FM DIGITAL RADIO STANDARD Document Overview March 6, 2003 Release
Jan 21, 2016
FM DIGITAL RADIO STANDARD
Document Overview
March 6, 2003
Release
2
Documentation Structure
• FM Digital Radio Standard – Top level overview of system and documentation structure.
• Annex A, B, C – Overview of the three main components of the system:
A: Audio Codec
B: Protocol Stack
C: Modem (Layer 1)
• iBiquity Reference Documents called out by Annexes
3
Documents SubmittedMarch 7, 2003
• Standard Documents:– FM Digital Radio Standard – Rev B– Annex A: PAC Encoder/Decoder – Rev B– Annex B: Transport and Service Multiplex – Rev B– Annex C: RF Transmission System – Rev B
• Reference Documents:– Layer 1 FM: 1011s Rev C - which includes
incorporated changes– Layer 2 Channel Multiplex Rev B– Transmission System Rev B
4
IBOC Digital Radio Broadcasting Model
Audio sourcecoding and
compression
Audio Subsystem
Transport and ServiceMultiplex Subsystem
ServiceMultiplex
Transport
MainProgramService
Audio
Station InformationService (SIS) Data
AdvancedApplication Service
(AAS) Data
Transport
Transport
RF/TransmissionSubsystem
Channel Coding
Modulation
IBOCReceiver
Analog Audio (Hybrid modes only)
Delay
Main ProgramService Data (PAD)
Transport
Annex A
Annex B
Amplifier
Annex C
5
HD Radio Broadcast System
MPA CodecProtocol
MPA Encoder(PAC)
MPA Transport
Layer 1 (Waveform / Transmission) - (L1 PDUs)
SIS AAS MPS Audio(MPA)
[3] 1020s
[4] 1028s
[5] 1027s
[6] 1011s
[2] 1017s
HD Radio Modulated Waveform
FutureService NFuture
Service 2FutureService 1
SIS
PD
Us
Fix
ed a
nd
Op
po
rtu
nis
tic
PD
Us
1 t
o 3
Str
eam
so
f M
PA
Co
dec
PD
Us
An
cilla
ryB
itst
ream
L2
PD
Us
Layer 2 (Channel Multiplex Protocol)[1] 1014s
SIS Transport
SISProtocol
SIS
Dat
a
AA
S D
ata
MP
AA
ud
io
Service Interfaces
MPS Data(PAD)
P1
P2
P3
PID
S
S1
S2
S3
S4
S5
SID
S
AASTransport
AncillaryBitstream
Str
eam
0
Str
eam
1
Str
eam
2
Opportunistic BandwidthStatus to AAS Transport
Ad
min
/ S
etu
p
6
The Standard - Rev B Change Summary
• Referenced Documents added
• Acronyms separated from terms employed
• Updated broadcasting model figure showing relationships between Annexes and subsystems
Annex A
PAC Encoder/Decoder Characteristics
Rev B
8
Block diagram of the basic Perceptual Audio Coder (PAC)
MDCTNoise
AllocationNoiseless
CodingFormatter
PerceptualModel
Fit Model toFilterbank
InputAudio
BitstreamOutput
9
FM Hybrid Audio Specifications
Encoded Audio Bitrate, kbit/s
Decoder Info. Rate – Enhanced, kbit/s
Reference Audio Specifications
Minimum Audio Frequency Response (Hz)
Dynamic Range (dB)
Minimum Stereo Separation (dB)
Quality Level FM Service Mode
96 98 20 to 20000 96 70 Virtual CD MP1-MP4
10
Block diagram of Single Stream PACencoder for Hybrid FM System
Switched Filterbank
MDCT
Noise/BitAllocation
HuffmanCoding
BitstreamFormatter
PerceptualModel
TemporalStatistical
Multiplexer
InputAudio
SwitchingCriterion
WaveletFilterbank
Noise/BitAllocation &
CapacityControl
11
FM All Digital Audio Performance atVarious Specified Bit Rates
Encoded Audio Bitrate Core / Enhanced, kbit/s
Decoder Info. Rate – Core, kbit/s
Decoder Info. Rate – Enhanced, kbit/s
Reference Audio Specifications
Minimum Audio Frequency Response (Hz)
Dynamic Range (dB)
Minimum Stereo Separation (dB)
Quality Level FM Service Modes
24 / 72 25 74
20 to 20000 96 70
Virtual CD MP5
48 / 48 50 49
20 to 20000 96 70
Virtual CD MP6
24 25 - 20 to 8000 50 None AM-like MP5
48 50 - 20 to 10000 62 None FM-mono MP6
12
Block diagram of Two-Stream classifier PAC encoder for All-Digital FM System
Switched Filterbank
MDCT
Noise/BitAllocation
HuffmanCoding
BitstreamFormatter
PerceptualModel
TemporalStatistical
Multiplexer
InputAudio
SwitchingCriterion
WaveletFilterbank
Noise/BitAllocation &
CapacityControl
C E
C
E
Output
E
C
C = Core
E = Enhancement
13
Block diagram of PAC Decoder
Input Buffer
BitstreamParser
InputBitstream
DecodedAudioOutputEHFC &
HuffmanDecode
ErrorMitigation
InverseTransform
14
Annex A - Rev B Change Summary
• List of figures and tables added
• Referenced documents added
• Acronyms added
• HD Radio Broadcast System Diagram added showing functional system description
• Audio specification tables clarified
Annex B
Transport and Service Multiplex Characteristics
Rev B
16
IBOC Digital Radio Broadcasting Model
Audio sourcecoding and
compression
Audio Subsystem
Transport and ServiceMultiplex Subsystem
ServiceMultiplex
Transport
MainProgramService
Audio
Station InformationService (SIS) Data
AdvancedApplication Service
(AAS) Data
Transport
Transport
RF/TransmissionSubsystem
Channel Coding
Modulation
IBOCReceiver
Analog Audio (Hybrid modes only)
Delay
Main ProgramService Data (PAD)
Transport
Annex A
Annex B
Amplifier
Annex C
17
HD Radio Broadcast System
MPA CodecProtocol
MPA Encoder(PAC)
MPA Transport
Layer 1 (Waveform / Transmission) - (L1 PDUs)
SIS AAS MPS Audio(MPA)
[3] 1020s
[4] 1028s
[5] 1027s
[6] 1011s
[2] 1017s
HD Radio Modulated Waveform
FutureService NFuture
Service 2FutureService 1
SIS
PD
Us
Fix
ed a
nd
Op
po
rtu
nis
tic
PD
Us
1 t
o 3
Str
eam
so
f M
PA
Co
dec
PD
Us
An
cilla
ryB
itst
ream
L2
PD
Us
Layer 2 (Channel Multiplex Protocol)[1] 1014s
SIS Transport
SISProtocol
SIS
Dat
a
AA
S D
ata
MP
AA
ud
io
Service Interfaces
MPS Data(PAD)
P1
P2
P3
PID
S
S1
S2
S3
S4
S5
SID
S
AASTransport
AncillaryBitstream
Str
eam
0
Str
eam
1
Str
eam
2
Opportunistic BandwidthStatus to AAS Transport
Ad
min
/ S
etu
p
18
MPA Codec Protocol Interface Diagram
MPS Audio Interface
MPA CodecProtocol
MPA Encoder(PAC)
MPA Transport
AncillaryBitstream
Fixed Length MPAAudio Frames
1 to
3 S
trea
ms
of
MP
A C
od
ecP
DU
s (g
oin
g t
oL
ayer
2)
Str
eam
0
Str
eam
1
Str
eam
2
OpportunisticBandwidth Statusto AAS Transport
19
Annex B - Rev B Change Summary
• References added
• Acronyms updated
• Reorganized overview section – clearer description
• More detailed broadcast system diagram (identical to Annex A and C)
• Service description broken down to follow diagram
• Updated MPA protocol diagram
Annex C
RF/Transmission System Characteristics
Rev B
21
IBOC Digital Radio Broadcasting Model
Audio sourcecoding and
compression
Audio Subsystem
Transport and ServiceMultiplex Subsystem
ServiceMultiplex
Transport
MainProgramService
Audio
Station InformationService (SIS) Data
AdvancedApplication Service
(AAS) Data
Transport
Transport
RF/TransmissionSubsystem
Channel Coding
Modulation
IBOCReceiver
Analog Audio (Hybrid modes only)
Delay
Main ProgramService Data (PAD)
Transport
Annex A
Annex B
Amplifier
Annex C
22
Figure 1‑1 HD Radio Broadcast System
MPA CodecProtocol
MPA Encoder(PAC)
MPA Transport
Layer 1 (Waveform / Transmission) - (L1 PDUs)
SIS AAS MPS Audio(MPA)
[3] 1020s
[4] 1028s
[5] 1027s
[6] 1011s
[2] 1017s
HD Radio Modulated Waveform
FutureService NFuture
Service 2FutureService 1
SIS
PD
Us
Fix
ed
an
d O
pp
ort
un
isti
c P
DU
s
1 t
o 3
Str
ea
ms
of
MP
A C
od
ec
PD
Us
An
cilla
ryB
its
tre
am
L2 P
DU
s
Layer 2 (Channel Multiplex Protocol)[1] 1014s
SIS Transport
SISProtocol
SIS
Da
ta
AA
S D
ata
MP
AA
ud
io
Service Interfaces
MPS Data(PAD)
P1
P2
P3
PID
S
S1
S2
S3
S4
S5
SID
S
AASTransport
AncillaryBitstream
Str
ea
m 0
Str
ea
m 1
Str
ea
m 2
Opportunistic BandwidthStatus to AAS Transport
Ad
min
/ S
etu
p
23
RF/Transmission Function
Transportand Multiplex
ApplicationEncoders
Audio
Data
Transmitter
Audio
Data
Presen
tation
Receiver
ApplicationDecoders
Scram
bler
ChannelEncoding
Interleaver
OFDM Subcarrier Mapping
OF
DM
Sig
nal
Gen
eration
TransferFrames
TransmissionSystem
Modem
Transportand
Demultiplex
TransferFrames
OFDM Demodulator
Deinterleaver
Channel Decoder
Descrambler
Modem
Tran
smissio
n F
orm
at
24
FM Air Interface Layer 1 Functional Block Diagram with data flow details
Channel Multiplex
Scrambling
Channel Encoding
Interleaving
OFDM Subcarrier Mapping
OFDM Signal Generation
Transmission Subsystem
P1
P1
SP
1G
X
SystemControl
Processing
SC
CH
Analog,SCA
Sources
P2
P3
PID
S S1
S2
S3
S4
S5
SID
S
Layer 1 SAP
P2
S
P3
S
PID
SS
S1
S
S2
S
S3
S
S4
S
S5
S
SID
SS
P2
G
PID
SG
P1 G
P3
G
SID
SG
S1
G
S2
G
S3
G
S1 G
S5
G
S4
G
PM
PX
1
PX
2
SM
SX
1
SX
2
SP
SB
Control /Status
Baseband
Co
ntro
l /S
tatus
yn(t)
s(t)
R
25
Interleaving Conceptual Block Diagram
P1
G
P2
G
P3
G
S1
G
S2
G
S3
G
S5
G
PID
SG
PM
SID
SG
PM IP PX IP SM IP SX IP SP IP SB IP
SID
SG
S4
GFrom Channel Encoding
To OFDM Subcarrier Mapping
PX1 PX2 SM SX1 SX2 SB
Control
(PSM, SSM,P3IS from the
ChannelMultiplex)
S1
G
P1
G
SP
26
System Control Processing Conceptual Diagram
To / From the Channel Multiplex
To OFDM Subcarrier Mapping
System Control Data Sequence Assembler
Differential Encoder
SCCH
r
R
27
OFDM Subcarrier Mapping Conceptual Block Diagram
PM PX1
X
From Interleaving
To OFDM Signal Generation
R
FromSystem Control
Processing
Signal Constellation Mapper
Scaler
OFDM Subcarrier Mapper
PX2 SM SX1 SX2 SP SB
(Service Modefrom Channel
Multiplex)
Control
28
From OFDM SignalGeneration
VHF FM IBOCWaveform
SymbolConcatenation
Up-Conversion
FromAnalog Source
Analog FM Modulator
Hybrid andExtended Hybridwaveforms only
yn(t)m(t)
a(t)
s(t)
z(t)
y(t)
(optional) SCASubcarriers
Hybrid/Extended Hybrid Transmission Subsystem Functional Block Diagram
29
Annex C - Rev B Change Summary
• Reference documents added
• Acronym list updated
• Broadcast system diagram added (same as Annex A and B)
• Layer 1 SAP typo fixed
SY_IDD_1014s
Air Interface Design Description – Layer 2 Channel Multiplex
Protocol
Rev B
31
HD Radio Broadcast System
MPA CodecProtocol
MPA Encoder(PAC)
MPA Transport
Layer 1 (Waveform / Transmission) - (L1 PDUs)
SIS AAS MPS Audio(MPA)
[3] 1020s
[4] 1028s
[5] 1027s
[6] 1011s
[2] 1017s
HD Radio Modulated Waveform
FutureService NFuture
Service 2FutureService 1
SIS
PD
Us
Fix
ed
an
d O
pp
ort
un
isti
c P
DU
s
1 t
o 3
Str
ea
ms
of
MP
A C
od
ec
PD
Us
An
cilla
ryB
its
tre
am
L2 P
DU
s
Layer 2 (Channel Multiplex Protocol)[1] 1014s
SIS Transport
SISProtocol
SIS
Da
ta
AA
S D
ata
MP
AA
ud
io
Service Interfaces
MPS Data(PAD)
P1
P2
P3
PID
S
S1
S2
S3
S4
S5
SID
S
AASTransport
AncillaryBitstream
Str
ea
m 0
Str
ea
m 1
Str
ea
m 2
Opportunistic BandwidthStatus to AAS Transport
Ad
min
/ S
etu
p
32
SIS
PD
Us
fro
mth
e S
IST
ran
spo
rt
Fix
ed a
nd
Op
po
rtu
nis
tic
PD
Us
fro
m t
he
AA
S T
ran
spo
rt
1 t
o 3
Str
eam
so
f M
PA
Co
dec
PD
Us
fro
m t
he
MP
A T
ran
spo
rt
L2
PD
Us
Layer 2 (Channel Multiplex Protocol)[1] 1014s
P1
P2
P3
PID
S
S1
S2
S3
S4
S5
SID
S
L2 PDUs to Layer 1 (Waveform / Transmission)
Level 2 Channel Multiplex Protocol Interface Diagram
33
MPA Codec PDUonly
MPA Codec, &OpportunisticPDU(s)
MPA Codec &Fixed PDU(s)
MPA Codec,Opportunistic &Fixed PDU(s)
Fixed PDU only
MPA Codec PDU
Fir
st
Bit
La
st
Bit
MPA Codec PDU Opportunistic PDU
MPA Codec PDU Fixed PDU
MPA Codec PDU Fixed PDUOpportunistic
PDU
Fixed PDU
Layer 2 PDU Structure
34
payloadh h h h h hpayload ...
First Bit Last Bit
payload payload payload payload payload
MPA and AAS Transfer Frame Structure
35
1014s - Rev B Change Summary
• Removed copyrights section
• Embellished document overview section
• Added reference documents
• Updated acronym list
• Added layer 2 channel multiplexing Section
• Fixed numbering issues
SY_IDD_1026s
Transmission System Specifications
Rev B
37
HD Radio FM Hybrid Mode Noise and Spurious Emission Limits
-350-400 -300 -250 -200 -150 -100 -50 0 50 100 150 200 300 350250 400
Frequency offset, KHz
Hybrid HPA Noise & Spurious Performance Measured with Analog Carrier Present*
dB
in a
1 k
Hz
ban
dw
idth
-90
0
-20
-30
-40
-60
-100
-10
-50
-70
-80
-450-500-550-600-650 450 500 550 600 650
Nominal Hybrid Carrier Power Spectral Density
Nominal Analog Carrier Power Spectral Density
* Note: Refer to Subsection 5.1.3 for additional information
38
HD Radio FM All-Digital Mode Noise and Spurious Emission Limits
-350-400 -300 -250 -200 -150 -100 -50 0 50 100 150 200 300 350250 400
Frequency offset, KHz
All Digital HPA Noise Performance*
dB
in a
1 k
Hz
ban
dw
idth
-90
0
-20
-30
-40
-60
-100
-10
-50
-70
-80
-450-500-550-600-650 450 500 550 600 650
Nominal All Digital Power Spectral Density
* Note: Refer to Subsection 5.1.3 for additional information
39
1026s - Rev B Change Summary
• Fixed proper revision lettering
• Added references
• Updated acronym list
• Removed mathematical operations table
• Added sections on frequency translators and on-channel boosters
SY_IDD_1011s
Air Interface Design Description Layer 1 FM
Rev C
41
1011s Rev C Overview
• Only minor changes made, therefore revision “D” not generated – new Revision C dated March 6, 2003
• 6 DCRs generated from:– NRSC questions and comments from
meetings since September– Ongoing internal document process
• Changes listed in following slides
42
1011s – Rev C Change SummaryDCR 128
1. Page 4 -Change expansion for UTC to "Coordinated Universal Time“ (item #3 in attachment)
2. Need to add the definition for "Reference Subcarrier" to the Glossary (item #12 in attachment)
3. Page 24 Section 6.4 last sentence to be corrected as - ""...not part of the transmitted HD...""(item #16 in attachment)-delete the entire sentence
4. Table 6-7 last row contains ""l"" instead of ""1""-this needs to be corrected. (item #19 in attachment)
5. TOC need to corrected to correctly number the document-this has been corrected in the internal version needs to be fixed in the SY_IDD_1011s (item #1 in attachment)
6. Page 3 -correct the abbreviation for kilobits per second to ""kbit/sec""-this change has been completed in both the documents (item #2 in attachment)
7. Page 6 Note in italics that refers to Subsection 0, should be corrected to sections 3.5.-this has been corrected in both the documents. (item #4 in attachment)
43
1011s – Rev C Change Summary
DCR 129
1. Make appropriate changes in future generations of IBOC transmission hardware to allow leap second the data contained within the GPS signal to propagate to the receiver. (item #6 in the attachment).
2. Related to this DCR: Page 23, Section 6.4: ""The AFLN ... is used to schedule delivery of time-critical programming."" Repeating the comment made in (13), above, the AFLN alone is not sufficient to determine the current time (e.g., U.S. Standard Time). The leap-second count is also required. Provision should be made to communicate this information up from Level 1 to Level 2.(item #18 in the attachment)
44
1011s – Rev C Change Summary
DCR 131
1. Page 21, Section 6.2.1, first line explains that all values greater than binary 000110 are reserved for future expansion, yet 000111 was assigned to MP7 which was identified as an active primary service mode. The backward compatibility defaults on the next page only map to MP6 (and not MP7). Please indicate whether 000111 is reserved or not and if not, then should MP7 be mapped as a default .(item #13 in attachment).
2. Related to above: Page 21, Table 6-4: There seems to be a conflict between this table and Table 4-1 on page 7. In Table 4-1, both MP5 and MP7 show P3 at 25 kbit/s (kbits/sec). However, Table 6-4 shows MP5 as the default mode for MP7, with P3 ""free to be redefined."" Similarly, Tables 7-7 and 7-9 (page 29) seem to define P3 quite tightly in both MP5 and MP7. This MP7 has multiple contradictions. (item #14 in the attachment)
45
1011s – Rev C Change Summary
DCR132
Page. 23, 3rd and 4th line. Change MP7 to MP6 in both places. Only MP1 and MP6 don’t include the P3 logical channel. Also, include a reference to where long and short interleaver depth is defined. (item #15 in the attachment)
46
1011s – Rev C Change Summary
DCR 133
1. Page 28 Section 7.2.2-need to reconcile Table 7-2 with the middle paragraph above-change 2Tf to Tf for the L1Frame Pair in the Table 7-2.(item #22 in attachment)
2. Related to this DCR: Page 29 & 21 There is another conflict between Table 6-4 on page 21 and Tables 7-7 and 7-9 on page 29. In comparing MP7 to MP5, Table 6-4 says that P1' is backwards compatible and P1 may be redefined. However, Table 7-9 shows no P1' signal at all (e.g., no Tdd in P1 latency). This does not appear to be simply the omission of Tdd, since the Robustness drops from 1 to 4 also. Tables 7-7 through 7-9 depict no P’. (item #23 in the attachment)
47
1011s – Rev C Change SummaryDCR 144
Per the 12/4/02 NRSC review, several changes are recommended. See the attached questions.
• #3 - add words ""of the protocol stack"" to the definition of ""reserved"" in Tables 12-1 and 12-2.
• #6 - Page 40, add a phrase in front of last paragraph ""in cases where digital diversity delay is applied""
• #6 - Figures 7-6, 7-7, 7-8, change P1 to P1' in the extended sidebands. • #7 - Similarly, in Figures 7-10, 7-11, and 7-12, change S1 to S1' in the extended
sidebands. Also, page 40, section 10.2, ""Transmit"" should not be capitalized in mid sentence.
• #11 - Page 41, section 10.3.1, add a definition of S.• #14 - page 42, section 10.3.4 - replace ""That transfer frames define ..."" with ""The fact
that transfer frames define ...""• #17 - Page 61, Table 11-12 - The second occurrence of variable B should be lower case.• #21 - page 61 - delete the extra ""pt"" - note: This is pasted into word as an object that
floats over the text. Make sure it does not belong some other place in the text.• #22 - page 62 - Change text to ""readRow = INT(i / C)WriteRow= INT( (i MOD b) / C) ""• #24 - Section 11.3.1.2 - delete the extra period at the end of the section .• #25 - Change reference to ""Table 11-2 through Table 11-7""• #26 - delete ""="" from the subscript in 11.3.2.4• #29 - page 82 - change ""comprised"" to ""composed""