Lecture 11: FIR Filter Designs XILIANG LUO 2014/11 1
Windowing 2 Desired frequency response: Fourier series for a periodic function with period 2pi Convergence of the Fourier series
Windowing 3
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5 Rectangular window:
Common Windows 6
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8 Rectangular Window M=50
Common Windows 9 Hamming Window M=50
Common Windows 10 Blackman Window M=50
Comparisons 11
Kaiser Window 12
Kaiser Window 13
Kaiser Window 14
Kaiser Window 15
Kaiser Window 16
Optimal FIR Filter 17 Design Type-1 FIR filter:
Optimal FIR Filter 18
Optimal FIR Filter 19 Parks-McClellan algorithm is based on the reformulating the filter design problem as a problem in polynomial approximation.
Optimal FIR Filter 20 Approx. Error: only defined in interested subintervals of [0, pi]
Optimal FIR Filter 21 Parks-McClellan, MinMax criterion:
Optimal FIR Filter 22
Parks-McClellan 23 Alternation theorem gives necessary and sufficient conditions on the error for optimality in the Chebyshev or minimax sense! Optimal FIR should satisfy:
Parks-McClellan 24 2(L+2) unknowns
Parks-McClellan 25 Given set of the extremal frequencies, we can have:
Parks-McClellan 26 Given set of the extremal frequencies, we can have: Evaluate on other frequencies
Parks-McClellan 27
28 Flow Chart of Parks-McClellen
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