This standard specifies the structure and interface of the ground terminal equipment of the Tiandi digital television system. This specification applies to the design, development and production of non-broadcast-grade ground terminal equipment of the Tiandi digital television system. SJ 20815-2002 Structure and interface of ground terminal equipment of the Tiandi digital television system SJ20815-2002 Standard download decompression password: www.bzxz.net

Military Standard of the Electronic Industry of the People's Republic of China FL5821
SJ20815-—2002
System and interface on surface terminal equipment fordigital TV between heaven and earth
System and interface on surface terminal equipment fordigital TV between heaven and earth2002-01-31Published
2002-05-01Implementation
Approved by the Ministry of Information Industry of the People's Republic of China1 Scope
Military Standard of the Electronic Industry of the People's Republic of China System and interface of ground terminal equipment fordigital TV between heaven and earth1.1 Subject Content
This standard specifies the system and interface of ground terminal equipment for digital TV between heaven and earth. 1.2 Scope of Application
SJ20815-2002
This standard applies to the design, development and production of non-broadcast-grade ground terminal equipment for digital TV between heaven and earth. 2 Referenced Documents
EIA-RS-232-C
EIA-RS-422-A
EIA-RS-449
ITU-TG.165
ITU-TG.704
ITU-TG.726
ITU-TH.221
ITU-TH.261
3 Definitions
3.1 Terminology
Electrical characteristics of balanced voltage digital interface circuits between data terminal equipment and data circuit-terminating equipment using serial binary data interchange and 9-pin interface
Echo canceler
Physical/electrical characteristics of digital interfaces
Synchronous frame structure for 1544, 6312, 2048, 8488 and 44736 kbit/s series levels40, 32, 24, 16 kbit/s adaptive differential pulse code modulation (ADPCM)16 kbit/s speech coding using low-delay code excited linear prediction speech coding (LD-CELP)Structure of 64-1920 kbit/s channels in audio-visual user terminal servicesPX video codec for 64 kbit/s audio-visual services3.1.1 Image formatimageformat
Image source format used for video coding. In order to ensure the intercommunication of digital PAL and NTSC video, ITU-TH.261 stipulates that CIF and QCIF must be used as digital video formats for the intercommunication of the above two formats. 3.1.2 Echo Cancellation Echo cancellation is accomplished by an echo canceller. Its working principle is to compare the signals in the outgoing channel and the reverse channel, and remove the estimated echo from the voice signal containing the echo to achieve the effect of canceling the echo. Issued by the Ministry of Information Industry of the People's Republic of China on January 31, 2002IKANiKAca
Implementation on May 1, 2002
3.2 Abbreviations
SJ20815-—2002
3.2.1ACAuxiliaryChannelAuxiliary channel3.2.2BASBit-rateAllocation SignalBit rate allocation signal3.2.3 CIF CommonIntermediateFormatCommon intermediate format3.2.4ECSEncryptionControlSignalEncryption control signal3.2.5 FASFrameAlignmentSignalFrame alignment signal3.2.6QCIFQuarterCommonIntermediateFormatQuarterCommonIntermediateFormat 4 General requirements
4.1 Function
The main functions of the ground terminal equipment of the space-ground digital television system are as follows:a. Receive the digital television signal of the S-band data transmission channel on the manned spacecraft, decode and recover the signal or forward it to the command center:
b. The digital TV signal sent by the command and control center is transmitted to the manned spacecraft via the uplink digital transmission channel. 4.2 Equipment composition
The ground-to-earth digital TV system is mainly composed of digital TV ground terminal equipment, display, video recorder and camera at each measurement and control point and the command and control center. The digital TV terrestrial terminal equipment is composed of video compression codec, audio compression codec, multiplexer, line interface unit and controller, etc., and its schematic diagram is shown in Figure 1: A
Carry-on battle line
Service (four-wire)
Re-call current frequency
RGB component
S-yides
Audio compression
Codec
Video compression
Codec
User data
Remote monitoring data
Multiplexer
Controller
Line interface unit
Note: A-audio analog interface: B-video analog interface: C-digital service interface, D and E-a group of signal interfaces. Figure 1 Schematic diagram of the composition and interface of the ground terminal equipment of the ground digital television system 5 Detailed requirements
5.1 System and characteristics
5.1.1 Video compression codec
The video compression codec mainly consists of three parts: video encoding unit, video decoding unit and video error correction unit. 5.1.1.1 The video encoding unit completes the digitization of analog video signals (A/D conversion), format conversion (forming CIF or QCIF), and video compression encoding (the compression algorithm complies with ITU-TH.261). Under the action of the controller, the encoder should be able to achieve the functions of puncture (frame rate compression), fast refresh, forced refresh and image freezing. The controller can control the encoding buffer and delay size. 5.1.1.2 The video decoding unit completes video compression decoding, which is the inverse process of the above encoding. The decoder shall automatically decode according to the transmitted coded data stream, and shall also perform error concealment and error update according to the channel error conditions. It shall automatically freeze and display the last image when the channel is interrupted, and have the ability to recover from a crash. 5.1.1.3 The video error correction unit shall select BCH (511,493) error correction, RS (255,239) error correction or cascade error correction according to the channel error transmission performance.
5.1.2 Audio Compression Codec
The audio codec has two encoding and decoding modes: ITU-TG.726 32kbit/s and ITU-TG.728 16kbit/s, and has encryption function.
5.1.3 Multiplexer/Demultiplexer
The multiplexer/demultiplexer completes the multiplexing and demultiplexing of information such as video coded data and audio coded data. 5.1.4 Line interface unit
The line interface unit shall have the function of mutual transmission of group channel signals with the ground receiving and transmitting equipment of the Tiandi digital television system. 5.1.5 Controller
The controller shall complete the functions of equipment configuration, initialization, process monitoring, fault diagnosis, sound and light alarm and communication protocol processing. The controller shall have a display and an operation control panel. 5.2 Technical characteristics
5.2.1 Power supply
AC 220V±15%, 50±3Hz.
5.2.2 Environmental requirements
Land use:
Working temperature: 0℃~+40℃:
Storage temperature: -40℃～+70℃:
Humidity: Under working temperature conditions, the relative humidity is 15%～85%. Ship use:
Working temperature: -10℃~+50℃;
Storage temperature: -50℃～+70℃:
Humidity: When the temperature is +40℃, the relative humidity is 95%. 5.2.3 Video
5.2.3.1 Image format
QCIF: Y
352×288
176×144
176X144.
176X144;
88×72:
Cb88×72.
5.2.3.2 Video rate
The maximum frame rate is 25/second, and 12.5, 8.33, and 6.25 frames/second can be selected. TKAoNiKAca
5.2.3.3 Compression algorithm
Complies with ITU-TH.261 requirements.
5.2.3.4 Error correction method
The recommended error correction method is shown in Table 1.
Channel bit error rate
Better than 1×10-6
1×10-6~1×10-
5.2.3.5 Codec delay
SJ20815—2002
Table 1 Error correction method selection
Recommended error correction method
BCH (511,493)
RS (255, 239) or cascaded error correction
The codec delay is between 0.4 and 0.6s when the transmission rate is 768kbit/s. 5.2.4 Audio
5.2.4.1 Audio compression format
Complies with ITU-TG.726 32kbit/s and ITU-TG.728 16kbit/s.
5.2.4.2 Audio encryption
16kbit/s audio encryption, the encrypted rate is 48kbit/s. For ITU-TG.726 32kbit/s or ITU-TG.728 5.2.4.3 Lip sync
Synchronization error: The audio cannot be ahead of the video by 25ms, nor can it lag behind the video by 40ms: Delay adjustment range: 20~1000ms.
5.2.4.4 Echo cancellation
Complies with ITU-TG.165 requirements. wwW.bzxz.Net
5.2.5 Multiplexer/Demultiplexer
5.2.5.1 Rate
The information transmission rate is 64~1920kbit/s, that is, p×64kbit/s, p=1~30. 5.2.5.2 Frame Alignment Word (FAS)
Odd frame: FASo=x1xXXXXxB:
Odd frame: FASe=x00110IIB.
5.2.5.3 Determining rule
When x0011011B appears in the FAS position for the first time, x1xxxxxxB appears in the FAS position of the next frame, and x0011011B appears in the FAS position of the third frame, it can be determined as out of step. 5.2.5.4 Loss rule
In the state of determining the frame, if three consecutive frame alignment words are received with errors, it is determined that the frame alignment word has been lost. 5.2.5.5 Frame structure
Frame structure is divided into two forms, namely:
a. Frame structure when audio is ITU-TG.726 32kbit/s or audio encryption, see Figure 2:4
SJ20815-—2002
Figure 2 Frame structure when audio is ITU-TG.726 32kbit/s or audio encryption BAS is a bit allocation signal, which transmits the digital TV codec capability set. ECS is an encryption control signal for channel encryption. The AC channel is used to transmit asynchronous user data with a maximum rate of 5.6kbit/s. The audio channel is filled with audio data starting from the first bit. The rest is filled with video data as a video channel. b. Frame structure when audio is ITU-TG.728, please refer to the relevant provisions in ITU-TH.221. 5.3 Equipment Interface
5.3.1 Video Interface
5.3.1.1 Composite Video Interface
Level: 1Vp-p:
Impedance: 752.
5.3.1.2 RGB Component Interface
Level: 0.7Vp-p:
Impedance: 752.
5.3.1.3 S-Video Interface
Level: Y1Vp-pt
C0.3Vp-p;
Impedance: 75.
5.3.2 Audio Interface
5.3.2.1 Analog Line Interface
Level: -14~+4dBm:
Impedance: 6009 unbalanced.
-iKAoNiKAca-
5.3.2.2 Microphone interface
Level: -20~0dBm:
Impedance: 600Q unbalanced;
5.3.2.3 Service voice interface
Level: -14~+4dBm
Input impedance: 6kQ unbalanced;
Output impedance: 100Q unbalanced.
5.3.3 Data interface
5.3.3.1 Asynchronous user data interface
Interface characteristics: RS-232-C.
5.3.3.2 Remote monitoring data interface
Interface characteristics: RS-422-A/RS-449 asynchronous. 5.3.4 Line interface
5.3.4.1 RS-422-A/RS-449 interface
Interface characteristics: RS-422-A/RS-449:
Rate, 64~1920kbit/s.
5.3.4.2 E1 interface (with external clock input) Frame structure: in accordance with ITU-TG.704;
Interface level: in accordance with ITU-TG.703:
Impedance: 75Q unbalanced:
Rate: 2048kbit/s (information rate variable). Additional notes:
SJ20815-2002
This standard is under the jurisdiction of the Fourth Institute of Electronics of the Ministry of Information Industry. This standard was drafted by the 54th Institute of Electronics of the Ministry of Information Industry. The main drafters of this standard are Pei Wenduan, Wang Lizhong, and Heng Yongtian. Project code: B93004.
People's Republic of China
Military Standards for Electronic Industry
System and Interface of Ground Terminal Equipment for Digital Television System of Heaven and Earth
SJ20815—2002
China Electronics Standardization Institute
China Electronics Standardization Institute
China Electronics Standardization Institute
Tel: (010) 84029065Fax: (010) 64007812Address: Anyang, Beijing No. 1, Dingmen East Street
Postal code: 100007
Website: cesi.ac.cn
Format: 880×12301/16Printing:
First edition in April 2002
Word count: 16,000 words
First printing in April 2002
Copyright reserved. No reproduction allowed
Report phone number: (010) 64007804
-KAoNiKAca-5 Frame structure
Frame structure is divided into two forms, namely:
a. Frame structure when audio is ITU-TG.726 32kbit/s or audio encryption, see Figure 2: 4
SJ20815-—2002
Figure 2 Audio is ITU-TG.726 32kbit/s or audio encryption when the frame structure BAS is a bit allocation signal, which transmits the digital TV codec capability set. ECS is an encryption control signal for channel encryption. The AC channel is used to transmit asynchronous user data with a maximum rate of 5.6kbit/s. The audio channel is filled with audio data starting from the first bit. The rest is filled with video data as a video channel. b. Frame structure when audio is ITU-TG.728, please refer to the relevant provisions in ITU-TH.221. 5.3 Equipment Interface
5.3.1 Video Interface
5.3.1.1 Composite Video Interface
Level: 1Vp-p:
Impedance: 752.
5.3.1.2 RGB Component Interface
Level: 0.7Vp-p:
Impedance: 752.
5.3.1.3 S-Video Interface
Level: Y1Vp-pt
C0.3Vp-p;
Impedance: 75.
5.3.2 Audio Interface
5.3.2.1 Analog Line Interface
Level: -14~+4dBm:
Impedance: 6009 unbalanced.
-iKAoNiKAca-
5.3.2.2 Microphone interface
Level: -20~0dBm:
Impedance: 600Q unbalanced;
5.3.2.3 Service voice interface
Level: -14~+4dBm
Input impedance: 6kQ unbalanced;
Output impedance: 100Q unbalanced.
5.3.3 Data interface
5.3.3.1 Asynchronous user data interface
Interface characteristics: RS-232-C.
5.3.3.2 Remote monitoring data interface
Interface characteristics: RS-422-A/RS-449 asynchronous. 5.3.4 Line interface
5.3.4.1 RS-422-A/RS-449 interface
Interface characteristics: RS-422-A/RS-449:
Rate, 64~1920kbit/s.
5.3.4.2 E1 interface (with external clock input) Frame structure: in accordance with ITU-TG.704;
Interface level: in accordance with ITU-TG.703:
Impedance: 75Q unbalanced:
Rate: 2048kbit/s (information rate variable). Additional notes:
SJ20815-2002
This standard is under the jurisdiction of the Fourth Institute of Electronics of the Ministry of Information Industry. This standard was drafted by the 54th Institute of Electronics of the Ministry of Information Industry. The main drafters of this standard are Pei Wenduan, Wang Lizhong, and Heng Yongtian. Project code: B93004.
People's Republic of China
Military Standards for Electronic Industry
System and Interface of Ground Terminal Equipment for Digital Television System of Heaven and Earth
SJ20815—2002
China Electronics Standardization Institute
China Electronics Standardization Institute
China Electronics Standardization Institute
Tel: (010) 84029065Fax: (010) 64007812Address: Anyang, Beijing No. 1, Dingmen East Street
Postal code: 100007
Website: cesi.ac.cn
Format: 880×12301/16Printing:
First edition in April 2002
Word count: 16,000 words
First printing in April 2002
Copyright reserved. No reproduction allowed
Report phone number: (010) 64007804
-KAoNiKAca-5 Frame structure
Frame structure is divided into two forms, namely:
a. Frame structure when audio is ITU-TG.726 32kbit/s or audio encryption, see Figure 2: 4
SJ20815-—2002
Figure 2 Audio is ITU-TG.726 32kbit/s or audio encryption when the frame structure BAS is a bit allocation signal, which transmits the digital TV codec capability set. ECS is an encryption control signal for channel encryption. The AC channel is used to transmit asynchronous user data with a maximum rate of 5.6kbit/s. The audio channel is filled with audio data starting from the first bit. The rest is filled with video data as a video channel. b. Frame structure when audio is ITU-TG.728, please refer to the relevant provisions in ITU-TH.221. 5.3 Equipment Interface
5.3.1 Video Interface
5.3.1.1 Composite Video Interface
Level: 1Vp-p:
Impedance: 752.
5.3.1.2 RGB Component Interface
Level: 0.7Vp-p:
Impedance: 752.
5.3.1.3 S-Video Interface
Level: Y1Vp-pt
C0.3Vp-p;
Impedance: 75.
5.3.2 Audio Interface
5.3.2.1 Analog Line Interface
Level: -14~+4dBm:
Impedance: 6009 unbalanced.
-iKAoNiKAca-
5.3.2.2 Microphone interface
Level: -20~0dBm:
Impedance: 600Q unbalanced;
5.3.2.3 Service voice interface
Level: -14~+4dBm
Input impedance: 6kQ unbalanced;
Output impedance: 100Q unbalanced.
5.3.3 Data interface
5.3.3.1 Asynchronous user data interface
Interface characteristics: RS-232-C.
5.3.3.2 Remote monitoring data interface
Interface characteristics: RS-422-A/RS-449 asynchronous. 5.3.4 Line interface
5.3.4.1 RS-422-A/RS-449 interface
Interface characteristics: RS-422-A/RS-449:
Rate, 64~1920kbit/s.
5.3.4.2 E1 interface (with external clock input) Frame structure: in accordance with ITU-TG.704;
Interface level: in accordance with ITU-TG.703:
Impedance: 75Q unbalanced:
Rate: 2048kbit/s (information rate variable). Additional notes:
SJ20815-2002
This standard is under the jurisdiction of the Fourth Institute of Electronics of the Ministry of Information Industry. This standard was drafted by the 54th Institute of Electronics of the Ministry of Information Industry. The main drafters of this standard are Pei Wenduan, Wang Lizhong, and Heng Yongtian. Project code: B93004.
People's Republic of China
Military Standards for Electronic Industry
System and Interface of Ground Terminal Equipment for Digital Television System of Heaven and Earth
SJ20815—2002
China Electronics Standardization Institute
China Electronics Standardization Institute
China Electronics Standardization Institute
Tel: (010) 84029065Fax: (010) 64007812Address: Anyang, Beijing No. 1, Dingmen East Street
Postal code: 100007
Website: cesi.ac.cn
Format: 880×12301/16Printing:
First edition in April 2002
Word count: 16,000 words
First printing in April 2002
Copyright reserved. No reproduction allowed
Report phone number: (010) 64007804
-KAoNiKAca-
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