Method and device for analyzing DTMB-A single frequency network system

Abstract

The invention relates to an analysis method and device for a DTMB-A single frequency network system, and the method comprises the steps: generating an MIP packet according to a DTMB-A pre-transmitting mode and GPS information, inserting the MIP packet in pre-transmitted service data, calculating the number of service data packets and the number of zero padding contained in each OFDM frame according to the pre-transmitting mode, the service data stream is completely matched with the DTMB-A sending net code rate; the method comprises the following steps: receiving a service data stream and control information through each transmitting station, taking each MIP packet in the service data stream as a first data packet of an OFDM frame, and extracting a time label and a channel maximum delay in the MIP packet to calculate an additional delay; and modulating the service data stream and the control information, generating a multiframe synchronization channel according to the additional delay so as to multiplex the data frame information and the control frame information, generating a radio frequency signal corresponding to a multiplexing signal, and performing broadcast same-time transmission on the radio frequency signal. Therefore, the problem that a current single-frequency network adapter cannot meet the requirement of a DTMB-A system single-frequency network is solved.

Description

Technical Field

[0001] This application relates to the field of digital information transmission technology, and particularly relates to an analysis method and device for a DTMB-A single-frequency network system. Background Art

[0002] In traditional analog television broadcasting, to avoid co-channel interference, adjacent transmitting base stations transmit signals at different frequencies, and the same frequency can only be reused at a certain distance apart. This networking method of multiple frequency networks (MFN) causes serious waste of limited frequency resources.

[0003] With the transition of terrestrial television broadcasting from the analog era to the digital era, the number of digital TV channels has increased rapidly, and the frequency resources have become increasingly tense. The single-frequency network (SFN) networking gradually replaces the multiple frequency network with its advantages such as large coverage area, low transmitter cost, and high frequency utilization rate, and becomes the mainstream technical solution for wireless digital broadcast coverage networks. In a single-frequency network, multiple transmitting base stations transmit the same signal at the same time and at the same frequency, which greatly saves frequency resources and can provide diversity gain to enhance the reliability of reception. After the digitization of radio and television, the transmitted programs are clearer, the content is richer, and the processing and storage are more convenient. Compared with satellite digital TV and cable digital TV, the terrestrial transmission method has strong anti-interference ability, can be received under general indoor conditions, and has high flexibility, can support standard definition and high definition compatible TV broadcasting, mobile reception, and portable reception, and has low construction and maintenance costs. Wireless terrestrial digital TV will present a brand-new industrial operation model. There are the following two problems with the existing DTMB:

[0004] 1. Due to the characteristics of the frame structure of the DTMB system, the output of its SFN adapter is a legal MPEG-2 transport stream. The output TS packets are grouped into a set according to a certain number N, which is called a megaframe. Among them, N must be an integer, that is, after the DTMB baseband OFDM is framed, the number of TS packets it carries must also be an integer; then, the processing of the OFDM block and control information in the DTMB-A system is not specially processed, so the number of TS packets included in its OFDM frame data is no longer an integer. Therefore, the single-frequency network adapter and synchronization system of the current DTMB system cannot be used in the DTMB-A system.

[0005] 2. For the current single-frequency network (SFN) adapter, for the DTMB system with a payload rate of 5.414 Mbps to 32.484 Mbps, in order to reduce the clock processing of the SFN adapter, the implementation of the SFN can output the TS stream according to a clock of 7.56 MHz. However, for the DTMB-A system with a payload rate of 5.0 Mbps to 49.31 Mbps, due to the processing waiting time difference of the DTMB-A modulator, a single-frequency network adapter that outputs the TS stream at a fixed clock frequency cannot ensure that the MIP packet in the DTMB-A system must be the first TS packet of the OFDM frame data as required by the DTMB-A modulator.

[0006] In summary, the current single-frequency network adapter cannot meet the requirements of the DTMB-A system's single-frequency network and urgently needs to be solved. Summary of the Invention

[0007] This application provides an analysis method and device for a DTMB-A single-frequency network system to solve problems such as the current single-frequency network adapter not meeting the requirements of the DTMB-A system's single-frequency network.

[0008] The first aspect of the embodiments of this application provides an analysis method for a DTMB-A single-frequency network system, including the following steps: generating an MIP packet according to the pre-transmission mode and GPS information of the target DTMB-A single-frequency network system, and inserting the MIP packet into the pre-transmitted service data. At the same time, calculate the number of service data packets and the number of zero-padding in each OFDM frame according to the pre-transmission mode to obtain a service data stream that meets the preset matching requirements with the DTMB-A transmission net bit rate; receive the service data stream and control information through each preset transmitting station, and use each MIP packet in the service data stream as the first data packet of the OFDM frame in the target DTMB-A single-frequency network system, and extract the time tag and the maximum channel delay in the MIP packet to calculate the additional delay according to the time tag and the maximum channel delay; preprocess the service data stream and the control information, and perform scrambling, encoding, constellation mapping, and symbol interleaving on the preprocessed service data stream and control information to obtain corresponding data processing results, and perform OFDM modulation and frequency grouping on the data processing results and the preset PN-MC sequence to generate the data frame information corresponding to the service data stream and the control frame information corresponding to the control information; generate a multi-frame synchronization channel through the additional delay, and multiplex and synthesize the data frame information and the control frame information using the multi-frame synchronization channel to obtain a corresponding multiplexing signal, and convert the multiplexing signal into a radio frequency signal in the radio frequency band to broadcast and transmit the radio frequency signal simultaneously.

[0009] Optionally, in an embodiment of the present application, generating an MIP packet according to a pre-transmission mode and GPS information of a target DTMB-A single-frequency network system, inserting the MIP packet into pre-transmitted service data, and calculating the number of service data packets and the number of zero-padding in each OFDM frame according to the pre-transmission mode to obtain a service data stream that meets a preset matching requirement for the DTMB-A transmission net code rate, including: determining a plurality of target frames corresponding to the target DTMB-A single-frequency network system that meet the preset TS packet requirements, and inserting an MIP packet into the corresponding MPEG-2 transport stream every other target frame, where one target frame includes N TS packets, and adjusting the value of N according to the transmission rate of the TS code stream, and N is an integer; determining the working mode of the target DTMB-A single-frequency network system and the OFDM frame corresponding to each target frame in the plurality of target frames, and performing zero-padding operations at the tail of the service data pre-transmitted in each OFDM frame in the DTMB-A single-frequency network adapter of the target DTMB-A single-frequency network system according to the working mode to obtain a zero-padded MPEG-2 transport stream; obtaining the length information of each OFDM frame in the zero-padded MPEG-2 transport stream, and controlling the number of OFDM frames between adjacent MIP packets in the target DTMB-A single-frequency network system to be an integer and the interval between MIP packets to be less than 1 second according to the length information and the working mode, and controlling the TS code stream to output at different rate levels according to different modulation modes of the target DTMB-A single-frequency network system through a preset buffer unit.

[0010] Optionally, in an embodiment of the present application, receiving the service data stream through preset respective transmitting stations, using each MIP packet in the service data stream as the first data packet of an OFDM frame in the target DTMB-A single-frequency network system, and extracting the time tag and the channel maximum delay in the MIP packet to calculate an additional delay according to the time tag and the channel maximum delay, including: controlling a preset DTMB-A exciter to use each MIP packet in the service data stream as the first data packet of an OFDM frame in the target DTMB-A single-frequency network system, and detecting the service data stream; when detecting an MIP packet in the service data stream, obtaining the time difference between the start time of the OFDM frame corresponding to the MIP packet and the time of the pps signal generated by a preset global positioning system receiver, and extracting the time tag and the channel maximum delay in the MIP packet; calculating the additional delay corresponding to the service data stream based on the start time, the time difference, the time tag, the channel maximum delay, and a preset additional delay calculation strategy.

[0011] Optionally, in an embodiment of the present application, generating a multi-frame synchronization channel through the additional delay, multiplexing and synthesizing the data frame information and the control frame information by using the multi-frame synchronization channel to obtain a corresponding multiplexed signal, and converting the multiplexed signal into a radio frequency signal in the radio frequency band to perform broadcast simultaneous transmission on the radio frequency signal, includes: aligning the data frame information and the control frame information passing through different network paths according to the additional delay to synchronize the signal transmission time in the target DTMB-A single-frequency network system and generate the multi-frame synchronization channel; multiplexing and synthesizing the data frame information and the control frame information by using the multi-frame synchronization channel to obtain the multiplexed signal, and performing post-baseband processing on the multiplexed signal to generate a baseband transmission signal; performing quadrature up-conversion operation on the baseband transmission signal to convert the multiplexed signal into a radio frequency signal in the radio frequency band, and performing broadcast simultaneous transmission on the radio frequency signal.

[0012] Optionally, in an embodiment of the present application, the mathematical expression of the additional delay calculation strategy is:

[0013] STS + MD = Measured Delay + Additional Delay

[0014] Wherein, STS represents the time tag; MD represents the maximum channel delay; Measured Delay represents the time difference; Additional Delay represents the additional delay.

[0015] An analysis device for a DTMB-A single-frequency network system according to an embodiment of the second aspect of the present application includes: a pre-transmission service bitstream processing module, configured to generate an MIP packet according to a pre-transmission mode and GPS information of a target DTMB-A single-frequency network system, insert the MIP packet into pre-transmitted service data, and calculate the number of service data packets and the number of zero-padding in each OFDM frame according to the pre-transmission mode, so as to obtain a service data stream that meets a preset matching requirement with the DTMB-A transmission net bit rate; a receiving module, configured to receive the service data stream and control information through each preset transmitting station, use each MIP packet in the service data stream as the first data packet of an OFDM frame in the target DTMB-A single-frequency network system, and extract a time tag and a channel maximum delay in the MIP packet, so as to calculate an additional delay according to the time tag and the channel maximum delay; a modulation module, configured to perform preprocessing on the service data stream and the control information, and perform scrambling, encoding, constellation mapping, and symbol interleaving processing on the preprocessed service data stream and control information, so as to obtain corresponding data processing results, and perform OFDM modulation and frequency grouping on the data processing results and a preset PN-MC sequence, so as to generate data frame information corresponding to the service data stream and control frame information corresponding to the control information; a transmitting module, configured to generate a multi-frame synchronization channel through the additional delay, and multiplex and synthesize the data frame information and the control frame information by using the multi-frame synchronization channel to obtain a corresponding multiplexing signal, and convert the multiplexing signal into a radio-frequency signal in a radio frequency band, so as to perform simultaneous broadcast transmission on the radio-frequency signal.

[0016] Optionally, in an embodiment of the present application, the pre-transmission service stream processing module includes: an insertion unit, configured to determine a plurality of target frames corresponding to the target DTMB-A single-frequency network system that meet the preset TS packet requirements, and insert an MIP packet into the corresponding MPEG-2 transport stream every other target frame, where one target frame includes N TS packets, and the value of N is adjusted according to the transmission rate of the TS stream, and N is an integer; a zero-padding unit, configured to determine the working mode of the target DTMB-A single-frequency network system and the OFDM frame corresponding to each target frame among the plurality of target frames, and perform a zero-padding operation at the tail of the service data pre-transmitted in each OFDM frame in the DTMB-A single-frequency network adapter of the target DTMB-A single-frequency network system to obtain a zero-padded MPEG-2 transport stream; a control unit, configured to obtain the length information of each OFDM frame in the zero-padded MPEG-2 transport stream, and control the number of OFDM frames between adjacent MIP packets in the target DTMB-A single-frequency network system to be an integer and the interval between MIP packets to be less than 1 second according to the length information and the working mode, and control the TS stream to output at different rate levels according to different modulation modes of the target DTMB-A single-frequency network system through a preset buffer unit.

[0017] Optionally, in an embodiment of the present application, the receiving module includes: a determination unit, configured to control a preset DTMB-A exciter to use each MIP packet in the service data stream as the first data packet of the OFDM frame in the target DTMB-A single-frequency network system, and detect the service data stream; a detection unit, configured to, when detecting an MIP packet in the service data stream, obtain the time difference between the start time of the OFDM frame corresponding to the MIP packet and the time of the pps signal generated by a preset global positioning system receiver, and extract a time tag and a channel maximum delay in the MIP packet; a calculation unit, configured to calculate the additional delay corresponding to the service data stream based on the start time, the time difference, the time tag, the channel maximum delay, and a preset additional delay calculation strategy.

[0018] Optionally, in an embodiment of the present application, the transmitting module includes: a synchronization unit, configured to align the data frame information and the control frame information passing through different network paths according to the additional delay, so as to synchronize the signal transmission time in the target DTMB-A single-frequency network system and generate the multi-frame synchronization channel; a multiplexing unit, configured to multiplex and synthesize the data frame information and the control frame information by using the multi-frame synchronization channel to obtain a multi-frame, so as to obtain the multiplexed signal, and perform baseband post-processing on the multiplexed signal to generate a baseband transmission signal; a frequency conversion unit, configured to perform quadrature up-conversion operation on the baseband transmission signal to convert the multiplexed signal into a radio-frequency signal in the radio frequency band, and perform broadcast simultaneous transmission on the radio-frequency signal.

[0019] Optionally, in an embodiment of the present application, the mathematical expression of the additional delay calculation strategy is:

[0020] STS + MD = Measured Delay + Additional Delay

[0021] Wherein, STS represents the time tag; MD represents the maximum channel delay; Measured Delay represents the time difference; Additional Delay represents the additional delay.

[0022] An embodiment of the third aspect of the present application provides an electronic device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, and the processor executes the program to implement the analysis method of the DTMB-A single-frequency network system as described in the above embodiment.

[0023] An embodiment of the fourth aspect of the present application provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the program is executed by a processor, the analysis method of the DTMB-A single-frequency network system as described above is implemented.

[0024] An embodiment of the fifth aspect of the present application provides a computer program product, including a computer program, and the computer program is executed to implement the analysis method of the DTMB-A single-frequency network system as described above.

[0025] Therefore, the embodiments of the present application have the following beneficial effects:

[0026] Embodiments of the present application can generate MIP packets according to the pre-transmission mode of the target DTMB-A single-frequency network system and GPS information, insert the MIP packets into the pre-transmitted service data, and calculate the number of service data packets and the number of zero-padding in each OFDM frame according to the pre-transmission mode to obtain a service data stream that meets the preset matching requirements with the DTMB-A transmission net code rate; receive the service data stream and control information through each preset transmitting station, use each MIP packet in the service data stream as the first data packet of the OFDM frame in the target DTMB-A single-frequency network system, and extract the time tag and the maximum channel delay in the MIP packet to calculate the additional delay according to the time tag and the maximum channel delay; preprocess the service data stream and control information, and perform scrambling, encoding, constellation mapping, and symbol interleaving processing on the preprocessed service data stream and control information to obtain corresponding data processing results, and perform OFDM modulation and frequency grouping on the data processing results and the preset PN-MC sequence to generate data frame information corresponding to the service data stream and control frame information corresponding to the control information; generate a complex frame synchronization channel through the additional delay, and multiplex and synthesize the data frame information and the control frame information using the complex frame synchronization channel to obtain a corresponding multiplexed signal, and convert the multiplexed signal into a radio frequency signal in the radio frequency band to perform simultaneous broadcast transmission on the radio frequency signal, thereby avoiding the synchronization system calculation delay error caused by the waiting time of the DTMB-A modulator in processing the TS stream and meeting the requirements of the DTMB-A system single-frequency network. Thus, problems such as the current single-frequency network adapter not meeting the requirements of the DTMB-A system single-frequency network are solved.

[0027] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of the embodiments in conjunction with the drawings, in which:

[0029] Figure 1 is a flowchart of an analysis method for a DTMB-A single-frequency network system according to an embodiment of the present application;

[0030] Figure 2 is a schematic diagram of the measurement delay of a synchronization system provided by an embodiment of the present application;

[0031] Figure 3 is a schematic diagram of the control structure of an analysis system for a target DTMB-A single-frequency network system provided by an embodiment of the present application;

[0032] Figure 4A schematic diagram of inserting zeros and complementing in an MIP packet provided by an embodiment of the present application;

[0033] Figure 5 A schematic diagram of a time tag provided by an embodiment of the present application;

[0034] Figure 6 A principle block diagram of the transmitting end of a DTMB-A system provided by an embodiment of the present application;

[0035] Figure 7 An example diagram of an analysis device for a DTMB-A single-frequency network system according to an embodiment of the present application;

[0036] Figure 8 A schematic structural diagram of an electronic device provided by an embodiment of the present application.

[0037] Among them, 10 is the analysis device of the DTMB-A single-frequency network system; 100 is the pre-transmission service code stream processing module, 200 is the receiving module, 300 is the modulation module, 400 is the transmitting module; 801 is the memory, 802 is the processor, and 803 is the communication interface. Detailed implementation manners

[0038] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and should not be construed as limiting the present application.

[0039] The analysis method and device of the DTMB-A single-frequency network system according to the embodiments of the present application will be described below with reference to the accompanying drawings. In view of the problems mentioned in the above background art, the present application provides an analysis method for a DTMB-A single-frequency network system. In this method, an MIP packet is generated according to the pre-transmission mode and GPS information of the target DTMB-A single-frequency network system, and the MIP packet is inserted into the service data to be pre-transmitted. At the same time, the number of service data packets and the number of zero-padding included in each OFDM frame are calculated according to the pre-transmission mode, so as to obtain a service data stream that meets the preset matching requirements with the DTMB-A transmission net code rate; the service data stream and control information are received by each preset transmitting station, and each MIP packet in the service data stream is used as the first data packet of the OFDM frame in the target DTMB-A single-frequency network system, and the time tag and the maximum channel delay in the MIP packet are extracted to calculate the additional delay according to the time tag and the maximum channel delay; the service data stream and control information are preprocessed, and the preprocessed service data stream and control information are scrambled, encoded, constellation mapped and symbol interleaved to obtain corresponding data processing results, and the data processing results and the preset PN-MC sequence are OFDM modulated and frequency grouped to generate data frame information corresponding to the service data stream and control frame information corresponding to the control information; through the additional delay, a multi-frame synchronization channel is generated, and the data frame information and control frame information are multiplexed and synthesized into a multi-frame by using the multi-frame synchronization channel to obtain corresponding multiplexed signals, and the multiplexed signals are converted into radio frequency signals in the radio frequency band to perform broadcast simultaneous transmission on the radio frequency signals, so as to avoid the synchronization system calculation delay error caused by the waiting time of the DTMB-A modulator in processing the TS stream, and meet the requirements of the DTMB-A system single-frequency network. Thus, problems such as the current single-frequency network adapter not meeting the requirements of the DTMB-A system single-frequency network are solved.

[0040] Specifically, Figure 1 is a flowchart of an analysis method for a DTMB-A single-frequency network system provided by an embodiment of the present application.

[0041] As Figure 1 shown, the analysis method of the DTMB-A single-frequency network system includes the following steps:

[0042] In step S101, an MIP packet is generated according to the pre-transmission mode and GPS information of the target DTMB-A single-frequency network system, and the MIP packet is inserted into the service data to be pre-transmitted. At the same time, the number of service data packets and the number of zero-padding included in each OFDM frame are calculated according to the pre-transmission mode, so as to obtain a service data stream that meets the preset matching requirements with the DTMB-A transmission net code rate.

[0043] In step S102, each preset transmitting station receives the service data stream and control information, and takes each MIP packet in the service data stream as the first data packet of the OFDM frame in the target DTMB-A single-frequency network system, and extracts the time tag and the maximum channel delay in the MIP packet, so as to calculate the additional delay according to the time tag and the maximum channel delay.

[0044] An embodiment of the present application can first generate an MIP packet according to the pre-transmission mode of the target DTMB-A single-frequency network system and GPS information, insert this MIP packet into the pre-transmitted service data, and calculate the number of service data packets and the number of zero-padding in each OFDM frame according to the pre-transmission mode of DTMB-A, and finally obtain a group of service data streams that exactly match the DTMB-A transmission net code rate.

[0045] Secondly, an embodiment of the present application can receive the service data stream and control information through each transmitting station, take each MIP packet in the service data stream as the first data packet of the OFDM frame in the target DTMB-A single-frequency network system, and extract the time tag and the maximum channel delay in the MIP packet, so as to calculate the additional delay according to the time tag and the maximum channel delay, as Figure 2 shown.

[0046] Optionally, in an embodiment of the present application, an MIP packet is generated according to the pre-transmission mode of the target DTMB-A single-frequency network system and GPS information, and the MIP packet is inserted into the pre-transmitted service data. At the same time, the number of service data packets and the number of zero-padding in each OFDM frame are calculated according to the pre-transmission mode to obtain a service data stream that meets the preset matching requirements with the DTMB-A transmission net code rate, including: determining multiple target frames corresponding to the target DTMB-A single-frequency network system that meet the preset TS packet requirements, and inserting an MIP packet into the corresponding MPEG-2 transport stream every other target frame, where one target frame contains N TS packets, and the value of N is adjusted according to the transmission rate of the TS stream, and N is an integer; determining the working mode of the target DTMB-A single-frequency network system and the OFDM frame corresponding to each target frame in the multiple target frames, and performing zero-padding operations at the end of the service data pre-transmitted in each OFDM frame in the DTMB-A single-frequency network adapter of the target DTMB-A single-frequency network system according to the working mode to obtain a zero-padded MPEG-2 transport stream; obtaining the length information of each OFDM frame in the zero-padded MPEG-2 transport stream, and controlling the number of OFDM frames between adjacent MIP packets in the target DTMB-A single-frequency network system to be an integer and the interval of MIP packets to be less than 1 second according to the length information and the working mode, and controlling the TS stream to output at different rate levels according to different modulation modes of the target DTMB-A single-frequency network system through a preset buffer unit.

[0047] It should be noted that the embodiments of the present application utilize the control structure of the analysis system of the target DTMB-A single-frequency network system as shown in Figure 3 to process the TS bitstream, so as to obtain and output the Figure 4 specific steps of the bitstream order shown in are as follows:

[0048] S1. Insert an MIP packet into the MPEG-2 transport stream every other large frame. The MIP packet carries the synchronization time tag related to the GPS receiver and the system maximum delay information to each relay station. Among them, a large frame contains N TS packets, N is an integer, and the value of N can be adjusted according to the transmission rate of the TS bitstream;

[0049] S2. Utilize the forward error control method combining LDPC and BCH. Among them, the BCH code is used to provide error protection for the scrambled bitstream, and the scrambled and BCH-encoded bitstream is subjected to FEC encoding.

[0050] As an implementable method, the embodiments of the present application can adopt LDPC codes, which include two different code lengths of 61440 and 15360 and three different code rates of 1 / 2, 2 / 3, and 5 / 6. In addition, the target DTMB-A single-frequency network system can adopt quasi-cyclic LDPC codes;

[0051] S3. The embodiments of the present application can use a large frame as an OFDM frame in the target DTMB-A single-frequency network system, and the time tag is as shown in Figure 5 ; In addition, in the DTMB-A single-frequency network adapter, the embodiments of the present application can, according to the specific working mode of the target DTMB-A single-frequency network system, perform zero-padding operations at the end of the service data for each OFDM frame of the target DTMB-A single-frequency network system, as shown in Figure 4 ; In order to ensure that the service data sent by the DTMB-A exciters of each relay transmitting station is exactly the same, no data can be inserted into the service data required for each OFDM frame of the target DTMB-A single-frequency network system;

[0052] S4. Between adjacent MIP packets, the embodiments of the present application can control the number of OFDM frames of the target DTMB-A single-frequency network system to be an integer according to the specific working mode of DTMB-A and the length of the OFDM frame, and the interval of the MIP packets is less than 1 second, so as to generate data frame information and control frame information.

[0053] In summary, in the embodiments of the present application, in the DTMB-A single-frequency network adapter, according to the specific working mode of the target DTMB-A single-frequency network system, for each OFDM frame of the target DTMB-A single-frequency network system, corresponding zero-padding operations are performed at the end of its service data; meanwhile, the DTMB-A single-frequency network adapter controls to ensure that between adjacent MIP packets, there are an integer number of OFDM frames of DTMB-A.

[0054] Those skilled in the art should understand that due to the large range of DTMB-A payload rates, when finally outputting in the SFN single-frequency network, adding a data buffer unit can enable the TS stream to output the TS stream at different rate levels according to different modulation modes of DTMB-A, so as to avoid the synchronization system calculation delay error caused by the waiting time of the DTMB-A modulator in processing the TS stream.

[0055] In addition, it can be understood that in the embodiments of the present application, instead of adding an MIP packet every fixed 500 milliseconds, according to the specific working mode of DTMB-A and the length of the OFDM frame, it can not only ensure that there are an integer number of OFDM frames between two adjacent MIP packets, but also ensure that the interval between MIP packets is less than 1 second.

[0056] In step S103, the service data stream and control information are preprocessed, and the preprocessed service data stream and control information are subjected to scrambling, encoding, constellation mapping, and symbol interleaving processing to obtain corresponding data processing results, and the data processing results and a preset PN-MC sequence are subjected to OFDM modulation and frequency grouping to generate data frame information corresponding to the service data stream and control frame information corresponding to the control information.

[0057] In step S104, by adding additional delay, a complex frame synchronization channel is generated, and the data frame information and control frame information are multiplexed and synthesized into a complex frame by using the complex frame synchronization channel to obtain corresponding multiplexed signals, and the multiplexed signals are converted into radio-frequency signals in the radio frequency band to perform broadcast simultaneous transmission on the radio-frequency signals.

[0058] Furthermore, in the embodiments of the present application, multiple collectors are also required to collect service data in the service data stream in the DTMB-A single-frequency network system, collect control information, and preprocess the collected multiple service data and control information to obtain standard service data corresponding to each service data in the multiple service data and standard control information corresponding to the control information; in addition, the embodiments of the present application can use the collected service data and control data to form a data channel and a control channel.

[0059] The data frames of the data channel use independent encoding and modulation, and their encoding and modulation modes can be flexibly configured according to actual needs. Each standard service data, after forward error correction encoding, constellation mapping, and symbol interleaving, forms a data frame through IDFT transformation and adding a frame header. The control frames of the control channel adopt low-code-rate forward error correction encoding, QPSK constellation mapping, and symbol interleaving, and are formed through IDFT transformation and adding a frame header, as Figure 6 shown.

[0060] In the actual execution process, the control frames and data frames can use the same or different frame header lengths and frame body lengths. Among them, the frame header is composed of a frequency-domain binary pseudo-random sequence (i.e., PN-MC sequence).

[0061] In addition, the DTMB-A single-frequency network system includes constellation mappings such as QPSK, 16ASPK, 64APSK, and 256APSK; among them, the control frame body, the multi-frame synchronization signal, and the frame header signal can use QPSK modulation, and the data frame body can use QPSK, 16APSK, 64APSK, or 256APSK modulation. Each service signal can use a fixed channel encoding and constellation mapping method.

[0062] Thus, the embodiments of the present application can perform scrambling, encoding, constellation mapping, and symbol interleaving processing on multiple preprocessed service data and control information, and after generating the PN-MC sequence, perform OFDM modulation and frequency grouping on the processed service data and the PN-MC sequence, so as to provide reliable data support for subsequent operations such as data multiplexing.

[0063] Furthermore, the embodiments of the present application can generate a multi-frame synchronization channel, and use the multi-frame synchronization channel to multiplex and synthesize the service data that has undergone OFDM modulation and frequency grouping into a multi-frame, and convert the multiplexed signal into a radio-frequency signal in the radio frequency band to prepare for broadcast simultaneous transmission.

[0064] Optionally, in an embodiment of the present application, each preset transmitting station receives a service data stream, and each MIP packet in the service data stream is used as the first data packet of an OFDM frame in the target DTMB-A single-frequency network system, and the time tag and the maximum channel delay in the MIP packet are extracted to calculate an additional delay according to the time tag and the maximum channel delay, including: controlling a preset DTMB-A exciter to use each MIP packet in the service data stream as the first data packet of an OFDM frame in the target DTMB-A single-frequency network system, and detecting the service data stream; when an MIP packet in the service data stream is detected, obtaining the time difference between the start time of the OFDM frame corresponding to the MIP packet and the time of the pps signal generated by a preset global positioning system receiver, and extracting the time tag and the maximum channel delay in the MIP packet; calculating the additional delay corresponding to the service data stream based on the start time, the time difference, the time tag, the maximum channel delay, and a preset additional delay calculation strategy.

[0065] It should be noted that in the embodiment of the present application, when starting to work, the MIP packet can be checked, and the DTMB-A exciter can be controlled to use the MIP packet as the first data packet of the OFDM frame in the DTMB-A single-frequency network system; afterwards, at each receiving point, when an MIP is detected, the embodiment of the present application can measure the time difference Measured Delay between the start time of the corresponding large frame locally and the pps signal obtained from the global positioning system receiver, and at the same time extract the STS time tag and the maximum delay MD information of the channel in the MIP, and then calculate the additional delay Additional Delay that should be added to the transport stream.

[0066] Optionally, in an embodiment of the present application, the mathematical expression of the additional delay calculation strategy is:

[0067] STS + MD = Measured Delay + Additional Delay

[0068] Wherein, STS represents the time tag; MD represents the maximum channel delay; Measured Delay represents the time difference; Additional Delay represents the additional delay.

[0069] It should be noted that the embodiment of the present application can calculate the additional delay Additional Delay that should be added to the transport stream through the following formula:

[0070] STS + MD = Measured Delay + Additional Delay

[0071] Among them, STS represents the time tag; MD represents the maximum channel delay; Measured Delay represents the time difference; Additional Delay represents the additional delay.

[0072] Optionally, in an embodiment of the present application, a multiplexed frame synchronization channel is generated through additional delay, and the data frame information and the control frame information are multiplexed and synthesized into a multiplexed frame by using the multiplexed frame synchronization channel to obtain a corresponding multiplexed signal, and the multiplexed signal is converted into a radio frequency signal in the radio frequency band to perform broadcast simultaneous transmission on the radio frequency signal, including: aligning the data frame information and the control frame information that have passed through different network paths according to the additional delay to synchronize the signal transmission time in the target DTMB-A single-frequency network system, and generating a multiplexed frame synchronization channel; multiplexing and synthesizing the data frame information and the control frame information into a multiplexed frame by using the multiplexed frame synchronization channel to obtain a multiplexed signal, and performing baseband post-processing on the multiplexed signal to generate a baseband transmission signal; performing quadrature up-conversion operation on the baseband transmission signal to convert the multiplexed signal into a radio frequency signal in the radio frequency band, and performing broadcast simultaneous transmission on the radio frequency signal.

[0073] It should be noted that the specific steps for the embodiment of the present application to prepare for broadcast simultaneous transmission are as follows:

[0074] S1. Align the transmission bitstreams that have propagated through different network paths according to the calculated additional delay to synchronize the signal transmission time in the DTMB-A single-frequency network system, as Figure 2 shown; and generate a multiplexed frame synchronization channel by using the calculated additional delay and the delayed signal;

[0075] S2. Multiplex and synthesize the service data that has been OFDM modulated and grouped into a multiplexed frame by using the multiplexed frame synchronization channel (that is, the control frame and the data frames formed by each path of service are multiplexed and synthesized into a multiplexed frame signal), and perform baseband post-processing on the multiplexed signal (that is, the multiplexed frame signal) to obtain a baseband transmission signal, and the baseband signal is quadrature up-converted to form a radio frequency signal in the radio frequency band to prepare for broadcast simultaneous transmission.

[0076] The following uses a specific embodiment to illustrate the execution logic of the analysis method of the DTMB-A single-frequency network system of the present application.

[0077] In practical applications, the DTMB-A single-frequency network adapter and its synchronization system have been successfully implemented using FPGA. The specific embodiment of the present application is specifically described by taking the guard interval K = 256, the LDPC coding rate 2 / 3, the OFDM frame block length N = 32768, and the constellation mapping using 256APSK as an example.

[0078] According to the working mode of the DTMB-A single-frequency network system, the control unit in the specific embodiment of the present application will control an OFDM frame to contain P = 27 TS packets, and the subsequent zero-padding process supplements "0" data of Q = 11 bytes. The above data constitutes a complete DTMB-A OFDM frame data. The specific calculation of the P and Q values needs to refer to the detailed parameters in the DTMB-A standard.

[0079] The control unit in the specific embodiment of the present application will control the MIP packet as the first data packet of an OFDM frame of a DTMB-A single-frequency network system. After adding P - 1 TS service data packets, the zero-padding process of the OFDM frame data of the DTMB-A single-frequency network system is performed, that is, Q bytes of "0" data are supplemented.

[0080] According to a specific working mode of DTMB-A, for example, when the working mode of the DTMB-A single-frequency network system adopts an OFDM frame block size of 32768, the data length of each OFDM frame is 227.163 milliseconds. According to the MIP insertion method in the embodiment of the present application, the time interval of the MIP packet can be 454.326 milliseconds or 681.49 milliseconds, that is, the time interval between every two adjacent MIP packets can be 2 or 3 DTMB-A OFDM frames.

[0081] In the specific embodiment of the present application, the symbol rate of the DTMB-A single-frequency network system in the Normal mode is 7.56 MHz. Under different signal frame lengths, different LDPC code rates, and modulation methods, the payload data rate range of the DTMB-A single-frequency network system is 5.0 Mbps to 49.31 Mbps. The payload data rates of the system in various modes are shown in Table 1.

[0082] Table 1

[0083]

[0084] For the constellation diagram using 256APSK, if the payload rate is below 30.24 Mbps, the TS bitstream is output at a rate of 3.78 MB / Hz; for the application modes with payload rates below 30.24 Mbps and 45.36 Mbps, the TS bitstream is output at a rate of 5.67 MB / Hz; for the application modes with payload rates exceeding 45.36 Mbps, the TS bitstream is output at a rate of 7.56 MB / Hz.

[0085] In a specific embodiment of the present application, a constellation diagram of 256APSK can be adopted. Each symbol contains 8-bit data information. The net payload data rate of the system is 39.41 Mbps, and the net payload symbol rate is approximately 39.41 / 8 = 4.93 Mbps. To avoid the calculation delay error of the synchronization system caused by the waiting time of the DTMB-A modulator in processing the TS stream, the buffer processing of its single-frequency network adapter outputs the TS stream at a rate of 5.67 MB / Hz.

[0086] Furthermore, the present application can also construct a corresponding analysis system for the DTMB-A single-frequency network system according to the analysis method of the DTMB-A single-frequency network system. The following will elaborate and introduce the analysis system of the DTMB-A single-frequency network system of the present application in conjunction with the accompanying drawings.

[0087] The analysis system of the DTMB-A single-frequency network system of the present application mainly includes a single-frequency network adapter, a DTMB-A modulator, and a global positioning system receiver.

[0088] Among them, the single-frequency network adapter is used to adaptively process the information frames in the DTMB-A single-frequency network system;

[0089] The DTMB-A modulator is used to analyze the synchronization time tag STS and the maximum delay MD in the DTMB-A single-frequency network system and calculate the additional delay;

[0090] The global positioning system receiver is used to receive the signals transmitted by the transmitter and generate a pps signal for time synchronization every second.

[0091] Specifically, the single-frequency network adapter includes an MPEG-2 generation module, an encoding processing module, a multiplexing module, a control module, and an output module;

[0092] Among them, the MPEG-2 generation module is used to insert an MIP packet into the MPEG-2 transport stream every other large frame. The MIP packet carries the synchronization time tag related to the GPS receiver and the system maximum delay information to each relay station; an OFDM frame in the DTMB-A single-frequency network system can be a large frame;

[0093] The encoding processing module is used to select the forward error control method of LDPC + BCH combination. The BCH code is used to provide error protection for the scrambled bit stream. The scrambled and BCH-encoded bit stream is subjected to FEC encoding using the LDPC code, including two different code lengths of 61440 and 15360 and three different code rates of 1 / 2, 2 / 3, and 5 / 6; the LDPC code adopted by the DTMB-A system is a quasi-cyclic LDPC code;

[0094] The multiplexing module is used to multiplex all received signals into a frame of signals;

[0095] The control module is used to control the adaptation of signals in the single-frequency network adapter;

[0096] The output module is used to output the MPEG-2 transport stream with MIP inserted.

[0097] As Figure 3 shown, the control module includes a zero-padding unit, a MIP insertion control unit, a rounding control unit, and a buffer control unit.

[0098] The zero-padding unit is used to perform zero-padding operations at the end of service data for each OFDM frame of the DTMB-A system according to the specific working mode of DTMB-A in the DTMB-A single-frequency network adapter;

[0099] The rounding control unit is used to control the number of OFDM frames of the DTMB-A single-frequency network system to be an integer and the interval of MIP packets to be less than 1 second between adjacent MIP packets according to the specific working mode of DTMB-A and the length of the OFDM frame;

[0100] The buffer unit is used to control the output of the TS stream at different rate levels.

[0101] The DTMB-A modulator includes a synchronization system module, an additional delay calculation module, and a speed selection module;

[0102] The synchronization system module is used to check the MIP packet at the beginning of operation and control the DTMB-A exciter to use the MIP packet as the first data packet of the OFDM frame of the DTMB-A system;

[0103] The additional delay calculation module is used to measure the time difference Measured Delay between the start time of the corresponding large frame locally and the pps signal obtained from the global positioning system receiver when detecting MIP at each receiving point, and at the same time extract the STS time tag and the maximum delay MD information of the channel from the MIP, and calculate the additional delay Additional Delay to be added to the transport stream by the following formula:

[0104] STS + MD = Measured Delay + Additional Delay

[0105] Where, STS represents the time tag; MD represents the maximum channel delay; Measured Delay represents the time difference; Additional Delay represents the additional delay.

[0106] Align the transmission bitstreams propagated through different network paths according to the calculated additional delay to synchronize the signal transmission times in the DTMB-A single-frequency network system;

[0107] The speed selection module is used to select different output speeds of the TS bitstream according to different modulation modes of DTMB-A and transmit the selected speed to the buffer unit.

[0108] The global positioning system receiver includes a receiving module and a pps signal generation module. Among them, the receiving module is used to receive the signal after adaptation and modulation; the pps signal generation module is used to generate and provide a 1PPS signal for time synchronization.

[0109] According to the analysis method of the DTMB-A single-frequency network system proposed in the embodiments of the present application, generate an MIP packet according to the pre-transmission mode and GPS information of the target DTMB-A single-frequency network system, insert the MIP packet into the pre-transmitted service data, and calculate the number of service data packets and the number of zero-padding in each OFDM frame according to the pre-transmission mode to obtain a service data stream that meets the preset matching requirements with the DTMB-A transmission net bit rate; receive the service data stream and control information through each preset transmitting station, and use each MIP packet in the service data stream as the first data packet of the OFDM frame in the target DTMB-A single-frequency network system, and extract the time tag and the maximum channel delay in the MIP packet to calculate the additional delay according to the time tag and the maximum channel delay; preprocess the service data stream and control information, and perform scrambling, encoding, constellation mapping, and symbol interleaving processing on the preprocessed service data stream and control information to obtain corresponding data processing results, and perform OFDM modulation and frequency grouping on the data processing results and the preset PN-MC sequence to generate data frame information corresponding to the service data stream and control frame information corresponding to the control information; generate a multi-frame synchronization channel through the additional delay, and multiplex and synthesize the data frame information and the control frame information using the multi-frame synchronization channel to obtain corresponding multiplexed signals, and convert the multiplexed signals into radio-frequency signals in the radio frequency band to broadcast and transmit the radio-frequency signals simultaneously, thereby avoiding the synchronization system calculation delay error caused by the waiting time of the DTMB-A modulator for processing the TS bitstream and meeting the requirements of the DTMB-A system single-frequency network.

[0110] Secondly, describe the analysis device of the DTMB-A single-frequency network system proposed in the embodiments of the present application with reference to the accompanying drawings.

[0111] Figure 7 It is a block diagram of the analysis device of the DTMB-A single-frequency network system according to the embodiments of the present application.

[0112] As Figure 7As shown in the figure, the analysis device 10 of the DTMB-A single-frequency network system includes: a pre-transmission service bitstream processing module 100, a receiving module 200, a modulation module 300, and a transmitting module 400.

[0113] Among them, the pre-transmission service bitstream processing module 100 is used to generate an MIP packet according to the pre-transmission mode and GPS information of the target DTMB-A single-frequency network system, insert the MIP packet into the pre-transmitted service data, and calculate the number of service data packets and the number of zero-padding in each OFDM frame according to the pre-transmission mode, so as to obtain a service data stream that meets the preset matching requirements with the DTMB-A transmission net bitrate.

[0114] The receiving module 200 is used to receive the service data stream and control information through each preset transmitting station, use each MIP packet in the service data stream as the first data packet of the OFDM frame in the target DTMB-A single-frequency network system, and extract the time tag and the maximum channel delay in the MIP packet, so as to calculate the additional delay according to the time tag and the maximum channel delay.

[0115] The modulation module 300 is used to preprocess the service data stream and control information, and perform scrambling, encoding, constellation mapping, and symbol interleaving processing on the preprocessed service data stream and control information to obtain corresponding data processing results, and perform OFDM modulation and frequency grouping on the data processing results and the preset PN-MC sequence to generate data frame information corresponding to the service data stream and control frame information corresponding to the control information.

[0116] The transmitting module 400 is used to generate a complex frame synchronization channel through the additional delay, and multiplex and synthesize the data frame information and the control frame information by using the complex frame synchronization channel to obtain a corresponding multiplexing signal, and convert the multiplexing signal into a radio frequency signal in the radio frequency band to perform simultaneous broadcast transmission on the radio frequency signal.

[0117] Optionally, in an embodiment of the present application, the pre-transmission service bitstream processing module 100 includes: an insertion unit, a zero-padding unit, and a control unit.

[0118] Among them, the insertion unit is used to determine multiple target frames corresponding to the target DTMB-A single-frequency network system that meet the preset TS packet requirements, and insert an MIP packet into the corresponding MPEG-2 transport stream every other target frame, where one target frame includes N TS packets, and adjust the value of N according to the transmission rate of the TS bitstream, and N is an integer.

[0119] A zero-padding unit is used to determine the working mode of the target DTMB-A single-frequency network system and the OFDM frame corresponding to each target frame among multiple target frames, and perform zero-padding operations on the tails of the service data pre-transmitted in each OFDM frame according to the working mode in the DTMB-A single-frequency network adapter of the target DTMB-A single-frequency network system to obtain zero-padded MPEG-2 transport streams.

[0120] A control unit is used to obtain the length information of each OFDM frame in the zero-padded MPEG-2 transport stream, and control the number of OFDM frames between adjacent MIP packets in the target DTMB-A single-frequency network system to be an integer and the interval of MIP packets to be less than 1 second according to the length information and the working mode, and control the TS stream to output at different rate levels according to different modulation modes of the target DTMB-A single-frequency network system through a preset buffer unit.

[0121] Optionally, in an embodiment of the present application, the receiving module 200 includes: a determination unit, a detection unit, and a calculation unit.

[0122] Among them, the determination unit is used to control a preset DTMB-A exciter to use each MIP packet in the service data stream as the first data packet of the OFDM frame in the target DTMB-A single-frequency network system and detect the service data stream.

[0123] The detection unit is used to, when detecting an MIP packet in the service data stream, obtain the time difference between the start time of the OFDM frame corresponding to the MIP packet and the time of the pps signal generated by a preset global positioning system receiver, and extract a time tag and a channel maximum delay in the MIP packet.

[0124] The calculation unit is used to calculate the additional delay corresponding to the service data stream based on the start time, the time difference, the time tag, the channel maximum delay, and a preset additional delay calculation strategy.

[0125] Optionally, in an embodiment of the present application, the transmitting module 400 includes: a synchronization unit, a multiplexing unit, and a frequency conversion unit.

[0126] The synchronization unit is used to align the data frame information and the control frame information passing through different network paths according to the additional delay to synchronize the signal transmission time in the target DTMB-A single-frequency network system and generate a multi-frame synchronization channel.

[0127] The multiplexing unit is used to multiplex and synthesize the data frame information and the control frame information using the multi-frame synchronization channel to obtain a multiplexed signal, and perform baseband post-processing on the multiplexed signal to generate a baseband transmission signal.

[0128] A frequency conversion unit is used to perform quadrature up-conversion operations on baseband transmission signals to convert multiplexed signals into radio-frequency signals in the radio frequency band and perform broadcast simultaneous transmission on the radio-frequency signals.

[0129] Optionally, in an embodiment of the present application, the mathematical expression of the additional delay calculation strategy is:

[0130] STS + MD = Measured Delay + Additional Delay

[0131] Wherein, STS represents the time tag; MD represents the maximum channel delay; Measured Delay represents the time difference; Additional Delay represents the additional delay.

[0132] It should be noted that the foregoing explanatory description of the embodiment of the analysis method of the DTMB-A single-frequency network system is also applicable to the analysis device of the DTMB-A single-frequency network system of this embodiment, and will not be elaborated here.

[0133] An analysis device of a DTMB-A single-frequency network system according to an embodiment of the present application includes a pre-transmission service code stream processing module, which is used to generate MIP packets according to the pre-transmission mode and GPS information of the target DTMB-A single-frequency network system, insert the MIP packets into the pre-transmitted service data, and calculate the number of service data packets and the number of zero-padding in each OFDM frame according to the pre-transmission mode to obtain a service data stream that meets the preset matching requirements with the DTMB-A transmission net code rate; a receiving module, which is used to receive the service data stream and control information through each preset transmitting station, and use each MIP packet in the service data stream as the first data packet of the OFDM frame in the target DTMB-A single-frequency network system, and extract the time tag and the maximum channel delay in the MIP packet to calculate the additional delay according to the time tag and the maximum channel delay; a modulation module, which is used to preprocess the service data stream and control information, and perform scrambling, encoding, constellation mapping and symbol interleaving processing on the preprocessed service data stream and control information to obtain corresponding data processing results, and perform OFDM modulation and frequency grouping on the data processing results and a preset PN-MC sequence to generate data frame information corresponding to the service data stream and control frame information corresponding to the control information; a transmitting module, which is used to generate a complex frame synchronization channel through the additional delay, and use the complex frame synchronization channel to multiplex and synthesize the data frame information and control frame information into a complex frame to obtain a corresponding multiplexed signal, and convert the multiplexed signal into a radio-frequency signal in the radio frequency band to perform broadcast simultaneous transmission on the radio-frequency signal, thereby avoiding the synchronous system calculation delay error caused by the waiting time of the DTMB-A modulator in processing the TS code stream and meeting the requirements of the DTMB-A system single-frequency network.

[0134] Figure 8 A structural schematic diagram of the electronic device provided by the embodiment of the present application. The electronic device may include:

[0135] A memory 801, a processor 802, and a computer program stored on the memory 801 and executable on the processor 802.

[0136] When the processor 802 executes the program, it implements the analysis method of the DTMB-A single-frequency network system provided in the above embodiment.

[0137] Furthermore, the electronic device further includes:

[0138] A communication interface 803 for communication between the memory 801 and the processor 802.

[0139] The memory 801 is used to store a computer program executable on the processor 802.

[0140] The memory 801 may include a high-speed RAM memory, and may also include a non-volatile memory, such as at least one disk memory.

[0141] If the memory 801, the processor 802, and the communication interface 803 are implemented independently, the communication interface 803, the memory 801, and the processor 802 may be interconnected through a bus and communicate with each other. The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For the sake of representation, Figure 8 only a thick line is used to represent it in the figure, but it does not mean that there is only one bus or one type of bus.

[0142] Optionally, in a specific implementation, if the memory 801, the processor 802, and the communication interface 803 are integrated on a chip, the memory 801, the processor 802, and the communication interface 803 may communicate with each other through an internal interface.

[0143] The processor 802 may be a Central Processing Unit (CPU), or an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0144] The embodiments of the present application further provide a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the analysis method of the DTMB-A single-frequency network system as described above is implemented.

[0145] The embodiments of the present application further provide a computer program product, including a computer program, and when the computer program is executed, it is used to implement the analysis method of the DTMB-A single-frequency network system as described above.

[0146] In the description of this specification, the descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples.

[0147] In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "N" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0148] Any process or method description shown in the flowchart or described in other ways herein may be understood to represent a module, segment, or portion of code including one or N executable instructions for implementing a customized logic function or process, and the scope of the preferred embodiments of the present application includes additional implementations, where the functions may be executed in a substantially simultaneous manner or in a reverse order according to the involved functions, rather than in the order shown or discussed, which should be understood by those skilled in the art of the embodiments of the present application.

[0149] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a definable sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or used in conjunction with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection part (electronic device) having one or N wirings, a portable computer disk cartridge (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically by optically scanning the paper or other media, followed by editing, interpretation, or otherwise processing as appropriate, and then storing it in a computer memory.

[0150] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or combinations thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented using hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0151] Those of ordinary skill in the art of this technology can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0152] In addition, each functional unit in various embodiments of the present application may be integrated into a processing module, may exist physically alone for each unit, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0153] The above-mentioned storage medium may be a read-only memory, a magnetic disk, an optical disc, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for analyzing a DTMB-A single frequency network system, characterized in that: The following steps are involved: Generate a MIP packet according to the pre-transmission mode and GPS information of the target DTMB-A single frequency network system, insert the MIP packet into the pre-transmitted service data, and calculate the number of service data packets and the number of zero padding contained in each OFDM frame according to the pre-transmission mode to obtain a service data stream that meets the preset matching requirements with the DTMB-A transmission net code rate; The service data stream and control information are received through each preset transmitting station, and each MIP packet in the service data stream is used as the first data packet of the OFDM frame in the target DTMB-A single frequency network system, and the time tag and the maximum channel delay in the MIP packet are extracted to calculate the additional delay according to the time tag and the maximum channel delay; Preprocessing the service data stream and the control information, and performing scrambling, encoding, constellation mapping and symbol interleaving processing on the preprocessed service data stream and control information to obtain corresponding data processing results, and performing OFDM modulation and group frequency on the data processing results and a preset PN-MC sequence to generate data frame information corresponding to the service data stream and control frame information corresponding to the control information; Through the additional delay, a multi-frame synchronization channel is generated, and the data frame information and the control frame information are multiplexed and synthesized into a multi-frame using the multi-frame synchronization channel to obtain a corresponding multiplexed signal, and the multiplexed signal is converted into a radio frequency signal in the radio frequency band to broadcast and transmit the radio frequency signal at the same time.

2. The method according to claim 1, characterized in that The method generates a MIP packet according to the pre-transmission mode and GPS information of the target DTMB-A single frequency network system, inserts the MIP packet into the pre-transmitted service data, and calculates the number of service data packets and the number of zero padding contained in each OFDM frame according to the pre-transmission mode to obtain a service data stream that meets the preset matching requirements with the DTMB-A transmission net code rate, including: Determine a plurality of target frames corresponding to the target DTMB-A single frequency network system that meet the preset TS packet requirements, and insert a MIP packet into the corresponding MPEG-2 transport stream every other target frame, wherein the target frame contains N TS packets, and the value of N is adjusted according to the transmission rate of the TS code stream, and N is an integer; Determine the working mode of the target DTMB-A single frequency network system and the OFDM frame corresponding to each target frame in the multiple target frames according to the multiple target frames, and perform a zero-padding operation on the tail of the service data pre-sent in each OFDM frame according to the working mode in the DTMB-A single frequency network adapter of the target DTMB-A single frequency network system to obtain a zero-padding MPEG-2 transport stream; The length information of each OFDM frame in the zero-padded MPEG-2 transport stream is obtained, and the number of OFDM frames between adjacent MIP packets in the target DTMB-A single frequency network system is controlled to be an integer and the interval between MIP packets is less than 1 second according to the length information and the working mode, and the TS code stream is controlled by a preset buffer unit to be output at different rate levels according to different modulation modes of the target DTMB-A single frequency network system.

3. The method according to claim 2, characterized in that The receiving of the service data stream through each preset transmitting station, and taking each MIP packet in the service data stream as the first data packet of the OFDM frame in the target DTMB-A single frequency network system, and extracting the time tag and the maximum channel delay in the MIP packet, so as to calculate the additional delay according to the time tag and the maximum channel delay, comprises: Controlling a preset DTMB-A exciter to use each MIP packet in the service data stream as the first data packet of an OFDM frame in the target DTMB-A single frequency network system, and detecting the service data stream; When a MIP packet in the service data stream is detected, the start time of the OFDM frame corresponding to the MIP packet and the time difference of the pps signal generated by the preset global positioning system receiver are obtained, and the time tag and the maximum channel delay are extracted from the MIP packet; Based on the start time, the time difference, the time tag, the maximum channel delay and a preset additional delay calculation strategy, the additional delay corresponding to the service data flow is calculated.

4. The method according to claim 1, characterized in that The method of generating a multiframe synchronization channel by the additional delay, and multiplexing the data frame information and the control frame information into a multiframe by using the multiframe synchronization channel to obtain a corresponding multiplexed signal, and converting the multiplexed signal into a radio frequency signal in a radio frequency band to broadcast and transmit the radio frequency signal at the same time, includes: Aligning the data frame information and the control frame information passing through different network paths according to the additional delay to synchronize the signal transmission time in the target DTMB-A single frequency network system and generate the multiframe synchronization channel; Using the multiframe synchronization channel, multiplexing the data frame information and the control frame information into a multiframe to obtain the multiplexed signal, and performing baseband post-processing on the multiplexed signal to generate a baseband transmission signal; An orthogonal up-conversion operation is performed on the baseband transmission signal to convert the multiplexed signal into a radio frequency signal in a radio frequency band, and the radio frequency signal is broadcast and transmitted simultaneously.

5. The method according to claim 3, characterized in that: The mathematical expression of the additional delay calculation strategy is: STS+MD=Measured Delay+Additional Delay Among them, STS represents the time tag; MD represents the maximum delay of the channel; Measured Delay represents the time difference; Additional Delay represents the additional delay.

6. An analysis device for a DTMB-A single frequency network system, characterized in that: include: A pre-transmission service code stream processing module is used to generate a MIP packet according to the pre-transmission mode and GPS information of the target DTMB-A single frequency network system, insert the MIP packet into the pre-transmission service data, and calculate the number of service data packets and the number of zero padding contained in each OFDM frame according to the pre-transmission mode, so as to obtain a service data stream that meets the preset matching requirements with the DTMB-A transmission net code rate; A receiving module, configured to receive the service data stream and control information through each preset transmitting station, and use each MIP packet in the service data stream as the first data packet of the OFDM frame in the target DTMB-A single frequency network system, and extract the time tag and the maximum channel delay in the MIP packet, so as to calculate the additional delay according to the time tag and the maximum channel delay; A modulation module, used to preprocess the service data stream and the control information, and perform scrambling, encoding, constellation mapping and symbol interleaving processing on the preprocessed service data stream and control information to obtain corresponding data processing results, and perform OFDM modulation and group frequency on the data processing results and a preset PN-MC sequence to generate data frame information corresponding to the service data stream and control frame information corresponding to the control information; The transmitting module is used to generate a multi-frame synchronization channel through the additional delay, and use the multi-frame synchronization channel to multiplex the data frame information and the control frame information to synthesize a multi-frame to obtain a corresponding multiplexed signal, and convert the multiplexed signal into a radio frequency signal in the radio frequency band to broadcast and transmit the radio frequency signal at the same time.

7. The device according to claim 6, characterized in that The pre-sending service code stream processing module includes: An inserting unit, used for determining a plurality of target frames corresponding to the target DTMB-A single frequency network system and meeting the preset TS packet requirements, and inserting a MIP packet into the corresponding MPEG-2 transport stream every other target frame, wherein the target frame contains N TS packets, and the value of N is adjusted according to the transmission rate of the TS code stream, and N is an integer; A zero padding unit, configured to determine the working mode of the target DTMB-A single frequency network system and the OFDM frame corresponding to each target frame in the multiple target frames according to the multiple target frames, and to perform a zero padding operation on the tail of the service data pre-sent in each OFDM frame according to the working mode in the DTMB-A single frequency network adapter of the target DTMB-A single frequency network system, so as to obtain a zero-padded MPEG-2 transport stream; A control unit is used to obtain the length information of each OFDM frame in the zero-padded MPEG-2 transport stream, and control the number of OFDM frames between adjacent MIP packets in the target DTMB-A single frequency network system to be an integer and the interval between MIP packets is less than 1 second according to the length information and the working mode, and control the TS code stream to be output at different rate levels according to different modulation modes of the target DTMB-A single frequency network system through a preset buffer unit.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the analysis method for the DTMB-A single frequency network system according to any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the analysis method of the DTMB-A single frequency network system according to any one of claims 1 to 5.

10. A computer program product, comprising a computer program, characterized in that The computer program is executed to implement the analysis method of the DTMB-A single frequency network system according to any one of claims 1 to 5.

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