I am trying to collect signal from Thuraya-3. Here is the setup I used:
USRP N210 + WBX
LNA with 30dB gain (ZHL-1217MLN)
Iridium Antenna (I don’t have specific antenna for Thuraya right now.
Since Iridium and Thuraya frequency bands are quite close, I suppose it
would work more or less)
Center frequency: 1530MHz
Sampling rate: 10MHz
From the spectrum (attached), I can see the Inmarsat signal, but no sign
of
Thuraya signal. Anyone has suggestion about how to receive the thuraya
signal?
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Interesting. That amplifier is basically a power amp, rather than a
receiver amp, and the noise figure isn’t stunning, and 1.5dB.
I think it’s TDMA/FDMA, not spread spectrum. Each channel is about 30KHz.
Best regards,
Cheng C.
Make sure that you’re tuned to the correct frequency, and that your link
margins are adequate. It could be that your antenna has insufficient
gain for the signals coming from Thuruya. The Iridium birds are strong, and also in fairly low orbits.
You might need a real LNA at those frequencies–a GPS LNA would work,
except that you’d likely have to remove the 1575MHz filter.
The resources I’ve read say that the downlink is 1525-1559 MHz, which is
a
ways off from Iridium’s frequency of 1616-1626 MHz.
This would suggest that you should find a different antenna, like this
one
which covers both bands:
On Wed, Jan 29, 2014 at 10:14:19AM +0800, Cheng C. wrote:
From the spectrum (attached), I can see the Inmarsat signal, but no sign of
Thuraya signal. Anyone has suggestion about how to receive the thuraya
signal?
Are you aware of OsmocomGMR[1]? It’s a project that is aimed at
receiving the Thuraya signals. Although, AFAIK, so far only Thuraya2 was
received, due to the physical location of the people involed.
Are you aware of OsmocomGMR[1]? It’s a project that is aimed at
receiving the Thuraya signals. Although, AFAIK, so far only Thuraya2 was
received, due to the physical location of the people involed.
No, no we got some Thuraya 3 reception as well.
Dimitri had some vacation in Asia and he of course had packed SDR and
antenna for the trip
This is the map with the spot beam we captured :
The green ones are Thuraya 3. (Each spot beam reports its own GPS
center location in the broadcast channel).
From the spectrum (attached), I can see the Inmarsat signal, but no sign of
Thuraya signal. Anyone has suggestion about how to receive the thuraya
signal?
Several issues to improve :
Your antenna has the wrong polarization, this will definitely kill
your signals
