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

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h1. 4. Results

This section explains how the Outdoor system has been installed and the results obtained measuring a real TV signal from a Satellite. 

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Optical system (transmitter + fiber + receiver)

h2. 4.1 Preparation

The optical transmitter has been put in an hermetic box.

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Hermetic box installed outdoors

Its interface consists of :

* The power supply plug to be connected to the mains ;

* The optical fiber harness (2 fibers) : only the red fiber is actually connected to optical transmitter ; the black fiber is not used, it will enable to have a b ;

* The type F coaxial cable to connect the Antenna Low Noise Block, LNB, to optical transmitter.

Optical transmitter is set to :

* To supply 18 V to LNB, which selects Horizontale polarization ;

* To provide 0 kHz tone to LNB, which set its Local Oscillator to 9.75 GHz to transpose lower Ku Band from  10.7 to 11.7 GHz into IF Band.

* This hermetic box has been mounted on Antenna mast. This Antenna is pointing to Astra 1KR/1L/1M/1N colocalized satellites on 19.2° East.

h2. 4.2 Trials

h3. 4.2.1 Inter Frequency Spectrum with Optical Link

RF output from Optical receiver has been analyzed with Rohde & Schwartz FSV spectrum analyzer :

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_IF Band, 1 Channel (with Optical Link)_

It is possible to distinguish several channels within the Inter Frequency, IF, band. There is a zoom on left side. The 3 dB channel bandwdith is 22 MHz.

The power is about -32 dBm for the channel centered around 1141 MHz.

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_TV channel at 1141 MHz_

h3. 4.2.2 Link Quality with Optical link

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Measurement setup based on TV, Tuner, IPRICOT SCB router with Optical Receiver (On screen : Einsfestival program on 10744 MHz Horizontal Polarization)

First, optical link performance enables to have a good TV quality (for example, Einsfestival Plus on 10744H).

Channel power and bandwidth have been checked with Spectrum Analyzer.

More deeply, physical link quality has been assessed with the information provided by IPRICOT SCB router :

* QPSK demodulation, Forward Error Correction Rate Detection , Frame Synchronization are set to green ;

* Eb/No is reported by IPRICOT.

This data has been compared with data from website like [www.lingsat.com] :

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Summary Table

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Channel Bandwidth & Power at 994 MHz (Ku channel @ 10744 MHz)

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Physical link parameter at 10744 MHz

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Channel Bandwidth & Power at 1494 MHz (Ku channel @ 11244 MHz)

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Physical link parameter at 11244 MHz