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Andreas Eversberg 5 years ago
parent 0b504dbeb3
commit dacf07ee9a
  1. 56
      docs/sdr.html

@ -79,17 +79,12 @@ In case of B-Netz, I use the following parameters:
--sdr-rx-gain 30 \
--sdr-tx-gain 30 \
--sdr-samplerate 5000000 \
--sdr-bandwidth 15000000 \
-s 100000 \
-k 17
</pre>
<p>
Be sure to select the right RX antenna input.
The frequencies we use require the low frequency filter network, so I suggest to connect your antenna to RX_1_L and select "--sdr-rx-antenna LNAL".
Different versions of LimeSuite have different default antenna inputs, so be sure to set your RX antenna.
</p>
<p>
In order to change from analog sound card to SDR, you need <b>--sdr-soapy</b> option.
In my setup I use antennas directly connected to the SDR.
@ -103,6 +98,30 @@ Note that channel 19 is not given here, but will be used automatically.
With B-Netz, the transmitter switches from any voice channel to the paging channel (19) whenever the phone gets paged.
</p>
<p>
Alternatively you can have these options pre-set by just a single option: <b>--limesdr</b>
But still you can add any SDR option afterwards to set or modify them.
</p>
<pre>
# bnetz --limesdr -k 17
</pre>
<p>
Be sure to select the right RX antenna input.
The frequencies we use require the low frequency filter network, so I suggest to connect your antenna to RX_1_L and select "--sdr-rx-antenna LNAL".
Different versions of LimeSuite have different default antenna inputs, so be sure to set your RX antenna.
</p>
<p>
My LimeSDR setup causes a bad RX signal, when the RX frequency of the channel (uplink) equals the center frequency of the RX spectrum.
This center frequency is used as RX frequency, when only one channel is created for the base station.
By creating two channels ('-k 15 -k 17') or an even number would eliminate the problem.
The center frequency is between the channels now.
</p>
<center><img src="display-iq.png"/></center>
<p>
@ -160,6 +179,12 @@ The software will notice you, if the channels wont fit into the spectrum.
In this case increase the sample rate (-s) to generate a wider spectrum. (--sdr-samplerate must not need to be changed)
</p>
<p>
If multiple channels are defined, the channel type for the first channel is automatically set to the control channel,
the other channels to voice channels.
You may still alter this by specifying channel type for each channel.
</p>
<p>
Note that the CPU usage increases for the main thread.
I suggest to monitor the usage using "top -H".
@ -181,6 +206,7 @@ Because C-Netz uses only odd channel numbers for 10 KHz spacing, we use channel
--sdr-rx-gain 30 \
--sdr-tx-gain 30 \
--sdr-samplerate 5000000 \
--sdr-bandwidth 15000000 \
-s 100000 \
-k 131 -k 135 \
-C 0,0
@ -203,6 +229,24 @@ Transmit PAL 'FUBK' test image on TV channel 21.
</pre>
<p>
<b>Example: Receive or transmit a radio broacast channel</b><br>
Receive radio station at 105.6 MHz with German stereo carrier (Pilot-Tone) and output it on sound card 0, device 0.
If you replace <b>--rx</b> by <b>--tx</b>, you will transmit from sound card.
</p>
<pre>
# osmoradio --limesdr \
-f 105600000
-M fm
-s 500000
-S
-a hw:0,0
--rx
</pre>
<hr><center>[<a href="index.html">Back to main page</a>]</center><hr>
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