, , , ( , ). ( ) , .
(n, k, d0), n , (r), k=n-r , d0 , . (t) () (t) () d0 :
,
,
, n,k: R = r / n , v = k / n .
. 10.3.
, ( . 10.3 ). () , - . , . /. ( , .. ) ( ). Parity () MODE (MS DOS). , / . /. / (. ).
(CRC)
, . , d0, ( d0=3 d0=4). .
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, ( ) :
(a0a1an-2an-1);
(an-1a0a1an-2);
.
() g(x) .
G(x)=gr xr + gr-1 xr-1 + + g0
gi={0,1}, x=2. , c
u(x) = uk-1 xk-1 + uk-2 xk-2 + +u0
A(x) = an-1 xn-1 + an-2 xn-2 + + a0
, , , , . 2.
(7,4,3), g(x) = x3 + x + 1, :
1) :
u(x) = uk-1 xk-1 + uk-2 xk-2 + +u0
k=4 0111
u(x) = x2 + x + 1
2) u(x) xr, r :
u(x) x3 = (x2 + x + 1) x3 = x5 + x4 + x3
3) g(x):
c(x) - (k1);
R(x) - (r-1);
2 ( ).
,
. 10.4 , (010) (r + k + 1=8). , 2 ( , 2). g(x). . , . ,
. 10.4. ( 5- 6- )
. , , k , . 2 ( ) 2r .
2, , ( 2-0 1) . (. 10.4) 2 , , "" 2 ( ), , , . , , , ( ) .
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, ( ), n, k d0. 2 4 (16 32 ), n, k d0 . . , . , ( ) l = r . , .
( d0) , , () . . . , . , , .
, () . ( ) . ( ) . ( ). .
. " " , , CRC (Cyclic Redundancy Check ). , , CRC, " " (FCS ), , . .
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( ), , , . ( n=1023) , d0 . (, ), , . (48 96 ) , .