Enhancing the sharpening performance of the short-time Fourier transform

<jats:p>Time-frequency reassignment and synchrosqueez-ing technique is commonly used to sharpen a time-frequency representation obtained by short-time Fourier transform (STFT) or others. However, the technique has a requirement on signal separability, i.e. signal components should be separable in time or frequency with respect to used analysis window. To weaken the limitation, this letter proposes a method to enhance the sharpening performance of STFT, firstly setting a narrow analysis window to ensure a high time resolution, and then artificially extrapolating signal frames via linear prediction to improve spectral resolution, and finally sharpen-ing the obtained STFT data. Using a Dolphin call signal, the performance is verified.</jats:p>