IFR estimation of overlapped multicomponent signals from time frequency rate distribution

Instantaneous frequency rate (IFR) estimation from multi-component signals can be applied in a variety of applications. Viterbi algorithm (VA) on cubic phase function (CPF) is a highly performed IFR estimator for the mono-component signal. However, for the multi-component signal, when signal components are intersected each other on the time frequency rate (TFR) plane, inaccurate IFRs may be tracked due to switch problem in VA and cross-terms in CPF. To address these two challenges, a directionally smoothed pseudo CPF (DSPCPF) is firstly introduced, where TFR points of CPF along the IFR curve are integrated to enhance the auto-terms. In addition, to suppress the SP, the direction matrix of DSPCPF is utilized to construct an additional directional penalty function for VA. The novel VA combined with DSPCPF is applied to estimate IFRs. To validate the method, comparison of the proposed algorithm with other VA-based methods is made by several multi-component frequency modulated signals. The experimental results indicate that the proposed algorithm can achieve higher accuracy than other improved VAs.