A Modified Viterbi Algorithm-Based IF Estimation Algorithm for Adaptive Directional Time–Frequency Distributions

• DOI: 10.1007/s00034-018-0960-z
• Publication Date: 2018-10-11T03:22:56Z
• Authors: Nabeel Ali Khan; Mokhtar Mohammadi; Igor Djurović
• Keywords: Viterbi algorithm; Instantaneous phase; SIGNAL (programming language); Iterative Viterbi decoding

Time–frequency (TF)-based instantaneous frequency estimation algorithms fail to achieve the desired performance when the underlying TF distribution suffers from low resolution of the signal components or signal components intersect each other in the TF domain. This paper addresses above-mentioned problems by (a) employing adaptive directional time–frequency distributions for resolving close components and (b) developing a variant of the Viterbi algorithm that employs both the direction and amplitude of the signal components for IF estimation of crossing components at low signal-to-noise ratio. Experimental results indicate that the proposed method outperforms state-of-the-art methods such as original Viterbi-based IF estimation algorithm and ridge path regrouping methods.