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GOMEZ, Ramon, 12/14/2015 05:57 PM


4. Results

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

transrecv.jpg
Optical system (transmitter + fiber + receiver)

4.1 Preparation

The optical transmitter has been put in an hermetic box.

installation.jpg
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 Horizontal 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 co-localized satellites on 19.2° East.


Hermetic box installed on Antenna Mast

4.2 Trials

4.2.1 Inter Frequency Spectrum with Optical Link

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

rsz_combine_images
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.

rsz_tv_channel.png
TV channel at 1141 MHz

4.2.2 Link Quality with Optical link

Setup TV IPRICOT
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 3 dB Channel bandwidth have been checked with Spectrum Analyzer.

More deeply, physical link quality has been assessed with the information provided by IPRICOT SCB router :
  • IPRICOT confirms that input signal is a QPSK modulation with Forward Error Correction Rate of 5/6 (RX_SIG & VITSYNC set to green). Moreover, IPRICOT is able to get the Frame Synchronization (FSYNC set to green) ;
  • Eb/No is reported by IPRICOT.

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

Ku Channel [MHz] IF Channel [MHz] TV www.lingsat.com Spectrum Analyzer IPRICOT
Channel Physical Protocol EIRP[dBW] 3 dB CH BW [MHz] CH Power [dBm] Physical Protocol Eb/No[dB]
10744H 994 Eins Plus DVB-S QPSK 22 Msps 5/6 About 22 -31.94 DVB-S QPSK 22 Msps 5/6 7.7
11244H 1494 Schau TV DVB-S QPSK 22 Msps 5/6 About 22 -32.81 DVB-S QPSK 22 Msps 5/6 7.9


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

rsz_ipr_sc.png
Physical link parameter at 10744 MHz