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ANALYSIS OF THE BASIC ENCODING PARAMETERS OF SATELLITE TV CHANNELS
Anvar I. Baramykov,
TV center of the JSC "Gazprom Space Systems", Moscow, Russia, abaramykov@gmail.com
Irina N. Zaitseva,
Yelets State Ivan Bunin University, Elets, Russia, irina-zai73@mail.ru
Keywords: DVB-DSNG format of the satellite TV channels, noise immunity, bandwidth, DVB-S2 standard.
The standards and formats of digital satellite television (TV) broadcasting are considered and analyzed for individual and collective receiving of TV for satellite dishes, and satellite news gathering through reportage stations. Currently, there are TV channels: DVB-S standard, DVB-DSNG (Digital Satellite News Gathering) format, DVB-S2 standard, and the introduction of its extended specification (format) DVB-S2X begins.
Is considered a line of TV channel standards and formats not higher than DVB-S2, which currently have the most operational application with the technical support of manufacturers of such equipment. The influence of encoding parameters on the main characteristics of the TV channel, throughput, in parts of more efficient use of the allocated frequency band of the transponder (satellite repeater), and noise immunity is analyzed. Based on the performed calculations, a step-by-step analysis of the effect of the basic encoding parameters on the realization of the advantages of the newly developed DVB-DSNG format with respect to the current DVB-S standard was carried out and the advantages of the new DVB-S2 standard compared to the existing DVB-DSNG are realized. At the same time, the obvious advantages and prospects of the DVB-DSNG TV channel in flexible variation by their parameters are shown.
The obtained results of calculations of the basic parameters of TV channels and conclusions can be recommended to specialists of satellite TV for the optimal choice of the coding rate depending on the types and parameters of the equipment of the stations used and the satellite coverage zone.
Information about authors:
Anvar I. Baramykov, TV center of the JSC "Gazprom Space Systems", Moscow, Russia
Irina N. Zaitseva, Yelets State Ivan Bunin University, associate professor, Lipetsk oblast, Elets, Russia
Для цитирования:
Барамыков А.И., Зайцева И.Н. Анализ основных параметров кодирования спутниковых телевизионных каналов // T-Comm: Телекоммуникации и транспорт. 2017. Том 11. №10. С. 74-79.
For citation:
Baramykov A.I., Zaitseva I.N. (2017). Analysis of the basic encoding parameters of satellite TV channels. T-Comm, vol. 11, no.10, рр. 74-79.
Introduction
For several decades, the technical base of the family of digital satellite television standards was formed in Russia, which has developed by the European Digital Broadcasting Project (DVB Project) for individual and collective receiving on satellite dishes, and satellite news gathering through reportage stations. Formation of this base was ensured by the Russian production of spacecrafts (SC) «Express» and «Yamal», and equipment of earth stations (ES).
The first standard was the DVB-S, which includes a 4-position QPSK convolution;!] encoder with coding rales of 1/2, 2/3, 3/4, 5/6, 7/8 and prov iding the operation of an internal FEC error protection system (forward Error correction) [1, 2]. The output transport stream passes the Reed Solomon encoder (RS), which ensures the work of the second stage of error correction (protection), goes to the QPSK modulator and then to the high-frequency path of the Up-Link RF station. Loading of wide-band transponders of the SC is produced by signals of the ES with different compression standards MPEG-2, MPEG-4 [1,2].
As is known, a digital TV signal is formed at the output of a transmitting television camera (camcorder), and digital transmission methods ensure high image quality after passing all links and paths from the signal source to the consumer.
The purpose of this article is to calculate the effect of coding parameters on the DVB-S, DVB-DSNG and DVB-S2 TV channel broadcasting parameters and to select the optimal parameters.
Development of the satellite system DVB-S
and the emergence of DVB-DSNG
The DVB-S standard was further upgraded successfully in the new satellite TV formal DVB-Digital Satellite News Gathering (DVB-DSNG), which had developed by the European Consortium in 1997-2000 [3] for rapid and high-quality collection of «digital news» from all points of the world in occasional mode. Parameters of broadcasting TV signals in this mode are following; types of transmitted (reportage) and received stations; the transponder number and its frequency range; features of the coverage area; angular parameters of the transmitting antenna of the reportage station; encoding parameters, etc. change from translation to translation.
The block diagram of one of the variants of the DVB-DSNG transmission system is shown in Figure I. Its configuration differs from the DVB-S transmission scheme [1,3] by the presence of advanced options for additional modulations of 8PSK and QAM.
The developers have set the following configuration structures of the stations:
- one or more mobile reportage stations such as Fly Away, Drive Away, depending on the method of their delivery to the survey object must have a small antenna size of 0.9-1.5 m (according to technical limitations) and limit of power radiation on technical and environmental requirements and considerations;
- receiving station is appointed at a fixed station (HUB) of a teleport FS with a large-diameter antenna and a branched telecommunications infrastructure for distributing the received TV reportage signals.
The type of modulation, the number of TV channels (one (SCPC) or more (MCPC) in the multiplex, the size of the antenna, the range and power of the transmitter of the reportage
station and the receiving station are determined by precalculation.
MPFÏM*°ur(t coding Lit J MiillLpkting
t£l
MUX adaptation ¿k energy dctpc-rsul
Outer coder
In lerne» ver
Bit-m lipping
into constellai ion
Baseband shaping
Quadrature modulator
Satellite Channel Atiapior
Fig. t. Block diagram of the TV channel DVB-DSNG
In Figure 2 shows possible types of modulation for DVB-S and DVB-DSNG.
DVB-S QPSK 1/2 DVB-S QPSK 2/3 DVB-S QPSK 3/4 DVB-S QPSK 5/6 DVB-S QPSK 7/8
DSNG8PSK 2/3 DSNG8PSK 5/6 DSNG8PSK 8/9 DSNG16QAM 3/4 DSN G 16QAM 7/8
Fig. 2. Possible modulation types for DVB-S and DVB-DSNG
The transition of DVB-DSNG to higher-order modulation methods ensure an increase information transfer rate within the allocated band of the 36 MHz transponder. In the original version, there were some limitations on the use of 16QAM modulation, sensitive to the actual parasitic AM conversion in phase modulation (FM) in amplifiers on nonlinearized TWTs, which increased errors. However, in almost two decades, outdated SCs were replaced, which allowed to remove the restriction on the use of 16QAM.
Comparison of energy and information characteristics of TV channels DVB-S and DVB-DSNG
To compare the listed types of modulation by noise immunity and the information transfer rate, we use a professional set of calculation formulas [4|, designed for all possible calculations in satellite communication systems. Calculations were carried out for the receiving station with a large antenna size. Absolute calculation values are applicable only for specific equipment configurations of both stations. Therefore, in the calculations for comparing different variants, we take the same frequency allocation band for signal placement equal to Af!l[c= 36 MHz (the most common value), and the signal-to-noise ratio (C / N) at the input of the demodulator receiver is 20 dB. This value is close to the real values for common parabolic antennas with a diameter of > 7.2 m in the Ku and new Ka bands.
The results of calculations for all possible types of modulation are presented in Table 1.
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Table 1
Modulation o — 5 if jg !■§ — cd M § e 2 >> v> 0 c s ~ uj S 1 u u c. Cß U S" Ö UJ cl O Z E Hb/No, threshold, ak to ct C 1 5 M S u c S CL ^ c ä s s O Ë € Z
DVB-S
QPSK 1/2 0.922 20.35 4.5 15,85 24.57
QPSK 2/3 1.229 19.1 5.0 14,1 32.77
QPSK 3/4 2 26.66 1.382 20.0 18.39 5.5 13.1 36.86
QPSK 5/6 1.536 18.13 6.0 12.13 40.96
QPSK 7/8 1.613 17.92 6.4 11.52 43.01
DVB-DSNG
8PSK 2/3 3 1.843 17.34 5.9 11.44 53.08
8PSK 5/6 3 2.30 16.37 8.9 7.47 66.35
8PSK 8/9 3 2,457 16.09 9,4 6.69 70.78
I6QAM 3/4 4 28,8 2.765 20.0 15.58 9.0 6.58 79.62
I6QAM 7/8 4 3.225 14.9! 10.7 4.21 92.89
The results of the calculations in Table ) show that highly efficient modulation methods increase the Information transf er rate up to several times, but inevitably lead to a decrease in the energy of the satellite radio link. However, considering the use of a receiving station with a large antenna size, this eliminates the energy budget problem. Necessary parameters for reportage: SC with a point of standing and coverage area; transponder (satellite repeater); frequency range; type of modulation; number of TV channels, one (SCPC) or (MCPC) in the multiplex; transmitter power; the dimensions of the antennas of the reportage station and the receiving station are pre-determined by the standard calculation method.
Transition to the new DVB-S2 standard. The study
of the characteristics of the internal encoder (LDPC)
Further improvements in the DVB-S standard for increasing information transfer rate and noise immunity would not be possible without profound changes in the structural composition of the encoders. Hughes Network Systems (HNS) made the largest contribution to research into ways to increase the transfer rale and noise immunity of satellite digital TV by developing the technology and the circuit implementation of the low-density parity check (LDPC) code found in 1962 by R. Gallagher [5,6].
The digital broadcasting community was delighted that the LDPC codes could outperform the turbo codes made using the new technology, and at first it was the surprise of specialists for the retro-return of HNS to unused and almost forgotten codes [7]. With this discovery, the epoch of the new ultimate DVB-S2 standard began.
Figure 3 shows the functional diagram of the transmitting path of the DVB-S2 system [8].
The test results of the dependence of the error density on the ratio of the symbol energy to the noise spectral density carried out by HNS are shown in Figure 4.
Rased on the results presented in the graphs, a rather sharp dependence of the level of reliability on the signal-to-noise raiio is observed. In addition, the dependence of BER = f (Eb / No) does not change significantly from the change in the coding rates. The transition from Es / No to ordinary Eb / No - the ratio of the bit energy to the noise spectral density can be performed, for example, as Eb / No = Es / No - 10 * log (n), where n is the spectral efficiency of the carrier.
Comparison of DVB-S2 TV channel parameters
with DVB-DSNG
The DVB-S2 standard has a wide range of modulation types |8-10] for meet the needs of TV companies an increased data rale and noise immunity of television channels.
Table 2 shows the calculations with the previously accepted values of AfBic and C / N for comparing the qualitative indicators of TV channels formed using DVB-DSNG and DVB-S2.
CO
DATA
ACM"*" VI MAN!»
Single In pu I Stream
i-------------H
Input interface & adaptation tools
ffl
nput interface & j 4 adaptation tools [' #1
___________M ML* M M M Hl JL* Hl M M M li„
Multiple Input Stream
modi: & stream adaptation
1/4,1/3.2/5, 1/2, 3/5.2/3, 3/4, 4/5, 5/6, 8/9, 9/10
BCII outer LDPC inner
FEC EN CODI SC
QPSK, 8PSK, I6APSK, 32APSK cons te I-lations
MAPPING
PL FRAMING
u=(>.25, (1.35, 0,2
nit Fflter &
Quadrature [Modulation
MODULATION
V s
BB FRAME
TlP stream lor BC modes
PL FRAME
to
the RF s a te Hi te channel
Fig. 3. Functional diagram of the transmitting path of the DVR-S2 system
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sion of modernization, there is no reason to raise the issue of preparing a replacement formal.
At the same time, the higher technical parameters of the DVB-S2 standard in comparison with DVB-DSNG (up to 3 dB for noise immunity and up to 7-10% for bandwidth), initiate studies of the use (integration) of DVB-S2 in the existing format of DVB-DSNG.
However, a simple replacement of DVB-DSNG equipped with some service and commentary channels and other reportage applications to standard DVB-S2 equipment will not ensure the preservation of the regular capabilities of a reportage link. The main reason is that you need to retrofit devices necessary to perform the existing and added functions of DVB-DSN.
In the technical plan, it is advisable to include the integration of selected key positions from the DVB-S2 standard into the list of upgrades of the DVB-DSNG: LDPC, BCH encoders and built-in options for high-definition television (HD-HDTV) transmission However, such issues require separate discussions and approvals between the equipment manufacturers.
The calculation part of the article, intended for specialists of satellite television systems, may well interest manufacturers of DVB-DSNG equipment.
1. Fedorov V.K. (2015). Standarty tstfrovogo televideniya pervogo pokoleniva. Moscow: DMK-Press, 312 p. (In Russian)
2. Karyakin V.L. (20)3), Tsifrovoe televidenie: uchebnoe posobie dlya vuzov, 2nd ed, Moscow: SOLON-PR YeSS, 451 p. (In Russian)
3. Morello A. and Mignone V. (19$). New DVB standard for DSNG - and contribution satellite links. EBU Technical Review, vol. 277, Autumn, pp. 1-23.
4. Jense, N. Saetre (1999-2011). Online Satellite Calculations [Electronic resource]. URL: hitp://www.sateliite-calculations.com {reference date: 12/03/2017).
5. Eroz M„ Sun F.-W. and Lee L.-N. (2004). DVB-S2 Low Density Parity Check Codes with near Shannon Limit Performance. InternationaI Journal on Satellite Communication Networks, vol. 22, pp. 269-279.
6. Moury, G. and Lesthievent G. (2003). DVB-S2 channel coding standardization process. Report to PIB Ilughes. CCSDS PI B Meeting -ESTEC - 1st April 2003. [Electronic resource], URL: https://cwe.ccsds.org/sls/docs/SLS-CandS
/Meet ing%20Materials/2003/200304%20ESTEC_Spring_ Meeting/DVB -S2%20status% 20report%20to%20PlB.pdf. (reference date: 15/04/2017), 12 p.
7. Yoshida, J, (2003) Hughes goes retro in digital satellite TV coding. Electronic Engineering Times fEE Times/, News & Analysis. [Electronic resource]. URL: http://www.eetimes.com/document.asp7doc_id =1147621 (reference dale: 10/03/2017).
8. Morel I o, A. and Mignone, V. (2006)/ DVB-S2: The Second Generation Standard for Satellite Broad-band Services. Proceedings of the IEEE, vol.94, pp. 210-227.
9. Bloh V.l. (2011). Pomekhoustojchivoe kodirovanie dlya pereda-clii cifrovogo televideniya po kanalam svyazi. Prilozhenie k Broadcasting. no. 6, pp. 12-16. (hi Russian)
10. Bloh V.l. (2012). Peredacha cifrovogo televideniya po radio-kanalam. Kody VSN i LDPC v standartah DVB-T i DVB-T2, Prilozhenie k Broadcasting, pp. 18-21. (In Russian)
References
www.ccsummit.ru 9 KBU "CoKO/ibHUKw" Poccmh MocKBa
CONNECTED CAR SUMMIT
T-Comm Tom 11. #10-2017
АНАЛИЗ ОСНОВНЫХ ПАРАМЕТРОВ КОДИРОВАНИЯ СПУТНИКОВЫХ ТЕЛЕВИЗИОННЫХ КАНАЛОВ
Барамыков Анвар Ибрагимович, Центр ТВ систем ОАО "Газпром космические системы", Москва, Россия,
abaramykov@gmail.com
Зайцева Ирина Николаевна, ФГБОУ ВО "Елецкий государственный университет им. И.А. Бунина", Липецкая область, Елец, Россия, irina-zai73@mail.ru
Aннотация
Рассматриваются и анализируются принятые в России стандарты и форматы цифрового спутникового телевизионного (ТВ) вещания для индивидуального и коллективного приема ТВ на спутниковые антенны, и спутникового сбора новостей через репортаж-ные станции. В настоящее время действуют такие ТВ каналы: стандарта DVB-S, формата DVB-DSNG (Digital Satellite News Gathering), стандарта DVB-S2, и начинается внедрение его расширенной спецификации (формата) DVB-S2X. Из всей линейки ТВ каналов рассмотрены стандарты и форматы не выше DVB-S2, которые на настоящее время имеют наибольшее эксплуатационное применение с технической поддержкой производителей такого оборудования.
Проанализировано влияние параметров кодирования на основные характеристики ТВ канала, пропускную способность, в части более эффективного использования выделяемой полосы частот транспондера (спутникового ретранслятора), и помехозащищенность.
На основании выполненных расчетов проведен поэтапный анализ влияния основных параметров кодирования на реализацию преимуществ появившегося формата DVB-DSNG по отношению к действующему в то время стандарту DVB-S, и на реализацию преимуществ нового стандарта DVB-S2 по сравнению с уже действующим DVB-DSNG. Вместе с тем показаны очевидные достоинства и перспективность ТВ канала формата DVB-DSNG в гибком варьировании своими параметрами.
Полученные результаты вычислений основных параметров ТВ каналов и выводы могут быть рекомендованы специалистам спутникового ТВ для оптимального выбора скорости кодирования в зависимости от типов и параметров оборудования используемых станций и зоны спутникового покрытия.
Ключевые слова: спутниковые ТВ каналы формата DVB-DSNG, помехозащищенность, пропускная способность, LDPC-коды, стандарт DVB-S2.
Литература
1. Федоров В.К. Стандарты цифрового телевидения первого поколения. М.: ДМК-Пресс, 20i5. 312 с.
2. Карякин В.Л. Цифровое телевидение: учебное пособие для вузов, 2-е изд., переработанное и дополненное. М: СОЛОН-ПРЕСС, 2013. 45i с.
3. A Morello and V. Mignone. New DVB standard for DSNG - and contribution satellite links // EBU Technical Review vol. 277, Autumn. i998. Pp. i-23.
4. Jense T. Saetre. Online Satellite Calculations i999-20ii Электронный ресурс. URL: http://www.satellite-calculations.com/ (дата обращения - 12.03.2017).
5. Eroz M., Sun F.-W., Lee L.-N. DVB-S2 Low Density Parity Check Codes with near Shannon Limit Performance // International Journal on Satellite Communication Networks. 2004. Vol. 22. Pр. 269-279.
6. Gilles Moury, Guy Lesthievent. DVB-S2 channel coding standardization process. Report to PiB Hughes. CCSDS PiB Meeting - ESTEC - ist April 2003. Электронный ресурс. URL: https://cwe.ccsds.org/sls/docs/SLS-CandS /Meeting %20Materials/2003/200304 %20ESTEC_Spring_Meeting/DVB-S2%20status%20report %20to%20PiB.pdf. (дата обращения - i5.04.20i7). i2 p.
7. J. Yoshida. Hughes goes retro in digital satellite TV coding. Electronic Engineering Times (EE Times), News & Analysis. 2003 Электронный ресурс . URL: http://www.eetimes.com/document.asp?doc_id=ii4762i. (дата обращения - i0.03.20i7).
8. A. Morello and V. Mignone. DVB-S2: The Second Generation Standard for Satellite Broad-band Services // Proceedings of the IEEE, vol. 94, Issue i, Jan. 2006. Pp. 2i0-227.
9. Блох В.И. Помехоустойчивое кодирование для передачи цифрового телевидения по каналам связи // Приложение к Broadcasting. 20ii. № 6. С. i2-i6.
10. Блох В.И. Передача цифрового телевидения по радиоканалам. Коды ВСН и LDPC в стандартах DVB-T и DVB-T2 // Приложение к Broadcasting. 20i2. С. i8-2i.
Информация об авторах:
Барамыков Анвар Ибрагимович, Центр ТВ систем ОАО "Газпром космические системы", ведущий специалист, к.т.н., Москва, Россия Зайцева Ирина Николаевна, ФГБОУ ВО "Елецкий государственный университет им. И.А. Бунина", доцент кафедры радиоэлектроники и компьютерной техники, к.п.н., Липецкая область, Елец, Россия
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