TITLE:
Computation of Hilbert Transform via Discrete Cosine Transform
AUTHORS:
Hannu Olkkonen, Peitsa Pesola, Juuso T. Olkkonen
KEYWORDS:
Hilbert Transform, Analytic Signal, Envelope Analysis, FFT
JOURNAL NAME:
Journal of Signal and Information Processing,
Vol.1 No.1,
December
1,
2010
ABSTRACT: Hilbert transform (HT) is an important tool in constructing analytic signals for various purposes, such as envelope and instantaneous frequency analysis, amplitude modulation, shift invariant wavelet analysis and Hilbert-Huang decomposition. In this work we introduce a method for computation of HT based on the discrete cosine transform (DCT). We show that the Hilbert transformed signal can be obtained by replacing the cosine kernel in inverse DCT by the sine kernel. We describe a FFT-based method for the computation of HT and the analytic signal. We show the usefulness of the proposed method in mechanical vibration and ultrasonic echo and transmission measurements.