Satellite and Radio Communication

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Recent Trends in Wireless Radio and Satellite Communication

Gori Shankar1, Rajiv Kumar2
Suresh Gyan Vihar University, M.Tech (VLSI) 1 ,Jaipur Engg. College, B.Tech (ECE) 2 gssharma1951@gmail.com,rajivresnick@gmail.com

Abstract- In this paper we discussed satellite and radio communication links. Satellites have evolutionized communication. Satellite and radio communication has served mankind in many ways for instance it is used to predict weather and broadcast storm warnings and also provides a wide range of communication. Here satellite and radio communication recent technical advances, role in various fields and there applications are discussed. And various term related to communication such as geosynchronous orbit, Software Defined radio (SDR) etc. Key Words: Advanced Communication Technology satellite (ACTS), Geosynchronous Orbit (GO), National Aeronautics and Space Administration (NASA)

INTRODUCON

In this present era, communication plays a vital role. We use a wide range of devices to communicate between two persons placed at different places (irrespective of the distance between them). Any earth-orbiting spacecraft that provides communication over long distances by reflecting or relaying radio-frequency signals. Satellites have evolutionized communication by making worldwide Telephone links and live broadcasts co mmo n occurrences. A satellite receives a microwave signal from a ground station on the earth (the uplink), then amplifies and retransmits the signal back to a receiving. The Satellite itself is also known as the space segment, and is composed of three separate units, namely the fuel system, the satellite and telemetry controls, and the transponder. Radio is the transmission of signals by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by

means of oscillating electromagnetic fields that pass through the air and the vacuum of space.

II. VARIOUS USES OF RADIO AND SATELLITE C O MM U N I C A T I O N

Traditional Telecommunications, Cellular, Television Signals, Telephony, Radar, Digital radio, heating, Telecommunication, Direct Telecast

III.GEOSYNCHRONOUS ORBIT

A satellite in a GO follows a circular orbit over the equator at an altitude of 35,800 km (22,300 mi), completing one orbit every 24 hours, in the time that it takes the earth to rotate once. Moving in the same direction as the earth's rotation, the satellite remains in a fixed position over a point on the equator, thereby providing uninterrupted contact between ground stations in its line of sight. The first communications satellite to be placed in this type of orbit was Syncom 2, launched by the (NASA) in 1963. Most communications satellites that followed were also placed in GO.

4. Recent Technical Advances

Communications s a t e l l i t e systems have entered a period of transition from point-to-point high-capacity trunk communications between large, costly ground terminals to multipoint-to-multipoint communications between small, low-cost stations. The development of m u l t i p l e access methods has both hastened and facilitated this transition. With TDMA, each ground station is assigned a time slot on the same channel for use in transmitting its communications; all other stations monitor theses lots and select the communications directed to them. By amplifying a single carrier frequency in each satellite repeater, TDMA ensures the most efficient use of the satellite's onboard power supply.

A technique called frequency reuse allows satellites to communicate with a number of ground stations using the same frequency by transmitting in narrow beams pointed toward each of the stations....
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