[Discuss-gnuradio] Re: question on GNU Radio

[Eric Blossom]

On Mon, Feb 19, 2007 at 12:49:04PM -0800, Candy Yiu wrote:
> Hi Eric,
> 
> I never meet you but just have some question which I guess no one can 
> answer.
> We are trying to build a smart antenna using the USRP board. I watched 
> the video which you guy gave a talk about it and mention it can support 
> up to 4 tx and 4 rx (there are 4 A/D as well). I was wondering if you 
> guy have a daughter board which has two tx and rx or any tip to connect 
> two daughter board?
> 
> thanks a lot,
> Candy
> 
> Portland State University

To use 4 in's and 4 out's with the USRP you'll need to use two 
"Basic Rx" and two "Basic Tx" daughterboards.

There are two main constraints:
 
  FPGA space
  USB bandwidth (32MB/s total)


We provide standard FPGA configurations with:

  (a) 2 receive paths (with half-band filters) and 2 transmit paths.

or

  (b) 4 receive paths (no half-band filters) and 0 transmit paths.

Eric