调制特性 IDFTIX((K+DNRN]=WNx(n)=eNx(n iE: IDFTIX((k +D))R(k)]= IDdFTIX(k+ORN(k) IDFSLX(K+DR(n) W(nr(n=wx(n) 时域序列的调制等效于频域的圆周移位调制特性： 时域序列的调制等效于频域的圆周移位 2 [ (( )) ( )] ( ) ( ) j nl nl N N N N IDFT X k l R k W x n e x n      [ (( )) ( )] [ ( ) ( )] N N N IDFT X k l R k  IDFT X k l R k 证：  [ ( )] ( ) N  IDFS X k  l R n  ( ) ( ) ( ) nl nl WN N N  x n R n  W x n