Usrp transmit have some unknown peaks

Hi all,
I use usrp and rfx900 transmit signal, beside the main signal, dc
offset, i
q imbalance. there are still
some peaks which I don’t know how them generated and do they harm for
the
main signal.
in the attachment photo, the three peaks in the middle is main signal,
dc
offset, i q imbalance. and
there are two other peaks in left and right. so what are they?

Regards