Re: [Discuss-gnuradio] Question regarding vector_sink_c

[Wee Shinhan]

> 
> Message: 1
> Date: Wed, 9 Jan 2008 17:44:57 -0800 (PST)
> From: Wee Shinhan <address@hidden>
> Subject: Re: [Discuss-gnuradio] Question regarding
> vector_sink_c
> To: Eric Blossom <address@hidden>, GNU radio
> <address@hidden>
> Message-ID:
> <address@hidden>
> Content-Type: text/plain; charset=iso-8859-1
> 
> Hi eric, 
> 
> Thanks for the reply, i have connected it to the
> channel filters, i trying to do an estimate on
> wireless channel coefficient. Therefore i'm trying
> to
> capture the complex data received before
> de-modulation. I havent have much success using
> vector
> sink even when i set a range for the data captured,
> all doesnt seems right.
> 
> Is there any blks that will be useful for my
> experiment? Or do i have to write my own C++ blk to
> process my needs. Thanks again.
> 
> regards,
> ShinHan
> 
> --- Eric Blossom <address@hidden> wrote:
> 
> > On Tue, Jan 08, 2008 at 08:26:43PM -0800, Wee
> > Shinhan wrote:
> > > Hi guys,
> > > 
> > > I'm using the vector_sink block to capture
> complex
> > > data from the receiver USRP (in the hope to be
> > able to
> > > predict the wireless channel coeff) I printed
> the
> > > recevied complex data using the rx_callback
> > function
> > > in receive_path.py script. The problem is the
> > > vector_sink produces endless amount of complex
> > number
> > > even though my transmitter has already finish
> > > transmitting. I connect my vector sink to
> > > self.packect_receiver in receive_path.py, the
> > vector
> > > sink should be empty if no packet is received
> > right?
> > > If so why am i experiencing this problem. Please
> > > advice. Thanks in advance.
> > > 
> > 
> > It depends on where you've connected the
> > vector_sink.
> > 
> > Note that vector_sink was really designed to be
> used
> > only during QA
> > testing.  It's not generally useful because it
> ends
> > up trying to store
> > a potentially infinite number of samples.
> > 
> > Eric
> > 
> 
> 
> 
> 
> Message: 2
> Date: Wed, 09 Jan 2008 18:00:06 -0800
> From: Dan Halperin <address@hidden>
> Subject: Re: [Discuss-gnuradio] Question regarding
> vector_sink_c
> Cc: GNU radio <address@hidden>
> Message-ID: <address@hidden>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> 
> 
> Wee Shinhan wrote:
> > Hi eric, 
> > 
> > Thanks for the reply, i have connected it to the
> > channel filters, i trying to do an estimate on
> > wireless channel coefficient. Therefore i'm trying
> to
> > capture the complex data received before
> > de-modulation. I havent have much success using
> vector
> > sink even when i set a range for the data
> captured,
> > all doesnt seems right.
> > 
> > Is there any blks that will be useful for my
> > experiment? Or do i have to write my own C++ blk
> to
> > process my needs. Thanks again.
> 
> Look at blocks like gr.probe_*
> (ingnuradio/gnuradio-core/src/lib/general/)
> 
> These will tell you some properties of the raw
> signal (namely,
> amplitude). Something like that might be the kind of
> thing you want --
> you could easily write a block in a similar style
> that computed some
> other metric.


> 
> ------------------------------
> 
> Message: 3
> Date: Thu, 10 Jan 2008 09:56:36 +0000
> From: Tom Rondeau <address@hidden>
> Subject: Re: [Discuss-gnuradio] Question regarding
> vector_sink_c
> To: GNU radio <address@hidden>
> Message-ID: <address@hidden>
> Content-Type: text/plain; charset=ISO-8859-1;
> format=flowed
> 
> Wee Shinhan wrote:
> > Hi eric, 
> >
> > Thanks for the reply, i have connected it to the
> > channel filters, i trying to do an estimate on
> > wireless channel coefficient. Therefore i'm trying
> to
> > capture the complex data received before
> > de-modulation. I havent have much success using
> vector
> 
=== message truncated ===

Hi guys thanks for the reply, Tom i realised that the
problem of collecting data from the channel filters
and have changed my data collection from the usrp
source in the receiver but it still seems like the
samples are not sync with the received data. I will
look into gr.probe and hopefully get some idea on how
to process my needs. thanks alot of the time guys.

regards,
shinhan


      
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