Re: [Discuss-gnuradio] Re: Re: what is the rate(sampling) of the impulse response using usrp_sounder.py ?

[Johnathan Corgan]

On Tue, Dec 16, 2008 at 8:26 AM, Bruhtesfa Ebrahim <address@hidden> wrote:

> My objective is to measure impulse response of a room and extract
> information on the movement of people inside the room.

As I had mentioned earlier, this will be difficult, as the time
resolution of the sounder impulse response will be on the order of
30-60 ft.  You might be able to use that; it depends on how you
process it.

> 1. I tried to monitor the impulse response of the room for 5 sec. So,
> according to the discussion above(i.e since the FPGA computes impulse
> response of length 4095,32MHZ in 0.5sec), I will have 10 impulse
> response vectors in 5sec. But when i set { samples = 10 *
> self._length**2 in usrp_sounder_rx.py } and run the code, it takes about
> 160 seconds to complete. So, I am confused. Does the recorded impulse
> response correspond to 5sec or 160sec?

I don't understand how you've modified the script to collect 5 seconds of data.

> 2. As, expected there is frequency offset on the received impulse
> response.  what can i do to synchronize transmitter and receiver
> daughter boards?     Thanks!

You will need to use a stable time reference like a GPSDO on both the
transmitter and receiver.

-Johnathan