A SEMINAR

ON “SATELLITE DIGITAL RADIO”

Guided By: Submitted by: Mrs.Shikha Gupta Geeta Gupta (EC07035)

  www.powerpointpresentationon.blogspot.com

CONTENTSSATELLITE RADIOSIRIUS SATELLITE RADIOWORLD SPACEBASIC COMPONENT OF SATELLITE RADIOXM SATELLITE RADIOGROUND REPEATERSTHE SATELLITE RADIO RECEIVERSTECHNOLOGY FREQUENCY OF OPERATIONEARTH ORBITS

SATELLITE RADIOSatellite radio is a subscriber based radio service

that broadcast directly from satellites.

It is an advanced form of mobile radio service where one can receive compact disc quality music and other entertainment channels.

Even if the person is miles away from the radio station, the quality of the program is not affected

Sirius Satellite Radio

Operated in the United States and Canada

Provides 69 channels of music

65 channels of news, sports and entertainment

Broadcast 24 hours a day commercial free from three satellites

WorldSpaceBased in Silver SpringFirst stated by wanting to improve literacy in

AfricaCovers Asia, Europe, and AfricaLicensed to serve Central and South America AfriStar (serves Africa) and AsiaStar (serves Asia

and Europe)3 transmission beams; 50 channels eachWorldSpace satellite receivers are capable of

receiving data at a rate of 128 kilobits per second (Kbps).

BASIC COMPONENTS OF SATELLITE RADIO

The three satellite radio systems:

Satellites

Ground Repeaters

Radio Receivers

XM Satellite RadioUnited States and Canada73 music, 39 news, sports and entertainment, 29

regional traffic and weather, 23 play-by-play sports.XM Radio uses two Boeing HS 702 satellites,

appropriately dubbed "Rock" and "Roll," placed in parallel geostationary orbit, one at 85 degrees west longitude and the other at 115 degrees west longitude.

Geostationary Earth orbit (GED) is about 22.223 miles (35,764 km) above Earth, and is the type of orbit most commonly used for communications satellites

GROUND REPEATERS:

Satellite radio reception, poses threats from weather, tall building_ and mountains that can potentially interfere with broadcasts.

To avoid the interference caused by tall structures, both Sirius and XM Radio are supplementing their satellite coverage with terrestrial transmitters, called ground repeaters.

THE SATELLITE RADIO RECEIVER:

Existing AM/FM car radio will not be able to receive satellite radio broadcasts.

Replacement of the radio with a 3-band capable receiver (AM, FM, Sirius or XM Satellite).

11

Technology25 MHz in S band 2.3 GHz

2 multichannel operators 2320-2332.5 MHz (Sirius) 2332.5-2345 MHz (XM)

complementary terrestrial repeaters to overcome effects of

satellite signal blockage and multipath interference

AM/FM/SAT receivers

Spring 2006

FREQUENCY OF OPERATION

Digital radio is operated in a frequency range of between 215 - 230 MHz (Mega Hertz).

This part of the radio spectrum is sometimes called Band III, or VHF, and was previously used for some television transmissions and by the military.

The central frequency for the BBC National Multiplex is 225.648MHz.

Satellite Radio vs. OthersListening availability- SR very high, others

are moderate to low

Sound Quality-SR high, AM=very low, FM=High

Variety-SR Highest, Variable due to economic factors

Earth Orbits

15

Orbits

Spring 2006

Low Earth OrbitsHeight: 700-2000 km

Rotation Period: 90 min.Time in LOS of

earth station: 15 min.

Medium Earth OrbitsHeight: 8000-12000 km

Rotation Period: 5-12 hrs.Time in LOS of

earth station: 2-4 hrs.

Geostationary OrbitsHeight:35,780 km

Rotation Period: 24 hrs.Time in LOS of

earth station: 24 hrs.

GSONGSO

Geosynchronous Orbit (GSO) Uses XM (85oW 115oW) Communications (DBS, data)

Advantages 1 orbit per siderial day (23h56m) (geostationary) wide coverage

Disadvantages round trip latencies exceed .5 seconds weak coverage inadequate elevation angles at high latitudes Congestion

Medium Earth Orbit (MEO)Uses

Cellular telephone communicationsGPS (global positioning system)

Advantagesantenna size and power are relatively modest

and the latency is still smallDisadvantages

Proximity to Van Allen belt creates hazards to electronic systems

Low Earth Orbit (LEO) Uses

Data-communications (Little LEO)Data-and-voice communications (Big LEO)

AdvantagesLow power requirementsShort propagation delays

DisadvantagesGreater no. of satellites needed for coverage

Big LEO req’d to provide continuous service to US

CONCLUSIONIt will be an intelligent communications device that will offer more services and conveniences than can be provided by conventional analog technology.

For the broadcaster, digital radio is not just a way to stay competitive with other forms of digital sound, but one that offers numerous new business opportunities as well.

It is a bright future for listeners and broadcasters alike: a future that truly promises to provide 'the best sound on the airwaves' for the world.

REFERENCES

http://www.seminar.com/article/sdr_1.html, http://www.spinnakerlabs.com/Satellite

digital radio.pdf http://www.worldspace.comhttp://xmradio.com/whatisxm/index.xmc

THANK YOU....

QUERIES???