XE31CZS Exercise - Design of IIR Filters
Tasks to do:
- IIR filters design - low-pass
- Design low-pass filters using same order and different approximation
of magnitude response. Compare frequency repsonses for obtained results.
Butterword - fc = 800 Hz, fs = 8 kHz, N = 6
Chebysev I (I-st type) - fc = 800 Hz, fs = 8
kHz, N = 6, Rp = 1 dB
Chebysev II (II-nd type) - fc = 800 Hz, fs = 8
kHz, N = 6, Rs = 30 dB
Elliptic (Cauer) - fc = 800 Hz, fs = 8
kHz, N = 6, Rp = 1 dB, Rs = 30 dB
- Observe achieved frequency response of the filter, i.e. amplitude and
phase response (fcn freqz).
- Observe location of zeros and poles of filter transfer function
(fcn zplane) - Discuss if designed filters are stable.
- Compare these equivalent results for different approximation.
- Try to design similar way high-pass, band-pass, and band-stop
filters according to your own specification.
- Design of IIR filter from given tolerance scheme
- Design high-pass IIR filter fulfilling following requirements:
- fs = 8000 Hz
- pass-band border: fp = 300 Hz
- stop-band border: fs = 200 Hz
- pass-band ripple: Rp = 0.1 dB
- stop-band ripple: Rs = 40 dB
- Find the lowest order fulfilling given requirements for all
possible approximations of IIR filter magnitude response (use
functions buttord, cheb1ord, cheb2ord,
ellipord) and compare achieved orders.
- Compare frequency responses of achived filters and check their
- Design of equiripple FIR filter
- Design the Park-MCClellan equiripple high-pass FIR filter (Remez
algorithm) fulfilling same
requirements as in the task above.
functions firpmord and firpm (in older MATLAB version remezord and remez).
- Compare achieved order and frequency responses with above achieved
results for IIR filters.