Re: [Discuss-gnuradio] High bandwidth channel estimation using the USRP

[Stefan Brüns]

On Monday 15 December 2008 17:28:31 Emanuel Birge wrote:
> Hi!
>
> My name is Emanuel and I'm doing my master thesis project for a small
> company called Actiwave (http://www.actiwave.se). We recently bought a
> USRP-board together with an assortment of daughterboards. The dboards I'll
> be using for my thesis are the BasicTX & -RX. After that short introduction
> I'll move right to the topic:
>
> Question A:
> I'm interested in calculating an estimate of the impulse response of a
> speaker cable, using pseudo-white noise and bypassing all forms of
> interpolation/decimation/modulation/demodulation-blocks, for as wide a
> bandwidth as possible. However, and please correct me if I'm wrong, the
> USB-interface on the USRP is too slow (8 MHz) to, so to speak, do this
> "online". Say I want to use 10,000 pseudo-white samples with at least 8bit
> resolution. Is this possible without rewriting very much of the
> Verilog-code?

As long as you stick to humans as your intended audience, and not bats, 100kHz 
should be more then enough. As the frequency response of the DDC filters is 
flat for ~0.5 of the sampling bandwidth (you can find the FR in the USRP 
FAQ), a sampling rate of 200kHz is more than satisfactory for your work. 
Everything else is esoteric ...

Stefan

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