[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Discuss-gnuradio] Re: transmitter code

From: harshal jadhav
Subject: [Discuss-gnuradio] Re: transmitter code
Date: Thu, 17 Sep 2009 14:56:30 -0700

Thanks a lot Eric...Your suggestion worked perfectly fine....the result is even more clear if u increase the distance between the transmitting antenna..
at the receiver end i was using GRC. So i had to connect only one antenna. I havent found an option in GRC, wherein i can use two USRP sink for the same USRP board. For two USRP sink i have to use two boards.. Have to find a way of using the daughterboards of the same USRP board to receive the signal, thus making the system purely MIMO. The system that has worked for me is MISO.

On Wed, Sep 16, 2009 at 10:06 AM, Eric Blossom <address@hidden> wrote:
On Mon, Sep 14, 2009 at 08:01:17PM -0700, harshal jadhav wrote:
> Hi Eric,
> I have a few questions regarding MIMO + GNU RADIO.
> 1. How can i use MIMO with GRC?
> If i use one USRP sink, it considers one whole USRP board. I cannot use two
> daughter boards of the same USRP board using USRP sink.

Josh is the right person to handle this part, though it's just a
matter of setting up the transmit mux and interleaving the samples.

> 2. In gnuradio-examples/python/usrp/fm_tx_2_daughterboards.py  can i use
> flex 900 boards?


> I have tried implementing the example with the flex 900 board but it shows
> more of noise. I changed the sinusoid signal frequency to 4000 Hz and 10000
> Hz. While running the code it asks for carrier frequency for both the
> signals. I have given the frequency to 900 MHz.

Your baseband frequency needs to be representable without aliasing
given the baseband sample rate.  With interp=400, the baseband rate is
128e6/400 = 320kS/s, so you should be able to represent anything from
about -150kHz to +150kHz.

For your MIMO usage, set both the side-A-tx-freq and side-B-tx-freq to
the same value, say 906e6.

The example multiplies the signals by 10000.  Try using a smaller
value for if_gain, say 4000.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]