An IF Estimator for Multicomponent Signals from Time Frequency Distribution

Viterbi algorithm (VA) applied to time frequency (TF) distribution is a highly performed instantaneous frequency (IF) estimator, but it suffers from switch problem (SP) at the intersected points of multi-components on the TF plane. In order to suppress the SP in VA, an improved VA (IVA) in this paper assumes the IF variation trends between two adjacent IF points are not large, then a new penalty function is introduced and added to the original VA. To validate the algorithm, the proposed algorithm applied to a multi-component signal is firstly simulated; then, how parameter in the new penalty function influences the performance is analyzed. Comparison with VA is also made in this part. Simulations indicate while VA can only obtain accurate IFs for some components, IVA can effectively suppress the SP and acquire more accurate IFs for all the components at different SNRs.