Transmission and reception using two USRP N200 devices about gr-dvbt HOT 8 CLOSED

Hi,

the gr-dvbt has been tested with two USRP N210 for all possible configurations of parameters and it worked just fine.

To answer to your question, if you open dvbt_tx_demo.grc and dvbt_rx_demo.grc you will see disabled USRP source/sinks. If you use those instead of file source/sink you should be fine as they are configured already.

More precisely, the sample rate for gr-dvbt with a 8Mhz bandwidth should be 9.14Msps but given the fact that USRP N210 cannot support that, the rational resampler block is used to upsample/downsample at 10Msps sample rate. Therefore the USRP N210 works at 10Msps which gives 10Mhz bandwidth.

B

from gr-dvbt.

Ok, thanks!

I also did almost the same thing.
The only differences are my devices which are USRPN200s plus xcvr2450 daughterboards.
xcvr2450 can produce 2.4-2.5 GHz and 5-6 GHz. Therefore I change frequency to 2.4 GHz. However it has to work.

I will test again and write here. For now, it seems like everything gets distorted and I receive only very distorted symbols that even their symbol indexes are wrong.

from gr-dvbt.

Hi there,

I get these warnings, i wonder if you also get them:

gr::buffer::allocate_buffer: warning: tried to allocate
43 items of size 1512. Due to alignment requirements
512 were allocated. If this isn't OK, consider padding
your structure to a power-of-two bytes.
On this platform, our allocation granularity is 4096 bytes.
gr::buffer::allocate_buffer: warning: tried to allocate
43 items of size 1504. Due to alignment requirements
128 were allocated. If this isn't OK, consider padding
your structure to a power-of-two bytes.
On this platform, our allocation granularity is 4096 bytes.
gr::buffer::allocate_buffer: warning: tried to allocate
43 items of size 1512. Due to alignment requirements
512 were allocated. If this isn't OK, consider padding
your structure to a power-of-two bytes.
On this platform, our allocation granularity is 4096 bytes.
gr::buffer::allocate_buffer: warning: tried to allocate
40 items of size 1632. Due to alignment requirements
128 were allocated. If this isn't OK, consider padding
your structure to a power-of-two bytes.
On this platform, our allocation granularity is 4096 bytes.
gr::buffer::allocate_buffer: warning: tried to allocate
43 items of size 1512. Due to alignment requirements
512 were allocated. If this isn't OK, consider padding
your structure to a power-of-two bytes.
On this platform, our allocation granularity is 4096 bytes.

NE

from gr-dvbt.

Hi, I do get those, however, these are jut warnings from gnuradio and should not affect the functionality.

/B

from gr-dvbt.

I attached .grc files, it will be nice of you to help me!

from gr-dvbt.

As I understand it is also a synchronization issue...
When two usrps transmitt and receive at the same time it fails either to synch. or frequency/phase correction.

from gr-dvbt.

Perfect! it worked: http://lists.gnu.org/archive/html/discuss-gnuradio/2014-03/msg00683.html

from gr-dvbt.

Thanks a lot!

from gr-dvbt.