1、BSI Standards PublicationCable networks for television signals, sound signals and interactive servicesPart 3-3: Active wideband equipment for cable networks Methods of measurement of the maximum operating output level in the return pathPD CLC/TS 50083-3-3:2014National forewordThis Published Document
2、 is the UK implementation of CLC/TS 50083-3-3:2014.The UK participation in its preparation was entrusted by Technical Com-mittee EPL/100, Audio, video and multimedia systems and equipment, to Subcommittee EPL/100/4, Cable distribution equipment and systems.A list of organizations represented on this
3、 committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2014.Published by BSI Standards Limited 2014ISBN 978 0 580 85962 5ICS 33
4、.060.40Compliance with a British Standard cannot confer immunity fromlegal obligations.This Published Document was published under the authority of theStandards Policy and Strategy Committee on 30 November 2014.Amendments/corrigenda issued since publicationDate Text affectedPUBLISHED DOCUMENTPD CLC/
5、TS 50083-3-3:2014TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CLC/TS 50083-3-3 November 2014 ICS 33.060.40 English Version Cable networks for television signals, sound signals and interactive services - Part 3-3: Active wideband equipment for cable networks - Methods of me
6、asurement of the maximum operating output level in the return path Rseaux de distribution par cbles pour signaux de tlvision, signaux de radiodiffusion sonore et services interactifs - Partie 3-3: Matriel actifs large bande utiliss dans les rseaux de distribution - Mthodes de mesure du niveau de sor
7、tie maximal de fonctionnement dans la voie de retour Kabelnetze fr Fernsehsignale, Tonsignale und interaktive Dienste - Teil 3-3: Aktive Breitbandgerte fr Kabelnetze - Messverfahren fr den maximalen Betriebs-Ausgangspegel im Rckweg This Technical Specification was approved by CENELEC on 2014-09-30.
8、CENELEC members are required to announce the existence of this TS in the same way as for an EN and to make the TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force. CENELEC members are the national electrotechnical committe
9、es of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slov
10、enia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CENELEC All
11、rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. CLC/TS 50083-3-3:2014 E PD CLC/TS 50083-3-3:2014CLC/TS 50083-3-3:2014 - 2 - Contents Page Foreword. 3 Introduction 4 1 Scope . 5 2 Normative references . 5 3 Terms, definitions, symbols and abbreviat
12、ions 5 3.1 Terms and definitions 5 3.2 Symbols . 7 3.3 Abbreviations 8 4 Method of measurement of the maximum operating output level in the return path 8 4.1 General. 8 4.1.1 Channel load and modulation format . 8 4.1.2 Return path frequency ranges 8 4.1.3 Applied limit values 8 4.2 Measurement para
13、meters for full channel load (N = 6 or N = 8) 9 4.3 Equipment required 9 4.4 Connection of the equipment 10 4.5 Measurement procedure 10 4.6 Presentation of the measurement results 11 4.7 Maximum operating output level for reduced channel loads 11 Annex A (normative) Null packet and PRBS definitions
14、 12 A.1 Null packet definition . 12 A.2 PRBS definition . 13 Annex B (informative) Calculation formula for the maximum operating output level for reduced channel loads 14 B.1 General. 14 B.2 Measurement results as basis for calculation formula for reduced channel loads 14 B.3 Calculation formula for
15、 median value 15 B.4 Calculation formula for worst-case value 15 Bibliography . 16 PD CLC/TS 50083-3-3:2014- 3 - CLC/TS 50083-3-3:2014 Foreword This document (CLC/TS 50083-3-3:2014) has been prepared by CLC/TC 209 “Cable networks for television signals, sound signals and interactive services”. Atten
16、tion is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. PD CLC/TS 50083-3-3:2014CLC/TS 50083-3-3:2014 - 4 - Introduction Standards and deliverables
17、 of EN 60728 series and EN 50083 series deal with cable networks including equipment and associated methods of measurement for headend reception, processing and distribution of television and sound signals and for processing, interfacing and transmitting all kinds of data signals for interactive ser
18、vices using all applicable transmission media. These signals are typically transmitted in networks by frequency-multiplexing techniques. This includes for instance regional and local broadband cable networks, extended satellite and terrestrial television distribution systems, individual satellite an
19、d terrestrial television receiving systems, and all kinds of equipment, systems and installations used in such cable networks, distribution and receiving systems. The extent of this standardization work is from the antennas and/or special signal source inputs to the headend or other interface points
20、 to the network up to the terminal input of the customer premises equipment. The standardization work will consider coexistence with users of the RF spectrum in wired and wireless transmission systems. The standardization of any user terminals (i.e. tuners, receivers, decoders, multimedia terminals
21、etc.) as well as of any coaxial, balanced and optical cables and accessories thereof is excluded. PD CLC/TS 50083-3-3:2014- 5 - CLC/TS 50083-3-3:2014 1 Scope This Technical Specification is applicable to the method of nonlinearity measurement for active cable network equipment which carry a digital
22、channel load in the return path. The digital channel load is represented by standard DVB-C signals. The method of measurement of the maximum operating output level takes account of a full channel load in the return path frequency range although different applications of return path amplifiers with p
23、artial channel load or single channel load are also in practical use. The maximum operating output level for applications with reduced channel loads could be derived from the result with a full channel load by applying a given calculation formula. The method considers the specific signal form and be
24、haviour of digitally modulated signals and can be applied in the return path frequency range (5 MHz to 65 MHz) as well as in the extended return path frequency range (5 MHz to 85 MHz) according to EN 60728-10. 2 Normative references The following documents, in whole or in part, are normatively refer
25、enced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 60728-10, Cable networks for television signals, sound signals and inte
26、ractive services Part 10: System performance for return paths (IEC 60728-10) ISO/IEC 13818-1, Information technology Generic coding of moving pictures and associated audio information: Systems Part 1 3 Terms, definitions, symbols and abbreviations For the purposes of this document, the following ter
27、ms, definitions, symbols and abbreviations apply. 3.1 Terms and definitions 3.1.1 attenuation ratio of the input power to the output power of an equipment or system, usually expressed in decibels 3.1.2 bit error ratio BER ratio between erroneous bits and the total number of transmitted bits 3.1.3 ga
28、in ratio of the output power to the input power, usually expressed in decibels 3.1.4 level decibel ratio of any power P1to the standard reference power P0, i.e 01lg10PPdecibel ratio of any voltage U1to the standard reference voltage U0, i.e 01lg20UUNote 1 to entry: The power level may be expressed i
29、n decibels relative to P0= (U02/R) = (1/75) pW, i.e. in dB(P0), taking into account that the level of P0corresponds to 0 dB(P0) or, as more usually, in dB(pW), taking into account that the level of P0corresponds to 18,75 dB(pW). The voltage level is expressed in decibels relative to 1 V (across 75 )
30、, i.e. in dB(V). PD CLC/TS 50083-3-3:2014CLC/TS 50083-3-3:2014 - 6 - 3.1.5 maximum operating output level (worst-case) Umax (N)worst-case of maximum channel output level of a digitally modulated signal in the 64 QAM format with a symbol rate of 6,9 MSymb/s with 15 % cosine roll-off, measured with fu
31、ll digital channel load 3.1.6 maximum operating output level Umax,i (N)measured maximum operating output level of a single measurement channel i with full digital channel load 3.1.7 modulation error ratio MER sum of the squares of the magnitudes of the ideal symbol vectors is divided by the sum of t
32、he squares of the magnitudes of the symbol error vectors of a sequence of symbols, the result being expressed as a power ratio in dB ( )( )dBinlg10122122+=NjjjNjjjQIQIMER 3.1.8 modulation error ratio of EUT MEREUTcalculated value of modulation error ratio of the EUT following Figure 1 and using the
33、following formula Figure 1 Interrelation between different MER contributions Meas Source10 10EUT10 lg 10 10MER MERMER=Note 1 to entry: The calculation with 10lg is used for simplification reasons although it is well known that the disturbing signal comprises of noise and nonlinear portions. PD CLC/T
34、S 50083-3-3:2014- 7 - CLC/TS 50083-3-3:2014 3.1.9 modulation error ratio of complete measurement setup MERMeasmeasured value of modulation error ratio of the complete measurement setup according to Figure 1 including the equipment under test (EUT) 3.1.10 modulation error ratio of signal source MERSo
35、urcemeasured value of modulation error ratio of the signal generator when signal generator and measurement receiver are directly connected 3.1.11 slope difference in gain or attenuation at two specified frequencies between any two points in an equipment or system Note 1 to entry: The slope sign is c
36、onsidered a) negative when the attenuation increases with frequency (cables) or the gain (amplifiers) decreases with frequency, b) positive when the gain (amplifiers) increases with frequency (compensating slope). 3.2 Symbols The following graphical symbols are used in the figures of this Technical
37、Specification. These symbols are either listed in IEC 60617 or based on symbols defined in IEC 60617. Symbols Terms Symbols Terms Equipment Under Test based on IEC 60617-S00059 (200107) Combiner based on IEC 60617-S00059 (200107) Variable attenuator IEC 60617-S01245 (200107) Amplifier IEC 60617-S012
38、39 (200107 Modulator IEC 60617-S01278 (200107) Demodulator IEC 60617-S01278 (200107 PD CLC/TS 50083-3-3:2014CLC/TS 50083-3-3:2014 - 8 - 3.3 Abbreviations BER bit error ratio BERSourcebit error ratio of source and measurement equipment BERMess measured bit error ratio value on measuring set DOCSIS Da
39、ta Over Cable Service Interface Specification DVB Digital Video Broadcasting DVB-C Digital Video Broadcasting, Cable EUT equipment under test MER modulation error ratio MEREUT modulation error ratio of EUT MERMeas modulation error ratio of complete measurement setup MERSource modulation error ratio
40、of signal source PRBS pseudo-random bit sequence QAM quadrature amplitude modulation RF radio frequency Umax (N)worst-case of maximum operating output level with channel load of N carriers in the 64 QAM format Umax,i (N)measured maximum operating output level of a single measurement channel i with N
41、 channels load UnCalculated output level for n channels 4 Method of measurement of the maximum operating output level in the return path 4.1 General 4.1.1 Channel load and modulation format The method of measurement describes the measurement of the bit error ratio (BER) (before Reed Solomon decoder
42、of the measurement receiver) of the output signal of the equipment under test (EUT) (e.g. a return path amplifier) when handling a full load of digitally modulated DVB-C signals. To simplify matters, DVB-C signals are used to simulate DOCSIS signals (according to e.g. ETSI EN 302 878, all parts) usu
43、ally used in cable networks for data transmission purposes. 4.1.2 Return path frequency ranges The method of measurement is applicable in the return path frequency range (5 MHz to 65 MHz) as well as in the extended return path frequency range (5 MHz to 85 MHz) according to EN 60728-10. For EUT desig
44、ned for the return path frequency range (5 MHz to 65 MHz), this test is able to define the performance (maximum output level) of the EUT when loaded with a number N = 6 of digitally modulated signals in the 64 QAM format covering a maximum frequency range from 16 MHz to 64 MHz for full channel load
45、with a raster of 8 MHz. For EUT designed for the extended return path frequency range (5 MHz to 85 MHz), this test is able to define the performance (maximum output level) of the EUT when loaded with a number N = 8 of digitally modulated signals in the 64 QAM format covering a maximum frequency rang
46、e from 16 MHz to 80 MHz for full channel load with a raster of 8 MHz. 4.1.3 Applied limit values The maximum operating output level is defined for a limit value of the bit error ratio BER 1 108. This limit value corresponds with correct operation and a good quality output of the EUT. PD CLC/TS 50083
47、-3-3:2014- 9 - CLC/TS 50083-3-3:2014 In addition to this BER limit value, a limit value for the modulation error ratio of MEREUT 35 dB shall be achieved according to the definition in 3.1.7. This limit value is above the minimum system requirement for 64 QAM signals which is MER 26 dB and allows a m
48、argin to cascade several active equipment in the return path. The measurements shall be performed using the measurement parameters as described hereafter. 4.2 Measurement parameters for full channel load (N = 6 or N = 8) The measurement parameters for full channel load are given in Table 1. Table 1
49、Measurement parameters for full channel load Return path frequency range (5 MHz to 65 MHz) Extended return path frequency range (5 MHz to 85 MHz) Modulation format 64 QAM Symbol rate 6,9 MSymb/s Channel bandwidth 8 MHz Number of channels N 6 8 Channel raster with centre frequencies 20, 28, 36, 44, 52 and 60 MHz 20, 28, 36, 44, 52, 60, 68 and 76 MHz BER limit value 1108MEREUTlimit value 35 dB One channel (i) is taken as the measurement channel and the remaining five or seve
