Multi-component instantaneous frequency estimation using locally adaptive directional time frequency distributions

Abstract

This paper presents a locally adaptive time-frequency (t,f) method for estimating the instantaneous frequency (IF) of multi-component signals. A high-resolution adaptive directional time-frequency distribution (ADTFD) is defined by locally adapting the direction of its smoothing kernel at each (t,f) point based on the direction of the energy distribution in the (t,f) domain. The IF of signal components is then estimated from the ADTFD using an image processing algorithm. Using the mean square error between the original IF and estimated IF as a performance criterion, experimental results indicate that the ADTFD gives better IF estimation performance compared with other TFDs for a multi-component signal. For example, for signal-to-noise ratio of 12dB, the IF estimate obtained using the ADTFD achieves a mean square error of ?42dB for a weak signal component, which is an improvement of ?12dB compared with other TFDs.