Analog Signals and Systems - Digital Signal Processing: An Introduction with MATLAB and Applications - page 7

0.6

0.5

0.4

0.3

0.2

0.1

0

0 1 2 3 4 5 6 7 8 9 10

Frequency, Hz

Fig. 1.4 Spectrum of the two-component signal, x(t) = sin(x o t) ? cos(5 x o t)

Processed
Digital
Signal

Digital
Signal

x(t),
Analog
Input
Signal

y(t),
Analog
Output
Signal

r(n) p(n)

A / D DSP D / A

Fig. 1.5 Block diagram of a generic signal processing system

modified analog signal. A diagrammatic view of a general digital signal processing
system is shown in Fig. 1.5 .

1.1.6 Digital Signal Processing Versus Analog Signal Processing

Digital signal processing has a number of advantages over analog signal pro-
cessing (ASP), namely:

1. DSP is less susceptible to noise and power supply disturbances than ASP.
2. DSP can more accurately and reliably represent signals and systems.
3. Storage of signals is easier in DSP.
4. DSP is more flexible and versatile, especially in changing the system param-
eters to accommodate changing environments (e.g., in adaptive filtering).

1.1.7 System Modeling

A single input-single output system can be represented mathematically in the time
domain as an operator or transformation T on the input signal, as shown in
Fig. 1.6 .