ECE 464/564
Digital Signal Processing
http://classes.engr.oregonstate.edu/eecs/
KEC 1003,TR 5:00-6:50 pm
Winter Quarter 2006
School of Electrical Engineering and Computer Science
Oregon State University
Instructor
? Luca Lucchese
? KEC 3005
? E-mail,luca@eecs.orst.edu
? Phone,737-2980
? Office Hours,Mondays and Wednesdays
2:30 - 4:00 pm
? Ji-seok Liew
? E-mail,liewj@eecs.oregonstate.edu
? Office Hours,TBD
T.A,
Textbook
? S.K,Mitra,Digital Signal Processing – A
Computer-Based Approach,Third Ed.,
McGraw-Hill,2005
http://www.mhhe.com/engcs/electrical/mitra/
? William J,Palm III,Introduction to Matlab
6 for Engineers,McGraw-Hill,2001
Matlab Reference
http://www.mhhe.com/engcs/general/palm/
? Sound knowledge of linear algebra and
calculus
? Signals and systems (ECE 351 and ECE
352 or equivalent courses)
? Basic Matlab programming skills
Requirements
? Short review of important concepts from
ECE 351 and ECE 352
? Digital Signal Processing (DSP) vs,Analog
Signal Processing (ASP)
? Advantages and disadvantages of DSP
? Course Roadmap
Why DSP?
? Continuous-Time (CT) Linear System
? CT Linear and Time-Invariant (LTI) System
Analog Signal Processing
( ) (,) ( )y t h t x d? ? ?? ?
?
( ) ( ) ( ) ( ) ( )y t h t x d h t x t? ? ?? ? ? ??
?(,) ( )h t h t????
()xt ()yt
analog signal analog signal
CT System
Analog Signal Processor (ASP) or Analog Filter
? Laplace Transform
? Continuous-Time Fourier Transform (CTFT)
? Fourier Series (FS)
Frequency Domain Analysis
of CT Signals and Systems
analysis equation
synthesis equation
time
domain frequency domain ()xt
( ),Xs
()X ?
()Xs
? ?k kc ?¢
? ?k kc ?¢
()X ?
sj?? ? ?
Digital Signal Processing
digital signal
[]xn []yn
digital signal
DT System
? Discrete-Time (DT) Linear System
? DT Linear and Time-Invariant (LTI)
System
[ ] [,] [ ]
m
y n h n m x m
?
? ?

[ ] [ ] [ ] [ ] [ ]
m
y n h n m x m h n x n
?
? ? ? ??
¢[,] [ ]h n m h n m??
Digital Signal Processor (DSP) or Digital Filter
? z-Transform
? Discrete-Time Fourier Transform (DTFT)
? Discrete Fourier Transform (DFT)
Frequency Domain Analysis
of DT Signals and Systems
()Xz
()jXe ?
[]Xk
()jXe ?[]xn
analysis equation
synthesis equation
time
domain frequency domain
()Xz
[]Xk
Digital Processing of Analog Signals
?LPFinis the Prefilter or Antialiasing Filter,it conditions the analog
signal to prevent aliasing (Sampling Theorem,)
?ADC is the Analog-to-Digital Converter,it consists of an ideal
sampler followed by a quantizer and produces a stream of binary
digits encoding the samples of taken at a rate,T
being the sampling period
m a x2TFF?
[]xn []yn ()ayt()axt
DSP ADC DAC LPFin LPFout
10011001LL00101011LL
()xt% ()yt%
()axt
()xt% 1/TFT?[]xn
Digital Processing of Analog Signals
?DSP is the Digital Signal Processor,it’s the heart of the DSP system
and can represent a computer,special-purpose HW,a SW algorithm,etc,
?DAC is the Digital-to-Analog Converter,it consits of an interpolator
and produces a staircase waveform from the sequence of binary
digits representing,the processed version of
?LPFout is the Postfilter,it performs the smoothing of into
[]xn []yn ()ayt()axt
DSP ADC DAC LPFin LPFout
10011001LL00101011LL
()xt% ()yt%
()yt%
[]yn []xn
()yt% ()ayt
Digital Processing of
Analog Signals
()axt ()aytASP
()ayt()axt
1 4 4 4 4 4 4 4 4 2 4 4 4 4 4 4 4 4 3
Equivalent Analog Signal Processor
DSP ADC DAC LPFin LPFout
? DSP systems can be developed using SW running
on a general-purpose computer (convenient to
develop and test)
? DSP operations are based solely on additions and
multiplications
? DSP operations can be modified in real time
(program changes,register reloading)
? Digital circuits are less sensitive to component
tolerance and fairly independent of temperature,
aging,and most external parameters
Advantages of DSP
? Unlike analog circuits,digital circuits can be
cascaded without any loading problems
? DSP has lower cost thanks to VLSI technology
(single-chip implementation)
? Digital implementations allow the realization of
certain characteristics not possible with analog
implementations (e.g.,linear phase and multirate
processing)
? DSP is applicable to very low-frequency signals
Advantages of DSP
? Digital signals can be stored indefinitely (at least,in
principle) without any loss of information on
various storage media (magnetic tapes and disks,
optical media,etc.)
? Quality of processing is limited only by economic
considerations
? Arbitrarily low signal degradations achieved with
desired quality by increasing the number of bits in
data/coefficient representation
? An increase of 1 bit in the representation results in
an improvement of 6 dB in the SNR
Advantages of DSP
? Increased system complexity in the digital
processing of analog (need for ADC,DAC,and
LPF’s)
? Limited range of frequencies available for
processing (dictated by the Sampling Theorem)
? Digital systems are built using active devices
which consume electrical power (as opposed to
passive analog circuits)
Disadvantages of DSP
Course Program
? Discrete-Time Signals and Systems (Chapter 2)
– Linearity,Time-Invariance,Causality,Stability,
Convolution,Correlation
? Discrete-Time Fourier Transform (Chapter 3)
? Finite-Length Discrete Transforms (Chapter 5)
? Z-Transform (Chapter 6)
? LTI Discrete-Time Systems in the Transform
Domain (Chapter 7)
– Frequency Response,Transfer Function,Phase
and Group Delay,Basic FIR and IIR Digital
Filters
? Digital Processing of Continuous-Time
Signals (Chapter 4)
– Sampling and Reconstruction of Continuous-
Time Signals,Analog Lowpass Filter Design
Course Program
? Digital Filter Structures (Chapter 8)
– Block Diagram Representation of Digital Filters,
Basic FIR and IIR Digital Filter Structures
? IIR Digital Filter Design (Chapter 9)
– Basic Approaches to Digital Filter Design,Bilinear
Transformation,Design of Lowpass IIR Digital
Filters,
? FIR Digital Filter Design (Chapter 10)
– FIR filter design based on Windowed Fourier
Series
Course Program
Grading Policy
? Homework – 30%
? Midterm Exam (Feb,9,5:00-7:00 pm) - 35%
? Final Exam (Mar,21,8:00-10:00 pm)- 35 %
? Homework assignments to be posted on
the course website and due back in class