Hamming 74 code explained

1
Hamming 7-4 code explained
Given an information word...
of seven bits.
The code word...
is 11 bits.
Place the seven information bits in the code
word...
The control bits are numbered 1, 2, 4 and 8. How
are the four control bits determined?
Write each information bit number in the
code word as a sum of the control bit numbers. So
0
0
1
0

• Bit 3 of the code word is the first information
  bit in the code and 312...

• Write the value of the information bit in both
  yellow boxes...

Repeat this process for bit 5, 6, 7, 9, 10 and
11 of the code word...
To determine the value of the first control bit
of the code word (I.e. bit number 1)

• Count the number of 1s in the column...

• If this number is even, then the control bit
  becomes 0, else it becomes 1.

Repeat this process for the second, third and
fourth control bit...
Ready!