Download - Formule Final 2010
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Forma direct --> forma latice
, ,, , 1, 2, , , = : -1: 2, = 1:1:1
i j i i i jN j j i i i i j
i
a k aa a k a a i N j i
k
= = = -1
2, ,0
-1
,1
, , 1,N
N N i i k k k ik i
b c c b c a i N N= +
= = = " Forma latice --> forma direct
, ,0 , 1, 1,, 1, , = 2 :1: , = 1:1:i i i i i j i j i i i ja k a a a k a i N j i = = = + Decimare:
( ) ( )y n x nM= 110
1( )M
k MM
kY z X W z
M
=
= ( ) ( )11 2
0
1 yy M j kj Mk
Y e X eM
=
= Expandare:
, ,( )
0, i n rest
nx n kL kLy n
= =
L ( ) ( )LY z X z= j jy yY e X e =
Algoritmi rapizi de calcul TFD: ( ) ( )10
, 0,1, ,N
nkN
nX k x n W k N
=1= = 2j nknk NNW e =
In baza R cu decimare in timp: 1 2 1 2
1 2 1 2
, 0,1, , 1, 0,1, ,
, 0,1, , 1, 0,1, , 1;
Nn Rn n n n RR
N Nk k k k k RR R
1;= + = =
= + = =
In baza R cu decimare in frecventa 1 2 1 2
1 2 1 2
, 0,1, , 1, 0,1, , 1;
, 0,1, , 1, 0,1, , 1;
N Nn n n n n RR R
Nk Rk k k k RR
= + = =
= + = =
Q
cu baze mixte 1 2 1 2 2 2undeQ Q QN N N N N N N N N= = =" "