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From: | Mallesham Dasari |
Subject: | Re: [Discuss-gnuradio] usrp_spectrum_sense.py raw iq samples |
Date: | Fri, 6 Jan 2017 14:54:45 -0500 |
Hi Mallesham,
I meant that with your B210 you can only capture up to 56 MHz of real
time bandwidth (in theory).
> By whole WiFi band, I mean from 2.401G to 2.473G,
However, you require over 70MHz at once. I didn't realize that you still
want to use the sweeping approach.
In that case, the flow graph I suggested is not sufficient.
You might want to take a look at [1] which is the block
usrp_spectrum_sense.py is using internally and modify it to your needs.
I guess you could just remove the FFT and Complex to Mag Square block
from usrp_spectrum_sense.py
(change self.connect(self.u, s2v, ffter, c2mag, stats) to
self.connect(self.u, s2v, stats)) and make sure
that [1] accepts a vector of complex float as input and stores it to a
file instead of sending a message to the top block.
Or you take a look at [2].
The USRP Source can be controlled via a message interface. Therefore,
you could create a block that writes N samples to a file and then sends
a tune command
back to the USRP Source.
If you need more help, let me know.
[1]
http://gnuradio.org/doc/doxygen/classgr_1_1blocks_1_ 1bin__statistics__f.html
[2] http://gnuradio.org/doc/doxygen/page_uhd.html#uhd_ command_syntax
Cheers,
Julian
On 01/04/2017 10:42 PM, Mallesham Dasari wrote:
> Hi Julian,
>
> Thank you so much again. I am able to collect the raw IQ samples using
> USRP source and File sink with gnuradio-companion. But, I am confused
> why you said that I will run into additional problems.
>
> On Wed, Jan 4, 2017 at 12:22 PM, Mallesham Dasari
> <address@hidden <mailto:address@hiddenedu >> wrote:
>
> Hi Julian,
>
> Thank you so much for the response. By whole WiFi band, I mean
> from 2.401G to 2.473G, which is complete WiFi band. Is it possible
> to sweep entire band by using the approach you mentioned? I
> thought using gnuradio-companion, we can scan only one or few
> channels depending on the sample rate.
>
> Regarding Hardware: I am using USRP B210 with a sample rate of 8Msps.
>
> On Wed, Jan 4, 2017 at 4:00 AM, Julian Arnold
> > address@hidden <mailto:address@hidden> <address@hidden <mailto:address@hidden>> wrote:
>
> Hi Mallesham,
>
> the easiest way would probably be to create your own simple
> flowgraph
> using GRC like so:
>
> |---------------------| |-----------------|
> | USRP Source | ----------> | File Sink |
> |---------------------| |-----------------|
>
> However, remember that writing to a file can be slow. You
> might want to
> consider using a ramdisk.
> Also, what whole Wifi band are you talking about? Depending on
> your
> hardware configuration you might run into additional problems.
>
> Cheers,
> Julian
>
> On 01/03/2017 09:04 PM, Mallesham Dasari wrote:
> > Hello,
> >
> > I am writing the raw IQ samples (m.raw_data) from
> > usrp_spectrum_sense.py to a file. I would like to bypass the FFT
> > overhead, which I will do later. I want to scan the whole
> wide band of
> > wifi as fast as possible. Can anyone throw some light on how
> to take
> > only raw samples without FFT?
> >
> > --
> > Best Regards,
> > *Mallesham Dasari*
> > Department of Computer Science
> > Stony Brook University
> > USA - 11794
> >
> >
> > _______________________________________________
> > Discuss-gnuradio mailing list
org >
> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> <https://lists.gnu.org/mailman/listinfo/discuss- >gnuradio
>
>
>
>
>
> --
> Best Regards,
> *Mallesham Dasari*
> Department of Computer Science
> Stony Brook University
> USA - 11794
>
>
>
>
> --
> Best Regards,
> *Mallesham Dasari*
> Department of Computer Science
> Stony Brook University
> USA - 11794
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