IBOC Handbook
Table of Contents
Section I - Background
Chapter 1
What is IBOC Radio?
Services Overview
Program Services
Multicasting
Tomorrow Radio
The HD Digital Radio Alliance
Program Service Data (PSD)
Station Information Service (SIS)
Advanced Data Services (ADS)
HD Radio Data Enhancements
The Digital Radio Environment
FCC First Report and Order
Dissent
The Rise of IBOC
The NRSC and IBOC Development
NRSC Test and Evaluation Process
Digital Radio Transmission Technologies
Eureka-147 DAB
Cam-D
DVB-T
DVB-H
Integrated Services Digital Broadcasting for Terrestrial Sound Broadcasting (ISDBTSB)
Satellite Digital Audio Radio Services (SDARS)
XM and Sirius Satellite Radio
SDARS Terrestrial Repeaters
Worldspace Satellite
Extended Digital Services
Digital Radio Express (DRE)
Stratos Audio Inc. and StratosInteractive
A Context For IBOC
Chapter 2
IBOC Precursors
IBOC’s Beginnings
New Technical Muscle
NRSC Cranks It Up
Testing Proponents’ Technologies: TGWG
Regulatory Progress
Evaluation Process: EWG
Standardization Testing: TPWG and EWG
Response to the Testing
Finally, Standards-Setting: ISDWG
FM Subcarrier Compatibility: DAB Subcommittee and Others
The Path to the HDC Codec: TPWG and EWG
AM Nighttime Performance and Compatibility: Outside-NRSC Review
Multicasting and the SIDTG
Surround Sound: The SSATG
Composite Surround Transport
Component Surround Transport
Surround Sound Case Studies
KUVO-FM, Colorado Public Radio
WZLX 100.7, CBS Boston
WGUC-FM 90.9, Cincinnati Public Radio
A Complete Standard in Two Steps: Data Put on Temporary Hold
After the Standard: DRB Subcommittee
Moving On
Section II – The Protocol Stack
Chapter 3
NRSC-5 Versions
Reference Documents
Informative References
The NRSC-5 Standard
Protocol Stack
Open Systems Model
NRSC-5 As Open System
One Standard, Several Modalities
“Services” Versus “Transports”
Structure of Section 2
Chapter 4
Audio Codec
Coded Audio Payload
Side Processes: The Configuration Administrator
Audio Transport
Program Service Data (“PSD”)
MPS and SPS PDU’s
Opportunistic Data
Program Service Data
PSD Protocol and Transport
PSD ID3 Tags
PSD Etiquette
PSD Harmonization with RDS
PSD Transport
PSD Metadata
Audio Transport to Channel Multiplex
Chapter 5
Logical Channels
Logical Channels and the Frequency Domain
Logical Channels in the Time Domain
Logical Channel Types and Rates
Layer 2 PDU Structure
Folding in Data
L2 PDU Types
Layer 1—Processes Common to AM and FM
Scrambling
The Spectral Challenge of OFDM
How Scrambling Works
Convolutional Coding
Vectors and Matrices
FM IBOC Rate 2/5 Encoder Example
Puncturing
How Convolutional Encoding Helps
A Diagram Is Worth a Thousand Words
Puncturing
Interleaving
Layer 1 Continues
Chapter 6
Layer 1 Structure
System Control
IBOC in the Time Domain
Audio Sampling Rate Implications
Frame and Block Duration
Diversity Delay
AM Time Diversity
FM Time Diversity
The Symbol
Sync-ing Up
System Control Processing
Differential Encoding
Universal Time
Service Modes
AM Service Modes
FM Service Modes
Backward Compatibility
From Logical to Physical
Chapter 7
FM IBOC OFDM Spectrum
FM IBOC OFDM Frequency Plan
FM IBOC OFDM Modulation: Symbols
Constellation
FM IBOC OFDM Modulation: Computational Basis
Convolution
OFDM Sinusoidal Subcarriers
OFDM Symbol Pulses
Guard Interval
Cyclic Prefix
Pulse Shaping Function
Discrete Fourier Transform
Windowing
Functions in Frequency and Time Domains
DFT Computation
Insert Pulse Shaping Function
A Stream of Symbols
Convolution Revisited
Chapter 8
AM IBOC OFDM System
AM Parameters
Modulation
Amplitude Scaling
The Negated Complex Conjugate
Analog Channel
Complex Conjugate
Interference Protection
AM Pulse Shaping
Chapter 9
AM and FM Transmission System Specifications
Timing Issues
Signal Quality Issues
Error Vector Magnitude
Phase Noise
Flatness
AM Amplitude and Phase Symmetry
Where to Measure AM and FM IBOC Specs
Spectral Emissions
Spectral Emissions Limits
Existing Analog Masks
IBOC Masks
Spectral Density
PSD and Spectrum Analyzer Settings
Spectrum Analyzer Detectors and Averaging
FM Mask
Digital-to-Digital Intermodulation
Analog/Digital Intermodulation
NRSC-5-A Mask (Hybrid FM IBOC)
Digital Sideband Self-Intermodulation
Hybrid Mask Fine Tuning
NRSC-5-A Mask (All-Digital FM IBOC)
OFDM Subcarrier Scaling
AM Mask
Analog-to Digital and Digital-to-Digital Intermodulation
NRSC-5-A Mask (Hybrid AM IBOC)
Analog Host Performance with Hybrid
NRSC-5-A Mask (All-Digital AM IBOC)
Discrete Components Exception
OFDM Subcarrier Scaling
IBOC or IBAC?
IBAC Characteristics Differ From IBOC
The Radio "Channel"
Chapter 10
Station Information Service Protocol
Station Name (Short Format) a.k.a. Call Sign Standard
Call Sign Universal
Station Name (Long) a.k.a. Station Slogan Standard
Station Slogan Universal
Station ID Number
Station Location
Station Message
Time – ALFN and Time Parameters
ALFN
Leap Seconds
SIS Parameter Messages
Leap Second Offsets
Local Time Data
Station Information Service Transport
Dedicated GPS Time Data
SIS PDU Housekeeping
SIS Scheduling Strategy
SIS Recap
Chapter 11
Advanced Applications Services Transport (AAT)
Data Transport Packet
AAT PDU
AAT PDU Stream
Reed-Solomon FEC
Interleaving
Block Boundaries
Bearer Channels
Data Transport Packet Format
Port Number
Sequence Number
HDLC-Like Framing
Reed-Solomon Coding and Interleaving
Insertion into Bearer Channel
Opportunistic BearerError! Bookmark not defined.
Fixed Bearer
Above AAT— What Happens Outside NRSC-5?
Learning from History
A Better Reason to Use AAT Subchannels
The Radio Broadcasting Model for Advanced Data Services
Revenue Comparisons
Network Design Modeling
The Flow of IBOC Transmissions
The Concept of Multiple Services Sharing the Pipe
Use Cases and Service & Receiver Classifications
Applications Examples
Features Examples
Service Classes
Use Mapping
Receiver Classes
Classes Are the Key to Interoperability
Use Cases Lead to Protocols
Advanced Data Service Protocols (Not in NRSC-5)
Service Discovery
Telematics
Traffic Message Channel
End of the IBOC Stack
Section III - Implementation
Chapter 12
AM IBOC
Our AM Legacy
Backward Compatibility
What is Bandwidth, and What Does It Mean to Us?
Propelled from the Jet Age to the Space Age
Invisible IBOC
Antenna System Effects on the AM IBOC Signal
Outermost, or Primary, Sidebands
Outer or Secondary Sidebands
Inner or Tertiary Sidebands
Self-Canceling Sidebands
Transmitter Loading and System Bandwidth
Hermitian Symmetry
Measurement
Analog’s Regulatory Vicious Cycle
Intermodulation Products
Pattern Bandwidth
High-Performance, Precision Antenna Systems
Nighttime AM Testing and Analysis
Conclusion
Chapter 13
Antennas and Combining
Analog FM Signals
Multi-station Combining
Combining Digital Signals in the FM Band
Common Amplification
Co-Synthesis
Low-Level Combining
High-Level Combining
The High-Level Combiner
Why a 10-dB Combiner?
Efficiency and Heat Load
Mismatch and Isolation
Turn-around Loss
Minimizing Unwanted Interaction
Directivity
Isolation
Split-level Combining
Efficiency
Considering the Options
Isolation
Combining with Antennas
The IBOC-to-Antenna Path
Dual-Feed Antenna
Separate-Antenna Operation
Separate-Antenna Research
Separate-Antenna Regulation
Multi-Station Antenna Systems
Common-Line IBOC to Multi-Station Combiners
Separate-Line IBOC and Multi-Station Combining
Crest Factor and Peak Power in Hybrid IBOC Transmission
OFDM Peak to Average
Relate OFDM to Analog
OFDM Peak to Analog Peak
OFDM RMS to Analog RMS
Hybrid Crest Factor
Difference Between Hybrid and Analog Crest Factors
Chapter 14
Transmission
The Exciter
The Exgine
Connecting the Services to the Transmitter
Main Program Audio
Economizing for Multicasting
The Exporter
Breaking into the Protocol Stack
A New Transport Where None Had Been Necessary Before
Network Analysis
Quality of Service
Network Security
Another Approach
The Importer
Secure the Critical Network
Reception
Core Receiver Components
IBOC Coverage
FM Evaluation
Further FM Testing
Adjacent Channel Interference
AM Evaluation
Core & Enhanced
Nighttime
Effect of Adjacencies on AM IBOC Coverage
Conclusion of the IBOC Handbook
Appendix A:
IBOC Digital Radio Receiver Fundamentals
By DAVE WILSON, Consumer Electronics Association