10.1
Chapter 10
Error Detection
and
Correction
Docsity.com
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Guidelines and tips
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Error detection and Correction 2-Data Communication and Computer Networks-Lecture Slides, Slides of Data Communication Systems and Computer Networks
These are a set of Lecture Slides on the subject of Data Communication and Computer Networks at Univeristy of Delhi by Dr. Sonam Zinta. It includes: Error, Detection, Correction, Corrupted, Redundancy, Retransmission, Modular, Arithmetic
Typology: Slides
2011/2012
1 / 36
This page cannot be seen from the preview
Don't miss anything!
Related documents
Partial preview of the text
Download Error detection and Correction 2-Data Communication and Computer Networks-Lecture Slides and more Slides Data Communication Systems and Computer Networks in PDF only on Docsity!
Chapter 10
Error Detection
and
Correction
Docsity.com
Data can be corrupted
during transmission.
Some applications require that
errors be detected and corrected.
Note
Docsity.com
In a single-bit error, only 1 bit in the data
unit has changed.
Note
Docsity.com
Figure 10.1 Single-bit error
Docsity.com
Figure 10.2 Burst error of length 8
Docsity.com
To detect or correct errors, we need to
send extra (redundant) bits with data.
Note
Docsity.com
In this book, we concentrate on block
codes; we leave convolution codes
to advanced texts.
Note
Docsity.com
In modulo-N arithmetic, we use only the
integers in the range 0 to N −1, inclusive.
Note
Docsity.com
10-2 BLOCK CODING
In block coding, we divide our message into blocks, each of k bits, called datawords. We add r redundant bits to each block to make the length n = k + r. The resulting n-bit blocks are called codewords.
Error Detection Error Correction Hamming Distance Minimum Hamming Distance
Topics discussed in this section:
Docsity.com
Figure 10.5 Datawords and codewords in block coding
Docsity.com
Figure 10.6 Process of error detection in block coding
Docsity.com
Let us assume that k = 2 and n = 3. Table 10.1 shows the list of datawords and codewords. Later, we will see how to derive a codeword from a dataword.
Assume the sender encodes the dataword 01 as 011 and sends it to the receiver. Consider the following cases:
- The receiver receives 011. It is a valid codeword. The receiver extracts the dataword 01 from it.
Example 10.
Docsity.com
Table 10.1 A code for error detection (Example 10.2)
Docsity.com
An error-detecting code can detect
only the types of errors for which it is
designed; other types of errors may
remain undetected.
Note
Docsity.com