This preview shows pages 1–7. Sign up to view the full content.

Data Communications Additional Notes on Unit 2.4

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Data Communications Hamming Distance ± Hamming distance is a measure of a code’s strength. ± Given two bit patterns, the Hamming distance is defined as the number of bits that are different in the two patterns. ± Examples: ² Distance between 100 and 101 is one. ² Distance between 100 and 010 is two. ² Distance between 111 and 000 is three.
Data Communications Minimum Hamming Distance, d min ± Denote the minimum Hamming distance between codewords of a block code by d min . ± The maximum number of bit errors that can be detected is given by d min –1 . ± Example: the (4,3) Even Parity Check code. ± What is d min ? ± How many bit errors can be detected?

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Data Communications Example: (7,3) Parity Check Code ± There are three data bits: d 1 , d 2 , and d 3 . ± Four parity check bits are calculated as follows: ± The codewords are shown in the next slide.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.