IF Estimation for Multicomponent Signals Using Image Processing Techniques in the Time-Frequency Domain

摘要

This paper presents a method for estimating the instantaneous frequency (IF) of multicomponent signals. The technique involves, firstly, the transformation of the one dimensional signal to the two dimensional time-frequency domain using a reduced interference quadratic time-frequency distribution. IF estimation of signal components is then achieved by implementing two image processing steps: local peak detection of the time--frequency (TF) representation followed by an image processing technique called component linking. The proposed IF estimator is tested on noisy synthetic monocomponent and multicomponent signals exhibiting linear and nonlinear laws. For low signal to noise ratio (SNR) environments, a time-frequency peak filtering preprocessing step is used for signal enhancement. Application of the IF estimation scheme to real signals is illustrated with newborn EEG signals. Finally, to illustrate the potential use of the proposed IF estimation method in classifying signals based on their TF components\u27 IFs, a classification method using least squares data-fitting is proposed and illustrated on synthetic and real signals.