1、 ETSI TS 102 831 V1.2.1 (2012-08) Digital Video Broadcasting (DVB); Implementation guidelines for a second generation digital terrestrial television broadcasting system (DVB-T2) Technical Specification ETSI ETSI TS 102 831 V1.2.1 (2012-08)2Reference RTS/JTC-DVB-316 Keywords broadcasting, digital, DV
2、B, modulation, TV ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice Individual copies of the pres
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6、 by written permission. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2012. European Broadcasting Union 2012. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for th
7、e benefit of its Members. 3GPPTM and LTE are Trade Marks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Association. ETSI ETSI TS 102 831 V1.2.1 (2012-08)3Contents Intellectual Property R
8、ights 10g3Foreword . 10g3Introduction 10g31 Scope 12g32 References 12g32.1 Normative references . 12g32.2 Informative references 12g33 Definitions, symbols and abbreviations . 14g33.1 Definitions 14g33.2 Symbols 15g33.3 Abbreviations . 15g34 Overview of DVB-T2 . 17g34.1 Commercial requirements overv
9、iew . 17g34.2 Background design principles 17g34.3 Benefits of DVB-T2 compared to DVB-T . 18g34.4 System overview 18g34.4.1 Introduction. 18g34.4.2 Architectural model 19g34.4.3 Specification documents describing DVB-T2 21g34.4.4 Physical-layer specification 21g34.4.5 Additional sources of assistanc
10、e for implementers . 23g34.5 Key technologies 23g34.5.1 Physical Layer Pipes (PLPs) . 23g34.5.1.1 Input Mode A 24g34.5.1.2 Input Mode B 24g34.5.2 Additional bandwidths (1,7 MHz and 10 MHz) . 24g34.5.3 Extended carrier mode (for 8 K, 16 K, 32 K) . 24g34.5.4 Alamouti-based MISO (in frequency direction
11、) . 25g34.5.5 Preambles (P1 and P2) 25g34.5.6 Pilot patterns . 26g34.5.7 256-QAM 26g34.5.8 Rotated constellations . 27g34.5.9 16 K and 32 K FFT sizes and 1/128 guard-interval fraction . 28g34.5.10 LDPC/BCH error control coding 28g34.5.11 Interleaving stages (time, bit, cell, frequency) 29g34.5.12 Pe
12、ak-to-Average Power Ratio (PAPR) reduction techniques . 29g34.5.13 Future Extension Frames (FEFs) 29g34.6 Memory and complexity considerations . 30g34.7 Layer 2 signalling . 30g34.7.1 Overview 30g34.7.2 T2 delivery-system descriptor. 31g34.8 Network Topology and Modulator Interface (T2-MI) 31g34.9 T
13、ransmitter identification . 31g35 Choice of parameters 31g35.1 Choice of FFT size . 31g35.2 Choice of extended or normal carrier mode . 32g35.3 Choice of Guard interval 33g35.4 Choice of pilot pattern 34g35.5 Choice of frame length . 36g35.6 Choice of superframe length 37g35.7 Choice of input mode (
14、A or B) . 37g35.8 Choice of number of sub-slices 38g35.8.1 Avoiding undesirable interaction of subslicing with carrier mapping and frequency interleaving . 38g3ETSI ETSI TS 102 831 V1.2.1 (2012-08)45.8.2 Subslicing with multi-frame interleaving . 39g35.9 Choice of time interleaving parameters 39g35.
15、9.1 Trade-off between Time Diversity and Data Rate 40g35.9.2 Trade-off between Time Diversity and Latency . 41g35.9.3 Trade-off between Time Diversity and Power Saving 41g35.10 Choice of rotated constellations . 42g35.11 Choice of code rate, block length and constellation . 44g35.12 Choice of mode a
16、daptation options 44g36 Anatomy of the DVB-T2 signal . 44g36.1 Physical frame structure . 45g36.1.1 Superframe 45g36.1.2 T2-frame . 45g36.1.2.1 Frame-Closing Symbols 48g36.1.3 L1 signalling . 49g36.1.4 Physical-layer pipes 50g36.1.5 Dummy cells . 52g36.1.6 Auxiliary streams 53g36.1.7 FEFs 53g36.1.7.
17、1 FEF Basics 53g36.1.7.2 FEF Signalling 54g36.1.7.3 Possible use cases 55g36.2 Logical frame structure 56g36.2.1 Packets 56g36.2.2 BBFRAMEs, FECFrames and FEC blocks 56g36.2.2.1 BBFRAMEs. . 56g36.2.2.2 FECFRAMES . 56g36.2.2.3 FEC Blocks . 56g36.2.3 Interleaving Frames 56g36.2.4 TI blocks . 57g36.2.5
18、 Mapping to physical frame structure 57g36.2.6 The concept of a T2-system 58g36.3 Capacity 59g36.3.1 Capacity in cells and FEC blocks per frame . 59g36.3.2 Total bit-rates of the T2 system 61g36.3.3 Examples of bit-rates 62g36.4 Overview of interleaving 63g37 Modulator Interface (T2-MI) and network
19、topology 64g37.1 Overview 64g37.2 Statistical multiplexing and service splitting 64g37.3 The T2 gateway and T2-Modulator Interface (T2-MI) 65g37.3.1 The Basic T2-Gateway . 65g37.3.2 Practical T2-Gateways 65g37.4 Distribution of T2-MI packets to transmitters 65g37.5 Over-air distribution . 66g37.6 Re
20、gional/local content insertion . 66g37.7 Networks carrying composite T2-base/T2-lite signals . 67g38 T2-gateway . 67g38.1 Input interface 67g38.2 Generation of one Transport Stream per data PLP . 68g38.2.1 Separate TSs with common control 68g38.2.2 From one big TS . 69g38.2.3 Discussion . 69g38.3 Us
21、e of common PLPs . 69g38.4 PLP grouping and statistical multiplexing 72g38.4.1 PLP groups with the same modulation and coding . 72g38.4.2 T2-aware statistical multiplexing 72g38.5 Mode adaptation . 72g38.6 Scheduling 73g38.6.1 Model for allocating number of FEC blocks to each Interleaving Frame . 74
22、g38.6.1.1 Mode A . 74g3ETSI ETSI TS 102 831 V1.2.1 (2012-08)58.6.1.2 Mode B 74g38.6.1.2.1 Allocation model 1 74g38.6.1.2.2 Allocation model 2 78g38.6.1.2.3 Other allocation strategies . 78g38.6.1.2.4 Use of the allocation models with FEFs 79g38.6.1.2.5 Timing and alignment of collection windows . 79
23、g38.6.2 Scheduling of sub-slices . 80g38.7 Padding methods 80g38.8 Managing the de-jitter buffer 81g38.8.1 The receiver-buffer model 82g38.8.2 Principles of buffer management 83g38.8.3 Choice of design delay 84g38.8.3.1 Single PLP modes with multiple TI-blocks per Interleaving Frame . 84g38.8.3.2 Ty
24、pe 2 PLPs in multiple PLP modes 86g38.8.3.3 Common PLPs in multiple PLP modes . 86g38.8.3.4 Other cases 86g38.8.4 The de-jitter buffer budget 86g38.8.4.1 Multiple PLP cases with variable bit-rate . 86g38.8.4.2 Constant bit-rate 88g38.8.5 Receiver Buffer Management in T2-Lite 89g38.8.6 Other paramete
25、r checks required 89g38.8.6.1 Avoiding TDI overflow during P2 90g38.8.6.2 Avoiding TDI overflow during the first TI-block . 90g38.8.6.3 Avoiding DJB underflow / TDI overflow during common PLP decoding 91g38.8.7 Further guidance in Receiver Buffer Management . 91g38.9 Compensating Delay 91g38.10 Laye
26、r-1 signalling. 92g38.10.1 Overview 92g38.10.2 Repetition of L1-dynamic signalling 93g38.10.3 L1 change-indication mechanism . 94g38.10.4 Use of the L1 extension field 94g38.10.5 Example of L1 signalling 94g38.10.6 In-band L1-dynamic signalling . 97g38.10.6.1 Generation of the in-band type A signall
27、ing message . 97g38.10.6.2 Insertion of L1-dynamic information of other PLPs . 98g38.10.6.3 Which frame is signalled for same PLP and other PLPs . 98g38.10.6.4 Example of in-band signalling 100g38.10.6.5 In-band type B signalling 100g38.11 Layer-2 signalling. 101g38.11.1 Transport Streams . 101g38.1
28、1.2 Generic Streams. . 103g38.12 Generation of the T2-MI stream . 103g38.13 Generation of the T2-MIP 103g38.14 L1 Bias Balancing 104g38.14.1 L1 Bias balancing Techniques 105g38.14.1.1 P2 Tone Reservation . 105g38.14.1.2 L1 reserved bits and extension field 105g38.14.1.3 Bias balancing cells . 105g38
29、.14.1.4 L1-ACE . 105g38.14.2 Approach to bias balancing . 106g39 Modulators . 109g39.1 Operation with T2-MI input stream . 110g39.1.1 Overview 110g39.1.2 Buffering and timing relationships . 110g39.1.3 Generation of L1-signalling from T2-MI packets . 112g39.1.4 Generation of the PLP data from the T2
30、-MI input 113g39.1.5 Start-up behaviour 113g39.1.6 Modulator synchronisation . 114g39.1.6.1 Single-Frequency Network operation . 114g39.1.6.2 Modulator test modes for SFN operation 114g39.1.6.3 Testing SFN synchronisation using a spectrum analyser 116g3ETSI ETSI TS 102 831 V1.2.1 (2012-08)69.1.6.4 M
31、ultiple-frequency network operation 119g39.1.6.5 Operation with a composite signal with multiple profiles . 119g39.2 Bit-interleaved coding and modulation 119g39.2.1 FEC for the PLPs 119g39.2.1.1 FEC overview . 119g39.2.1.2 BCH code 120g39.2.1.3 LDPC code with multi-level constellations . 120g39.2.1
32、.3.1 LDPC code 120g39.2.1.3.2 Bit Interleaver and demux . 121g39.2.1.3.3 Constellation Mapping 123g39.2.2 FEC for the L1 signalling . 123g39.2.2.1 Shortening of BCH Information part 124g39.2.2.2 Example for shortening of BCH information 125g39.2.2.3 BCH encoding . 127g39.2.2.4 LDPC encoding . 127g39
33、.2.2.5 Puncturing of LDPC parity bits . 127g39.2.2.6 Example for Puncturing of LDPC parity bits 128g39.2.2.7 Removal of zero-padding bits . 130g39.2.2.8 Bit Interleaving and constellation mapping after shortening and puncturing 130g39.2.3 Rotated constellations . 131g39.2.4 Cell Interleaver . 133g39
34、.2.5 Time Interleaving 133g39.3 Frame-building and OFDM generation 134g39.3.1 Frame building 134g39.3.2 Frequency Interleaving . 134g39.3.3 MISO processing 136g39.3.4 Pilot insertion 137g39.3.4.1 Purpose of pilot insertion 137g39.3.4.2 Pilot locations 137g39.3.4.3 Number of pilot cells of each type
35、138g39.3.4.3.1 Pilots in normal symbols . 138g39.3.4.3.2 Pilots in P2 symbols 139g39.3.4.3.3 Pilots in Frame-Closing Symbols 140g39.3.4.4 Pilot boosting 140g39.3.4.5 MISO pilots . 141g39.3.4.5.1 Inversion of pilots 141g39.3.4.5.2 Additional P2 pilots . 141g39.3.4.6 Use of the reference sequence in n
36、ormal and extended carrier modes 141g39.3.5 Dummy carrier reservation . 142g39.3.6 Inverse Fast Fourier Transform (IFFT) . 142g39.3.7 P1 generation 143g39.3.8 PAPR reduction 143g39.3.8.1 Overview and comparison of the two techniques 143g39.3.8.2 ACE. 143g39.3.8.3 Tone Reservation 144g39.3.8.3.1 Rese
37、rved carriers and kernel 145g39.3.8.3.2 Peak-cancellation algorithm 146g39.3.8.3.3 Selection of the clipping level . 147g39.3.8.3.4 Selection of the number of iterations . 148g39.3.8.3.5 Further TR examples . 149g39.3.8.3.6 SFN issues . 151g310 Receivers 151g310.1 Overview 151g310.1.1 Receiver Model
38、 . 152g310.1.2 Acquisition scenarios 153g310.1.2.1 Initial scan. 153g310.1.2.2 Service-selection and reproduction . 154g310.1.2.3 Hand-over (portable and mobile cases) . 154g310.1.2.3.1 Automatic service following . 155g310.1.2.3.2 Announcements . 156g310.2 Acquisition and synchronisation 156g3ETSI
39、ETSI TS 102 831 V1.2.1 (2012-08)710.2.1 Overview of synchronisation 156g310.2.2 Use of P1 157g310.2.2.1 Introduction . 157g310.2.2.2 Structure of P1 157g310.2.2.3 P1 features . 158g310.2.2.4 Overview of the use of P1 during channel scanning . 158g310.2.2.5 P1 detection . 160g310.2.2.5.1 Summary . 16
40、0g310.2.2.5.2 Goals 160g310.2.2.5.3 Implementation 161g310.2.2.6 P1 validation . 162g310.2.2.6.1 Summary . 162g310.2.2.6.2 Goals 162g310.2.2.6.3 Implementation issues (coarse frequency correction) 163g310.2.2.7 Decoding the P1 signalling . 163g310.2.2.7.1 Summary . 163g310.2.2.7.2 Goals 163g310.2.2.
41、7.3 Implementation 163g310.2.2.8 Interpretation of P1 signalling fields . 164g310.2.2.9 The FEF loop 164g310.2.3 Determining the Guard Interval 164g310.2.3.1 Determining the Guard Interval using P2 165g310.2.3.2 Use of Guard Interval Correlation to determine the Guard Interval 165g310.2.3.3 Use of t
42、he Guard-Interval hinting information from P1 165g310.2.4 Time and Frequency synchronisation . 166g310.2.5 Use of Frame/Symbol level sequences for synchronisation 166g310.2.5.1 Introduction . 166g310.2.5.2 Definition of the reference sequence . 166g310.2.5.3 Synchronisation algorithm 168g310.2.5.4 F
43、ull synchronisation method . 168g310.2.5.5 Evaluation of Synchronisation features . 169g310.2.6 Use of P2 169g310.2.6.1 Initial Scan 169g310.2.6.1.1 Reception of P2 symbols during initial scan . 170g310.2.6.1.2 TX Basic parameters verification 170g310.2.6.1.3 Determining position in the super-frame
44、. 171g310.2.6.2 Channel-zapping . 171g310.2.6.2.1 Assumptions 171g310.2.6.2.2 Requirements for zapping between two channels 171g310.2.7 Receiver Synchronisation/Zapping time . 172g310.2.7.1 Initial scan time . 172g310.2.7.2 Zapping time . 172g310.3 OFDM Demodulation . 173g310.3.1 FFT . 173g310.3.2 C
45、hannel equalisation . 173g310.3.2.1 Common Phase-Error correction . 173g310.3.2.2 Locating the CPs . 174g310.3.2.3 SISO channel estimation . 175g310.3.2.3.1 Overview . 175g310.3.2.3.2 Fundamental limits 177g310.3.2.3.3 Interpolation 177g310.3.2.3.4 P2 symbols 181g310.3.2.3.5 Other special cases 181g
46、310.3.2.3.6 Further observations 183g310.3.2.4 MISO channel estimation 183g310.3.3 MISO decoding . 184g310.3.3.1 ZF and MMSE Alamouti matrix inversion . 185g310.3.3.2 Separation of Alamouti pairs by pilot cells . 185g310.4 De-interleaving and de-mapping 186g310.4.1 Frequency/L1 de-interleaver . 186g
47、310.4.1.1 Implementation of L1/Frequency de-interleaver 32 K 186g310.4.1.2 Implementation of the basic frequency de-interleaver in 1 K-16 K 188g3ETSI ETSI TS 102 831 V1.2.1 (2012-08)810.4.1.3 Implementation of the L1/ Frequency De-interleaver in 1 K-16 K . 189g310.4.2 Frame extraction . 190g310.4.2.
48、1 Extraction of the PLPs 190g310.4.2.2 Extraction of the L1 signalling cells . 190g310.4.2.3 Timing of L1 and PLP extraction and decoding in the P2 symbols 190g310.4.2.4 Use of in-band dynamic signalling 192g310.4.2.4.1 Interleaving over one T2 frame or less 192g310.4.2.4.2 In-band signalling when i
49、nterleaving over multiple T2 frames . 192g310.4.2.4.3 In-band signalling for PLPs not present in every T2-frame. 192g310.4.2.4.4 Reading the P2 symbols on reconfiguration 192g310.4.2.4.5 PLPs with zero FEC blocks in a given Interleaving Frame . 193g310.4.2.5 Power saving . 193g310.4.2.6 FEFs 193g310.4.2.7 Auxiliary streams 194g310.4.3 Time de-interleaver . 194g310.4.3.1 Phase of Time de-interleaving. 194g310.4.3.2 Memory-efficient implementation of time de-interleaver . 194g310.4.3.2.1 De-interleaver for constant bit-rate 194g310.4.3.2.2 Implementation details 197g310.4.3.2.3
