Frequency-chirprate reassignment.

In this paper, we consider a three-dimensional parameter space, which is the time-frequency-chirprate (TFCR), to characterize the time-varying features of multi-component non-stationary signals. By performing reassignment on the frequency-chirprate plane, a highly concentrated TFCR representation, named as the frequency-chirprate reassignment method (FCRM), is proposed. FCRM can provide the instantaneous frequency (IF) and chirprate (CR) estimates jointly, making the crossing of IFs appear as separated in the TFCR domain, which overcomes the limitation of the popular time-frequency post-processing methods that require input signal with non-overlapping IFs. Based on the chirplet transform, we derive the reassignment center of the FCRM, and a three-dimension ridge detection algorithm is introduced to extract the IFs and CRs from the FCRM. Numerical experiments demonstrate that the proposed FCRM provides a concentrated TFCR representation, obtaining a good IF estimation for the overlapped multi-component signals that contain cross-over IFs. [ABSTRACT FROM AUTHOR]