ITU-R BO 712-1-1992 HIGH-QUALITY SOUND DATA STANDARDS FOR THE BROADCASTING-SATELLITE SERVICE IN THE 12 GHz BAND《12G频段广播卫星业务的高质量声音 数据标准－第10 11B部分－系统》.pdf

1、Rec. 712-1 1RECOMMENDATION 712-1*HIGH-QUALITY SOUND/DATA STANDARDS FOR THE BROADCASTING-SATELLITESERVICE IN THE 12 GHz BAND(Questions 83/11 and 85/11)(1990-1992)Rec. 712-1The CCIR,consideringa) the needs expressed for the future development of satellite broadcasting both in the field of simultaneous

2、transmission of a series of radio programmes of a very high technical quality and in the field of high-capacity dataservices;b) the technical performance of the DSR (digital satellite radio) system which allows the transmission, in achannel of the 12 GHz band, of 16 stereophonic programmes of very h

3、igh quality with maximum ruggedness againsttransmission errors;c) the definition of the digital full-channel mode of operation of systems of the MAC/packet family which allowsfor flexible multiplexing (20 Mbit/s for systems C and D, 10 Mbit/s for the D2 system) of sound programmes of highquality as

4、well as any type of data;d) the technical flexibility of the MDS (multi-channel digital sound/data) system which allows not only thetransmission of 12 high quality stereo programmes, but also in the case of lower e.i.r.p., the transmission of 6 highquality programmes with an additional error correct

5、ion code;e) that the MAC/packet system, the DSR system and the MDS system are intended for use via broadcastingsatellites to fixed receivers;f) that other systems are being developed for sound broadcasting at UHF to fixed, portable and especially tomobile receivers,recommendsthat when a sound/data b

6、roadcasting-satellite service to fixed receivers is introduced in the 12 GHz band thepreferred systems should be (see Notes 1 and 2): the DSR system when the predominant consideration is the transmission of a number of very high-qualitysound programmes within a wide coverage area; the full-channel d

7、igital mode of one of the systems of the MAC/packet family when the predominantconsideration is the flexibility required for simultaneous transmission of high-quality sound programmesand high capacity data services; the MDS system when the predominant consideration is compatibility with the digital

8、sub-carrier/NTSCsystem.Note 1 The issue of a sound/data standard for the broadcasting-satellite service is still under consideration in Region 2.Note 2 Detailed system descriptions are given in Annex 1.Note 3 The following guide is given to assist in following the relationship of the Annexes and App

9、endices._*Note from the Director, CCIR Reports 953, 954, 1073 and 1228 were used in preparing this Recommendation.2 Rec. 712-1ANNEX 1APPENDIX 1 TO ANNEX 1ANNEX 1 TO APPENDIX 1ANNEX 2 TO APPENDIX 1ANNEX 3 TO APPENDIX 1ANNEX 4 TO APPENDIX 1ANNEX 5 TO APPENDIX 1APPENDIX 2 TO ANNEX 1APPENDIX 3 TO ANNEX

10、1ANNEX 1High quality sound/data standards forthe broadcasting-satellite service in the 12 GHz band1. IntroductionAccording to the current Radio Regulations, satellite channels in the 12 GHz band are assigned to eachadministration over which television programmes but also, alternatively, other servic

11、es may be broadcast, as long as thetransmitted signals do not cause more interference than conventional FM-TV signals. The appropriate TV standards arerecommended in Recommendation 650 and specified in the relevant parts of the CCIR special publication,“Specifications of Transmission Systems for the

12、 Broadcasting-Satellite Service”.The introduction of digital sound recording and reproduction techniques constitutes a challenge to thebroadcasting organizations to pass on such a quality to the subscribers which has been beyond the possibilities ofconventional transmission methods (e.g. FM stereo).

13、 Besides this, in a number of countries there is a need for theemission of a large number of high-quality sound channels over a coverage area as large as possible. In addition, thegrowing requirements for data broadcast facilities resulted in investigations of systems suitable to transmit both sound

14、and data in a flexible way.Several possible systems are in various stages of development within different administrations. This Annexbriefly describes the basic characteristics of three systems developed in the Federal Republic of Germany, by the EBUand in Japan.2. Summary description of the systems

15、This section gives the summary description of the main features of each of the systems considered. Table 1gives the list of relevant parameters of each system in a comparative way.2.1 The digital satellite radio (DSR) systemThe DSR system was developed in the Federal Republic of Germany to allow sim

16、ultaneous transmission of16 stereophonic or 32 monophonic high-quality sound channels (or any combinations of stereophonic or monophonicchannels) over a wide coverage area. In line with Recommendation 561, the sampling frequency is 32 kHz and theresolution equals 16 bits, preserving a quantizing noi

17、se performance comparable with that of the compact disc. For biterror correction/detection a BCH (63,44) code was chosen, capable of correcting two errors and detecting five errors perblock. In combination with the scale factor (see Appendix 1 to Annex 1) this bit error protection scheme offers a go

18、odsubjective sound quality at a BER of 2 103. The modulation method is differentially encoded, 4-PSK.Rec. 712-1 3 TABLE 1 Relevant parameters of satellite sound/data broadcasting standards for the 12 GHz BSS band Parameter Digital satellite radio MAC/packet family full-channel digital mode Multi-cha

19、nnel digital sound/data (DSR) D2 C/D satellite broadcasting (MDSD) Multiplex structure Synchronous time division multiplex (STD) Asynchronous time division multiplex (ATD) Sound: STD multiplex Data: ATD multiplex Total bit rate (Mbit/s) 20.48 10.125 20.252 24.576 MDS1 (2) : 18.432 (Mode A) 21.504 (M

20、ode B) Useful bit rate (1) (Mbit/s) 19.22 09.576 19.242 MDS2 (2) : 9.216 (Mode A) 10.752 (Mode B) Sound coding (3) 32 kHz sampling frequency 32 kHz sampling frequency (16 kHz for medium quality) Mode A: 32 kHz sampling frequency 14/10 bit near-instantaneous companding 16/14 bit floating point techni

21、que First coding law: 14/10 bit near-instantaneous compandor (HQI) (4) Mode B: 48 kHz sampling frequency 16 bit linear coding Second coding law: 14 bit linear coding (HQL) No pre-emphasis Pre-emphasis per CCITT Recommendation J.17 Pre-emphasis: 50 s (zero) + 15 s (pole) Dynamic range According to 16

22、 bit resolution (equal to compact disk) According to 14 bit resolution Mode A: According to 14 bit resolution Mode B: According to 16 bit resolution Bit-error protection BCH (63,44) code: corrects 2 errors in 63 bits or detects 5 errors. Additional protection by the scale factor First protection lev

23、el: 1 parity bit applied to the 6 MSB (HQI) or to the 10 MSB (HQL case) (error concealment only) MDS1: BCH (63,56) code: corrects 1 error and detects 2 errors. Additional protection by the 8 range information Second protection level: Hamming code (11,6) for HQI and Hamming code (16,11) for HQL: corr

24、ects 1 error or detects 2 erroneous bits. Additional protection by scale factor for both protection levels MDS2: BCH (63,50) code: addition to the above, the whole data is protected by (2,1) Viterbi decoding Number of sound configurations (i.e. combination of sound coding and error protection scheme

25、) One (see above) Four high quality configurations (4), (5) HQI1 HQL1 HQI2 HQL2 Two high quality configurations Mode A Mode B 4 Rec. 712-1TABLE 1 (continued)Parameter Digital satellite radioMAC/packet family full-channeldigital modeMulti-channel digital sound/data(DSR)D2 C/Dsatellite broadcasting (M

26、DSD)Sound channelcapacity (monophonic)32 HQI1: 26HQL1: 19HQI2: 19HQL2: 14HQI1: 53HQL1: 40HQI2: 40HQL2: 30MDS1: Mode A: 48 (maximum)Mode B: 24 (maximum)MDS2: Mode A: 24 (maximum)Mode B: 12 (maximum)Modulation 4-PSK differentiallyencodedFor D and D2: FM of duobinarycoded data signalFor C: 2-4 PSK, dif

27、ferentiallyencodedMinimum shift keying (MSK)C/N for BER = 103(overall link withreference to 27 MHzbandwidth)7.5 dB (6) 8 dB (7) for D: 9.5 dB (7)for C: 8.0 dB (8)8.0 dBLimit for perceptibility 2 1031st level protection: 1052nd level protection: 103MDS1: 1 103MDS2: 1 102(1) Useful bit rate (for sound

28、 transmission) = total bit rate minus sync, additional data and packet headers.(2) MDS1: a transmission class for a sufficient e.i.r.p. receiving condition.MDS2: a transmission class for a lower e.i.r.p. receiving condition.(3) All coding schemes used follow Recommendation 651.(4) HQI1 : High qualit

29、y, near-instantaneous companding, 1st protection levelHQL1: High quality, linear coding, 1st protection levelHQI2 : High quality, near-instantaneous companding, 2nd protection levelHQL2: High quality, linear coding, 2nd protection level.(5) In addition to high quality configurations, MAC/packet full

30、-channel digital mode allows four medium quality configurationsusing 16 kHz sampling.(6) Measured with a domestic receiver (first series of mass production).(7) Values for 27 MHz IF filter; improvements of around 2 dB are possible by using narrower filters and/or applying Viterbidecoding.(8) Typical

31、 value for differential demodulation. With coherent demodulation improvements are possible.Although the DSR system is mainly intended for high-quality sound transmission, it is also capable oftransmitting high-speed data in one or more stereophonic or monophonic channels in addition to the already e

32、xistingauxiliary low-bit rate data channel accompanying each sound channel.Regular service based on DSR commenced in the Federal Republic of Germany in August 1989. Transmit andreceive devices, the latter being based on VLSI technique, are commercially available.The detailed specification of the DSR

33、 system is given in Appendix 1 to Annex 1.2.2 MAC/packet family full-channel digital modeRecommendation 650 and the CCIR special publication, “Specifications of Transmission Systems for theBroadcasting-Satellite Service”, provide the specification of the MAC/packet family of systems when operating i

34、nnormal television mode. When the area of the television frame, normally reserved for the MAC vision signal (and itsfield-blanking interval), is replaced by data bursts, the MAC/packet is said to operate in the full-channel digital mode.Rec. 712-1 5The three members of the family (i.e. the C-MAC/pac

35、ket system, the D-MAC/packet system with FM andthe D2-MAC/packet system with FM) can be used in the full-channel digital mode providing the following sound/datacapacity: C-MAC/packet full-channel mode: nearly 20 Mbit/s or up to 53 high-quality sound channels with15 kHz bandwidth, with near-instantan

36、eous 14/10-bit companding and protected by one parity bit persample. D-MAC/packet full-channel mode: identical capacity as C-MAC/packet. D2-MAC/packet full-channel mode: nearly 10 Mbit/s or up to 26 high-quality sound channels with15 kHz bandwidth, with near-instantaneous 14/10-bit companding and pr

37、otected by one parity bit persample.The extension of the MAC/packet family specification with the full-channel digital mode provides thepossibility of a variety of facilities (i.e., sound or television data broadcasting, etc.). Within this concept it is possible todesign and implement universal rece

38、ivers to accommodate either television reception in the normal MAC/packet modeor sound/data reception in the full-channel digital mode.The extent to which all possible facilities will eventually be available to the public will depend both uponwhich of these services are transmitted and which of them

39、 the receivers are designed to receive.For MAC/packet full-channel digital mode, the decoders and integrated circuits are expected to be available atthe start of such a service.The detailed description of the MAC/packet full-channel digital mode is given in Appendix 2 to Annex 1.2.3 The multi-channe

40、l digital sound/data (MDS) systemThe MDS system has been studied in Japan for future high-quality sound and data broadcasting throughout thecountry via broadcasting satellites operating in the 12 GHz band. This system was developed for two classes of satellitetransmission. One transmission class, MD

41、S1, is used on condition that sufficient e.i.r.p. is obtained. The other class,MDS2, is suitable for the lower e.i.r.p. receiving condition. It has two modes. In Mode A, using 14/10 near-instantaneous companding, the same sound quality as FM broadcasting is available. In Mode B, sound quality not lo

42、werthan that of the compact disc is possible (20 kHz bandwidth and 16-bit resolution).The signal format of the MDS system is constructed in two multiplexing stages. The lower multiplexing stagehas the same format as the sound/data signals of the digital sub-carrier/NTSC system (Recommendation 650) w

43、ith atransmission bit rate of 2.048 Mbit/s. In this format, four Mode A sound channels with 480 kbit/s data signals or twoMode B sound channels with 224 kbit/s data can be selected. The data rate can be expanded to 1 760 kbit/s maximum,depending on the mode and number of sound channels. It allows da

44、ta broadcasting using packet transmission other thansound.At the higher multiplexing stage, 12 (MDS1) or 6 (MDS2) of these signals are further multiplexed. Thetransmission bit rate at this stage is 24.576 Mbit/s (MDS1) or 12.288 Mbit/s (MDS2).In order to maintain high-quality digital signal transmis

45、sion performance, the same error correction schemesused for digital sub-carrier/NTSC signals, such as BCH (63, 56) SEC-DED code and 3-bit range codes are applied.In class MDS2, a convolutional code (2, 1) is added to the whole signal and Viterbi decoding is applied to obtain moreerror correction cap

46、ability. The transmission bit rate is consequently 24.576 Mbit/s.The carrier is MSK-modulated by the above described multiplexed bit stream. The MSK modulation methodprovides higher performance against the non-linear characteristics of the TWT, and its AFC is easily constructed at alower cost.Transm

47、ission experiments on the MDS1 and MDS2 were carried out via satellites. The received carrierto noise ratio (27 MHz signal bandwidth) to obtain just-perceptible sound degradation is about 8 dB (BER = 1 103) inMDS1, or 4.5 dB (BER = 1 102) in MDS2, using home-type receivers.The detailed specification

48、s of the MDS system are given in Appendix 3 to Annex 1.6 Rec. 712-13. ConclusionPresently, three high-quality sound/data broadcasting systems are recommended for use in the 12 GHzbroadcasting-satellite service. These systems are already available at standardization level, and fulfil the requirements

49、 forthe broadcasting of very high-quality sound/data signals. The DSR system is already in operational service in the FederalRepublic of Germany and receivers are available on the market.APPENDIX 1TO ANNEX 1Specifications of the DSR system1. IntroductionTelevision broadcasting satellites will not only be used for the transmission of television programmes but alsofor the high-quality, exclusively digital transmission of 16 stereophonic sound broadcasting programmes over atransponder channel reserved solely for that purpose. Several studies and