ATSC A/327:2018
`
`Guidelines for the Physical Layer Protocol
`
`2 October 2018
`
`
`
`
`
`
`ATSC Recommended Practice:
`Guidelines for the Physical Layer Protocol
`(A/327)
`
`Doc. A/327:2018
`2 October 2018
`
`Advanced Television Systems Committee
`1776 K Street, N.W.
`Washington, D.C. 20006
`202-872-9160
`
`
`
`i
`
`1
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`LGE 1022
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`

`

`ATSC A/327:2018
`
`Guidelines for the Physical Layer Protocol
`
`2 October 2018
`
`The Advanced Television Systems Committee, Inc., is an international, non-profit organization
`developing voluntary standards and recommended practices for digital television. ATSC member
`organizations represent the broadcast, broadcast equipment, motion picture, consumer electronics,
`computer, cable, satellite, and semiconductor industries. ATSC also develops digital television
`implementation strategies and supports educational activities on ATSC standards. ATSC was
`formed in 1983 by the member organizations of the Joint Committee on Inter-society Coordination
`(JCIC): the Electronic Industries Association (EIA), the Institute of Electrical and Electronic
`Engineers (IEEE), the National Association of Broadcasters (NAB), the National Cable
`Telecommunications Association (NCTA), and the Society of Motion Picture and Television
`Engineers (SMPTE). For more information visit www.atsc.org.
`
`Note: The user's attention is called to the possibility that compliance with this standard may
`require use of an invention covered by patent rights. By publication of this standard, no position
`is taken with respect to the validity of this claim or of any patent rights in connection therewith.
`One or more patent holders have, however, filed a statement regarding the terms on which such
`patent holder(s) may be willing to grant a license under these rights to individuals or entities
`desiring to obtain such a license. Details may be obtained from the ATSC Secretary and the patent
`holder.
`
`Implementers with feedback, comments, or potential bug reports relating to this document may
`contact ATSC at https://www.atsc.org/feedback/.
`
`Version
`Recommended Practice approved
`
`
`
`Revision History
`
`Date
`2 October 2018
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`ATSC A/327:2018
`
`Guidelines for the Physical Layer Protocol
`
`2 October 2018
`
`Table of Contents
`1. SCOPE ..................................................................................................................................................... 1
`1.1
`1
`Introduction and Background
`1.2
`1
`Organization
`2. REFERENCES ......................................................................................................................................... 1
`3. DEFINITION OF TERMS .......................................................................................................................... 2
`3.1
`2
`Compliance Notation
`3.2
`2
`Acronyms and Abbreviations
`3.3
`5
`Terms
`4. SYSTEM OVERVIEW AND GUIDELINES FOR PHYSICAL LAYER MODE ........................................... 6
`4.1
`6
`System Overview
`4.2
`8
`Guidelines for Physical Layer Mode
`4.2.1
`8
`FFT Size
`4.2.2
`8
`Bandwidth and Bandwidth Reduction
`4.2.3
`9
`Pilot Pattern
`4.2.3.1
`9
`Separation of Pilot Carriers (Dx)
`4.2.3.2
`10
`Length of Pattern in Symbols (Dy)
`4.2.4
`10
`Pilot Boosting
`4.2.5
`12
`Frame and Subframe Length
`4.2.5.1
`12
`Frame Length
`4.2.5.2
`13
`Number of Preamble Symbols
`4.2.5.3
`13
`Subframe Configuration
`4.2.6
`14
`Symbol-Aligned or Time-Aligned Mode
`4.2.7
`15
`PLP Multiplexing
`4.2.7.1
`15
`PLP Cell Multiplexing
`4.2.7.2
`16
`Layered Division Multiplexing
`4.2.8
`16
`LDM Parameters
`4.2.8.1
`16
`LDM Injection Level
`4.2.8.2
`18
`LDM ModCod Combination
`4.2.9
`18
`Code Rate, Length and Constellation
`4.2.10
`20
`L1 Protection Mode
`4.2.11
`21
`Time Interleaver Mode
`4.2.11.1
`21
`Valid Conditions for CTI Mode
`4.2.11.2
`22
`Valid Conditions for HTI and No TI Mode
`4.2.11.3
`23
`Extended Time Interleaving
`4.2.12
`24
`Guard Interval
`4.2.13
`25
`Frequency Interleaver Mode
`4.2.14
`25
`Time Information Type
`4.2.15
`26
`Multiple Subframes within a Frame
`4.2.16
`26
`L1D_plp_fec_type
`4.2.17
`27
`Transmitter Identification (TxID)
`5. GUIDELINES FOR TRANSMITTER IMPLEMENTATION ...................................................................... 28
`5.1
`28
`Input Formatting
`5.1.1
`28
`Delivered Product in Multiple PLPs
`29
`Bit Interleaved and Coded Modulation (BICM)
`5.2.1
`29
`Forward Error Correction (FEC)
`
`5.2
`
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`Guidelines for the Physical Layer Protocol
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`2 October 2018
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`5.3
`
`30
`31
`32
`32
`34
`34
`35
`35
`36
`36
`36
`36
`37
`37
`38
`41
`41
`42
`
`5.2.1.1
`Inner Encoding
`5.2.2
`Bit Interleaving
`5.2.3
`Constellation Mapping
`5.2.4
`Layered Division Multiplexing (LDM)
`5.2.5
`Protection for L1-Signaling
`5.2.5.1
`Common Block for L1-Basic and L1-Detail
`5.2.5.2
`L1-Detail Specific Block: L1 Segmentation
`5.2.5.3
`L1-Detail Specific Block: Additional Parity
`Framing and Interleaving
`5.3.1
`Time Interleaving
`5.3.1.1
`Convolutional Time Interleaving (CTI)
`5.3.1.2
`Hybrid Time Interleaving (HTI)
`5.3.2
`Frame Structure
`5.3.2.1
`Example Scenario for Power Saving Aspect
`5.3.2.2
`Example Scenario for Performance Aspect
`5.3.3
`LDM and PLP Multiplexing
`5.3.3.1
`Definition of L1D_plp_start and L1D_plp_size
`5.3.3.2
`Indexing TI Groups
`5.3.3.3
`Injection Level (L1D_plp_ldm_injection_level) for Multiple
`43
`Enhanced PLPs
`44
`5.3.3.4
`Positioning Enhanced PLP(s) and Not Recommended LDM Cases
`45
`5.3.3.5
`LDM Configuration with Different TI Modes
`48
`5.3.3.6
`Combination with FDM
`50
`5.3.4
`Frequency Interleaving
`51
`Waveform Generation
`51
`5.4.1
`Pilot Insertion
`51
`5.4.1.1
`Scattered Pilot Insertion
`52
`5.4.1.2
`Continual Pilot Insertion
`52
`5.4.1.3
`Edge Pilot Insertion
`52
`5.4.1.4
`Preamble Pilot Insertion
`52
`5.4.1.5
`Subframe Boundary Pilot Insertion
`52
`5.4.2
`52
`5.4.2.1
`Signal Model
`53
`5.4.3
`Inverse Fast Fourier Transform (IFFT)
`53
`5.4.4
`Guard Interval
`54
`5.4.5
`Bootstrap
`55
`Channel Bonding
`55
`5.5.1
`Memory Considerations
`56
`5.5.2
`Channel Bonding Examples
`6. GUIDELINES FOR RECEIVER IMPLEMENTATION ............................................................................. 57
`6.1
`57
`Signal Discovery and Synchronization
`6.1.1
`57
`Use of Bootstrap for Signal Acquisition and Synchronization
`6.1.1.1
`57
`Signal Acquisition and Timing Synchronization
`6.1.1.2
`59
`Fractional Frequency Offset (FFO) Estimation
`6.1.1.3
`60
`Integer Frequency Offset (IFO) Estimation and Validation
`6.1.2
`60
`Signaling Detection of Bootstrap Symbols
`6.1.2.1
`60
`Time Domain Cyclic Shift Detection
`6.1.2.2
`62
`Gray De-Mapping
`
`5.4
`
`5.5
`
`MISO
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`Guidelines for the Physical Layer Protocol
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`2 October 2018
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`6.2
`
`6.3
`
`6.4
`
`6.5
`
`62
`Waveform Demodulation
`62
`6.2.1
`Channel Estimation and Equalization
`63
`6.2.1.1
`Channel Estimation for Mobile Reception
`64
`6.2.1.2
`Channel Estimation for Fixed Reception
`64
`6.2.2
`Removal of Peak to Average Power Ratio Reduction Techniques
`64
`De-Framing and De-Interleaving
`64
`6.3.1
`Frequency De-Interleaving
`65
`6.3.1.1
`Frequency De-Interleaving for 8K/16K FFT Size
`65
`6.3.1.2
`Frequency De-Interleaving for 32K FFT Size
`65
`6.3.2
`Time De-Interleaving
`65
`6.3.2.1
`Extended Time De-Interleaving
`66
`6.3.2.2
`Hybrid Time De-Interleaving
`70
`LDM Decoding
`71
`6.4.1
`Decoding Process of Core and Enhanced Layers
`71
`6.4.2
`Core PLP Decoding
`72
`6.4.3
`Core PLP Cancellation and Enhanced PLP Decoding
`73
`Channel Decoding
`74
`6.5.1
`LLR De-Mapping for Non-Uniform Constellations
`74
`6.5.1.1
`De-Mapping for 1D-NUC
`76
`6.5.1.2
`De-Mapping for 2D-NUC
`78
`6.5.2
`Bit De-Interleaving
`79
`6.5.3
`Inner and Outer Decoding
`82
`6.5.4
`Decoding of L1 Signaling
`7. GUIDELINES FOR MOBILE SERVICES................................................................................................ 83
`7.1
`83
`Input Formatting
`7.2
`83
`Bit Interleaved Coding and Modulation (BICM)
`7.2.1
`83
`BICM for Data Payload
`7.2.2
`84
`Protection for L1-Signaling
`84
`Framing and Interleaving
`7.3.1
`84
`Time Interleaving
`7.3.1.1
`84
`Time Interleaver Modes
`7.3.1.2
`84
`Time Interleaver Size
`7.3.2
`84
`Framing
`7.3.2.1
`84
`Frame Length
`7.3.2.2
`84
`PLP Multiplexing
`7.3.3
`85
`Frequency Interleaving
`85
`Waveform Generation
`7.4.1
`85
`Pilot Insertion
`7.4.2
`85
`Inverse Fast Fourier Transform (IFFT)
`7.4.3
`85
`Guard Interval
` : SYSTEM PERFORMANCE ........................................................................................................ 87
`87
`Introduction
`87
`Channel Models
`87
`Simulation, Laboratory Test and Field Test Results
` : ATSC 3.0 RECEIVER C/N MODEL ............................................................................................ 92
`92
`Introduction
`
`7.3
`
`7.4
`
`A.1
`A.2
`A.3
`
`B.1
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`ATSC A/327:2018
`
`Guidelines for the Physical Layer Protocol
`
`2 October 2018
`
`Calculation of Boosted Pilot Correction Factor
`Estimation of Channel Estimation Loss
`
`Method
`B.2.1
`B.2.2
`B.2.3
`Example C/N calculation
`
`Estimation of Average Value of 𝒇𝒇𝒇𝒇𝒇𝒇𝒇𝒇
`Example Calculated values of 𝚫𝚫𝑩𝑩𝑩𝑩
`Calculated values of 𝚫𝚫𝑹𝑹𝑹𝑹𝑹𝑹
`
`B.2
`
`B.3
`B.4
`B.5
`B.6
`
`92
`93
`93
`94
`95
`96
`97
`98
`Expected receiver AWGN C/N based on Calculation Model
` : ATSC 3.0 SERVICE EXAMPLES ............................................................................................. 114
`114
`C.1
`Single PLP Service
`C.2 Multiple PLP Subframe Service
`115
`C.3 Multiple PLP TDM Service
`116
`C.4 Multiple PLP LDM Service
`117
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`ATSC A/327:2018
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`Guidelines for the Physical Layer Protocol
`
`2 October 2018
`
`Index of Figures
`Figure 4.1 High level ATSC 3.0 physical layer protocol diagram enabling an example of
`multiple-PLP architecture.
`
`Figure 4.2 Equalized SNR performance for 𝑫𝑫𝑫𝑫= 𝟐𝟐 (left) and 𝑫𝑫𝑫𝑫= 𝟒𝟒 (right) with
`
`7
`
`12
`linear frequency interpolation (top) and DFT frequency interpolation (bottom).
`Figure 4.3 Injection level control of Enhanced PLP(s).
`17
`Figure 5.1 Format of FEC frame when BCH/CRC is used (top) or not (bottom).
`30
`Figure 5.2 PCM structure of (a) Type A LDPC and (b) Type B LDPC.
`31
`Figure 5.3 Bit interleaver structure: Parity, group-wise and block interleavers.
`31
`Figure 5.4 A two-layer LDM transmitter configuration.
`33
`Figure 5.5 Grouping of FFT sizes: (a) Not recommended, random order, (b) Recommended,
`in 8K, 16K and 32K order.
`38
`Figure 5.6 Example at subframe boundary from SP3_2 to SP6_4.
`38
`Figure 5.7 Example at subframe boundary from SP3_2 to SP4_4.
`39
`Figure 5.8 Example at subframe boundary from SP12_2 to SP6_4.
`39
`Figure 5.9 Example showing channel at a receiver before interpolation with scattered pilots
`Dx = 6 and Dy = 4.
`Figure 5.10 Example at a receiver showing that after time and frequency interpolation the
`channel can be well estimated up to Tu/6.
`Figure 5.11 Example at a receiver with Dx = 12 and Dy = 4 showing that the receiver
`cannot estimate the channel well in this case, since the variation is greater than Tu/12
`40
`which is the maximum that can be interpolated.
`Figure 5.12 Example at subframe boundary from SP16_2 to SP6_4.
`41
`Figure 5.13 L1D_plp_start and L1D_plp_size definitions for Core and Enhanced PLPs.
`42
`Figure 5.14 TI Group assignment for multiple Core PLPs.
`43
`Figure 5.15 Two Enhanced PLPs injected into a single Core PLP.
`43
`Figure 5.16 Not recommended LDM configuration example #1.
`44
`Figure 5.17 Not recommended LDM configuration example #2.
`45
`Figure 5.18 Allowed LDM configuration example #1 using the CTI mode.
`46
`Figure 5.19 Allowed LDM configuration example #2 using the CTI mode.
`46
`Figure 5.20 Allowed LDM configuration example using the HTI mode.
`47
`Figure 5.21 Recommended use of TI Blocks for HTI-based LTDM or LFDM configurations. 48
`Figure 5.22 FLDM configuration example.
`49
`Figure 5.23 LFDM configuration example.
`50
`Figure 5.24 Scattered pilot pattern SP12_2 (Dx = 12, Dy = 2).
`51
`Figure 5.25 1-PLP 2-Channel Bonding example transmitter architecture.
`56
`Figure 5.26 1-PLP 2-Channel Bonding example receiver architecture.
`56
`Figure 5.27 4-PLP channel bonding example transmitter architecture.
`57
`Figure 5.28 4-PLP channel bonding example receiver architecture.
`57
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`ATSC A/327:2018
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`Guidelines for the Physical Layer Protocol
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`2 October 2018
`
`58
`66
`
`68
`
`Figure 6.1 Delayed correlation diagram.
`Figure 6.2 Memory reconfiguration to support the extended de-interleaving.
`Figure 6.3 Example of input TI Block and output TI Block in a TBI operation: (a) The 0-th
`TI Block, (b) The 1-st TI Block.
`Figure 6.4 Example of input TI Block and output TI Block in TBDI operation: (a) Memory
`data cells for the 0-th TI Block, (b) Address generation for reading the 0-th input TI
`Block, (c) Memory data cells for the 1-st TI Block, (d) Address generation for reading the
`1-st input TI Block.
`69
`Figure 6.5 Example of time interleaving/de-interleaving with virtual FEC Blocks: (a) Output
`data cells after TBI operation, (b) Memory data cells after writing into TBDI memory.
`70
`Figure 6.6 LDM decoding block diagram.
`71
`Figure 6.7 LDM FEC Block decoding process of Core and Enhanced Layers.
`71
`Figure 6.8 CL signal re-generation: (1) Whole codeword, (2) Information + outer code parity,
`and (3) Information-only cases.
`73
`Figure 6.9 De-mapper structure for 1D-NUC.
`74
`Figure 6.10 De-mapper structure for 2D-NUC.
`76
`Figure 6.11 De-interleaving process of Type A block de-interleaver.
`78
`Figure 6.12 LDPC code performance based on various decoding algorithms (Code rate =
`10/15, Code length = 64800, AWGN channel).
`
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`ATSC A/327:2018
`
`Guidelines for the Physical Layer Protocol
`
`2 October 2018
`
`Index of Tables
`Table 4.1 Scattered Pilot Pattern Overheads
`10
`Table 4.2 Maximum Recommended Number of Preamble Symbols for Different FFT Sizes 13
`Table 4.3 Required SNRs (dB) for all ModCod Combinations, Long LDPC codes (64800
`bits) and AWGN Channel
`Table 4.4 Required SNRs (dB) for all ModCod Combinations, Long LDPC Codes (64800
`bits) and i.i.d. Rayleigh Channel
`Table 4.5 Required SNRs (dB) for all ModCod Combinations, Short LDPC Codes (16200
`bits) and AWGN Channel
`Table 4.6 Required SNRs (dB) for all ModCod Combinations, Short LDPC Codes (16200
`bits) and i.i.d. Rayleigh Channel
`Table 4.7 Mandatory ModCod Combinations for Long Codes (64800 bits)
`Table 4.8 Mandatory ModCod Combinations for Short Codes (16200 bits)
`Table 4.9 Definition of L1 Protection Modes
`Table 4.10 Performance of L1-Basic and L1-Detail Modes Under AWGN and Rayleigh
`Channels (FER=10-4)
`Table 4.11 Required SNRs of the Preamble when TxID is Injected (AWGN Channel)
`Table 5.1 Types of Pilots in Each Type of Symbol
`Table 5.2 Allowed Combinations of GI and FFT Sizes
`Table 5.3 Statistical Multiplexing Gains
`Table 5.4 Example Parameters and Bit Rate for 1-PLP Channel Bonding
`Table 6.1 Optimized Offset and Scaling Values
`Table 6.2 Performance Difference from the Shannon Capacity Limit to the Theoretical
`Thresholds and Simulation Results (Short Code Cases)
`Table 6.3 Performance Difference from the Shannon Capacity Limit to the Theoretical
`Thresholds and Simulation Results (Long Code Cases)
`Table 7.1 Recommended ModCod Combinations for ATSC 3.0 Mobile Services (Ninner =
`16200 bits, i.e., Short Codes)
`Table 7.2 Recommended Scattered Pilot Patterns for ATSC 3.0 Mobile Services
`Table 7.3 Recommended Guard Intervals for ATSC 3.0 Mobile Services
`Table A.3.1 System Parameters for Simulations, Laboratory Tests, and Field Tests
`Table A.3.2 Required C/N for BER = 10-6 After LDPC and BCH Decoding Under
`AWGN Channel
`Table A.3.3 Required C/N for BER = 10-6 After LDPC and BCH Decoding Under Rician
`Channel
`Table A.3.4 Required C/N for BER = 10-6 After LDPC and BCH Decoding Under
`Rayleigh Channel
`
`18
`
`18
`
`19
`
`19
`19
`19
`20
`
`21
`27
`51
`54
`55
`56
`80
`
`80
`
`81
`
`84
`85
`86
`88
`
`89
`
`90
`
`91
`96
`97
`99
`
`Table B.4.1 Calculated Values of Δ𝐵𝐵𝐵𝐵
`Table B.5.1 Calculated Values of Δ𝑅𝑅𝑅𝑅𝑅𝑅
`
`Table B.6.1 Gaussian Channel 8K FFT, QPSK Expected C/N Values
`
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`ATSC A/327:2018
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`Guidelines for the Physical Layer Protocol
`
`2 October 2018
`
`Table B.6.2 Gaussian Channel 8K FFT, 16QAM Expected C/N Values
`100
`Table B.6.3 Gaussian Channel 8K FFT, 64QAM Expected C/N Values
`101
`Table B.6.4 Gaussian Channel 8K FFT, 256QAM Expected C/N Values
`102
`Table B.6.5 Gaussian Channel 8K FFT, 1024 and 4096QAM Expected C/N Values
`103
`Table B.6.6 Gaussian Channel 16K FFT, QPSK Expected C/N Values
`104
`Table B.6.7 Gaussian Channel 16K FFT, 16QAM Expected C/N Values
`105
`Table B.6.8 Gaussian Channel 16K FFT, 64QAM Expected C/N Values
`106
`Table B.6.9 Gaussian Channel 16K FFT, 256QAM Expected C/N Values
`107
`Table B.6.10 Gaussian Channel 16K FFT, 1024QAM and 4096QAM Expected C/N Values 108
`Table B.6.11 Gaussian Channel 32K FFT, QPSK Expected C/N Values
`109
`Table B.6.12 Gaussian Channel 32K FFT, 16QAM Expected C/N Values
`110
`Table B.6.13 Gaussian Channel 32K FFT, 64QAM Expected C/N Values
`111
`Table B.6.14 Gaussian Channel 32K FFT, 256QAM Expected C/N Values
`112
`Table B.6.15 Gaussian Channel 32K FFT, 1024QAM and 4096QAM Expected C/N Values 113
`Table C.1.1 Example of Physical Layer Parameters for Single-PLP Service
`114
`Table C.2.1 Example of Physical Layer Parameters for 2-Subframe Service
`115
`Table C.3.1 Example of Physical Layer Parameters for 2-PLP TDM Service
`116
`Table C.4.1 Example of Physical Layer Parameters for 2-PLP LDM Service
`117
`
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`ATSC A/327:2018
`
`Guidelines for the Physical Layer Protocol
`
`2 October 2018
`
`ATSC Recommended Practice:
`Guidelines for the Physical Layer Protocol
`
`1. SCOPE
`This document provides recommended practices for the ATSC 3.0 physical layer protocol
`standards specified by A/321 [2] and A/322 [3]. The intent of this document is to make
`recommendations for physical layer operating modes so that readers can make informed decisions
`about physical layer configurations. Also, this document provides some implementation guidelines
`to aid with flexible configurations of physical layer design resources in transmitter and receiver
`manufacturers’ equipment.
`
`1.1 Introduction and Background
`The ATSC 3.0 physical layer protocol is designed to provide a toolbox of technology that allows
`flexible operating modes for a variety of harsh channel conditions (e.g., indoor or mobile) while
`maintaining efficient use of spectrum resources. This document provides recommended parameter
`and technology choices in A/321 [2] and A/322 [3] so that broadcasters can optimally deliver
`intended service(s). It also contains detailed guidelines for transmitter and receiver design
`implementations based on engineering studies of the latest technologies in the ATSC 3.0 physical
`layer. Guidelines for broadcasters’ mobile service(s) are provided with operating modes and
`parameter choices of A/322 [3] in aspects of robustness and power consumption. The ATSC 3.0
`system performance and recommended service examples cover aspects of real field experiences
`and are intended to provide practical guidance for all readers.
`
`1.2 Organization
`This document is organized as follows:
`• Section 1 – The scope of this document and general introduction
`• Section 2 – References and applicable documents
`• Section 3 – Definition of terms, acronyms, and abbreviations used
`• Section 4 – System overview and guidelines for physical layer parameter choices
`• Section 5 – Guidelines in detail for transmitter implementation
`• Section 6 – Guidelines in detail for receiver implementation
`• Section 7 – Guidelines for mobile services
`• Annex A – ATSC 3.0 system performance: Simulation, laboratory and field test results
`• Annex B – ATSC 3.0 receiver C/N models
`• Annex C – ATSC 3.0 service examples
`
`2. REFERENCES
`All referenced documents are subject to revision. Users of this Recommended Practice are
`cautioned that newer editions might or might not be compatible.
`The following documents, in whole or in part, as referenced in this document, contain specific
`provisions that should be followed in order to facilitate implementation and application of this
`Recommended Practice.
`[1] IEEE: “Use of the International Systems of Units (SI): The Modern Metric System,” Doc. SI
`10, Institute of Electrical and Electronics Engineers, New York, N.Y.
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`ATSC A/327:2018
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`Guidelines for the Physical Layer Protocol
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`[2] ATSC: “ATSC Standard: System Discovery and Signaling,” Doc. A/321:2016, Advanced
`Television System Committee, Washington, D.C., 23 March 2016.
`[3] ATSC: “ATSC Standard: Physical Layer Protocol,” Doc. A/322:2017, Advanced Television
`System Committee, Washington, D.C., 6 June 2017.
`[4] ATSC: “ATSC Standard: Link-Layer Protocol,” Doc. A/330:2016, Advanced Television
`System Committee, Washington, D.C., 19 September 2016.
`[5] ATSC: “ATSC Standard: Scheduler / Studio to Transmitter Link,” Doc. A/324:2018,
`Advanced Television System Committee, Washington, D.C., 2 January 2018.
`[6] ATSC: “ATSC Standard: Signaling, Delivery, Synchronization, and Error Protection,” Doc.
`A/331:2017, Advanced Television System Committee, Washington, D.C., 6 December 2017.
`[7] NorDig Unified Requirements for Integrated Receiver Decoders for use in cable, satellite,
`terrestrial and IP-based networks, January 2017.
`[8] EBU Tech 3348: “Frequency and Network Planning Aspects of DVB-T2,” 2014.
`[9] DTG D-Book 9: “Digital Terrestrial Television Requirements for Interoperability,” 2016.
`[10] ETSI TS 102 831: “Digital Video Broadcasting (DVB); Implementation guidelines for a
`second generation digital terrestrial television broadcasting system (DVB-T2),” V1.2.1,
`August 2012.
`[11] ETSI EN 300 744: “Digital Video Broadcasting (DVB); Framing structure, channel coding
`and modulation for digital terrestrial television,” V1.6.2, October 2015.
`ISO/IEC: “Information Technology – Telecommunications and information exchange
`[12]
`between systems – Part 3: Standard for Ethernet,” Doc. ISO/IEC 8802-3:2017, International
`Organization for Standardization/International Electrotechnical Commission, Geneva,
`Switzerland.
`
`3. DEFINITION OF TERMS
`With respect to definition of terms, abbreviations, and units, the practice of the Institute of
`Electrical and Electronics Engineers (IEEE) as outlined in the Institute’s published standards [1]
`is used. Where an abbreviation is not covered by IEEE practice or industry practice differs from
`IEEE practice, the abbreviation in question will be described in Section 3.2 of this document.
`
`3.1 Compliance Notation
`This section defines compliance terms for use by this document:
`should – This word indicates that a certain course of action is preferred but not necessarily
`required.
`should not – This phrase means a certain possibility or course of action is undesirable but not
`prohibited.
`
`3.2 Acronyms and Abbreviations
`The following acronyms and abbreviations are used within this document.
`ACE
`Active Constellation Extension
`ALP
`ATSC 3.0 Link layer Protocol
`AP
`Additional Parity
`ATSC
`Advanced Television Systems Committee
`AWGN Additive White Gaussian Noise
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`BaseBand Packet
`BBP
`BCH
`Bose, Chaudhuri, Hocquenghem
`BER
`Bit Error Rate
`Bit-Interleaved and Coded Modulation
`BICM
`Bit InterLeaver
`BIL
`Baseband Sampling Rate
`BSR
`CDL
`Convolutional Delay Line
`Carrier Frequency Offset
`CFO
`CFR
`Channel Frequency Response
`CL
`Core Layer
`CLI
`Cross-Layer Interference
`Code rate
`Cod
`CP
`Continual Pilot
`CPM
`Circulant Permutation Matrix
`CRC
`Cyclic Redundancy Check
`Convolutional Time De-Interleaver
`CTDI
`Convolutional Time Interleaver
`CTI
`dB
`decibel
`DFT
`Discrete Fourier Transform
`DRAM Dynamic Random Access Memory
`EL
`Enhanced Layer
`FDI
`Frequency De-Interleaver
`FDM
`Frequency Division Multiplexing
`FEC
`Forward Error Correction
`FER
`Frame Error Rate
`FFO
`Fractional Frequency Offset
`FFT
`Fast Fourier Transform
`FI
`Frequency Interleaver
`FIFO
`First-In-First-Out
`GI
`Guard Interval
`GUR
`Guard Utilization Ratio
`HTDI
`Hybrid Time De-Interleaver
`HTI
`Hybrid Time Interleaver
`IFFT
`Inverse Fast Fourier Transform
`IFO
`Integer Frequency Offset
`i.i.d.
`Independent and Identically Distributed
`ISO
`International Organization for Standardization
`IU
`Interleaving Unit
`L1
`Layer 1
`LDM
`Layered Division Multiplexing
`LDPC
`Low-Density Parity Check
`LFDM
`Layered Frequency Division Multiplexing
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`LLR
`Log-Likelihood Ratio
`LLS
`Low Level Signaling
`LMT
`Link Mapping Table
`LS
`Least Square
`LSB
`Least-Significant Bit
`LSI
`Large Scale Integration
`megabits per second
`Mbps
`megahertz
`MHz
`MIMO Multiple Input Multiple Output
`MISO Multiple Input Single Output
`Mod
`Modulation
`ModCod Modulation and Code Rate
`MS
`Min-Sum Algorithm
`MSB
`Most-Significant Bit
`msec
`milliseconds
`N/A
`Not Allowed
`NMS
`Normalized Min-Sum Algorithm
`NoA
`Number of Active (cells)
`NoC
`Number of (useful) Carriers
`NUC
`Non-Uniform Constellation
`OFDM Orthogonal Frequency Division Multiplexing
`OMSA Offset Min-Sum Algorithm
`OTA
`Over the Air
`PAM
`Pulse Amplitude Modulation
`PAPR
`Peak-to-Average Power Ratio
`PCM
`Parity Check Matrix
`pdf
`Probability Distribution Function
`PH
`Phase Hopping
`PLP
`Physical Layer Pipe
`PRBS
`Pseudo Random Bit Sequence
`PSR
`Number of Punctured Bits to Number of Shortened Bits Ratio
`PTP
`Precision Time Protocol
`QAM
`Quadrature Amplitude Modulation
`QEF
`Quasi Error Free
`QPSK
`Quadrature Phase Shift Keying
`RF
`Radio Frequency
`RFU
`Reserved for Future Use
`SBS
`Subframe Boundary Symbol
`SFN
`Single Frequency Network
`SHVC
`Scalable High Efficiency Video Coding
`SINR
`Signal-to-Interference plus Noise Ratio
`SISO
`Single Input Single Output
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`Service Layer Signaling
`SLS
`Service List Table
`SLT
`Signal-to-Noise Ratio
`SNR
`SP
`Scattered Pilot
`SPA
`Sum-Product Algorithm
`SRAM
`Static Random Access Memory
`SSM
`Subslice Multiplexing
`STL
`Studio-Transmitter Link
`STO
`Symbol Timing Offset
`TBDI
`Twisted Block De-Interleaver
`TBI
`Twisted Block Interleaver
`TDCFS Transmit Diversity Code Filter Sets
`TDM
`Time Division Multiplexing
`TI
`Time Interleaver
`TR
`Tone Reservation
`TxID
`Transmitter Identification
`
`3.3 Terms
`The following terms are used within this document.
`Base Field – The first portion of a Baseband Packet Header.
`Base Layer – The smallest video sub-stream (first layer) of SHVC.
`Baseband Packet – A set of Kpayload bits which form the input to a FEC encoding process. There
`is one Baseband Packet per FEC Frame.
`Baseband Packet Header – The header portion of a Baseband Packet.
`Block Interleaver – An interleaver where the input data is written along the rows of a memory
`configured as a matrix, and read out along the columns.
`Cell – One pair of encoded I/Q components in a constellation.
`Cell Interleaver – An interleaver operating at the cell level.
`Combined PLP – A PLP comprised of the Layered Division Multiplexing of a Core PLP and one
`or more Enhanced PLP(s) after processing by the LDM injection block.
`Concatenated code – A code having an outer code followed by an inner code.
`Constellation – A pair of encoded (I component/Q component) points in the I/Q plane.
`Core Layer – The first layer of a 2-layer LDM system. The only layer in a non-LDM system.
`Core PLP – A PLP belonging to the Core Layer.
`Data Payload Symbols – Data and Subframe Boundary Symbols (i.e., non-Preamble symbols).
`Enhanced Layer – The second layer of a 2-layer LDM system.
`Enhanced PLP – A PLP belonging to the Enhanced Layer.
`Enhancement Layer – The larger video sub-stream (second layer) of SHVC.
`Extension Field – The third portion of a Baseband Packet Header.
`FEC Block – A FEC Frame after constellation mapping to cells.
`FEC Frame – A single Baseband Packet with its associated FEC parity bits attached, having a
`total size of 64800 or 16200 bits (per FEC Frame).
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`Frequency Interleaver – An interleaver which takes cells and interleaves them in frequency
`within a particular OFDM symbol.
`Inner Code – One code of a concatenated code system.
`Interleaver – A device used to counteract the effect of burst errors.
`Layered Division Multiplexing – A multiplexing scheme where multiple PLPs are combined in
`layers with a specific power ratio.
`ModCod – A combination of modulation and code rate that together determine the robustness of
`the PLP and the size of the Baseband Packet.
`Non-Uniform Constellation – A constellation with a non-uniform spread of constellation points.
`Optional Field – The second portion of a Baseband Packet Header.
`Outer Code – One code of a concatenated code system.
`Physical Layer Pipe – A data-carrying structure specified to an allocated capacity and robustness
`that can be adjusted to broadcaster needs.
`reserved – Set aside for future use by a Standard.
`Systematic – A property of a code in which the codeword is composed of the original data in its
`sequential order followed by the parity data for the codeword.
`TI Block – An integer number of FEC Blocks.
`Time Interleaver – An interleaver which takes cells and interleaves them over a particular time
`period.
`
`4. SYSTEM OVERVIEW AND GUIDELINES FOR PHYSICAL LAYER MODE
`
`4.1 System Overview
`The ATSC 3.0 physical layer protocol described by A/321 [2] and A/322 [3] provides distinct
`features and descriptions of the physical layer technologies. For a channel coding method, a well-
`optimized Bit-Interleaved Coded Modulation (BICM) chain, comprised of Low Density Parity
`Check (LDPC) codes (2/15 – 13/15 code rates), Bit Interleavers, and Non-Uniform Constellations
`(QPSK – 4096QAM modulation orders), is used to achieve near Shannon limit performance of
`channel error mitigation across a wide range of SNR values. Multiple data streams can be carried
`by one or multiple Physical Layer Pipes (PLPs) using flexible choices of framing and multiplexing
`techniques including Time Division Multiplexing (TDM), SubSlice Multiplexing (SSM),
`Frequency Division Multiplexing (FDM), and Layered Division Multiplexing (LDM). Waveform
`parameters based on Orthogonal Frequency Division Multiplexing (OFDM) modulation also
`support a wide range of guard intervals, pilot patterns, and FFT sizes for broadcasters to select
`optimal system performance of intended services. Optional technologies such as channel bonding,
`Multiple-Input Single-Output (MISO), Multiple-Input Multiple-Output (MIMO), and Transmitter
`Identification (TxID) are included as additional features in the ATSC 3.0 physical layer protocol.
`Figure 4.1 shows a high-level ATSC 3.0 physical layer protocol diagram of an example
`multiple-PLP architecture. Multiple data streams intended to have different robustness levels are
`delivered by input PLPs. After each PLP is processed by independent Input Formatting and BICM
`blocks, further block processes are selected depending on the choices of multiplexing methods.
`TDM, SSM, and FDM can be achieved in the Framing and Interleaving block (bypassing the LDM
`Combining block) by using PLP multiplexing within a subframe. When different waveform
`parameters such as guard intervals, pilot patterns and FFT sizes are configured in the Waveform
`Generation block, TDM can also be enabled by constructing multiple subframes with each PLP
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`contained in a separate subframe. LDM can be achieved with data processing right after the BICM
`stage as it contains combinations of data cells. A 2-layer LDM may be combined with TDM and/or
`FDM to configure multiple PLPs as shown in Figure 4.1.
`
`
`
`Figure 4.1 High level ATSC 3.0 physical layer protocol diagram enabling an
`example of multiple-PLP architecture.
`
`The key technologies of the ATSC 3.0 physical layer protocol can be summarized as following.
`• Bit-Interleaved and Coded Modulation (BICM)
`▫ FEC: LDPC (inner code), BCH / CRC (outer code)
`▫ Code rate: 2/15 – 13/15 (64800, 16200 bits)
`▫ Constellations: QPSK, 16QAM – 4096QAM (Non-uniform constellations)
`• Time Interleaver
`▫ Convolutional Time Interleaver (CTI)
`▫ Hybrid Time Interleaver (HTI): Cell Interleaver, Twisted Block Interleaver,
`Convolutional Delay Line
`▫ Maximum TI memory size: 219 ce