Two synchronized USRPs receive the same sine wave emitted by an another USRP, there is a phase shift random and obvious between the signals received from the 2 receivers

Hello world!

First of all, I use a USRP as a transmitter to emit a sine wave (the signal is exp(j2*pi*f*t)), and then I use the external clock to synchronize the two USRPs (Ref as PPS in are connected to the clock) as receivers. Receivers are in sync, and they are at the same distance from the transmitter, I thought that the signal they receive should have a nearly the same phase. However, in practice, the phase shift is big enough, and this problem really confuses me.

It's the received signals of 2 receivers.

Yes. What you observe is expected.

Near the bottof of this document read the area 'alignment Phase vs Phase coherence '.

http://www.NI.com/white-paper/14311/en/

And also, for the alignment phase, see the following 'Angle of arrival detection with NI USRP '.

https://decibel.NI.com/content/docs/doc-25716

Erik

Tags: NI Products

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