离散周期序列的傅里叶级数展开式 ∑ xn(n)e n=<N> jk 2兀-n N k k=<N W Wu=e e k ∑x(m)W SCWI k=<N>离散周期序列的傅里叶级数展开式 N j N W e 2 − =  =  = k N j k n N k N x n c e 2 ( )  =  − = n N j k n k N N x n e N c 2 ( ) 1 nk N j kn N W e 2 − = nk N j kn N W e 2 = −  =  = n N kn k N n WN x N c ( ) 1  =  − = k N kn N k WN x (n) c