Hey all,
Is it possible to increase and decrease the USRP or daughter-boards
oscillator frequency in real time in order to transmit a frequency
modulated continuous wave from the frontend?
Bruh
On Tue, Jun 30, 2009 at 11:28 AM, B. Godana[email protected] wrote:
Hey all,
Is it possible to increase and decrease the USRP or daughter-boards
oscillator frequency in real time in order to transmit a frequency
modulated continuous wave from the frontend?
Is there a reason you wouldn’t just want to do this at baseband and
modulate it?
Brian
On Tue, Jun 30, 2009 at 08:28, B. Godana[email protected] wrote:
Is it possible to increase and decrease the USRP or daughter-boards
oscillator frequency in real time in order to transmit a frequency
modulated continuous wave from the frontend?
Not really, no. But it is easy to send a baseband FM waveform to the
USRP to be upconverted to your center frequency of interest.
Johnathan
Brian P. wrote:
On Tue, Jun 30, 2009 at 11:28 AM, B. Godana[email protected] wrote:
Hey all,
Is it possible to increase and decrease the USRP or daughter-boards
oscillator frequency in real time in order to transmit a frequency
modulated continuous wave from the frontend?Is there a reason you wouldn’t just want to do this at baseband and
modulate it?Brian
Yes, I want to do that to utilize more bandwidth of the daughter-boards
rather than being limited by the sampling rate of the ADC/DAC.
But, it looks it is impossible?
On Tue, Jun 30, 2009 at 10:12, B. Godana[email protected] wrote:
Yes, I want to do that to utilize more bandwidth of the daughter-boards
rather than being limited by the sampling rate of the ADC/DAC.But, it looks it is impossible?
If you reprogram the USRP(1) FPGA code, you can generate waveforms up
to 32 Msps into the AD9862, which uses 1:4 hardware upsampling to get
to the 128 Msps of the DAC. Theoretically this gives you 64 MHz of
(complex baseband) bandwidth, though the passband of the AD9862
upsampling filter will limit this to about 50 MHz of usable bandwidth.
On the receive side, you do get the full 64 MHz downconverted
passband, but the anti-aliasing filters on most of the daughterboards
will effectively limit this to < 60 MHz.
Johnathan