5.6.10 Comparison of modulations 1)Efficiency,Rb~W,or n 2)Reliability,P~Eb/No In the physical chaRefer to the BW of a waveform,we simply conclude that, are used to transm BB pulse:W=R/2 PB signals:W=Rs {,am,} For M-D signals, BB pulse:W=MR/2 PB signals:W=MRg We define the normalized data rate (alse called spectral Specifically, efficiency)as ·Baseband(BB) Rp 7= 。 Passband(PB) W kR.(bps/Hz) k=l0g2 M The essential physical features of the waveform is the 1)The BW:denoted by W; 2)The energy:denoted by Es (if unequal,Eav),or Eb=Es/k; UESTC-Digital transmission through the AWGN channel Prof李晓峰 7