Error Detection Procedures of Hamming code

1. ERROR DETECTION & CORRECTION
Presented by-
Mufti Mahamud Alrazi
Department Of EETE
Dhaka International University
Date – 6th of April, 2018

2. OUTLINES
• Introduction
• Error Types
• Forward Error
• Forward Error Correction
• Burst Error
• Burst Error Correction
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3. INTRODUCTION
• A digital signal can be error when it is transmitted trough a channel.
• The error might be occurred a single bit or multiple bits.
• As it is digital signal , The error bit can be changed into 1 instead of 0 and vice-
versa .
• To detect this , Richard Humming found a way during the invention “Hamming
Code”.
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4. TYPES OF ERROR
• There are two types of error in "Hamming Code”:-
1. Single Bit Error:
 In a single-bit error, only one bit in the data unit has changed.
2.Burst Error :
 A burst error means that 2 or more bits in the data unit have changed.
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5. FORWARD ERROR DETECTION
• It can only detect a single bit error of a “Humming Code”
Error Bit
Humming Code
R1
R2
R3
R4
R5
0 1 1 1 0
1 1 0 0 0 0 0 1 0 0 0 1 1 1 0 0 1 0
1 0 0 1 0 1 1 0 0
1 0 0 1 0 1 1 0 1
0 0 0 0 1 1 1 0
0 0 0 0 1 0 0 0
1 1 0
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6. BURST ERROR DETECTION
• It can detect more than one error
• HC= 11101 11011
• For 1st Segment
Error in 2nd bit 0 1 0
1 1 0 1 1
1 1 0 1 1
1 1 0 1 1
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7. BURST ERROR DETECTION (CONT.)
• For 2nd Segment
Error in 3rd bit
0 1 1
1 1 1 0 1
1 1 1 0 1
1 1 1 0 1
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8. WHERE TO USE
• Computer Memories
• Photographs From Spacecraft
• Compact Discs
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9. Any
Question???