Satellite demodulation equipment frame synchronization method

Abstract

The application discloses a satellite demodulation equipment frame synchronization method, which comprises a frame synchronization step for acquiring a TDMA burst time T' of a leading demodulation equipment receiving a TDMA burst. The synchronization method acquires a frame plan and initial TDMA burst decoding data, and the satellite demodulation equipment can receive DVB signals and TDMA signals, and frame synchronization can be realized without interaction with a main substation; the synchronization method is also provided with a synchronization result checking step and a synchronization time following step, so that the receiving correct probability is improved, and the false alarm and missed detection probabilities are reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of communication, and particularly relates to a frame synchronization method for a satellite demodulation device. BACKGROUND

[0002] In a satellite signal receiving system, the burst guide reception of a TDMA carrier has strict requirements for the burst start time. Since the burst time indicated by the network control signaling in the DVB main carrier is deviated from the actual transmission time of the TDMA station burst in time, the burst signaling mark time and the actual satellite received TDMA station burst time may not be aligned, and the satellite signal receiving and demodulation cannot be guided according to the network control signaling.

[0003] In addition, even if the signaling indicated burst time 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 misaligned due to the different delays of the DVB carrier detection and the TDMA carrier detection of the demodulation device, so the frame synchronization process is a necessary process.

[0004] In the forward VSAT network design, the correction process is completed by the main station and the station in the system, and the demodulation device as a third-party receiver does not interact with the main station, and if the TDMA burst is to be correctly guided to be received, the time synchronization needs to be realized in the demodulation device. SUMMARY

[0005] The present application aims to provide a frame synchronization method for a satellite demodulation device, which can realize frame synchronization on the basis that the demodulation device does not interact with the main station.

[0006] The method comprises a frame synchronization step for acquiring the TDMA burst time T' for guiding the demodulation device to receive and detect the TDMA burst, and the specific steps are as follows:

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

[0008] Step SA2: determining the TDMA burst search time range in the following manner

[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] 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: from the A 起始时间 start to acquire TDMA burst, until the A 结束时间 of TDMA burst search time range A

[0014] Step SA4: take the length of a frame based on the first TDMA burst in the TDMA burst search time range A, match the burst allocation in the frame plan with the first TDMA burst in the taken frame, if the match is successful, execute SA5; if the match is not successful, execute SA8:

[0015] Step SA5: calculate the time difference Δτ according to the following way:

[0016] Δτ = T i -T j

[0017] In the formula: 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 which matches the first TDMA burst in the TDMA burst search time range A;

[0018] Step SA6: calculate the TDMA burst time T' according to the following way:

[0019] T' = T" + Δτ

[0020] In the formula: 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: use the TDMA burst time T' obtained in step SA6 to guide the demodulation equipment to start detecting and receiving the TDMA burst, and realize the frame synchronization of the satellite demodulation equipment;

[0022] Step SA8: If the matching is unsuccessful, a frame is taken as a length based on the second TDMA burst in the TDMA burst search time range A, and a graphic matching is made with the burst allocation in the frame plan based on the first TDMA burst in the taken frame. If the matching is successful, step SA5 is executed. If the matching is unsuccessful, a graphic matching is made by continuing to move one burst backward and taking a frame as a length based on the third TDMA burst in the TDMA burst search time range A, and so on until the matching is successful. If the current TDMA burst search time range A cannot complete the matching, the starting time of the remaining frames in the frame plan and the length of the frames are repeated to execute steps SA2-SA8 until the matching is successful.

[0023] Further, the synchronization method further comprises a synchronization result checking step, and the specific steps are as follows:

[0024] Step SB1: A TDMA burst search time range A' of the current superframe is determined.

[0025] Step SB2: The TDMA bursts of the current frame are acquired from the starting time of the TDMA burst search time range A' determined in step SB1 until the ending time of the TDMA burst search time range A'.

[0026] Step SB3: The TDMA bursts in the TDMA burst search time range A' are matched with the current superframe in the frame plan in a graphic manner. If the matching is successful, it indicates that the time difference obtained in step SA5 can be applied to the current superframe.

[0027] Step SB4: Steps SB1-SB3 are repeated for a specified number of times. When the number of times of successful matching is greater than or equal to a specified threshold, the time difference Δτ obtained in step SA5 is correct. Otherwise, it indicates that the time difference Δτ obtained in step SA5 is incorrect, and steps SA1-SA5 are re-executed to obtain the time difference Δτ.

[0028] Further, the TDMA burst search time range A' is [t1+Δτ, t1+Δτ+T], wherein t1 is the starting 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] Further, the synchronization method further comprises a synchronization time following step, and the step is specifically as follows: The demodulation device receives and detects the superframe according to the sum of the burst starting time in each superframe, the time difference Δτ obtained in step SA5 and the link delay, acquires the TDMA bursts in the superframe for matching with the corresponding TDMA bursts in the frame plan, and if the matching is successful, the superframe is verified to be successful. The average error of the burst time corresponding to each pair is calculated, the error is a time difference generated in the running process, and the value is compensated to the time difference Δτ obtained in step SA5 to obtain an updated time difference Δτ.

[0030] If the matching is unsuccessful, the current superframe check fails; if the check failure ratio exceeds a specified threshold, the frame synchronization step is re-executed.

[0031] Further, the frame plan and TDMA decoding data are obtained through the following steps:

[0032] Step SA11: The satellite demodulation device locks the frame of the DVB host signal and outputs DVB host decoding data.

[0033] Step SA12: The frame plan is parsed according to the DVB decoding data.

[0034] Step SA13: The TDMA burst is decoded according to the parsed frame plan and decoding parameters, and TDMA burst decoding data is obtained.

[0035] Further, the satellite demodulation device uses the same clock source to receive the host signal and the TDMA burst signal, and performs demodulation and decoding to obtain DVB decoding data and TDMA burst decoding data.

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

[0037] A first receiving channel for receiving the host signal;

[0038] A second receiving channel for receiving the TDMA burst;

[0039] A frame synchronization module for obtaining the TDMA burst time T' of the TDMA burst for guiding the demodulation device to receive the TDMA burst and detecting the TDMA burst, and performing the frame synchronization step as follows:

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

[0041] Step SA2: Determine the TDMA burst search time range in the following manner

[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] In the formula, A1 is the starting time of a frame in the frame plan, A2 is the length of a frame in the frame plan, and A τ is a time offset.

[0046] Step SA3: From the A of the TDMA burst search time range A determined in step SA2, the TDMA burst is searched in the range of A起始时间 Start to acquire TDMA burst until the first TDMA burst in TDMA burst search time range A 结束时间 ;

[0047] Step SA4: Take the length of a frame based on the first TDMA burst in TDMA burst search time range A, and match the burst allocation in the frame plan with the pattern based on the first TDMA burst in the taken frame. If the matching is successful, execute step SA5; if the matching is unsuccessful, execute step SA8.

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

[0049] Δτ = T i -T j

[0050] In the formula, T i is the starting time of the first TDMA burst in TDMA burst search time range A; T j is the allocation starting time of the TDMA burst in the frame plan that matches the pattern of the first TDMA burst in TDMA burst search time range A.

[0051] Step SA6: Calculate the TDMA burst time T' according to the following manner:

[0052] T' = T" + Δτ

[0053] In the formula, T" is the burst starting time of the target TDMA burst configured in the frame plan; and Δτ is the time difference obtained in step SA5.

[0054] Step SA7: Direct the demodulation device to start detecting and receiving the TDMA burst based on the TDMA burst time T' obtained in step SA6, so as to realize the frame synchronization of the satellite demodulation device.

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

[0056] Further, the device is further configured with a synchronization result verification module, which executes the following steps:

[0057] Step SB1: determining a TDMA burst search time range A' of a current superframe;

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

[0059] Step SB3: performing a graphic matching between the TDMA burst in the TDMA burst search time range A' and a current superframe in the frame plan, and if the matching is successful, it indicates that the time difference obtained in step SA5 can be applied to the current superframe.

[0060] Step SB4: repeating steps SB1-SB3 for a specified number of times, and when the number of times of successful matching is greater than or equal to a specified threshold, the time difference obtained in step SA5 is correct; otherwise, it indicates that the time difference obtained in step SA5 is incorrect, and steps SA1-SA5 are re-executed to obtain the time difference Δτ.

[0061] Further, the device is further configured with a synchronization time following module, which performs the following steps: guiding the demodulation device to receive and detect a superframe according to a sum of a burst start time in each superframe, the time difference Δτ obtained in step SA5 and a link delay, acquiring a TDMA burst in the superframe for matching with a corresponding TDMA burst in the frame plan, and if the matching is successful, the superframe is verified to be successful, an average error of a burst time corresponding to each pair in the superframe is calculated, the error is a time difference generated in the running process, and the value is compensated to the time difference Δτ obtained in step SA5 to obtain an updated time difference Δτ.

[0062] If the matching is unsuccessful, the current superframe fails to pass the verification, and if a verification failure rate exceeds a specified threshold, the frame synchronization step is re-executed.

[0063] The application further provides a computer device, which comprises a memory, a processor and a computer program stored in the memory, and the computer program is executed by the processor to implement the steps of the method.

[0064] The application has the following beneficial effects:

[0065] 1) The synchronization method acquires a frame plan and initial TDMA burst decoding data, and a satellite demodulation device can receive DVB signals and TDMA signals, and frame synchronization can be achieved without interaction with a main substation.

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

[0067] In order to illustrate the embodiments of the present application more clearly, the following will briefly introduce the drawings needed to be used or referred to in the embodiments. Obviously, the drawings in the following description only some of the embodiments of the present application, and other drawings can be obtained from these drawings without paying creative labor:

[0068] Figure 1 Sliding match process diagram;

[0069] Figure 2 DVB and TDMA burst relative time state diagram at various processing nodes. DETAILED DESCRIPTION

[0070] This section describes the present application in more detail with reference to the drawings, in which illustrative embodiments of the present application are shown. The present application, however, is not limited to these embodiments. Rather, these embodiments are described so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0071] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. 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 "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups 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 this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0073] The network control signaling guides the satellite signal receiving mainly in three steps: 1) analyzing the network control signaling, obtaining the frame plan of each TDMA frame indicated in the network control signaling, the frame plan containing the key parameters of each frame burst such as the starting time, modulation mode, symbol rate, code length, code rate and coding mode; 2) implementing frame synchronization, aligning the starting time of each frame burst indicated in the network control signaling in the frame plan with the TDMA frame in the satellite signal in time; 3) completing burst demodulation receiving, configuring the receiving and demodulation processing parameters according to each burst parameter indicated in the network control signaling in the frame plan, and realizing the demodulation, decoding and sorting of each burst of the satellite signal. In the three steps of the network control signaling guiding the satellite signal receiving, the frame synchronization is the key step. Since the satellite signal propagation condition in the air is complex and changeable, the signal delay to the receiving device is constantly changing, and the burst starting time indicated by the network control signaling needs to be dynamically adjusted according to the signal receiving delay condition, so as to realize the continuous guiding receiving and demodulation of the network control signaling.

[0074] After the demodulation device locks the DVB signal, the DVB decoding data is output, the frame plan is obtained through signaling analysis, the frame plan contains the frame number, frame start time, carrier information and burst allocation information of each carrier of the current frame. After configuring the demodulation device 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, and the decoding data contains detection information of each burst of a certain carrier, such as detection time, modulation mode, code rate and the like.

[0075] The frame plan and initial TDMA burst decoding data are transmitted into the frame synchronization module, and after frame synchronization processing, the time difference between the signaling time marked in the DVB and the actual TDMA burst time is obtained; according to the time difference, the TDMA burst time T' of each frame TDMA burst can be calculated, and then the demodulation device can be guided to receive and detect the TDMA burst according to the TDMA burst time T' and the parsed burst configuration, so as to realize frame synchronization.

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

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

[0078] Step SA2: determining the TDMA burst search time range in the following way

[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] wherein: 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 configured according to the equipment to which the synchronization method is applied, such as ±20 ms, or, in order to accelerate the frame synchronization speed, the time offset range can be reduced, such as ±5 ms, ±10 ms, or ±15 ms.

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

[0084] Step SA4: Take the length of a frame based on the first TDMA burst in the TDMA burst search time range A, and match the burst allocation in the frame plan with the first TDMA burst in the taken frame as the reference; if the matching is successful, execute SA5; if the matching is not successful, execute SA8:

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

[0086] Δτ = T i -T j

[0087] wherein: 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 in the TDMA burst search time range A;

[0088] Step SA6: Calculate the TDMA burst time T' according to the following manner:

[0089] T' = T" + Δτ

[0090] wherein: 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: Direct the demodulation equipment to start receiving the TDMA burst and detection based on the TDMA burst time T' obtained in step SA6, so as to realize the frame synchronization of the satellite demodulation equipment;

[0092] Step SA8: If the matching is unsuccessful, a frame is taken as a length based on the second TDMA burst in the TDMA burst search time range A, and a pattern matching is performed with the burst allocation in the frame plan based on the first TDMA burst in the taken frame. If the matching is successful, step SA5 is executed; if the matching is unsuccessful, a pattern matching is continuously performed by moving one burst backward and taking a frame as a length based on the third TDMA burst in the TDMA burst search time range A, and so on until the matching is successful. If the matching cannot be completed in the current TDMA burst search time range A, steps SA2-SA8 are repeated with the starting time of the remaining frames in the frame plan and the length of the frames until the matching is successful.

[0093] The matching process performed by the frame synchronization module is a sliding matching. The principle is shown in Fig. 2. Figure 1 The successful pattern matching of the TDMA bursts is shown in Fig. 3. Figure 2

[0094] Since there is a false detection in the TDMA burst time (reception and detection) and the burst duration is short, the result of one-time sliding matching cannot be guaranteed to be correct. To ensure that the time difference Δτ calculated by the sliding matching is the correct time difference between the frame plan and the TDMA burst, the correctness of the result of the time difference Δτ needs to be verified. If the result is correct, the burst detection time in the search range can be corresponded to the burst time in the frame plan one by one.

[0095] Therefore, the synchronization method further has a synchronization result verification step, which includes:

[0096] Step SB1: A TDMA burst search time range A' [t1+Δτ, t1+Δτ+T] of the current superframe is determined, where t1 is the starting 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: The TDMA bursts of the current frame are obtained from the starting time of the TDMA burst search time range A' determined in step SB1 until the ending time of the TDMA burst search time range A'.

[0098] Step SB3: The TDMA bursts in the TDMA burst search time range A' are pattern matched with the current superframe in the frame plan. If the matching is successful, it indicates that the time difference Δτ obtained in step SA5 can be applied to the current superframe.

[0099] Step SB4: Steps SB1-SB3 are repeated for a specified number of times. When the number of successful matching is greater than or equal to a specified threshold, the time difference Δτ obtained in step SA5 is correct; otherwise, it indicates that the time difference Δτ obtained in step SA5 is incorrect, and steps SA1-SA5 are re-executed 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 successfully guide, so the synchronization time needs to be corrected to make the synchronization time follow the frame plan and the TDMA deviation.

[0101] Therefore, the synchronization method further comprises a synchronization time following step, which comprises: guiding the demodulation equipment 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 matching is successful, the superframe verification is successful, the average error of the burst time corresponding to each pair of the superframe is calculated, the error is the time difference generated during the operation, and the value is compensated to the time difference Δτ obtained in step SA5 to obtain the updated time difference Δτ; if the matching is not successful, the current superframe verification fails; and if the verification failure rate exceeds a specified threshold, the frame synchronization step is re-executed to re-calculate the time difference through the sliding matching.

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

[0103] 1) Locking the DVB host signal, and outputting the DVB host decoding data through the DVB decoder;

[0104] 2) Configuring the signal star differential and the LNB;

[0105] 3) Using the same clock source for the DVB and the TDMA, and synchronizing the clock;

[0106] 4) Parsing the frame plan according to the DVB decoding data;

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

[0108] 6) Issuing the decoding parameters according to the parsed frame plan information, and outputting the TDMA decoding data.

[0109] Through the method, the time difference between the DVB frame plan and the TDMA frame can be obtained, and the pattern position matched with the burst allocation pattern in the DVB frame plan needs to be found from the continuous TDMA detection burst. According to the different reference points of the DVB and the TDMA of different manufacturers (as shown in Figure 2 , the time offset between the initial DVB signal and the TDMA signal is also different. Some signals indicate the relative time deviation between the DVB and the TDMA in the DVB signaling, and some signals do not have time difference indication, and the approximate time difference needs to be obtained according to the signal analysis.

[0110] Before synchronization, since the demodulation device does not know when and with which specification to detect the burst, the demodulation device can only blindly detect the TDMA burst, which needs to be detected at each time position, and is interfered by noise, and may detect a burst at a time position without a burst, causing false alarm; or does not detect a burst at a burst position, causing missed detection. After successful synchronization by the method, the TDMA burst time T' is used to guide the demodulation device to receive and demodulate the TDMA burst at the TDMA burst time T', and then the received and detected TDMA burst is demodulated and decoded according to the specific information of the modulation mode, code rate, frame length, type, and allocated substation id of the TDMA burst configured in the frame plan; the following problems are solved: a) determining the ACM (Adaptive Coding and Modulation) burst reception demodulation parameters in the carrier; b) solving the problem of inaccurate burst classification (the burst belongs to a substation and its burst type); c) reducing the false alarm and missed detection probability, and improving the correct reception probability.

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

[0112] a first receiving channel for receiving a main station signal;

[0113] a second receiving channel for receiving a TDMA burst;

[0114] a frame synchronization module for performing the aforementioned frame synchronization step;

[0115] a synchronization result verification module for performing the aforementioned synchronization result verification step;

[0116] a synchronization time following module for performing the aforementioned synchronization time following step.

[0117] The synchronization method can also be implemented by a computer device, which includes a memory, a processor, and a computer program stored in the memory, which is written by computer readable code and debugged successfully; the processor is connected with the memory through 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 synchronization method.

[0118] The memory in the device can be any kind of 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 disc memory, etc. The processor can be built by any kind of single-chip microcomputer, digital processor, ARM, etc. which can run computer programs.

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

[0120] The present disclosure has been described by the above-mentioned related embodiments, however, 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, the changes and modifications made without departing from the spirit and scope of the present disclosure are all within the scope of the patent protection of the present disclosure.

Claims

1. A method of frame synchronization for a satellite demodulation apparatus, characterized by, The method comprises a frame synchronization step for acquiring a TDMA burst to be received by the demodulation device and detecting a TDMA burst time T' of the TDMA burst, and the specific steps are as follows: Step SA1: acquiring a 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 ] by: A 起始时间 = A1- A τ A 结束时间 = A1+ A2+ A τ wherein: 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: A of the TDMA burst search time range A determined from step SA2 is searched for a TDMA burst 起始时间 Start acquiring TDMA bursts until A of the TDMA burst search time range A 结束时间 ; Step SA4: taking the length of one frame based on the first TDMA burst in the TDMA burst search time range A, matching the burst allocation in the frame plan with the first TDMA burst in the taken frame as a graph, if the matching is successful, executing step SA5; if the matching is unsuccessful, executing step SA8: Step SA5: calculating the time difference Δτ according to the following manner: Δτ = T i -T j In the formula, T i is the start time of the first TDMA burst in the TDMA burst search time range A. T j to assign a start time for a TDMA burst in the frame plan that matches the first TDMA burst pattern in the TDMA burst search time range A; Step SA6: calculating the TDMA burst time T' according to the following manner: T' = T" + Δτ In the formula, T" is the burst start time of the target TDMA burst configured in the frame plan; and Δτ is the time difference obtained in step SA5. Step SA7: guiding the demodulation device to start detecting and receiving the TDMA burst based on the TDMA burst time T' obtained in step SA6, so as to realize the frame synchronization of the satellite demodulation device. Step SA8: if the matching is unsuccessful, taking the length of one frame based on the second TDMA burst in the TDMA burst search time range A, matching the burst allocation in the frame plan with the first TDMA burst in the taken frame as a graph, if the matching is successful, executing step SA5; if the matching is unsuccessful, continuing to move one burst, taking the length of one frame based on the third TDMA burst in the TDMA burst search time range A to perform the graph matching, and so on until the matching is successful, if the current TDMA burst search time range A cannot complete the matching, repeating steps SA2-SA8 based on the start time of the remaining frames in the frame plan and the length of the frames until the matching is successful.

2. The method of frame synchronization of a satellite demodulation apparatus according to claim 1, characterized by, The method further comprises a synchronization result checking step, and the specific steps are as follows: Step SB1: determining a TDMA burst search time range A' of a current superframe; Step SB2: acquiring the TDMA burst of the current frame starting 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: matching the TDMA burst in the TDMA burst search time range A' with the current superframe in the frame plan as a graph, if the matching is successful, it indicates that the time difference obtained in step SA5 can be applied to the current superframe; Step SB4: repeating steps SB1-SB3 for a specified number of times, if the number of times of successful matching is greater than or equal to a specified threshold, the time difference Δτ obtained in step SA5 is correct; otherwise, it indicates that the time difference Δτ obtained in step SA5 is incorrect, and steps SA1-SA5 are re-executed to acquire the time difference Δτ.

3. The method of frame synchronization of a satellite demodulation apparatus according to claim 2, characterized by, The TDMA burst search time range A' is [t1+Δτ, t1+Δτ+T], wherein 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 method of frame synchronization of a satellite demodulation apparatus according to claim 1, characterized by, Also included is a step of synchronizing time, which is specifically: 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 matching is successful, the superframe verification is successful, the average error of the burst time corresponding to each pair of the superframe is calculated, the error is the time difference generated during operation, and the value is compensated to the time difference Δτ obtained in step SA5 to obtain an updated time difference Δτ; If the matching is not successful, the current superframe verification fails; if the verification failure rate exceeds a specified threshold, the frame synchronization step is re-executed.

5. The method of frame synchronization of a satellite demodulation apparatus according to claim 1, characterized by, The frame plan and the TDMA decoding data are obtained through the following steps: Step SA11: the satellite demodulation device locks the frame of the DVB host station signal and outputs DVB host decoding data; Step SA12: the frame plan is parsed according to the DVB decoding data; Step SA13: the decoding parameters are issued according to the parsed frame plan to decode the TDMA burst to obtain TDMA burst decoding data.

6. The method of frame synchronization of a satellite demodulation apparatus according to claim 5, characterized by, The satellite demodulation device uses the same clock source to receive the host 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 apparatus characterized by comprising: The device is configured with: A first receiving channel for receiving the host station signal; A second receiving channel for receiving the TDMA burst; A frame synchronization module for obtaining the TDMA burst time T' of guiding the demodulation device to receive and detect the TDMA burst, and performing the frame synchronization step as follows: Step SA1: obtaining the 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 ] by: A 起始时间 = A1- A τ A 结束时间 = A1+ A2+ A τ wherein: 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: A of the TDMA burst search time range A determined from step SA2 is searched for a TDMA burst 起始时间 Start acquiring TDMA bursts until A of the TDMA burst search time range A 结束时间 ; Step SA4: taking the first TDMA burst in the search time range A of the TDMA burst as a reference, taking the length of a frame, and taking the first TDMA burst in the taken frame as a reference to perform graphical matching with the burst allocation in the frame plan, if the matching is successful, step SA5 is executed; if the matching is not successful, step SA8 is executed: Step SA5: calculating the time difference Δτ according to the following manner: Δτ = T i -T j In the formula, T i is the start time of the first TDMA burst in the TDMA burst search time range A. T j to assign a start time for a TDMA burst in the frame plan that matches the first TDMA burst pattern in the TDMA burst search time range A; Step SA6: calculating the TDMA burst time T' according to the following manner: T′=T″+Δτ In the formula: 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: guiding the demodulation device to start detecting and receiving the TDMA burst according to the TDMA burst time T' obtained in step SA6 to realize frame synchronization of the satellite demodulation device; Step SA8: If the matching is unsuccessful, a frame is taken in length based on the second TDMA burst in the TDMA burst search time range A, and a pattern matching is performed with the burst allocation in the frame plan based on the first TDMA burst in the taken frame. If the matching is successful, step SA5 is executed. If the matching is unsuccessful, the pattern matching is continued by shifting one burst backward, and a frame is taken in length based on the third TDMA burst in the TDMA burst search time range A, and the pattern matching is continued in this way until the matching is successful. If the matching cannot be completed in the current TDMA burst search time range A, the starting time of the remaining frames in the frame plan and the length of the frames are repeated to execute steps SA2-SA8 until the matching is successful.

8. The satellite demodulation apparatus according to claim 7, characterized by The device is further configured with a synchronization result checking module, which performs the following steps: Step SB1: Determine the TDMA burst search time range A' of the current superframe; Step SB2: Obtain the TDMA bursts of the current frame from the starting time of the TDMA burst search time range A' determined in step SB1 until the ending time of the TDMA burst search time range A'; Step SB3: Perform a pattern matching of the TDMA bursts in the TDMA burst search time range A' with the current superframe in the frame plan. If the matching is successful, it indicates 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 times of successful matching is greater than or equal to a specified threshold, the time difference Δτ obtained in step SA5 is correct. Otherwise, it indicates that the time difference Δτ obtained in step SA5 is incorrect, and steps SA1-SA5 are re-executed to obtain the time difference Δτ.

9. The satellite demodulation apparatus according to claim 7, characterized by The device is further configured with a synchronization time following module, which performs the following steps: The demodulation device is guided to receive and detect a superframe according to the sum of the burst starting time in each superframe, the time difference Δτ obtained in step SA5, and the link delay, and the TDMA bursts in the superframe are obtained for matching with the corresponding TDMA bursts in the frame plan. If the matching is successful, the superframe is verified to be successful, and the average error of the burst time corresponding to each pair in the superframe is calculated. The error is a time difference generated during the operation, and the value is compensated to the time difference Δτ obtained in step SA5 to obtain an updated time difference Δτ. If the matching is unsuccessful, the current superframe fails the verification. If the proportion of verification failures exceeds a specified threshold, the frame synchronization steps are re-executed.

10. A computer apparatus comprising a memory, a processor, and a computer program stored on the memory, wherein the computer program, when executed by the processor, causes the processor to perform the method of any one of claims 1 to 9. The computer program is executed by the processor to implement the steps of the method of claim 1 or 2 or 3 or 4 or 5 or 6. The computer program is executed by the processor to implement the steps of the method of claim 1 or 2 or 3 or 4 or 5 or 6.

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