Download DT1_Assgn1_Solution 33KB Jan 26 2016 06:53:02 AM

Digital Techniques I and Lab
Solution for Assignment 1
1. Analog signal varies continuously between two amplitudes over the given interval of time.
Between these limits of amplitude and time, the signal can take any value at any instant of time.
Discrete time signal varies between two given amplitudes, but its value within this range is sampled
(or is available) only at discrete time intervals over the specified time range.
Digital signal also varies over the given amplitude limits and is sampled at discrete time intervals
over the specified time range, but its amplitude cannot take any value in the given range, but only
some specified values. The value it takes is closest to the value of discrete time signal at that
particular instant of time.
2. Ease of design, ease of data storage, less affected by noise, more reliable, etc.
3.
4. The real world is mainly analog. Most physical quantities are analog in nature, and it is these
quantities that are often the inputs and outputs that are being monitored, operated on, and
controlled by a system. Digital signals are often an approximation of the analog data (like
voice or video) that is obtained through a process called quantisation. The digital
representation is never the exact signal but it’s most closely approximated digital form.
So it’s accuracy depends on the degree of approximation taken in quantisation process.
OR
We live in an analog world. There are an infinite amount of colors to paint an object (even if
the difference is indiscernible to our eye), there are an infinite number of tones we can hear,
and there are an infinite number of smells we can smell. The common theme among all of
these analog signals is their infinite possibilities.
Digital signals and objects deal in the realm of the discrete or finite, meaning there is a
limited set of values they can be. That could mean just two total possible values, 255,
4,294,967,296, or anything as long as it’s not ∞ (infinity).
5. Because a signal varies over time, it’s helpful to plot it on a graph where time is plotted on
the horizontal, x-axis, and voltage on the vertical, y-axis. Looking at a graph of a signal is
usually the easiest way to identify if it’s analog or digital; a time-versus-voltage graph of an
analog signal should be smooth and continuous.
6.
Digital System
Analog
DAC
Output
A
D
C