View
216
Download
0
Category
Preview:
Citation preview
8/11/2019 Hd Radio
1/20
HD RA
TECHNOL
ASJAD
NI
8/11/2019 Hd Radio
2/20
INTRODUCTION
It is a multicasting program channels and operating modes.
HD Radio is the technology used by AM and FM rad
stations to transmit audio and data by using a digital sig
embedded on-frequency immediately above and belowstation's standard analog signal, providing the means to list
to the same program in either HD (digital radio with le
noise) or as a standard broadcast (analog radio with standa
sound quality)
8/11/2019 Hd Radio
3/20
The HD format also provides the means for a single radstation to simultaneously broadcast one or more differe
programs in addition to the program being transmitted
the radio station's analog channel.
It was selected by the United States Fede
Communications Commission (FCC) in 2002 as a digital aud
broadcasting method for the United States, and is the on
digital system approved by the FCC for digital AM/F
broadcasts in the United States.
8/11/2019 Hd Radio
4/20
HOW DOES IT WORK?
Broadcaster analog a
digital audio as well
digital data information.
Audio and data informati
is sent from the studio
the transmitter site.
Digital and analog sign
are transmitt
simultaneously.
8/11/2019 Hd Radio
5/20
Signal travel throughout the broadcast area.
Digitally compressed for, multicasting and enhance
services.
Same as regular radio, except a bundled signal (digital ananalog).
HD radio equipped receivers now experience free, cryst
clear digital audio and additional FM content.
8/11/2019 Hd Radio
6/20
THE HD RADIO SYSTEM
Once Main Program Service(MPS) was established, broadcasters becamintrigued with HD Radio's ability to deliver multiple, independent, prog
streams, over the same digital signal as Supplemental Program Service
which is now commonly referred to as multicast.
Its transmitters signal using these functions
Importer
Exgine
Exporter
Synchronizer
8/11/2019 Hd Radio
7/20
IMPORTER
The importer contains the hardware and software necessa
to deliver Advanced Application Services (AAS).
The importer establishes session connections betwe
multiple service providers. Once a session is establisheservice providers can pass service data over the importer-t
exporter link (I2E),we will be broadcast over the air to
Radio digital receivers.
8/11/2019 Hd Radio
8/20
EXGINE
The exgine subsystem accepts the exporter-to-exgine l
(E2X) data from the exciter's host processor and performs t
Orthogonal Frequency Division Multiplexing (OFD
modulation for the digital portion of the HD Radio waveform
The HD Radio data stream is fed to the exgine over a simp
UDP Ethernet connection.
8/11/2019 Hd Radio
9/20
EXPORTER
The Exporter accepting the MPS AES audio, PSD, multiplexSPS audio, and advanced application service data from t
importer.
An exporter is essentially a Gen II exciter without the RFU a
DUC sub-assemblies.
The exporter accepts digital MPS audio over its aud
interface, bit reduces (i.e. compresses) the audio and outp
the bit-reduced audio to the exgine over the simplex E2X.
8/11/2019 Hd Radio
10/20
SYNCHRONIZER
The synchronizer accepts MPS audio and rate converts it
system clock.
The synchronizer provides the master system clock used by t
This master clock is also synchronized to the exciter's clock
GPS unit. The synchronizer derives the master clock from an
unit's 10MHz output signal.
The synchronizer is also used to bypass (or redirect) the ana
from being passed through the exporter in the event th
removed for maintenance.
8/11/2019 Hd Radio
11/20
SIGNAL TRANSMITTING AND
RECEIVING
Digital information
is transmitted using
COFDM with an
audio compression
algorithm called
PAC (Perceptualaudio coder).
8/11/2019 Hd Radio
12/20
AM
SIGNALS
AM HD Station locking
AM channel sending d
approximately 20k
through two 33Kbit/s ana
telephone lines.
The HD Radio AM hyb
mode offers two optio
which can ca
approximately 40 or
Kbit/s of data, but most A
digital stations default to t
more-robust 40 Kbit/s mo
which features redunda
(same signal broadc
twice).
http://en.wikipedia.org/wiki/File:KNX_HDlock.jpg8/11/2019 Hd Radio
13/20
The pure digital mode transmissions will stay within the AM station
channel instead of spilling into the channels next to the stati
transmitting "HD radio" as the hybrid digital stations do.
AM radio stations are spaced at 9 kHz (Europe) or 10 kHz (America
intervals, much of the digital information overlaps adjacent channe
when in hybrid mode.
The digital radio signal received on a conventional AM receiver tun
to an adjacent channel sounds like a large waterfall or similar wh
noise-like hiss, as can be heard in the audio sound clip referenced
the previous sentence.
AM is used DRM system, Digital Radio Mondiale (DRM) is a syste
designed primarily for world band radio and AM Radio. DRM is ve
similar to AM HD Radio in that each station is broadcast via a chann
20 kilohertz wide (+/-10 kHz).
8/11/2019 Hd Radio
14/20
FM
SIGNALS
Spectrum of FM broadcast stationwithout HD Radio
FM provides a "fallba
condition where it reverts t
more-robust 25 Kbit/s signal.
FM stations have the option
subdivide their Data Stream i
sub-channels (e.g., 88.1 H
HD2, and HD3) of varying au
quality.
Stations may eventually go
digital, thus allowing as many
three full-power channels
four low-power channels (se
totals).
http://en.wikipedia.org/wiki/File:FM_spectrum_IBOC.png8/11/2019 Hd Radio
15/20
Stations can transmit HD Radio through their existing antennas usin
diplexer as on AM, or are permitted by the FCC to use a separ
antenna at the same location, or at a site licensed as an ana
auxiliary, provided it is within a certain distance and height referencto the analog main signal.
FM is use DBA system, That station is then subdivided into multi
digital streams of between 9 and 12 programs. In contrast FM HD Ra
is assigned to the traditional 200 kilohertz-wide channels, w
capability of 300 Kbit/s in pure digital mode.
FM HD Radio uses a codec based upon the MPEG-4HE-AAC standa
Several psychoacoustic studies/tests have shown HE-AAC code
achieve the same perceived quality as MP2.
8/11/2019 Hd Radio
16/20
FEATURES
Real time updates.
Artists information. HD radio Review.
Store and replay.
Multimedia support.
On Demand Audio Services.
Worldwide FM band support.
Worldwide AM (MW) band support. Digital audio output.
FM multi-path channel equalizer.
Dynamic AM and FM channel bandwidth control.
Configurable AM and FM noise blanking.
Configurable FM stereo-mono blend.
Multi-path detection and mitigation.
8/11/2019 Hd Radio
17/20
BROADCAST STATUS OF HD RADIO IN U
8/11/2019 Hd Radio
18/20
BROADCAST STATUS OF HD RADIO OVE
THE WORLD
8/11/2019 Hd Radio
19/20
APPLICATION
S
OEM car radio systems.
OEM automotive infotainment systems.
Aftermarket car radio systems.
OEM car PND docking system.
8/11/2019 Hd Radio
20/20
THANKS
TO
GIVE YOUR
ATTENTION
Recommended