[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] Smart Antenna
From: |
Martin Dvh |
Subject: |
Re: [Discuss-gnuradio] Smart Antenna |
Date: |
Sun, 21 Jan 2007 23:48:42 +0100 |
User-agent: |
Debian Thunderbird 1.0.2 (X11/20061113) |
Roberto Mastrodonato wrote:
> Hi all
>
> is there anybody that experienced USRP projects with SMART Antenna
> technology? If yes, where can I find codes or something else related to
> USRP-SMART Antenna?
> Thanks a lot
I have been experimenting with direction finding and passive radar using
gnuradio and multiple antenna's.
These experiments are on hold for now, due to lack of time, but I hope to
continue with them sometime in the future.
What exactly would you like to do and with how much array-elements.
The simplest smart antenna using usrp/gnuradio I can think of is a smart
transmitter using two antenna's.
The phase-difference you introduce between the two signals, combined with the
positioning of your two antenna's determines the maximum and
minimum gain direction(s) of the whole system.
Introducing a fixed phase difference is just multiplying with a const complex
number.
Phi=wanted phase difference in radians
signal=original signal to transmit
sink1=sink where the first output should go
sink2=sink where the second output should go
phasediff=gr.multiply_const_cc(gr_complex(cos(Phi),sin(Phi))
fg.connect(signal,sink1)
fg.connect(signal,phasediff,sink2)
The same goes for reception:
Phi=expected phase difference in radians
input1=signal from first antenna
input2=signal from second antenna
receiver=reception chain
phasediff=gr.multiply_const_cc(gr_complex(cos(Phi),sin(Phi))
adder=gr.add_cc()
fg.connect(signal1,(adder,0))
fg.connect(signal2,phasediff,(adder,1))
fg.connect(adder,receiver)
If you want to automatically determine the phase-differences and amplitudes
things get much more complicated but can still be done.
I even tested with a very slow correlator and agc which automatically
determined the phase difference of the strongest signal received and tuned
the two antenna array for maximum sensitivity for this signal.
Greetings,
Martin
>
> Roberto
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio