written 7.7 years ago by
teamques10
★ 67k
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modified 7.7 years ago
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$\therefore P = \begin{bmatrix} \ 1 & 1 & 1 \\ \ 1 & 1 & 0 \\ \ 0 & 1 & 1 \\ \end{bmatrix} H = \begin{bmatrix} \ 1 1 0 & 1 0 0 \\ \ 1 1 1 & 0 1 0 \\ \ 1 0 1 & 0 0 1 \\ \end{bmatrix}$
Number of different message vector $2^k = 2^3 = 8$
$C4 = d_1 \oplus d_2 \oplus d_3\\
C5 = d_1 \oplus d_2\\
C6 = d_2 \oplus d_3$
Where [C] = [M] [P]
Let $d_1, d_2, d_3$ are message bits
M = [$d_1 \hspace{1cm} d_2 \hspace{1cm} d_3$]
C = [$C_4 \hspace{1cm} C_5 \hspace{1cm} C_6$]
$d_1$ |
$d_2$ |
$d_3$ |
$C_4$ |
$C-5$ |
$C_6$ |
codeword |
Weight |
0 |
0 |
0 |
0 |
0 |
0 |
000 000 |
- |
0 |
0 |
1 |
1 |
0 |
1 |
001 101 |
3 |
0 |
1 |
0 |
1 |
1 |
1 |
010 111 |
4 |
0 |
1 |
1 |
0 |
1 |
0 |
011 010 |
3 |
1 |
0 |
0 |
1 |
1 |
0 |
100 110 |
3 |
1 |
0 |
1 |
0 |
1 |
1 |
101 011 |
4 |
1 |
1 |
0 |
0 |
0 |
1 |
110 001 |
3 |
1 |
1 |
1 |
1 |
0 |
0 |
111 100 |
4 |
$d_{min} = MIN [w(x)]\\
\therefore d_{min} = 3$
Error deletion capability:
$d_{min} \geq S + 1\\
3 \geq S + 1\\
\therefore S \leq 2$
Error correction Capability:
$d_{min} \geq 2t + 1\\
\therefore t \leq 1$
It can correct up to 1 bit in error.
Number of single bit error pattern = $n_c1 = 6_C1 = 6$
Decoding table is:-
Error pattern |
Syndrome |
|
$E_1$ 1 0 0 0 0 0 |
1 1 1 |
$S_1$ |
$E_2$ 0 1 0 0 0 0 |
1 1 0 |
$S_2$ |
$E_3$ 0 0 1 0 0 0 |
0 1 1 |
$S_3$ |
$E_4$ 0 0 0 1 0 0 |
1 0 0 |
$S_4$ |
$E_5$ 0 0 0 0 1 0 |
0 1 0 |
$s_5$ |
$H^T = \begin{bmatrix} \ 1 & 1 & 1 \\ \ 1 & 1 & 0 \\ \ 0 & 1 & 1 \\ \ 1 & 0 & 0 \\ \ 0 & 1 & 0 \\ \ 0 & 0 & 1 \\ \end{bmatrix}$
Let $y_1$ = 1 0 1 1 0 1
$S_1 = y_1 . H^T = [1 0 1 1 0 1] \begin{bmatrix} \ 1 & 1 & 1 \\ \ 1 & 1 & 0 \\ \ 0 & 1 & 1 \\ \ 1 & 0 & 0 \\ \ 0 & 1 & 0 \\ \ 0 & 0 & 1 \\ \end{bmatrix} \\
= \begin{bmatrix} 1 \oplus 1 & 1 \oplus 1 & 1 \oplus 1 \oplus 1 \end{bmatrix} \\
= \begin{bmatrix} 0 & 0 & 1 \end{bmatrix} \hspace{2cm} S_1 \neq 0 \Rightarrow error$
Corresponding error pattern is 0 0 0 0 0 1
Corrected codeword will be 1 0 1 1 1 0