Digital Signal Processing Reference
In-Depth Information
13.22. Given the 4-tap Daubechies wavelet coefficients
h 0 ( k ) ¼ [0.483 0.837 0.224 0.129]
determine h 1 ðkÞ and plot magnitude frequency responses for both h 0 ðkÞ and h 1 ðkÞ .
13.23. Given the sample values [8 2 4 1], use the Haar wavelet to determine the level-2 wavelet
coefficients.
13.24. Given the sample values [8 2430 1 2 0], use the Haar wavelet to determine the level-
3 wavelet coefficients.
13.25. Given the level-2 wavelet coefficients [4 2 1 2], use the Haar wavelet to determine the
sampled signal vector f ðkÞ .
13.26. Given the level-3 wavelet coefficients [4 2 1 2 0 0 0 0], use the Haar wavelet to determine
the sampled signal vector f ðkÞ .
13.27. Given the level-1 wavelet coefficients [4 2 1 2], use the Haar wavelet to determine the
sampled signal vector f ðkÞ .
13.28. The four-level DWT coefficients are given as follows:
W ¼ [100 20 16 5 342 64612 302 1]
List the wavelet coefficients to achieve each of the following compression ratios:
a. 2:1
b. 4:1
c. 8:1
d. 16:1
13.10.1 MATLAB Problems
Use MATLAB to solve Problems 13.29 to 13.31.
13.29. Use the 16-tap PR-CQF coefficients and MATLAB to verify the following conditions:
N 1
k ¼ 0 h 0 ðkÞh 0 ðk þ 2 nÞ¼dðnÞ
2 nÞ¼
RðzÞþRðzÞ¼ 2
Plot the frequency responses for h 0 ðkÞ and h 1 ðkÞ .
13.30. Use the MATLAB functions provided in Section 13.8 [dwt(), idwt()] to verify Problems
13.23-13.27.
13.31. Consider a 20-Hz sinusoidal signal plus random noise sampled at 8,000 Hz with 1,024 samples:
xðnÞ¼ 100 cos ð 2 p 20 nTÞþ 50 randn
where T ¼ 1 = 8 ; 000 seconds and randn is a random noise generator with a unit power and
Gaussian distribution.
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