Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Error Detection and Correction
Coding:
Redundancy

is achieved through various
coding Scheme.
The sender adds the redundancy bit to
the original messag...
The Structure of encoder and
decoder
2 categories
Block coding
2. Convolution coding-more complex(less
use)
1.
Modular Arithmetic
Use

only limited range of integers.
We, define upper limit, called a ,modulus
N.
Then use only the ...
Modulo-2 Arithmetic
Here

modulus N is 2. we can use only 0
and 1. operation in this arithmetic are
very simple.
The add...
Block coding
Divide

the message into blocks, each of k
bits, called datawords. Then add r
redundant bit to make length n...
Error Detection
The

receiver can detect a change in the
original codeword. by
1. The receiver has a list of valid codewo...
Error Detection
Example code word
Error Correction
Upcoming SlideShare
Loading in …5
×

Error detection and correction

24,638 views

Published on

Computer Network

Published in: Technology

Error detection and correction

  1. 1. Error Detection and Correction
  2. 2. Coding: Redundancy is achieved through various coding Scheme. The sender adds the redundancy bit to the original message and create relationship. The receiver checks the relationship b/w two sets of bits to detect (or) correct the errors. Robustness of the process are important factors in any coding scheme.
  3. 3. The Structure of encoder and decoder
  4. 4. 2 categories Block coding 2. Convolution coding-more complex(less use) 1.
  5. 5. Modular Arithmetic Use only limited range of integers. We, define upper limit, called a ,modulus N. Then use only the integers 0 to N-1. This is modulo-N arithmetic.
  6. 6. Modulo-2 Arithmetic Here modulus N is 2. we can use only 0 and 1. operation in this arithmetic are very simple. The addition and subtraction give the same results. Here, we use XOR operation for both the add and sub. The result of an XOR operation is 0(if both the bits are same. The result is 1 if the any of the two bit is different.)
  7. 7. Block coding Divide the message into blocks, each of k bits, called datawords. Then add r redundant bit to make length n=k+r The resulting n-bit blocks are called codewords.
  8. 8. Error Detection The receiver can detect a change in the original codeword. by 1. The receiver has a list of valid codewords. 2. The original codeword has changed to an invalid one.
  9. 9. Error Detection
  10. 10. Example code word
  11. 11. Error Correction

×