Stanford University, EE 264,
Fall
2008
Digital Processing of Analog Signals
•
A-to-D conversion:
sampling and quantization
•
Numerical algorithm:
convolution, difference
equations, DFT, LPC
– Implemented on PCs with 64-bit floating-point or
special instructions
– Implemented on DSP chips or ASICs with finite-
precision arithmetic
•
D-to-A conversion:
quantization and filtering
Digital
Computer
D-to-A
A-to-D
x
c
(
t
)
x
[
n
]
y
[
n
]
y
c
(
t
)
Stanford University, EE 264,
Fall
2008
hearing aids
disk drives
Today, DSP Applications are Everywhere
Internet audio
cell phones
digital cameras
media players
Stanford University, EE 264,
Fall
2008
Advantages of Digital Representations
• Permanence and robustness of signal
representations
• Advanced IC technology works well for digital
systems
• Virtually infinite flexibility with digital systems
* Multi-functionality
* Multi-input/multi-output
A-to-D
Converter
D-to-A
Converter
DSP Chip
Input
Output
Stanford University, EE 264,
Fall
2008
Basic Concepts and Issues in DSP
•
Digital Filters:
Filter design, noise analysis,
structures
•
Fourier Analysis
:
Spectrum estimation, FFT,
cosine transform, cepstrum, short-time FT
•
Signal Modeling and Analysis
:
Linear prediction,
wavelets, chaos, fractals, compressed sensing
•
Hardware and Software
:
Minicomputers, DSP
chips, workstations, PCs, MATLAB, real-time
operating systems
•
Applications:
Speech, radar, image, video, data,
...