Forouzan Chapter 4 Identification Flashcards
we discuss _ techniques,
methods which convert digital data to digital signals.
digital-to-digital conversion
The conversion
involves three techniques: _, _, and _.
line coding,block coding,scrambling
_ is the process of converting digital data to a digital signal.
Line coding
We can roughly divide line coding schemes into five broad categories: ,,,,and _.
.
unipolar,polar, bipolar, multilevel, multitransition
Block coding provides _ to ensure _ and inherent error detection.
redundancy,synchronization
Block coding provides redundancy to ensure _ and _.
synchronization,inherent error detection
Block coding is normally referred to as _; it replaces each m-bit group with an n-bit group.
mB/nB coding
_ provides synchronization without increasing the number of bits. Two
Scrambling
common scrambling techniques are _ and _.
B8ZS,HDB3
The most common technique to change an analog signal to digital data (_)
is called _.
digitization,pulse code modulation (PCM)
The first step in PCM is _. The analog signal is sampled every Ts s, where Ts
is the sample interval or period.
sampling
The inverse of the sampling interval is called the
_ and denoted by fs, where fs =l/Ts.
sampling rate or sampling frequency
There are
three sampling methods-_, , and.
ideal,natural, flat-top
According to the_, to reproduce the original analog signal, one
necessary condition is that the sampling rate be at least twice the highest frequency
in the original signal.
Nyquist theorem
Other sampling techniques have been developed to reduce the complexity of PCM.
The simplest is _.
delta modulation
PCM finds the value of the signal amplitude for
each sample; DM finds the _ from the previous sample.
change
While there is only one way to send parallel data, there are three subclasses of
serial transmission: _, _, and _.
asynchronous,synchronous,isochronous
In _, we send 1 start bit (0) at the beginning and 1 or
more stop bits (1 s) at the end of each byte.
asynchronous transmission
In _, we send bits one after another without start or stop
bits or gaps. It is the responsibility of the receiver to group the bits.
synchronous transmission
The _ provides synchronized for the entire stream of bits must. In
other words, it guarantees that the data arrive at a fixed rate.
isochronous mode
