频域离散化证明x0)揪7X()92x(0￠里 ●频域采样点数N,采样间隔DwX=2=2 ●频域Xo)与的M)=a以-mDW相乘, ●时域cmTy与FBWm?adtm)卷积, 邋dt-n)揪 2 ad(t-n7)揪o r a dw- nDW F减m:m则=2.,n
X 第 1 频域离散化证明 页 2 2 ( ) ( ) FT n n t nT n T T p p d d w ゥ = - ? - ? Q 邋 - 揪 ? ) ) 2 ( ( FT n n T d t nT d w n p ¥ ¥ = - ? = ? - \ - å 揪 ® å - DW ⚫ 频域采样点数N，采样间隔 S 2 2 N N T T S W p p DW= = = × ⚫ 频域Xa (ω)与 ( ) ( ) 相乘， n w d w n ¥ D W = - ? D = - DW å % ⚫ 时域xa (nTS )与 卷积， 1 [ ( )] ( ) n F T t nT w d ¥ - D W = - ? D = ? å % 1 [ ( )] ( ) n n 2 T F n t nT d w d p ゥ - = - ? - ? \ - DW = ? 邋 ( ) ( ) 2 ( ) FT FT x t X x t 揪 w p 井 -
