1、- -.” 3404583 O023329 8 I NFURMA r I OE.; SHEET I EN suoao Rue de Srassari. 35 - 1050 Bruxelles TBI (+ 322) 519 68.71 - Fax: (+ 32 2) 519 69.19 Teletex 206 2210097 = CENCEL - Tx 172210097 1 SSUI? 1 1991-05-30 RF characteristics of MAC AM-VSB cable receivers May 1991 Caractristiques RF des rcepteurs
2、MAC en MAIBLR pour tlvision par cables RF Merkmale von MAC AM-RSB Kabel-Empfngern This European Standard consists of the following: - Title Page Related to Directive: - - Text prepared by CENELEC Technical Cornittee TC 106 date of ratification : 1991-03-15 date of announcement : 1991-09-01 date of l
3、atest publication : 1992-03-01 date of withdrawal : 1992-03-01 LIST OF NATIONAL STANDARDS IS GIVEN OVERLEAF HARMONIZE0 NATIONAL STANDARDS EN 50080:1991 I Y AT : BE : CH : DE : DK : ES : FI : FR : GE : GR : IE : IS : IT : LU : NL : NO : PT : SE : EUROPEAN STANDARD P NORME EUROPEENNE EUROPISCHE NORM E
4、N 50080 May 1991 UDC 621.397.743:621.397.63 Descriptors: Telecommunication, cabled television, receiver, demodulator, signal, characteristic ENGLISH VERSION RF CHARACTERISTICS OF MAC AM-VSB CABLE RECEIVERS Caractristiques RF des rcepteurs MAC en MAIBLR pour tlvision par cbles RF Merkmale von MAC AM-
5、RSB Kabel-Empfngern This European Standard was approved by CENELEC on 1991-03-15. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date list a
6、nd bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the respo
7、nsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy , Luxembourg,
8、 Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comite Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, 8-1050 Brussels 19
9、91 Copyright reserved to CENELEC members Ref. No. EN 50080:1991 E Page 2 EN 50080:1991 FOREWORD This European Standard has been prepared by CENELEC Technical Committee TC 106, MAC receiving equipment. The text was submitted to the CENELEC Unique Acceptance Procedure (UAP) in July 1990. The text of t
10、he draf was approved by all CENELEC members with the exception of Finland as EN 50080 on 15 March 1991. The following dates were fixed: - latest date of publication of an identical national standard - latest date of withdrawal of conflicting national standards (dop) 1992-03-01 (dow) 1992-03-01 Annex
11、es designated “normative” are pari of the body of the standard. In this standard, annex A is normative. 1 NTROD UCTiON The introduction of MAC transmission standards and the need to provide a possibility to introduce HDMAC signals at a later stage, gave rise for the need to standardize the RF charac
12、teristics of MAC AM-VSB cable receivers. This standard is so far restricted to the use of MAC signals in the hyperband, some countries are however envisaging additional transmissions outside this band. The most notable difference with the RF characteristics in case of conventional transmissions is t
13、he location of the vision Nyquist slope, which is the transmitter. This is done to improve the noise properties of the whole transmission chain. Optimized behaviour of the complete AM-VSB CATV system will be attained only by correctly matching both RF receiver characteristics as well as RF transmitt
14、er characteristics. Therefore the RF transmitter characteristics described in Annex A are normative. i F Page 3 EN 50080:1991 1. SCOPE This standard specifies the RF characteristics for MAC AM-VSB cable receivers and defines the behaviour of the receiver demodulator by referring to the characteristi
15、cs of the modulated signal. It takes into account the development of the HDMAC specification and ensures compatibility with the HDMAC transmission parameters. 2. RF CHARACTERISTICS OF MAC AM-VSB CABLE RECEIVERS Freauencv band: Sianal level: Hyperband 300-470 MHz 70 dB pV range 60-84 dB p,V Channel s
16、oacina: 12 MHz (note 1) Receiver filter characteristic: see fig. 1 (note 2) Grouo delav characteristic: flat (linear phase characteristic) 3. CHARACTERISTICS OF THE MODULATED SIGNAL: Modulation Dolaritv: negative Amolitude at black level: 100% Residual carrier level: 10% (see fig. 2) Notes: I. 12 MH
17、z channel spacing is required for DMAC and HDMAC and the bandwidth available for D2MAC signals received by satellite can be maintained. Unless special measures like e. g. scrambling of the wanted channel and/or frequency offsetting are taken, the lower adjacent channel shall not be a system B/G/I or
18、 system L signal, because the sound carrier will give rise to interference. 2. The receiver filter is a so called window filter. . Page4 EN 50080:1991 T- a+ U 3 c = 3404583 0023334 L m B a W W LIC LLI I I- L O 0 L .- - d 3404583 0023135 3 = Page 5 r EN 50080:1991 I i Black Level 100% - 55% 10% Grey
19、Level White Level (residual carrier level) Fig. 2: CARRIER LEVELS Annex A (Normative) CORRESPONDING CABLE PARAMETERS The following essential cable parameters are assumed to ensure a good performance of the receiver. They are given here as far they are not clear from clause 2. A complete cable specif
20、ication will be defined by CLC/TC109. Maximum level difference between adjacent channels: Filter characteristics of the modulator: Minimum C/N, levei: 3 dB see fig. A.1 (note 1) 50 dB at 1 MHz bandwidth (note 2) SIGNALS RECEIVED FROM SATELLITE SERVICES: Any energy dispersal waveform added to the MAC
21、/packet signal shall be removed prior to transmission in cable systems. The linear pre-emphasis specified in the MAC packet specification for the FM transmission shall be removed prior to transmission in cable systems. MAC/packet systems may use maximum amplitude colourdifference signals. For broadc
22、asting via satellites, some systems may also use nominal data amplitudes for D-MAC which have been increased in order to optimize bit-error-rate performance. For both these cases over-modulation of the VSB/AM/MAC packet signal will occur If the simplest types of remodulation schemes are used. Notes: 1. 2. For HDMAC the so called HDMAC Nyquist slope around 10.1 25 MHz is not yet fully determined. For HDMAC the value Is still under consideration. 5 -! Co In 0- O h ?- r n cv Page 7 EN 50080:1991 N I H L 0 (d o .- L L O - a O O 2 W I I- l- cr) W - a
