ON THE INSTANTANEOUS FREQUENCIES OF MULTICOMPONENT AM-FM SIGNALS

We study the instantaneous frequencies (IF's) of multicomponent AM-FM signals by extending the recent work on the two-component case by Loug hlin and Tacer to the more general M-component case. A novel necessary and sufficient condition of the valid interpretation of the IF as a n onnegatively weighted average of the IF's of the components is propose d, which we apply as a method of interpreting the IF's of signals havi ng no more than three dominant components at each time. Our quantitati ve study shows that in general, the IF-based monocomponent AM-FM decom position is not appropriate for the modeling and analysis of multicomp onent AM-FM signals unless all the components are well separated in th e time domain.