Bypassing daughtercards

GNU Radio
1

I am currently working with GNU radio and USRP board with its
transceiver daughtercards for transmitting and receiving signals. I
have recently aqcuired new RF front end hardware that can mix a baseband
signal up to 3.4 GHz and transmit it. The interface to the new RF
hardware is thru BNC cables. I want to know if there is a way that I
can do all the processing in GNU radio, send the data through the usrp
board to and the transmit DAC’s, and then send the I and Q channels from
the DAC to the new RF front end hardware. For example, are there pins
on the USRP board (or daughtercards) that I can pull the I/Q data off of
to send to the new hardware?

Thanks
Nick

2

On 2/15/07, [email protected] [email protected] wrote:

I am currently working with GNU radio and USRP board with its transceiver daughtercards for transmitting and receiving signals. I have recently aqcuired new RF front end hardware that can mix a baseband signal up to 3.4 GHz and transmit it. The interface to the new RF hardware is thru BNC cables. I want to know if there is a way that I can do all the processing in GNU radio, send the data through the usrp board to and the transmit DAC’s, and then send the I and Q channels from the DAC to the new RF front end hardware. For example, are there pins on the USRP board (or daughtercards) that I can pull the I/Q data off of to send to the new hardware?

Thanks
Nick

You can pick up the baseband differential analog signals of I/Q from
the daugherboard header. I believe the dboard.sch in the usrp-hw
module under SVN would be helpful.

http://gnuradio.org/trac/browser/usrp-hw/trunk/usrp

Brian

3

[email protected] wrote:

I am currently working with GNU radio and USRP board with its transceiver daughtercards for transmitting and receiving signals. I have recently aqcuired new RF front end hardware that can mix a baseband signal up to 3.4 GHz and transmit it. The interface to the new RF hardware is thru BNC cables. I want to know if there is a way that I can do all the processing in GNU radio, send the data through the usrp board to and the transmit DAC’s, and then send the I and Q channels from the DAC to the new RF front end hardware. For example, are there pins on the USRP board (or daughtercards) that I can pull the I/Q data off of to send to the new hardware?

The correct way to do this is to use the BasicTX, which was designed
specifically for this. It has 2 SMA outputs, one for I and one for Q.

Matt