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Channel Impulse Response

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Channel Impulse Response

daviko
Hi
I want to find "channel impulse response" for my project using sounding techniques
I came to know about the 'gr-sounder' application which does just the thing and was implemented in previous versions of gnuradio. I have version 3.6.0

how can I use this app for my purpose?
any help is appreciated

Thanks in advance
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Re: Channel Impulse Response

Johnathan Corgan-3
On Fri, Nov 16, 2012 at 12:30 PM, daviko <[hidden email]> wrote:
 
I came to know about the 'gr-sounder' application which does just the thing
and was implemented in previous versions of gnuradio. I have version 3.6.0

how can I use this app for my purpose?
any help is appreciated

The gr-sounder app was a custom FPGA implementation based off the obsolete GNU Radio libusrp2 package for USRP2.  It would have to reimplemented from scratch using the current UHD package from Ettus Research.

The use of the FPGA was to enable the sounding waveform to cover a wider bandwidth than could be sent over the GbE transport for processing on the PC.  If your channel is narrow enough, you could implement the same algorithm in GNU Radio.  The transmitter was sending BPSK modulated PN sequences and the receiver was calculating correlation at successive time lags to estimate the channel impulse response.

Johnathan

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Re: Channel Impulse Response

Nazmul Islam
In reply to this post by daviko
Hello Daviko,

I used gnuradio in channel sounding experiments during the summer. I did not use gr-sounder. Rather, I designed my own transmitter and receiver block diagrams using GRC.

You can do both sliding correlator and frequency domain channel sounding using GNUradio. Sliding correlator method directly generates the channel impulse response. Frequency domain sounding allows you to find the impulse response through inverse FFT procedure. There might be other methods that I am unaware of.

In general, the frequency domain channel sounding method gives you the channel strengths at different carrier frequencies.Let's say, your desired frequency band is 700-720 MHz region. You can transmit a sinusoid from the transmitter that repeatedly hops at 700, 701, 702, ..., 720, 700, 701, .. , 720 MHz. Your receiver's carrier frequency should hop repeatedly in the same list. If you can time synchronize your Tx & Rx, you will know the path loss by taking FFT and observing the strength of the floating points in the desired FFT bin.
 
Thanks,

Nazmul
 

On Fri, Nov 16, 2012 at 3:30 PM, daviko <[hidden email]> wrote:
Hi
I want to find *"channel impulse response"* for my project using sounding
techniques
I came to know about the 'gr-sounder' application which does just the thing
and was implemented in previous versions of gnuradio. I have version 3.6.0

how can I use this app for my purpose?
any help is appreciated

Thanks in advance



--
View this message in context: http://gnuradio.4.n7.nabble.com/Channel-Impulse-Response-tp38383.html
Sent from the GnuRadio mailing list archive at Nabble.com.

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--
Muhammad Nazmul Islam

Graduate Student
Electrical & Computer Engineering
Wireless Information & Networking Laboratory
Rutgers, USA.


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Re: Channel Impulse Response

daviko
Thanks  a lot

I'll try to implement these techniques, and If I can't do that ... Can you help me to achieve it?
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