Digital Signal Processing
EIE 515
MODULE 7
Digital Filters
Lecturer(s): Dr. S.A Daramola, Shobayo Olamilekan, Etinosa Noma-Osaghae.
, Learning Outcomes
Understand the principles of the Finite Impulse Response (FIR) filter design
Investigate the Fourier Transform and Window methods for the realization
Finite Impulse Response (FIR) filters.
Realize FIR filters using the Transversal Form.
Understand the principles of the Infinite Impulse Response (IIR) filter design.
Investigate conversion of analogue (IIR) filters in to digital (IIR) filters using
the Bilinear Transformation Method.
Design the Butterworth and Chebyshev low pass, high pass, band pass and
band stop filters.
Realize IIR filters using the Direct Form 1, Direct Form II, Cascade and
Parallel methods.
State at least five differences between IIR and FIR filters.
,The FIR filter is completely described by the
input-output equation:
FIR filter coefficients
FIR filter length
The transfer function is given as:
, PRINCIPLES OF THE FINITE IMPULSE
RESPONSE (FIR) FILTER DESIGN
• Its transfer function has a constant term and all other terms
each have a negative power of z.
• All the poles of the finite response filter are at the origin and
thus its stability is guaranteed.
• Its impulse response has a finite number of terms.
• To design the FIR filter, multiply the filter inputs by their
corresponding coefficients and accumulate them.
• The implementation of the FIR filter is pretty straight forward.
• The FIR filter has a linear phase property . This shows that all
passed frequencies will have the same constant delay at the
output, which equals M samples. Hence, Phase distortion is
avoided.
EIE 515
MODULE 7
Digital Filters
Lecturer(s): Dr. S.A Daramola, Shobayo Olamilekan, Etinosa Noma-Osaghae.
, Learning Outcomes
Understand the principles of the Finite Impulse Response (FIR) filter design
Investigate the Fourier Transform and Window methods for the realization
Finite Impulse Response (FIR) filters.
Realize FIR filters using the Transversal Form.
Understand the principles of the Infinite Impulse Response (IIR) filter design.
Investigate conversion of analogue (IIR) filters in to digital (IIR) filters using
the Bilinear Transformation Method.
Design the Butterworth and Chebyshev low pass, high pass, band pass and
band stop filters.
Realize IIR filters using the Direct Form 1, Direct Form II, Cascade and
Parallel methods.
State at least five differences between IIR and FIR filters.
,The FIR filter is completely described by the
input-output equation:
FIR filter coefficients
FIR filter length
The transfer function is given as:
, PRINCIPLES OF THE FINITE IMPULSE
RESPONSE (FIR) FILTER DESIGN
• Its transfer function has a constant term and all other terms
each have a negative power of z.
• All the poles of the finite response filter are at the origin and
thus its stability is guaranteed.
• Its impulse response has a finite number of terms.
• To design the FIR filter, multiply the filter inputs by their
corresponding coefficients and accumulate them.
• The implementation of the FIR filter is pretty straight forward.
• The FIR filter has a linear phase property . This shows that all
passed frequencies will have the same constant delay at the
output, which equals M samples. Hence, Phase distortion is
avoided.
