NATIONAL SOCIETY OF BLACK ENGINEERSNATIONAL SOCIETY OF BLACK ENGINEERS

EARTH STATION CONFIGRATIONEARTH STATION CONFIGRATIONPresented By: Linus Antonio Ofori Agyekum ANU08130018

N A T I O N A L S O C I E T Y O F B L A C K E N G I N E E R SN A T I O N A L S O C I E T Y O F B L A C K E N G I N E E R Sw w w . n s b e . o r gw w w . n s b e . o r g

Contents

General Configuration of Earth Station

1

Transmitter 2

Receiver 3

N A T I O N A L S O C I E T Y O F B L A C K E N G I N E E R SN A T I O N A L S O C I E T Y O F B L A C K E N G I N E E R Sw w w . n s b e . o r gw w w . n s b e . o r g

General configuration of Earth Station

N A T I O N A L S O C I E T Y O F B L A C K E N G I N E E R SN A T I O N A L S O C I E T Y O F B L A C K E N G I N E E R Sw w w . n s b e . o r gw w w . n s b e . o r g

Transmitter

Digital information from terrestrial networks is filtered, multiplexed, formatted etc. by the base band equipment.

The encoder performs error correction coding(introducing extra digits into digital stream generated by the base band equipment.)

Modulator modulates I.F carrier using accepted symbol stream from encoder . (in satellite communication I.F carrier frequency is chosen at 70MHz for 36MHz transponder bandwidth and 140MHz for 54 or 72MHz transponder bandwidth.)

The up-converter translates I.F frequency to uplink R.F frequency.

Modulated R.F carrier is then amplified by the high power amplifier (HPA) to a suitable level for transmission and radiation by the antenna to the satellite.

N A T I O N A L S O C I E T Y O F B L A C K E N G I N E E R SN A T I O N A L S O C I E T Y O F B L A C K E N G I N E E R Sw w w . n s b e . o r gw w w . n s b e . o r g

Receiver

The earth station antenna receives the low-level modulated R.F carrier in the downlink frequency spectrum.

LNA is used to amplify the weak received signals and improve the SNR.

The down converter reconverts R.F to I.F at 70 or 140 MHz because it is easier design a demodulator to work at these frequencies than 4 or 12 GHz.

The up-converter translates I.F frequency to uplink R.F frequency.

Demodulator estimate the possible symbols transmitted based on observation of the received I.F carrier.

The decoder performs a function opposite that of the encoder.

The information stream is fed to the base-band equipment.

The tracking equipments track the satellite and align the beam towards it to facilitate communication.

NATIONAL SOCIETY OF BLACK ENGINEERSNATIONAL SOCIETY OF BLACK ENGINEERS