Free induction decay in NMR (as stated in Pavia)

There is a statement in a very popular textbook of spectroscopy by Pavia (Chapter 3, Intro. to Spectroscopy), it says "*The observed FID is actually an interference signal between the radiofrequency source (300 MHz in this case) and the frequency emitted by the excited nucleus*"


As per my understanding this statement is not fully correct, as the free induction decay signal is acquired after the excitation pulse is turned off. Does anyone know if there is a overlap in timings of pulse excitation and signal acquisition? 


