Now Xint n]can be related to x[n] through xint[n]=x[n]c[n] [1,n=0,±M,+2M,… 0,otherwise A convenient representation is given by(Problem 10.4) 时2r M-1 k=0 where Wy =e-i2zIMNow xint[n] can be related to x[n] through [ ] [ ] [ ] xint n = x n c n       = ± ± = otherwise n M M c n 0, 1, 0, , 2 ,... [ ] A convenient representation is given by(Problem 10.4) 1 0 1 [ ] M kn M k cn W M − − = = ∑ where j M M W e− 2π / =