Digital Signal Processing Reference
In-Depth Information
Exercises on Chapter 9
Exercise 1
(d)
Why can there not be a software-based - i.e. computer-based conversion of real
analog signals into digital signals?
(e)
What does the file of a digital signal of this kind contain and how can the informa-
tion be presented pictorially?
Exercise 2
(a)
Transform the circuit simulation of an A/D converter in Illustration 184 by means
of DASY
Lab
in such a way that the accuracy is 4 bit or 6 bit instead of 5 bit
(2
5
= 32).
(b)
Instead of the AND process use a “Relay”.
(c)
How could the string of numbers in the binary system be represented by means of
DASY
Lab
? What would have to be added to the circuit in Illustration 184.
Exercise 3
(a)
Explain the principle of a D/A converter in Illustration 185, i.e. the term and the
formula in the mathematics module (binary/deca).
(b)
Explain the conversion of numbers in the decimal system into the numbers of a
different system with the base 2, 3 and 4 based on Illustration 186
Exercise 4
(a)
Where are analog pulse modulation processes used in practice?
(b)
Why are these processes so important in measuring technology?
(c)
Compare the pulse modulation signals in Illustration 187 with reference to their
bandwidth.
Exercise 5
(a)
Explain the general difference between an analog and digital signal in the time
domain
(b)
What graphic possibilities does DASY
Lab
provide for digital signals (see Illustra-
tion 188 and Illustration 189)?
(c)
Digital signals can only be analyzed in segments. What problems result from this?
(d)
Explain the influence of the two quantities block length n and sampling rate f
S
on
the representation of a digital signal in the time domain. How should these quanti-
ties be selected so that the digital signal on the screen is as similar as possible to the
analog input signal?
(e)
Explain the term “digital period length T
D
”
(f)
When is the spectrum of a periodic analog signal reproduced correctly via digital
signal processing by means of FFT?
