Re : audio transmission between two usrp

when i am trying to transfer an audio signal from one usrp to another, i
can’t able to get the signal exactly. can anyone please help me in getting
the original signal without noise.

Hi Lingeswar,
Make sure the transmitted signal level is good enough. Also try to
adjust (increase) the channel gain of the receiver (usrp). This can
optimize the SNR.
You might experience that the received audio signal plays at different
rate (low or fast). If this happens, then verify the sample rate of the
signal you send to the audio sink.
Regards.
Dominique.
— En date de: Jeu 8.11.12, [email protected]
[email protected] a crit:

De: [email protected] [email protected]
Objet: Discuss-gnuradio Digest, Vol 120, Issue 9
: [email protected]
Date: Jeudi 8 novembre 2012, 18h00

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Today’s Topics:

  1. Re: File Sink slow? (Eral T?rkyilmaz)
  2. Re: Separate samples from 2 receive channels (Josh B.)
  3. Re: File Sink slow? ([email protected])
  4. Re: File Sink slow? (Eral T?rkyilmaz)
  5. Re: File Sink slow? (Eral T?rkyilmaz)
  6. Re: howto_square_ff require Gruel (Gong Z.)
  7. audio transmission between two usrp (Lingeswar Lingeswar)

Message: 1
Date: Wed, 7 Nov 2012 17:30:39 +0000 (UTC)
From: Eral T?rkyilmaz [email protected]
To: [email protected]
Subject: Re: [Discuss-gnuradio] File Sink slow?
Message-ID: [email protected]
Content-Type: text/plain; charset=utf-8

<mleech ripnet.com> writes:

There have been problems with the 82579LM dropping packets,
even when there’s no
reason to.? There’s a horrible bug in its FIFO logic, apparently.?
Various driver
patches have been applied over the years in Linux to try to get around
it,
but at
the end of the day, it’s the hardware.?
It wouldn’t surprise me if your problem is
related to that.
?

Thank you very much for that hint. Do you recommend any special network
card?


Message: 2
Date: Wed, 07 Nov 2012 09:55:34 -0800
From: Josh B. [email protected]
To: [email protected]
Subject: Re: [Discuss-gnuradio] Separate samples from 2 receive
channels
Message-ID: [email protected]
Content-Type: text/plain; charset=ISO-8859-1

On 11/06/2012 11:15 PM, Dekst wrote:

You might want to look at rx_multi_samples.cpp as an example of a
streamer w/ multiple channels. Basically, the recv() call will fill 2
buffers in this case, not one. In other words, the data is not
interleaved.

I also recommend using the gnuradio companion. You can make a simple
flow graph with a USRP source with two output stream and simply connect
2 file sinks.

-josh

Thanks,
Pei


Discuss-gnuradio mailing list
[email protected]
Discuss-gnuradio Info Page


Message: 3
Date: Wed, 07 Nov 2012 13:36:00 -0500
From: [email protected]
To: [email protected]
Subject: Re: [Discuss-gnuradio] File Sink slow?
Message-ID: [email protected]
Content-Type: text/plain; charset=“utf-8”

On 07 Nov 2012 12:30, Eral T?rkyilmaz wrote:

ripnet.com>
writes:

There have been problems with the 82579LM dropping
packets,

even when there’s no
reason to. There’s a horrible bug
in its FIFO logic, apparently.
Various driver
patches have been
applied over the years in Linux to try to get around it,
but at

the end of the day, it’s the hardware.

It wouldn’t surprise me if
your problem is
related to that.

Thank you very much for
that hint. Do you recommend any special network card?


Discuss-gnuradio
mailing list
[email protected]

https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

To be clear,
the 82579LM issue is something you should look in to. Not guaranteed
that’s you’re problem, but I can’t think of another reason.

Also, to
be sure. You are using this interface in 1GiGE mode, right? Connected
directly to the N210 without any switches or other detritus in the
middle?

I use a number of different network interfaces on my machines,
they all work. Even the cheezy RealTek $25.00 1GiGe PCI or PCIe cards
should work for you, particularly at lower sample rates.

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Message: 4
Date: Wed, 7 Nov 2012 19:12:22 +0000 (UTC)
From: Eral T?rkyilmaz [email protected]
To: [email protected]
Subject: Re: [Discuss-gnuradio] File Sink slow?
Message-ID: [email protected]
Content-Type: text/plain; charset=utf-8

To be clear, the 82579LM issue is something you should look in to.? Not
guaranteed that’s you’re problem, but I can’t think of another reason.
Also, to be sure.? You are using this interface in 1GiGE mode, right??
Connected directly to the N210 without any switches or other detritus in
the
middle?
I use a number of different network interfaces on my machines, they all work.?
Even the cheezy RealTek $25.00 1GiGe PCI or PCIe cards should work for
you,
particularly at lower sample rates.
?

I have now tested the same graph
(http://s14.postimage.org/r5ekme5pd/dump_test.jpg) at a lower speed of 1
MS/s
with the 82579LM. It still produces over-runs.

Then I have tested it with two other Intel Network cards (82583V,
82574L)
also at 1 MS/s. They don’t produce overruns. But if I double the sample
rate to 2MS/s I get overruns again.

So the 82579LM definitely performs worse. But the other cards are not
really
much better.

I would like to ask if anybody could try to capture data (see flowgraph)
with
the USRP N210 at such speeds > 2MS/s upto 10MS/s for a longer period of
time
and look if there are overflows?


Message: 5
Date: Wed, 7 Nov 2012 22:42:36 +0000 (UTC)
From: Eral T?rkyilmaz [email protected]
To: [email protected]
Subject: Re: [Discuss-gnuradio] File Sink slow?
Message-ID: [email protected]
Content-Type: text/plain; charset=utf-8

<mleech ripnet.com> writes:

To be clear, the 82579LM issue is something you should look in to.?
Not guaranteed that’s you’re problem, but I can’t think of another
reason.
Also, to be sure.? You are using this interface in 1GiGE mode, right??
Connected directly to the N210 without any switches or other
detritus in the middle?
I use a number of different network interfaces on my machines, they all work.?
Even the cheezy RealTek $25.00 1GiGe PCI or PCIe cards should work for
you,
particularly at lower sample rates.
?

All cards are in gigabit ethernet mode and the USRP is directly
connected to
the network card, so nothing in between.


Message: 6
Date: Thu, 08 Nov 2012 17:13:54 +0800
From: Gong Z. [email protected]
To: Tom R. [email protected]
Cc: [email protected]
Subject: Re: [Discuss-gnuradio] howto_square_ff require Gruel
Message-ID: [email protected]
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Tom R. wrote:

build an out-of-tree project; that is, not inside of the GNU Radio
source code. Use “gr_modtool.py newmod” and then in gr- use “gr_modtool.py add” to add howto_ff. You should see that
gr-/cmake/Modules has a file “FindGruel.cmake” that the
component will use to find the installed GNU Radio packages and build
against them.

Tom

I’m quite sorry that I failed to explain my question clearly.what I
wanna is add the ‘howto’ module to gnuradio so I can use it in grc.As
you seen I excute cmake in ~/gnuradio.3.6.1/build but not
~/gnuradio/gr-howto/build.Thank you for your patience.


Message: 7
Date: Thu, 8 Nov 2012 16:35:20 +0530
From: Lingeswar Lingeswar [email protected]
To: [email protected]
Subject: [Discuss-gnuradio] audio transmission between two usrp
Message-ID:
[email protected]
Content-Type: text/plain; charset=“iso-8859-1”

when i am trying to transfer an audio signal from one usrp to another, i
can’t able to get the signal exactly. can anyone please help me in
getting
the original signal without noise.

regards,

lingeswar
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