Hello everyone,
I was experimenting with two USRPs and encountered something I could not explain. The setup is: HostA -> B210 -> Cable+Attenuator -> N310 -> HostB. GNURadio on the TX side is simply playing a signal via the signal source block into the
UHD USRP Sink. On the RX side the USRP Source block is saving the signal through a head block into a file sink. The received signal seems to contain sudden, periodic jumps as can be seen in the picture below. For the attached picture the raw I and Q signal
is plotted. The jumps happen at different tested sample rates, frequencies and gains on both sides. In the depicted example the signal source block sent a constant with amplitude one. Center frequency was set to 2,48 GHz with sample rates on both sides at
25,6 MHz. One can see the center frequency offset as expected but the signal is sometimes jumping in 2 adjacent samples which indicates to me that the receiver is adjusting something. This effect can also be seen at other sent waveforms.
Does somebody know what causes such a behavior? Thank you in advance!
Kind regards
Michael