Re: [Discuss-gnuradio] GNU radio implementation for measuring frequency response

[Marcus Müller]

Hi Suman,

be careful with "use instantly": Well, what you're doing is channel sounding, and as such, the results are up to your interpretation – for example, in the 100 MHz (!) wide channel you're testing, what coherency times do you expect from your environment? That is the time a single channel impulse response is valid. Basically, how fast do the paths the signal can take change, e.g. by movement of reflecting objects, or absorbing (human, for example) bodies, or the transmitter or receiver? With a 100 MHz overall observation bandwidth, you'd get a spatial resolution of ~1.5m; so, if this is, for example, a room where people move, this is the time where noone moves out of their position by any significant amount of distance; that might be in the order of seconds. If this is a channel between to moving cars, more like milliseconds.

Another aspect: I assume you're doing this with COTS SDR devices. These typically are *not* calibrated devices, so you'll have to figure out a way to remove the effect that your devices (from the DAC over the filters, mixers, amplifiers, cables, antennas, to the ADC and DSP) from your measurement.

So, if you get data, don't forget that it's not a sufficient description of the world, unless you understand the model of the world you're using.

That being said: Haven't tried it in ages, but gr-channelsounder[1] sounds a bit like what you're looking for.

Best regards,
Marcus

[1] https://github.com/gbaier/gr_channelsounder

On 20.10.2017 23:48, Suman Bhunia wrote:

Hi !

I want to measure frequency response of of a material in the 2.4 GHz ISM band. I was wondering if there is any GNURadio based implementation anyone is aware of that I can use instantly. Any suggestion regarding the implementation is also welcome. 

I want to measure the frequency response from 2.4 GHz to 2.5 GHz. I want to use 2 USRP boards one as Tx and another as Rx. Alternatively, I can use the same board and use the two different ports if it makes more sense. 

Thanks for your help in advance.

Suman

_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

smime.p7s
Description: S/MIME Cryptographic Signature