|Subject:||Re: [Discuss-gnuradio] Broadband Applications with USRP|
|Date:||Thu, 04 Dec 2014 23:41:47 -0800|
|User-agent:||Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.6.0|
You can try my DVB-S2 modulator to do some transmit benchmarking.|
With the test flow graph, to send a 30 MHz wide signal (which is actually
typical for real DVB-S2 uplinks), you'll need to set the symbol rate to
30 / 1.2 or 25 Msymbols/sec. Since the modulator uses 2X oversampling,
the sample rate will be 50 Msps.
You'll need an SDR that can operate at that sample rate with an
interface that can keep up. A B2x0 could work if you have a good
The CPU bottleneck on the DVB-S2 flow is the FEC (both LDPC and BCH)
generation. The net bit-rate at 25 Msyms/s with the test flow graph
will be 87 Mbps.
In general, receive is usually much worse CPU wise. Again, the FEC can
take an enormous amount of CPU cycles.
On 12/04/2014 01:44 PM, Lefteris Kampianakis wrote:
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