6.1 ISI and zero-ISI condition Consider the general block diagram as follows.Without loss of generality,we consider baseband (BB)case. C(f)=0,f八≤B。 G(f) c(f) G(f)） Det. a. y() {a} 8r() n(t) gx(1) Sym-timing Tx Channel Rx where, GT(f)represents the freq-characteristic of the transmission signal,which is determined by the pulse shape. C(f)the freq-response of the channel. GR(f)the freq-response of the receiving filter.(eg.the MF) The corresponding time representations are gr(t),c(t)and gR(t) respectively. UESTC-Digital transmission thro BL AWGN channels Prof李晓峰 5