SIST EN 62753:2016
(Main)Digital Terrestrial Television Receivers for the DTMB system (IEC 62753:2015)
Digital Terrestrial Television Receivers for the DTMB system (IEC 62753:2015)
IEC 62753:2015(E) specifies the basic functions, interfaces, performance requirements and test methods of the receivers for the Digital Terrestrial/Television Multimedia Broadcasting (DTMB) system. This standard can be applied to digital television terrestrial receivers carrying multiple SDTV programs or HDTV programs for both mobile and stationary receptions.
Digitale terrestrische Fernsehempfänger für das DTMB-System (IEC 62753:2015)
Récepteurs de Télévision Numérique Terrestre destiné au système DTMB (IEC 62753:2015)
L'IEC 62753:2015 spécifie les fonctions de base, les interfaces, les exigences de performance et les méthodes d'essai des récepteurs pour le système DTMB (Digital Terrestrial/Television Multimedia Broadcasting). La présente norme peut s'appliquer aux récepteurs de télévision numérique terrestre qui diffusent plusieurs programmes SDTV ou HDTV pour les réceptions mobiles et stationnaires.
Sprejemniki digitalne prizemne televizije za sistem DTMB (IEC 62753:2015)
Ta mednarodni standard določa osnovne funkcije, vmesnike, zahteve glede delovanja in preskusne metode sprejemnikov za sistem digitalne prizemne televizije/sistem televizijskega večpredstavnostnega oddajanja (DTMB). Ta standard je mogoče uveljavljati pri prizemnih sprejemnikih digitalne televizije z več programi SDTV ali HDTV za mobilni in stacionarni sprejem.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-februar-2016
Sprejemniki digitalne prizemne televizije za sistem DTMB (IEC 62753:2015)
Digital Terrestrial Television Receivers for the DTMB system (IEC 62753:2015)
Digitale terrestrische Fernsehempfänger für das DTMB-System (IEC 62753:2015)
Récepteurs de Télévision Numérique Terrestre destiné au système DTMB (IEC
62753:2015)
Ta slovenski standard je istoveten z: EN 62753:2015
ICS:
33.160.25 Televizijski sprejemniki Television receivers
33.170 Televizijska in radijska Television and radio
difuzija broadcasting
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN 62753
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2015
ICS 33.160; 33.170
English Version
Digital terrestrial television receivers for the DTMB system
(IEC 62753:2015)
Récepteurs de Télévision Numérique Terrestre destiné Digitale terrestrische Fernsehempfänger
au système DTMB für das DTMB-System
(IEC 62753:2015) (IEC 62753:2015)
This European Standard was approved by CENELEC on 2015-07-10. 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 lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre 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 responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees 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, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 62753:2015 E
European foreword
The text of document 100/2108/CDV, future edition 1 of IEC 62753, prepared by
Technical Area 1 "Terminals for audio, video and data services and contents" of IEC/TC 100 "Audio,
video and multimedia systems and equipment" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN 62753:2015.
The following dates are fixed:
• latest date by which the document has to be (dop) 2016-04-10
implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2018-07-10
• latest date by which the national
standards conflicting with the
document have to be withdrawn
Attention 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.
Endorsement notice
The text of the International Standard IEC 62753:2015 was approved by CENELEC as a European
Standard without any modification.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced 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.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu
Publication Year Title EN/HD Year
IEC 61937-12 - Digital audio - Interface for non-linear EN 61937-12 -
PCM encoded audio bitstreams applying
IEC 60958 -
Part 12: Non-linear PCM bitstreams
according to the DRA formats
ISO/IEC 13818-1 - Information technology - Generic coding - -
of moving pictures and associated audio
information -
Part 1: Systems
ISO/IEC 13818-2 - Information technology - Generic coding of - -
moving pictures and associated audio
information -
Part 2: Video
ISO/IEC 13818-3 - Information technology - Generic coding of - -
moving pictures and associated audio
information -
Part 3: Audio
ETSI ETR 154 - Digital Video Broadcasting (DVB); - -
Implementation guidelines for the use of
MPEG-2 Systems, Video and Audio in
satellite, cable and terrestrial broadcasting
applications
ETSI TS 102 366 - Digital Audio Compression (AC-3, - -
Enhanced AC-3) Standard
IEC 62753 ®
Edition 1.0 2015-06
INTERNATIONAL
STANDARD
Digital terrestrial television receivers for the DTMB system
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.160; 33.170 ISBN 978-2-8322-2696-4
– 2 – IEC 62753:2015 © IEC 2015
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references. 10
3 Abbreviations and symbols . 10
4 Summary of DTMB transmission system . 12
4.1 General . 12
4.2 Processing of DTMB transmitter . 12
4.3 Processing of DTMB receiver . 13
5 Receiver capabilities . 13
5.1 Frequency spectrum . 13
5.1.1 Frequency range . 13
5.1.2 Channel bandwidth . 13
5.1.3 Frequency acquisition range . 13
5.2 Power supply requirements . 13
5.3 Interface requirements . 13
5.4 Working modes . 14
5.5 Program search and tuning . 14
5.5.1 General . 14
5.5.2 Receive quality display . 14
5.5.3 Automatic search . 15
5.5.4 Manual search . 15
5.5.5 Modulation parameters change . 15
5.6 Demultiplex characteristics . 15
5.6.1 General . 15
5.6.2 TS data rate . 15
5.6.3 STC recovery . 15
5.6.4 Error control . 15
5.6.5 PID filters . 15
5.6.6 Multi-component programs . 15
5.7 Transport stream decoding characteristics . 16
5.7.1 Service and program information . 16
5.7.2 EPG . 18
5.7.3 Presentation of subtitle . 18
5.8 Function requirements . 18
5.8.1 General . 18
5.8.2 Software version update . 19
5.8.3 Chinese graphical operation interface . 19
5.8.4 Service list . 19
5.8.5 Status bar . 20
5.8.6 User parameter settings and storage . 20
5.8.7 Power failure memory . 20
5.8.8 Restore factory settings . 21
5.8.9 Real time clock . 21
6 Video and audio system characteristics . 21
IEC 62753:2015 © IEC 2015 – 3 –
6.1 Video system characteristics . 21
6.1.1 General . 21
6.1.2 Fast acquisition . 21
6.1.3 Still images . 21
6.1.4 Baseband video input format . 21
6.2 Audio system characteristics . 22
7 RF part and channel decoder . 22
7.1 RF port . 22
7.1.1 RF input port . 22
7.1.2 RF loop output port . 22
7.2 Performance . 23
7.2.1 Failure point criteria . 23
7.2.2 Carrier to noise ratio threshold . 23
7.2.3 Minimum signal input levels . 23
7.2.4 Maximum signal input level . 23
7.2.5 Immunity to analogue signals in an adjacent channel . 23
7.2.6 Immunity to co-channel analogue signals . 24
7.2.7 Immunity to digital signals in an adjacent channel . 24
7.2.8 Immunity to co-channel digital signals . 25
7.2.9 Resistance to 0 dB echo. 25
7.2.10 Resistance to dynamic multipath channel . 26
7.2.11 Resistance to pulse noise interference . 26
8 Test method . 26
8.1 RF demodulation and channel decoding . 26
8.1.1 General . 26
8.1.2 Frequency range . 27
8.1.3 Frequency acquisition range . 27
8.1.4 Program search and tuning . 27
8.1.5 Return loss of RF input port . 28
8.1.6 C/N threshold of Gaussian . 29
8.1.7 Signal input level range . 29
8.1.8 Immunity to analogue signals in adjacent channels . 30
8.1.9 Immunity to analogue signals in a co-channel . 30
8.1.10 Immunity to digital signals in adjacent channels . 31
8.1.11 Immunity to digital signals in a co-channel . 31
8.1.12 Resistance to 0 dB echo. 32
8.1.13 Resistance to a dynamic multipath channel . 32
8.1.14 Resistance to pulse noise interference . 33
8.2 Demultiplex characteristics . 33
8.2.1 TS data rate . 33
8.2.2 STC recovery . 34
8.2.3 Error control . 34
8.2.4 PID filters . 35
8.2.5 Multi-component programs processing . 35
8.3 Transport stream decoding . 35
8.3.1 Service and program information . 35
8.3.2 EPG . 36
8.3.3 Presentation of text . 36
8.4 Power endurance . 36
– 4 – IEC 62753:2015 © IEC 2015
8.4.1 Power voltage endurance . 36
8.4.2 Power frequency endurance . 37
Annex A (normative) Acceptable error free . 38
Annex B (normative) Multipath channel models . 39
B.1 Rayleigh channel model . 39
B.2 Rice channel model . 39
B.3 Dynamic multipath channel model . 40
Annex C (informative) Guide to the implementing of a DRA audio decoder in a DTMB
receiver . 41
C.1 General . 41
C.2 Outline, terms and definitions . 41
C.2.1 Outline . 41
C.2.2 Terms and definitions . 43
C.3 DRA syntax structure . 45
C.3.1 General . 45
C.3.2 DRA bit stream . 45
C.3.3 Frame . 45
C.3.4 Frame header . 46
C.4 Semantic. 47
C.4.1 General . 47
C.4.2 Bit stream . 47
C.4.3 Frame . 47
C.4.4 Frame header . 48
C.4.5 Unpacking window sequence bits . 52
C.4.6 Unpacking Huffman code book selection and application range bits . 54
C.4.7 Unpacking quantization index bits of subband samples . 54
C.4.8 Unpacking quantization stepsize index bits . 54
C.4.9 Unpacking sum/difference coding decision bits . 54
C.4.10 Unpacking joint intensity coding scale factor bits . 55
C.4.11 Unpacking padding bits . 55
C.4.12 Unpacking auxiliary data . 55
C.5 Decoding . 55
C.5.1 Channel arranging and configuration . 55
C.5.2 Downmixing . 57
C.5.3 De-interleaving . 58
C.5.4 Reconstruction of the number of quantification units . 59
C.5.5 Dequantizer . 59
C.5.6 Joint intensity decoding . 60
C.5.7 Sum/difference decoding . 60
C.5.8 Variable resolution synthesis filter bank . 60
C.5.9 Reconstruction of the short/brief window function sequence . 63
Bibliography . 64
Figure 1 – Diagram of DTMB transmitter processing . 12
Figure 2 – Diagram of DTMB receiver processing . 13
Figure 3 – Test set-up for frequency range . 27
Figure 4 – Test set-up for program search and tuning . 28
Figure 5 – Test set-up for return loss . 29
IEC 62753:2015 © IEC 2015 – 5 –
Figure 6 – Test set-up for C/N threshold of Gaussian . 29
Figure 7 – Test set-up for signal input level range . 29
Figure 8 – Test set-up for immunity to analogue signals in adjacent channels . 30
Figure 9 – Test set-up for immunity to digital signals in adjacent channels . 31
Figure 10 – Test set-up for resistance to 0 dB echo . 32
Figure 11 – Test set-up for immunity to pulse noise interference . 33
Figure 12 – Test set-up for TS data rate . 33
Figure 13 – Test set-up for STC recovery . 34
Figure 14 – Test set-up for power voltage and frequency endurance . 36
Figure C.1 – Decoder . 42
Table 1 – Power supply requirements . 13
Table 2 – Requirements of interface . 14
Table 3 – Required working modes . 14
Table 4 – Requirements of EPG supporting . 18
Table 5 – Supporting functions . 19
Table 6 – Video parameters . 21
Table 7 – Video format . 22
Table 8 – C/N for reference AEF . 23
Table 9 – Minimum received signal level . 23
Table 10 – Immunity to analogue signals in a N − 1 adjacent channel . 24
Table 11 – Immunity to analogue signals in a N + 1 adjacent channel . 24
Table 12 – Immunity to co-channel analogue signals . 24
Table 13 – Immunity to digital signals in an adjacent channel . 25
Table 14 – Immunity to co-channel digital signals . 25
Table 15 – Requirements of delay to 0 dB echo . 25
Table 16 – Requirements of C/N thresholds to 30 µs echo . 26
Table 17 – Resistance to dynamic multipath channel . 26
Table 18 – Requirements of pulse noise interference length . 26
Table B.1 – Rayleigh channel model (static) . 39
Table B.2 – Rice channel model (static) . 40
Table B.3 – Dynamic multipath channel model . 40
Table C.1 – Frame structure. 47
Table C.2 – Data structure of a normal channel . 48
Table C.3 – Data structure of LFE channel . 48
Table C.4 – Frame header type . 49
Table C.5 – Difference between two types of frame headers . 49
Table C.6 – Number of bits used for decoding the length of audio data frame . 49
Table C.7 – Sampling frequency supported by this annex . 50
Table C.8 – Number of bits used for decoding the number of normal channels . 50
Table C.9 – Number of bits used for decoding the number of LFE channels . 51
Table C.10 – Channel configuration auxiliary information decision . 51
Table C.11 – Sum/difference coding decision . 51
– 6 – IEC 62753:2015 © IEC 2015
Table C.12 – Intensity joint coding decision . 51
Table C.13 – Window function index . 52
Table C.14 – Number of transient clusters . 53
Table C.15 – Implicit length of a transient cluster of a stationary frame . 53
Table C.16 – Starting location of the first transient cluster and the location where the
first transient occurs . 53
Table C.17 – Variables used to decode sum/difference coding decision . 54
Table C.18 – All unused sum/difference coding decision . 55
Table C.19 – Sum/difference coding decision . 55
Table C.20 – Default normal channel configuration . 56
Table C.21 –Presentation of a normal channel configuration . 56
Table C.22 – Audio data arranging the order of each channel in the audio frame . 56
Table C.23 – Arranging the order of audio data for 5.1 channel surround sound in the
audio frame . 57
Table C.24 – Subband samples arranged in a natural order . 58
Table C.25 – Subband samples arranged in interleaving order . 59
Table C.26 – Optional window function around the transient location . 63
IEC 62753:2015 © IEC 2015 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DIGITAL TERRESTRIAL TELEVISION RECEIVERS
FOR THE DTMB SYSTEM
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62753 has been prepared by technical area 1: Terminals for audio,
video and data services and contents of IEC technical committee 100: Audio, video and
multimedia systems and equipment.
The text of this standard is based on the following documents:
CDV Report on voting
100/2108/CDV 100/2429A/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
– 8 – IEC 62753:2015 © IEC 2015
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
IEC 62753:2015 © IEC 2015 – 9 –
INTRODUCTION
This International Standard contains baseline specifications and test methods of receivers for
the DTMB system. The DTMB (Digital Terrestrial/Television Multimedia Broadcasting) is the
digital television terrestrial broadcasting standard of China published in August 2006. The
main technologies adopted in this standard are: frame header design and guard interval
padding with pseudo-random noise sequences, which can be used for fast synchronization
and high-efficiency channel estimation/equalization, low-density parity-check channel coding,
spread spectrum transmission of system information. This standard can support payload data
rate ranging from 4,813 Mbit/s to 32,486 Mbit/s, standard-definition TV and high-definition TV
services, mobile and stationary receptions, multiple frequency network and single frequency
network.
• Digital television, as a new generation of TV technology, can improve the transmission
quality and make it possible to provide more services. With the worldwide transition from
the analogue TV to digital TV, the developing prospect of the DTMB system can be
expected in the future.
– 10 – IEC 62753:2015 © IEC 2015
DIGITAL TERRESTRIAL TELEVISION RECEIVERS
FOR THE DTMB SYSTEM
1 Scope
This International Standard specifies the basic functions, interfaces, performance
requirements and test methods of the receivers for the Digital Terrestrial/Television
Multimedia Broadcasting (DTMB) system. This standard can be applied to digital television
terrestrial receivers carrying multiple SDTV programs or HDTV programs for both mobile and
stationary receptions.
2 Normative references
The following documents, in whole or in part, are normatively referenced 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.
IEC 61937-12, Digital audio –Interface for non-linear PCM encoded audio bitstreams
applying IEC 60958 – Part 12: Non-linear PCM bitstreams according to the DRA formats
ISO/IEC 13818-1, Information technology – Generic coding of moving pictures and
associated audio information: Systems
ISO/IEC 13818-2, Information technology – Generic coding of moving pictures and
associated audio information: Video
ISO/IEC 13818-3, Information technology – Generic coding of moving pictures and
associated audio information –Part 3: Audio
ETSI ETR 154, Digital Video Broadcasting (DVB); Implementation guidelines for the use of
MPEG-2 Systems, Video and Audio in satellite, cable and terrestrial broadcasting applications
ETSI TS 102 366, Digital Audio Compression (AC-3, Enhanced AC-3) Standard
3 Abbreviations and symbols
For the purposes of this document, the following abbreviations apply.
AEF Acceptable Error Free
BCH Bose-Chaudhuri-Hocquenghem code
CA Conditional Access
CAT Conditional Access Table
C/N Carrier-Noise ratio
Demux Demultiplexer
DRA Dynamic Resolution Adaptation
DTMB Digital Terrestrial/Television Multimedia Broadcasting
ECM Entitlement Control Message
EIT Event Information Table
IEC 62753:2015 © IEC 2015 – 11 –
EIT p/f EIT present/following
EMM Entitlement Management Message
EPG Electronic Program Guide
ES Elementary Stream
FEC Forward Error Correction
FS Full Scale
HDTV High Definition Television
ID IDentification
LDPC Low Density Parity Check
LFE Low Frequency Enhancement
MDCT Modified Discrete Cosine Transform
MPEG Moving Pictute Experts Group
MP@HL Main Profile at High Level
MP@ML Main Profile at Main Level
MQAM M-ary Quadrature Amplitude Modulation
Mux Multiplexer
NIT Network Information Table
PAT Program Association Table
PCM Pulse Code Modulation
PCR Program Clock Reference
PES Packetized Elementary Stream
PID Packet Identifier
PMT Program Map Table
PSI Program Specific Information
PTS Presentation Time Stamp
QAM Quadrature Amplitude Modulation
QAM-NR Quadrature Amplitude Modulation – Nordstrom Robinson
RF Radio Frequency
SDT Service Description Table
SDTV Standard Definition Television
SI Service Information
STC System Time Clock
TDT Time and Date Table
TOT Time Offset Table
TS Transport Stream
TPS Transmission Parameters Signaling
UHF Ultra High Frequency
UTC Universal Time Co-ordinated
VHF Very High Frequency
Y/C Luminance/Chrominance
– 12 – IEC 62753:2015 © IEC 2015
4 Summary of DTMB transmission system
4.1 General
This part of IEC 62753 provides the overview of the DTMB transmission system, including
transmitters and receivers. Normative characteristics and requirements are provided in detail
in Clauses 5 to 8.
4.2 Processing of DTMB transmitter
The digital television terrestrial broadcasting system is used to convert the input data stream
to the output RF signal. The following baseband processing will be applied to the input data
stream sequentially:
• Scrambling
15-1
Pseudo random binary sequence of 2 bit long is used to randomize the input MPEG-2
input data before the channel coding block.
• FEC
LDPC code is used as part of the FEC. There are three different LDPC coding rates:
LDPC (7 493, 3 048), LDPC (7 493, 4 572), LDPC (7 493, 6 096). A BCH (762, 752) is
concatenated outside the LDPC.
• Constellation mapping
The output binary sequence of FEC is converted to MQAM symbol stream. DTMB supports
the following constellations: 64QAM, 32QAM, 16QAM, 4QAM, and 4QAM-NR.
• Interleaving
A convolutional interleaver is utilized across many OFDM signal frames.
• Multiplex of basic data block and system information
Each frame body consists of 36 TPS symbols and 3 744 data symbols. The total length of
FB is 3 780 symbols.
• Combine the frame body and frame header to build the signal frame
Each signal frame consists of frame header and frame body. The baseband symbol rate is
7,56 Msymbol/s. There are three different frame header lengths of 420, 595 and 945
symbols (with the relative guard interval length of 1/9, 1/6, and 1/4).
• Baseband processing
Squared root raised cosine filter with 0,05 roll-off factor is adopted to shape the baseband
signal and limit the bandwidth to 8 MHz.
After these processings, the baseband signal will be up-converted to an RF signal in UHF or
VHF band.
The diagram of DTMB transmitter processing is shown in Figure 1.
Frame header
Baseband
Data Mapping and
Up
Scrambler FEC RF
Combine post
input interleaving
Frame
converter output
M
processing
body
U
data
X
processing
System
information
IEC
Figure 1 – Diagram of DTMB transmitter processing
IEC 62753:2015 © IEC 2015 – 13 –
4.3 Processing of DTMB receiver
A digital terrestrial television receiver completes the conversion from RF input signal to audio
output and video display. First, RF input signal is demodulated to TS. The TS is demultiplexed
by demultiplexing module with SI/PSI and EPG information. Then, the elementary stream is
decoded by the audio/video decoding module. Finally, the audio and video signals are
transported to speakers and screens.
The diagram of DTMB receiver processing is shown in Figure 2.
Speaker
Speaker
Audio
ES
output
Baseband
D
decoding
Demodulating E
TS Video
RF signal
/channel M
input
decoding
U
X
SI/PSI
Format Display
EPG
Display
conversion
output
IEC
Figure 2 – Diagram of DTMB receiver processing
5 Receiver capabilities
5.1 Frequency spectrum
5.1.1 Frequency range
The receiver shall be able to receive all TV channels in the VHF and UHF bands.
5.1.2 Channel bandwidth
Channel bandwidth is 8 MHz. Effective bandwidth is 7,56 MHz.
Occupied bandwidth of each channel is 7,56 × (1 + α)=7,938 MHz (α = 0,05).
5.1.3 Frequency acquisition range
The receiver shall be able to receive RF signal with frequency offset no more than ±150 kHz.
5.2 Power supply requirements
Power supply requirements are shown in Table 1.
Table 1 – Power supply requirements
No. Item Unit Requirement
+10%,-20%
1 Power supply voltage V 220 V
2 Power supply frequency Hz 50 ± 2 %
5.3 Interface requirements
The interface requirements are shown in Table 2.
– 14 – IEC 62753:2015 © IEC 2015
Table 2 – Requirements of interface
Number Interface type Requirements
1 RF input Required
2 RF loop output Optional
Composite video signal input Optional
Y/C input Optional
Y/P /P input Optional
B R
R/G/B input Optional
Audio input/output
4 Optional
(Dual channel)
5 Condition receiving general interface Optional
6 D-sub 15 pin VGA Optional
7 Digital visual interface Optional
8 Digital audio interface Optional
5.4 Working modes
The receiver should be able to demodulate all working modes of DTMB and shall be able to
demodulate at least the 7 modes in Table 3.
Table 3 – Required working modes
Net bit rate
Time
Number Carriers FEC Constellation Frame head
interleaving
Mbit/s
1 C = 3 780 0,4 16QAM PN945 720 9,626
2 C = 1 0,8 4QAM PN595 720 10,396
3 C= 3 780 0,6 16QAM PN945 720 14,438
4 C = 1 0,8 16QAM PN595 720 20,791
5 C = 3 780 0,8 16QAM PN420 720 21,658
6 C = 3 780 0,6 64QAM PN420 720 24,365
7 C = 1 0,8 32QAM PN595 720 25,989
5.5 Program search and tuning
5.5.1 General
The receiver shall provide a procedure for program search within full channel range. It shall
be able to demodulate and decode the input signal according to parameters found in PSI/SI.
5.5.2 Receive quality display
The receiver shall be able to display the receive status and program information. The
information includes the name of business, center frequency, signal indications, etc. The
signal indications are based on signal strength or quality.
The receiver should provide a function to display parameters of the receiving program, such
as center frequency, number of carriers, FEC rate, constellation, frame head, symbol
interleaving, etc.
----------------
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...