SOURCEFORGE » RALF » 2015 Evaluation and test of an optical / L-band tranceiver

Proposal of structure: 

Introduction - tell what is the aim of the project

State of art - talk about how L-band reception systems work currently

Project - Present our results, discuss them point by point

-Linearity - what is, show results, compare to the technical specification provided.

-Intermodulation - what is, show results, explain and compare to coax (theoretically)

-Phase/noise - what is, show results, explain and compare to coax (theoretically)

-Application

/////////////////START OF THE DOCUMENT//////////////////////////////////////////////////

h1. 1. Introduction

Earth stations are based on an indoor/outdoor unit architecture. The outdoor unit comprises antennas and the RF frontend (amplifier and up/down converter). The indoor unit includes the receiver, modem and network/application appliances. On typical consumer systems, the outdoor and indoor units are connected by means of a 75-ohm coaxial cable. The cable conveys the intermediate frequency (typically L band) signal between the indoor/outdoor units. 

This approach, while being cost effective, is not optimal from a signal quality standpoint and might severely impair the end-to-end link budget. For example, typical attenuation values for a coaxial cable at a frequency of 1 GHz are in the order of 15 dB/100 m.

The objective of this project is to test and evaluate a system that makes possible to convert the L-band RF signal from/to optical and use an optical fibre (up to 10 km) as primary interconnection media.  The signal is converted from optical back to RF in the indoor unit. As such, it is directed to DTH (Direct-To-Home) TV systems.

!schema.jpg!

h1. 2. State of the art

h1. 3. Measures

h2. 3.1 Linearity

h2. 3.2 Intermodulation

h2. 3.3 Phase/Noise

h1. 4. Results

h1. 5. Conclusions

h1. 6. Application