Bandpass filter design based on wavelet packet
ABSTRACT The experiment simulates a complex signal with several frequencies and the Rayleigh noise signal. We use a bandpass filter based on wavelet packet to analyze the signal. In the frequency domain, the results show that the method can separate any frequency signal from the original signal. In the time domain, the method can reconstruct the original signal correctly when the SNR is high, but when the SNR is low, the method can't reconstruct it effectively.
- [show abstract] [hide abstract]
ABSTRACT: A high-frequency wavelet filter which employs Gm-C blocks based on leap-frog (LF) multiple-loop feedback (MLF) structure is presented. The proposed method is well suitable for high-quality high-frequency operation since the Gm-C based filter can achieve high frequency, whilst LF MLF configuration has the characteristics of lower magnitude sensitivity and capability of realizing arbitrary rational functions. The Marr wavelet is selected as an example in this paper, and the design for a 100 MHz frequency operation is elaborated. The wavelet filter is simulated using TSMC 1.8 V 0.18 mum CMOS technology. Simulation results indicate that the proposed method is feasible for high frequency operation with relatively low power consumption.01/2009;
Conference Proceeding: Shiftability and filter bank design using Morlet wavelet[show abstract] [hide abstract]
ABSTRACT: A multi-resolution representation through wavelet transform has proved to be beneficial for many signal processing applications. For example, Morlet wavelet has shown good performance in tasks like audio coding and image enhancement. Unfortunately, wavelet transforms are unstable when the input signal is shifted in position. Prior works formalize this problem by defining a type of translation invariance called shiftability. Shiftability constraint is equivalent to the constraint that the response power of the transform in the sub-band is preserved with respect to translations of the input signal. In this paper, we propose constraints for filter bank design that guarantee shiftability. Also, we use the proposed constraints to design a filter bank that implements the Morlet wavelet transform. We use the Morlet wavelet based on the fact that it has good properties in joint time-frequency localization and it has shown approximate shiftability. The filter bank proposed presents good results with respect to shiftability.Computer Science Society, 2004. SCCC 2004. 24th International Conference of the Chilean; 12/2004
Conference Proceeding: Design of wavelet filters based on digital complex allpass filters[show abstract] [hide abstract]
ABSTRACT: A method for designing IIR complex wavelet filters based on complex allpass filters, that are maximally flat at ω=0 is presented. This allpass filter is obtained from a complex all-pole filter with a desired flatness at ω=0. The parameters of the complex allpass filter design are the order of the filter, N, the degree of flatness, K, and the phase, φ<sub>0</sub>, at ω=0. The real and imaginary parts of the filter coefficients are computed from the proposed iterative equations.Circuits and Systems, 2005. ISCAS 2005. IEEE International Symposium on; 06/2005