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recieve with two antenas individually and simultaneously

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recieve with two antenas individually and simultaneously

manjusha
Hi,

I have the following connections in my grc file.

usrp source(900M)-->gmsk mod-->packet decoder-->file sink1
usrp source(928M)-->gmsk mod-->packet decoder-->file sink2

I am trying to receive the packets at two different frequencies.I can definitely see some data in the file sinks i used.But,the problem is each file sink shows a certain number of packets only.For example,if usrp@900M receives packets 22,23,24,usrp@928M receives packets 25,27.As you can see that 26th packet is missing and might have been dropped.Each antenna is separating the continuous flow of packets and no duplicity of packets is formed.Can someone explain why is this happening?!And what can i do to get rid of this and receive all the packets individually on each antenna(like usrp@900 receives 21,22,23,24 and usrp@928M also received 21,22,23,24).

If i am unclear with the question,please do let me know.

Thanks,
Manjusha.
Manjusha
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Re: recieve with two antenas individually and simultaneously

mleech
> Hi,
>
> I have the following connections in my grc file.
>
> usrp source(900M)-->gmsk mod-->packet decoder-->file sink1
> usrp source(928M)-->gmsk mod-->packet decoder-->file sink2
>
> I am trying to receive the packets at two different frequencies.I can
> definitely see some data in the file sinks i used.But,the problem is each
> file sink shows a certain number of packets only.For example,if usrp@900M
> receives packets 22,23,24,usrp@928M receives packets 25,27.As you can see
> that 26th packet is missing and might have been dropped.Each antenna is
> separating the continuous flow of packets and no duplicity of packets is
> formed.Can someone explain why is this happening?!And what can i do to get
> rid of this and receive all the packets individually on each antenna(like
> usrp@900 receives 21,22,23,24 and usrp@928M also received 21,22,23,24).
>
> If i am unclear with the question,please do let me know.
>
> Thanks,
> Manjusha.
>
>
>
>
>
>
When asking this type of questions, it's best to actually attach your
flow-graph, or a pointer to a pastebin of your flow-graph, and give
*DETAILS*
   of your hardware setup.  What type of USRP?  How many and what type
of daughtercards, etc...



--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org



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Re: recieve with two antenas individually and simultaneously

manjusha
Okay..

Here are the additional details..

I am using USRP1,RFX900,750Mhz to 1050mhz transceiver daughter board. Also,kindly find the attached grc file i am using.

Please let me know if more details are required..

Thanks!final_msg_rx.grc
Manjusha
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Re: recieve with two antenas individually and simultaneously

mleech
> Okay..
>
> Here are the additional details..
>
> I am using USRP1,RFX900,750Mhz to 1050mhz transceiver daughter board.
> Also,kindly find the attached grc file i am using.
>
> Please let me know if more details are required..
>
> Thanks! final_msg_rx.grc
> <http://gnuradio.4.n7.nabble.com/file/n41495/final_msg_rx.grc>
>
>
>
> -----
> Manjusha
> --
> View this message in context: http://gnuradio.4.n7.nabble.com/recieve-with-two-antenas-individually-and-simultaneously-tp41492p41495.html
> Sent from the GnuRadio mailing list archive at Nabble.com.
>
> _______________________________________________
> Discuss-gnuradio mailing list
> [hidden email]
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
>
So, to clarify, you have a SINGLE USRP1, a SINGLE RFX900?

You flow-graph uses two independant UHD sources, which won't work.  You
need a single UHD source, configured for two output channels,
   and use the dual-DDC mode to extract your two frequencies (which, by
the way, are far enough apart that this will barely work).



--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org



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Re: recieve with two antenas individually and simultaneously

manjusha
using Volk machine: ssse3_64
-- Opening a USRP1 device...
-- Using FPGA clock rate of 64.000000MHz...
Traceback (most recent call last):
  File "/home/gnuradio/grc/Project/relays/top_block.py", line 126, in <module>
    tb = top_block()
  File "/home/gnuradio/grc/Project/relays/top_block.py", line 62, in __init__
    self.uhd_usrp_source_0.set_center_freq(900e6, 1)
  File "/usr/local/lib/python2.7/dist-packages/gnuradio/uhd/uhd_swig.py", line 1879, in set_center_freq
    return _uhd_swig.uhd_usrp_source_sptr_set_center_freq(self, *args)
RuntimeError: vector::_M_range_check

>>> Done

we just tried using single USRP source but we got the error which is shown  above,Is it possible to use a single usrp and single daughter-board at different frequencies and receive the signal.final_msg_rx.grc
for your reference the GRC file is attached

Thanks
Manjusha
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Re: recieve with two antenas individually and simultaneously

mleech
> using Volk machine: ssse3_64

> -- Opening a USRP1 device...
> -- Using FPGA clock rate of 64.000000MHz...
> Traceback (most recent call last):
>    File "/home/gnuradio/grc/Project/relays/top_block.py", line 126, in
> <module>
>      tb = top_block()
>    File "/home/gnuradio/grc/Project/relays/top_block.py", line 62, in
> __init__
>      self.uhd_usrp_source_0.set_center_freq(900e6, 1)
>    File "/usr/local/lib/python2.7/dist-packages/gnuradio/uhd/uhd_swig.py",
> line 1879, in set_center_freq
>      return _uhd_swig.uhd_usrp_source_sptr_set_center_freq(self, *args)
> RuntimeError: vector::_M_range_check
>
>>>> Done
> we just tried using single USRP source but we got the error which is shown
> above,Is it possible to use a single usrp and single daughter-board at
> different frequencies and receive the signal. final_msg_rx.grc
> <http://gnuradio.4.n7.nabble.com/file/n41518/final_msg_rx.grc>
> for your reference the GRC file is attached
>
> Thanks
>
>
>
>
> -----
> Manjusha
> --
> View this message in context: http://gnuradio.4.n7.nabble.com/recieve-with-two-antenas-individually-and-simultaneously-tp41492p41518.html
> Sent from the GnuRadio mailing list archive at Nabble.com.
>
> _______________________________________________
> Discuss-gnuradio mailing list
> [hidden email]
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
>
Here's an example of something that should work -- It uses a USRP2/N210
device addressing, but you should be able to change this for a USRP1.



--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org


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dual_channel_wbx.grc (27K) Download Attachment
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Re: recieve with two antenas individually and simultaneously

manjusha
I tried doing that..I gives me no output when i use Mb0 sub device specification.here is the file after changes are made.final_msg_rx.grc

Thanks!
Manjusha
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Re: recieve with two antenas individually and simultaneously

mleech
> I tried doing that..I gives me no output when i use Mb0 sub device
> specification.here is the file after changes are made. final_msg_rx.grc
> <http://gnuradio.4.n7.nabble.com/file/n41521/final_msg_rx.grc>
>
> Thanks!
>
>
>
> -----
> Manjusha
> --
> View this message in context: http://gnuradio.4.n7.nabble.com/recieve-with-two-antenas-individually-and-simultaneously-tp41492p41521.html
> Sent from the GnuRadio mailing list archive at Nabble.com.
>
> _______________________________________________
> Discuss-gnuradio mailing list
> [hidden email]
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
>
Does it give you errors, or just not hte output you expect?

How about you attach an FFT to both sides, and see if they are what you
expect?

I mean, at this point, we're debugging your flow-graph for you



--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org



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Re: recieve with two antenas individually and simultaneously

manjusha
It does not give me any error but there is no output at all. We have attached FFT as shown in the GRC file51.png Here attached the screen shot of the FFT plot
Manjusha
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Re: recieve with two antenas individually and simultaneously

manjusha
We will be happy if someone tells us where we are actually going wrong.

Thanks!
Manjusha
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