SatNEx
satellite communications tutorial
at ISTI - CNR, Pisa, Italy

Presentation

Satellite transmissions have an important role in telephone communications, television distribution, computer communications, maritime navigation, and military command and control. Moreover, due to their nature, in many situations they constitute the only way for communicating. Recent trends in telecommunications indicate that four major growth market/service areas are: messaging and navigation services (wireless and satellite), mobility services (wireless and satellite), video delivery services (cable and satellite), and interactive multimedia services (fiber, satellite, cable).

The major drawback in using geostationary satellites is the long delay that can have an important impact in the end-to-end delay user requirements. Moreover, atmospheric conditions may affect the data transmitted in a very heavy way.

The tutorial aims at giving the basic elements of telecommunications via geostationary satellite. LEO constellations are shortly examined: even after the failures of Iridium and Teledesic as commercial services, they promise to play an important role in the future. Aspects considered will include basic transmission and multiple access techniques, channel modeling and fade countermeasures, performance analysis by theoretical, experimental, and simulation tools.

Tutorial outline

1. A brief story of the satellite communications
2. GEO, MEO and LEO: an overview
3. Satellite payload & frequency bands
4. Basic transmission theory
   1. Isotropic source
   2. Antenna gain
   3. EIRP
   4. Noise temperature and G/T ratio
   5. Down-link requirements
   6. Design of satellite links for specified C/N
   7. Design of satellite links to achieve a specified performance
5. Modulation and Multiplexing techniques for satellite links
   1. FDM, TDM, BPSK, QPSK
6. Digital modulation and demodulation
   1. terminology
   2. modulation & coding
   3. bit and symbol rates
   4. types of codes
7. Multiple access
   1. FDMA
   2. TDMA
      1. frame, overhead (preamble and UW) and reference burst
      2. synchronisation and timing
      3. guard times
      4. (ALOHA, F-TDMA, DA-TDMA)
8. Estimating channel requirements
9. Rain attenuation
10. Fade countermeasures
    1. site/frequency diversity
    2. adaptive TDMA
11. Fade detection
12. An example of TDMA access scheme with fade countermeasure
13. A simulator for TDMA channel access schemes
14. What is a VSAT system
15. LEO constellations
    1. some examples

Subscription details

Intended audience: students of the SatNEx community
Provisional dates: September 27-28; December 16-17, 2004.
Minimum attendance: 8 persons registered 20 days before the provisional date
Tutorial duration: 10 hours
Registration fee: 200€ (2 lunch tickets included)

Subscription: write to Ettore Ricciardi <ettore.ricciardi@isti.cnr.it> with a subject of SatNEx satellite tutorial.