A time-varying kernel for ultrasound Doppler spectra

A new time-varying kernel has been formulated and tested for the bilinear time-frequency representation (BTFR) of signals. This kernel reshapes itself to track the instantaneous frequency of the signal, so that kernel smoothing does not necessarily yield poor resolution. Performance analyses were based upon mono-component FM (deterministic) and ultrasound Doppler (non-deterministic) signals. The results show that the new kernel improves the compromise between cross-terms (or variance) reduction and time-frequency resolution.<
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