Enhanced discrete wavelet packet sub-band frequency edge detection using Hilbert transform

The wavelet packet transform as a mathematical tool has found recent application in spectrum sensing. The result of this application has produced very promising results. Primarily, wavelets were designed for edge detection in images. Recently, cognitive radio literature have reported on wavelet application to detect sub-band frequency edges in wide band spectrum. In this paper, we present the combination of the Hilbert transform and the wavelet packet transform with the aim of enhancing the detection of the sub-band frequency edges of a wavelet-packet-decomposed signal. The simulation results show the effectiveness of this approach. The new scheme detected sub-band frequency edges of the wavelet-packet-decomposed signal much better than the wavelet packet transform without combination with the Hilbert transform.