain TDMA burst decoded data.

6. The satellite demodulation device frame synchronization method according to claim 5, characterized in that: The satellite demodulation equipment uses the same clock source to receive the master station signal and the TDMA burst signal, performs demodulation and decoding, and obtains DVB decoding data and TDMA burst decoding data.

7. A satellite demodulation device, characterized in that: The device is configured with: A first receiving channel, used for receiving a master station signal; A second receiving channel for receiving TDMA bursts; The frame synchronization module is used to obtain the TDMA burst time T′ for guiding the demodulation device to receive the TDMA burst and detect the TDMA burst. The frame synchronization steps are as follows: Step SA1: Obtain frame plan and initial TDMA burst decoding data; Step SA2: Determine the TDMA burst search time range [A 起始时间 , A 结束时间 ]: A 起始时间 =A1-A τ <h2 style=";text-align:left;direction:ltr">A<h2 style=";text-align:left;direction:ltr"> 结束时间 <h2 style=";text-align:left;direction:ltr"> (A1+A2+A)<h2 style=";text-align:left;direction:ltr"> τ Where: A1 is the start time of a frame in the frame plan, A2 is the length of a frame in the frame plan, A τ is the time offset; Step SA3: Search the TDMA burst time range A from the TDMA burst time range A determined in step SA2. 起始时间 Start acquiring TDMA bursts until A of TDMA burst search time range A 结束时间 ; Step SA4: Taking the first TDMA burst in the TDMA burst search time range A as a reference, take the length of a frame, and take the first TDMA burst in the taken frame as a reference to perform a graphic match with the burst allocation in the frame plan. If the match is successful, execute SA5; if the match is unsuccessful, execute SA8: Step SA5: Calculate the time difference Δτ according to the following method: Δτ=T i -T j Where: T i The start time of the first TDMA burst in the TDMA burst search time range A; T j is the allocation start time of the TDMA burst in the frame plan that matches the first TDMA burst pattern within the TDMA burst search time range A; Step SA6: Calculate the TDMA burst time T′ according to the following method: T′=T"+Δτ Where: T″ is the burst start time of the target TDMA burst configured in the frame plan; Δτ is the time difference obtained in step SA5; Step SA7: using the TDMA burst time T′ obtained in step SA6 to guide the demodulation device to start detecting and receiving TDMA bursts, thereby achieving frame synchronization of the satellite demodulation device; Step SA8: If the match is unsuccessful, take the second TDMA burst within the TDMA burst search time range A as the reference to take the length of one frame, and take the first TDMA burst in the taken frame as the reference to perform graphic matching with the burst allocation in the frame plan. If the match is successful, execute step SA5; if the match is unsuccessful, continue to move back one burst, and take the third TDMA burst within the TDMA burst search time range A as the reference to take the length of one frame for graphic matching, and so on, until the match is successful. If the current TDMA burst search time range A cannot complete the match, repeat steps SA2-SA8 with the start time and frame length of the remaining frames in the frame plan until the match is successful.

8. The satellite demodulation device according to claim 7, characterized in that: The device is also configured with a synchronization result verification module, which performs the following steps: Step SB1: Determine the TDMA burst search time range A′ of the current superframe; Step SB2: acquiring the TDMA burst of the current frame from the start time of the TDMA burst search time range A′ determined in step SB1 until the end time of the TDMA burst search time range A′; Step SB3: Graphically match the TDMA burst within the TDMA burst search time range A′ with the current superframe in the frame plan. If the match is successful, it means that the time difference obtained in step SA5 can be applied to the current superframe; Step SB4: Repeat steps SB1-SB3 for a specified number of times. When the number of successful matches is greater than or equal to the specified threshold, the time difference Δτ obtained in step SA5 is correct; otherwise, it means that the time difference Δτ obtained in step SA5 is wrong. Re-execute steps SA1-SA5 to obtain the time difference Δτ.

9. The satellite demodulation device according to claim 7, characterized in that: The device is also configured with a synchronous time following module, which performs the following steps: guide the demodulation device to receive and detect the superframe according to the sum of the burst start time in each superframe, the time difference Δτ obtained in step SA5 and the link delay, obtain the TDMA burst in the superframe for matching with the corresponding TDMA burst in the frame plan, and if the match is successful, the superframe verification is successful, calculate the average error of each pair of burst times that can correspond to this superframe, and this error is the time difference generated during the operation, and compensate this value to the time difference Δτ obtained in step SA5 to obtain the updated time difference Δτ; If the match fails, the current superframe check fails. When the check failure ratio exceeds the specified threshold, the frame synchronization step is re-executed.

10. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The computer program is executed by the processor to implement the steps of the method of claims 1-6.

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