Solutions CH9 EE100-03
Problem 1:
“A signal can be thought of formally as a function of one or more variables that
convey information. So, basically any transmission, be it light, sound, electrical
impulses, or electromagnetic radiation can be considered a signal as long as it
contains information that can be extracted in some way.”
Problem 3:
An analog signal will have a data point for any fractional time value between 0 and 1
second. On the other hand, if we have a discrete-time signal, the number of data
points will be dependent on the resolution of the signal and will always be less than
infinity. So, a discrete-time signal divides the time variable up into a series of
discrete points at which the amplitude is known.
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-1
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0
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1
-20 -15 -10 -5 0 5 10 15 20
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-0.8
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1
Discrete
Analog
Problem 7:
Flexibility: As we noted earlier, an analog device, once developed, is fixed. In other
words, it cannot be changed or improved without changing circuit boards. A digital
system, on the other hand, can be changed simply by modifying the programming of
the device. For example, if you have ever upgraded the “firmware” on an electronic
product (digital camera, CD or DVD drive, or network switch for example), you have
changed the programming of the microprocessor. The flexibility of digital signal
processing devices is probably best illustrated by the computer. Based on the
program that is running, a computer can do numerous things that involve processing
signals from input and sending signals to output devices in a wide variety of ways.
Compare this to your television set. It receives a television signal and decodes it to
output the resulting signals to the screen and speakers. It can’t be easily reconfigured
to do anything else.
Ease of Development: While analog systems must be developed as electrical circuits,
digital signal processing can be developed as computer software and later moved to a
dedicated microprocessor system. Thus, development and testing of a digital signal
processor is easier and more cost-effective than the equivalent processes for an analog
signal processor.
