fm digital radio standard document overview march 6, 2003 release

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



compression

Audio Subsystem


ServiceMultiplex

Transport

MainProgramService

Audio



(AAS) Data

Transport

Transport


Channel Coding

Modulation

IBOCReceiver


Delay


Transport

Annex A

Annex B

Amplifier

Annex C

17


MPA CodecProtocol

MPA Encoder(PAC)

MPA Transport



[3] 1020s

[4] 1028s

[5] 1027s

[6] 1011s

[2] 1017s




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


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


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



compression

Audio Subsystem


ServiceMultiplex

Transport

MainProgramService

Audio



(AAS) Data

Transport

Transport


Channel Coding

Modulation

IBOCReceiver


Delay


Transport

Annex A

Annex B

Amplifier

Annex C

22

Figure 1‑1 HD Radio Broadcast System

MPA CodecProtocol

MPA Encoder(PAC)

MPA Transport



[3] 1020s

[4] 1028s

[5] 1027s

[6] 1011s

[2] 1017s




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


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


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


MPA CodecProtocol

MPA Encoder(PAC)

MPA Transport



[3] 1020s

[4] 1028s

[5] 1027s

[6] 1011s

[2] 1017s




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


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


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


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


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


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


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""

fm digital radio standard document overview march 6, 2003 release

Documents

shd radio

service multiplex rev

s rev c

standard documents

audio codecb

level overview of system

ratesblock diagram

c overview