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Chadlee88
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Homework Statement
Let S = {0101, 1010, 1100}. From first principles, find a basis B for the dual code C orthogonal (couldn't find symbol)
Homework Equations
http://www.maths.uq.edu.au/courses/MATH3302/files/codingnotes.pdf
i'm using page 19,20 and 21
The Attempt at a Solution
so i did my matrix using the codes of S
1. 0101
A = 1010
1100
2. then i used REF on this getting
1100 1100
0110 => 0110 = G
0101 0011
So is this my generating matrix G? like shown on page 20
The problem is the example on page 20 is in Reduced Row Echelon Form and not
not just Row Echelon Form like above. So i don't get G = (I X) like the example.
This is where i get stuck because I'm not getting the same form for G and so i can't
get H which i need as the columns of H form a basis for C orthogonal.
The solution to this problem i have i don't get either but maybe it might help you,
It's a different approach to what I'm taking but i don't get it.
Could someone please tell me if i got the correct G and how to get H because
that's where I'm really stuck.
Notes solution:
4. Let x1x2x3x4 2 C?. Then by the defnition of C? we have
(x1x2x3x4) x (0101) = 0 so x2 + x4 = 0
(x1x2x3x4) x (1010) = 0 so x1 + x3 = 0
(x1x2x3x4) x (1100) = 0 so x1 + x2 = 0
Thus we have x1 = x2 = x3 = x4. Thus
C orthogonal = {0000, 1111}
Thanx for helping,
Cheerz
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