Hello Ritvik,

I have a few questions, could you find a quick answer to each of them,
so that I understand the situation better?

I'm very confused, because you have a screenshot of a Flowgraph that has
multiple QT GUI sinks, but is set to WX. And then you have a screenshot
of QT Gui visualizations and also one of WX GUI visualizations.

Would you mind explaining these graphs a bit better? In which file do
you show what?

Why are you using real-world measured signal from a USRP source to test
the fading simulator in GNU Radio? Why not simply use a noise source?

>But as a result there is increment in the signal power which is excatly
the opposite of the theory.
What is it that you were expecting?

Thanks,
Marcus

On 05/07/2015 10:42 AM, Ritvik Pandey wrote:
>
> ---------- Forwarded message ----------
> From: *Ritvik Pandey* <[email protected]
> <mailto:[email protected]>>
> Date: Fri, May 1, 2015 at 9:59 AM
> Subject: Re: [Discuss-gnuradio] Multipath Fading
> To: Mostafa Alizadeh <[email protected]
> <mailto:[email protected]>>
>
>
> Hey, 
> I tried applying multipath fading in Gnu radio.
> But as a result there is increment in the signal power which is
> excatly the opposite of the theory.
> kindly find the attachments for the images.
>
> On Sat, Apr 25, 2015 at 10:28 PM, Ritvik Pandey
> <[email protected] <mailto:[email protected]>> wrote:
>
>     Thank You so much
>
>     On Sat, Apr 25, 2015 at 10:22 PM, Mostafa Alizadeh
>     <[email protected] <mailto:[email protected]>> wrote:
>
>         I think this block is just a single tap channel. If you want
>         to have multipath channel use channel_model2 instead: 
>
>         
> http://gnuradio.org/doc/doxygen/classgr_1_1channels_1_1channel__model2.html
>
>         Best, 
>         Mostafa
>
>         On Sat, Apr 25, 2015 at 8:44 PM, Ritvik Pandey
>         <[email protected] <mailto:[email protected]>> wrote:
>
>             Okay ill work on this and get back to you if i face any
>             problems...for now one last thing according to the theory
>             fading is a result of multipath so does this block
>             implements multipath and then shows the faded result or it
>             just filters the fading output of an input signal.
>
>
>             On Sat, Apr 25, 2015 at 9:41 PM, Mostafa Alizadeh
>             <[email protected] <mailto:[email protected]>>
>             wrote:
>
>                 The frequency measurement doesn't give any insight
>                 rather to see just time variation of the power of the
>                 signal (i think you're using a single tone source ). I
>                 prefer to plot the singal in time domain to see fading
>                 effects.
>
>                 The fading block has different parameters as said:
>                 
> http://gnuradio.org/doc/doxygen/classgr_1_1channels_1_1fading__model.html
>
>                 Set like this:
>                 N = 8
>                 FTds = .01
>                 LOS = false
>                 K = 4
>                 Seed = 1
>
>                 On Apr 25, 2015 8:27 PM, "Ritvik Pandey"
>                 <[email protected]
>                 <mailto:[email protected]>> wrote:
>
>                     See i am using a signal source and fast noise
>                     source as inputs...adding these it passes through
>                     the fading block and then towards the fft sink or
>                     waterfall sink. 
>
>                     Input Parameters in signal source: 
>                     Freq: 1 M
>                     Amplitude: 1
>
>                     Noise Source:
>                     Amplitude: 1
>
>                     Fading Block:
>                     Normalized Doppler: 10.0
>                     Rayleigh
>
>                     This for testing the fading block initially in the
>                     final stage i have to take the signal from usrp.
>
>
>
>                     On Sat, Apr 25, 2015 at 9:23 PM, Mostafa Alizadeh
>                     <[email protected]
>                     <mailto:[email protected]>> wrote:
>
>                         What is the input of the gnuradio's block
>                         you've set??
>                         I think you're using the gnuradio's block
>                         wrongly!
>
>                         Dear Mostafa,
>
>                         I have tried making a flowgraph using the
>                         fading blocks, but i am not able to understand
>                         the output. I have compared the input and
>                         output it seems almost the same. Can you guide
>                         to the mathematical model of the fading block
>                         in gnu radio, so that i can understand what
>                         actually is happening to the input signal?
>
>                         Regards
>
>                         On Sat, Apr 25, 2015 at 9:07 PM, Mostafa
>                         Alizadeh <[email protected]
>                         <mailto:[email protected]>> wrote:
>
>                             Hi Ritvik,
>
>                             If you have enough background knowledge
>                             you need classify channels as follow:
>
>                             1) Rician channel: which has a
>                             line-of-sight(LOS) path between a
>                             transmitter and a receiver.
>                             2) Rayleigh fading channel: which doesn't
>                             have any LOS. 
>                             3) Something between Rayleigh and Ricean
>                             channel: using Nakagami distribution with
>                             parameter K varying 0-inf.
>
>                             You need to first generate samples of
>                             these distributions.
>
>
>                             On Sat, Apr 25, 2015 at 4:06 PM, Ritvik
>                             Pandey <[email protected]
>                             <mailto:[email protected]>> wrote:
>
>                                 Regarding my last post i want to bring
>                                 it to your notice that i have to
>                                 implement a multipath fading channel
>                                 emulator so can you tell me how can i
>                                 do that?
>
>                                 On Sat, Apr 25, 2015 at 5:03 PM,
>                                 Ritvik Pandey <[email protected]
>                                 <mailto:[email protected]>> wrote:
>
>                                     Dear Sir/Mam,
>
>                                     Hello, i am a student working on
>                                     the development of a channel
>                                     emulator, Can you tell me how can
>                                     you make one in GNU Radio?
>
>
>
>                                 
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