BS EN 60835-3-14-1997 Methods of measurement for equipment used in digital microwave radio transmission systems - Measurements on satellite earth stations - Earth stations for sate.pdf

1、BRITISH STANDARD BS EN 60835-3-14: 1997 BS 7573-3.14: 1997 IEC 835-3-14: 1996 Methods of measurement for equipment used in digital microwave radio transmission systems Part 3: Measurements on satellite earth stations Section 3.14 Earth stations for satellite news gathering (SNG) The European Standar

2、d EN 60835-3-14:1996 has the status of a British Standard ICS 33.060.30BSEN 60835-3-14:1997 This British Standard, having been prepared under the direction of the Electrotechnical Sector Board, was published under the authority of the Standards Board and comes into effect on 15 February 1997 BSI 12-

3、1998 The following BSI references relate to the work on this standard: Committee reference EPL/12/5 Draft for comment 95/210491 DC ISBN 0 580 26933 7 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee EPL/12, Radio communica

4、tion, to Subcommittee EPL/12/5, Radio communication systems, upon which the following bodies were represented: British Broadcasting Corporation British Radio and Electronic Equipment Manufacturers Association British Telecommunications plc ERA Technology Ltd. Institution of Electrical Engineers Radi

5、o, Electrical and Television Retailers Association Radiocommunications Agency Amendments issued since publication Amd. No. Date CommentsBSEN60835-3-14:1997 BSI 12-1998 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN 60835-3-14 3 List of references

6、 Inside back coverBSEN 60835-3-14:1997 ii BSI 12-1998 National foreword This British Standard has been prepared by Subcommittee EPL/12/5 and is the English language version of EN 60835-3-14:1996 Methods of measurement for equipment used in digital microwave radio transmission systems Part3:Measureme

7、nts on satellite earth stations: Section 3.14 Earth stations for satellite news gathering (SNG), published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC 835-3-14:1996 published by the International Electrotechnical Commission (IEC). BS EN 60835 is

8、 published in three Parts. The other Parts are: Part 1: Measurement common to terrestrial radio-relay systems and satellite earth stations; Part 2: Measurements on terrestrial radio-relay systems. Some of the many Sections of the three Parts have appeared under the number BS7573, of the same generic

9、 title. This Section describes methods applicable to satellite news gathering (SNG) terminals. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does

10、not of itself confer immunity from legal obligations. Cross-references Publication referred to Corresponding British Standard BS EN 60835 Methods of measurement for equipment used in digital microwave radio transmission systems EN 60835-1-2:1993 (IEC 835-1-2:1992) Part 1 Measurements common to terre

11、strial radio-relay systems and satellite earth stations Section 1.2:1995 Basic characteristics Part 3 Measurements on satellite earth stations EN 60835-3-2:1996 (IEC 835-3-2:1995) Section 3.2:1996 Antenna EN 60835-3-7:1995 (IEC 835-3-7:1995) Section 3.7:1996 Figure-of-merit of receiving system EN 60

12、835-3-13:1996 (IEC 835-3-13:1996) Section 3.13:1997 VSAT systems Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages 2 to 10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had

13、 amendments incorporated. This will be indicated in the amendment table on theinside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60835-3-14 July 1996 ICS 33.060.30 Descriptors: Telecommunications, radiocommunications, communication equipment, earth station, microwave frequencies

14、, digital technics, measurements, characteristics English version Methods of measurement for equipment used in digital microwave radio transmission systems Part3:Measurements on satellite earth stations Section14:Earth stations for satellite news gathering(SNG) (IEC 835-3-14:1996) Mthodes de mesure

15、applicables au matriel utilis pour les systmes de transmission numrique en hyperfrquence Partie 3: Mesures applicables aux stations terriennes de tlcommunications par satellite Section 14: Stations terriennes pour le reportage dactualits par satellite (RAS) (CEI 835-3-14:1996) Meverfahren fr Gerte i

16、n digitalen Mikrowellen-Funkbertragungssystemen Teil 3: Messungen an Satelliten-Erdfunkstellen Hauptabschnitt 14: Erdfunkstellen fr Reportagen ber Satellit (SNG) (IEC 835-3-14:1996) This European Standard was approved by CENELEC on 1996-07-02. CENELEC members are bound to comply with the CEN/CENELEC

17、 Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENE

18、LEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions.

19、 CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardiza

20、tion Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B 1050 Brussels 1996 Copyright reserved to CENELEC members Ref. No. EN 60835-3-14:1996 EEN60835-3-14:1996 BSI 12-1998 2 Foreword The text of document 12E/259

21、/FDIS, future edition1ofIEC 835-3-14, prepared by SC 12E, Radio-relay and fixed satellite commmunication systems, of IEC TC 12, Radiocommunications, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60835-3-14 on1996-07-02. The following dates were fixed: Annexes desig

22、nated “normative” are part of the body of the standard. In this standard, annexZA is normative. AnnexZA has been added by CENELEC. Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3 Definition 3 4 General considerations 3 5 Methods of measurement 4 5.1 Antenna and r.f parameters 4 5.2 Bas

23、eband parameters 5 5.3 Power supply system 6 6 Reference documents 6 Annex ZA (normative) Normative references to international publications with their corresponding European publications 9 Figure 1 Typical example for a satellite network including an SNG terminal 7 Figure 2 Simplified block diagram

24、 of a typical SNG terminal (excluding communications channel) 8 latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1997-04-01 latest date by which the national standards conflicting with the EN have to be withd

25、rawn (dow) 1997-04-01EN60835-3-14:1996 BSI 12-1998 3 1 Scope This section of IEC835-3 deals with measurement methods applicable to satellite news gathering (SNG) terminals. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute p

26、rovisions of this section of IEC 835-3. At the time of publication, the editions indicated were valid. All normative documents are subject to revision, and parties to agreements based on this section of IEC835-3 are encouraged to investigate the possibility of applying the most recent editions of th

27、e normative documents indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 835-1-2:1992, Methods of measurement for equipment used in digital microwave radio transmission systems Part 1: Measurements common to terrestrial radio-relay systems and

28、satellite earth stations Section 2: Basic characteristics. IEC 835-3-7:1995, Methods of measurement for equipment used in digital microwave radio transmission systems Part 3: Measurements on satellite earth stations Section 7: Figure-of-merit of receiving system. IEC/DIS 835-3-2, Methods of measurem

29、ent for equipment used in digital microwave radio transmission systems Part 3: Measurements on satellite earth stations Section 2: Antenna 1) . IEC/DIS 835-3-13, Methods of measurement for equipment used in digital microwave radio transmission systems Part 3: Measurements on satellite earth stations

30、 Section 13: VSAT systems 1) . 3 Definition For the purpose of this section of IEC 835-3, the following definition applies. satellite news gathering (SNG) a highly portable news-gathering satellite uplink system of small size and weight operating in the fixed satellite service (FSS), transported to

31、the site of a news event, with the purpose of uplinking a local video programme with its associated sound programme. In addition to this main function, monitoring facilities are normally provided to assess the main quality parameters of the uplinked picture and sound signals. A two-way communication

32、 channel is available for voice communication between the SNG terminal and the earth station receiving the uplinked signals 4 General considerations A typical example for a satellite network including an SNG terminal is shown inFigure 1, depicting the signal paths linking the satellite earth station

33、, the SNG terminal, and the receive-only earth stations feeding TV broadcast transmitters, cable TV (CATV) networks, etc. Two kinds of SNG terminals may be used depending on the application field. Aflyaway SNG system is accommodated in several boxes suitable for delivery in an aircraft while avehicl

34、e SNG system includes, in addition to the items of a flyaway system, more comprehensive communications, monitoring, and power supply facilities. An SNG vehicle is used for the origination of TV broadcast material from locations which cannot be served by terrestrial means, but which are conveniently

35、accessible by the vehicle. 1) IEC/DIS 835-3-2 and IEC/DIS 835-3-13 are currently at the stage of final Draft International Standard12/247/FDIS and12E(CO)166 respectively.EN60835-3-14:1996 4 BSI 12-1998 A typical block diagram of an SNG terminal using digital modulation is shown in Figure 2. Accordin

36、g to this diagram, the video signal plus left and right components of the accompanying stereo sound signal are fed to a video/sound encoder, and the composite digital signal thus generated is used to modulate a quadrature phase shift keying (QPSK) modulator. This modulated signal is up-converted to

37、the UHF band by using a synthesized oscillator, which is tuneable for selecting the appropriate satellite transponder channel. The UHF band signal is again up-converted by a single-frequency oscillator and a broad-band converter covering the relevant transponder band. In the example shown, this sign

38、al is amplified by a high-power amplifier feeding, via a coupler and a switch, the transmit bandpass filter. The low-level port of the coupler can be connected to an external counter or spectrum analyzer for carrying out frequency or spectrum measurements. The switch is used to route the r.f.signal,

39、 during maintenance tests, to a dummy load for facilitating output power measurements. The antenna is coupled, via an ortho-mode transducer applied for separating the transmit and receive signals having orthogonal polarizations, to the transmit and receive bandpass filters. The output r.f. signal of

40、 the receive filter is coupled to the low-noise down-converter converting the r.f. signal to the UHF band. This broadband UHF signal is again down-converted into the i.f. band by a synthesized oscillator tuned to the appropriate transponder channel. A QPSK demodulator is used for demodulating the co

41、mposite digital signal and for feeding it to a video/sound decoder to recover the video and sound signals. SNG terminals utilizing analogue FM modulation, which are less portable because of the larger antenna and output power required, have been in use for many years. In their case, the two sound si

42、gnals are used to modulate two subcarriers which are then added to the video signal, and the composite signal is routed to an FM modulator producing an i.f. carrier. In the receive part, the composite signal is recovered by an FM demodulator yielding the video signal and the two sound subcarriers wh

43、ich are, in turn, demodulated to yield the stereo sound signals. It is desirable to assess the quality of the video and sound signals (see 5.2.3), uplinked by the SNG terminal, independently from other parts of the network shown in Figure 1. For this purpose, an r.f. loop is usually established, rea

44、lized either by satellite paths (see path 1A and 1B in Figure 1), or by a loop test translator inserted between the HPA (high power amplifier) or up-converter output and the low-noise down-converter input at r.f., converting the transmitted frequency into the received frequency. This loop test, elim

45、inating the satellite uplink and downlink paths and the space segment cost, is sometimes preferred. According to Figure 2, it is also possible to establish a loop by linking the up-converter 1 output to the down-converter 2 input in the UHF band. However, this looping arrangement would exclude from

46、the test the up-converter 2 and down-converter 1 and the r.f. portion of the terminal. 5 Methods of measurement 5.1 Antenna and r.f. parameters 5.1.1 Antenna performance Antenna gain, radiation pattern, and cross-polarization discrimination shall be measured as explained in the future IEC835-3-2. Du

47、e to the fact that an SNG antenna is repeatedly assembled and disassembled in the course of the site installation, reproducibility of the antenna performance should be confirmed following disassembly and reassembly of the antenna. 5.1.2 Antenna alignment Adjustment of elevation angle, azimuth angle,

48、 and polarization plane at the site are required so as to transmit the signal correctly towards the desired satellite. The verification tests shall be performed by receiving the test signal transmitted through the satellite from the cooperating earth station as follows. Install the SNG terminal at t

49、he specified test site, and adjust the elevation and azimuth angles and the polarization plane according to the known satellite position and location of the SNG terminal. Next, fine-tune the above parameters until the level of the received signal, as measured by a spectrum analyzer connected to the UHF band output of the low-noise converter (seeFigure 2), is at maximum, including the adjustment of the polarization angle of the antenna feed. Make sure that the received signal originates from the desired satellite by appro