Hi Folks, I have managed to use 2 different USRP N210's to measure the same signal with the same sampling rate (both center at 0 Hz DC) at approximately the same time (timing is an issue but irrelevant for this discussion). Examination of signal intensity does confirm the above to be true. However, when I compare individual tones between the 2 units, I see the phase differences between the tones jump around a lot. And they seem to cluster at +90/-90 locations. This is very puzzling and troublesome. I guess internally the USRP configures the FPGA in a way that is not visible. Is there a way that I con force the 2 USRP to configure the FPGA in the same identical configuration when taking data? Thanks for your inputs and help. LD
on 2013-01-23 09:17
Re: How to ensure 2 USRP to have the same internal FPGA configuration when measuring the same signal
on 2013-01-23 14:13
On 01/23/2013 03:16 AM, LD Zhang wrote: > > This is very puzzling and troublesome. I guess internally the USRP > configures the FPGA in a way that is not visible. Is there a way that > I con force the 2 USRP to configure the FPGA in the same identical > configuration when taking data? > > Thanks for your inputs and help. > > LD > > You aren't synchronizing the two N210s with an external clock reference, so there's no way there'll be phase coherence between the two devices.