5.2 Pulse amplitude modulation sm(0)=An8(t)cos2πfd 5.2.1.PAM:passband signals BPSK=Binary Phase-Shift- Keying "11 种10 "01 "00 2PAM Antipodal ● √E Baseband signal:its freq band is close to zero, often used in wire-line transmission. 2PAM Unipolar Passband signal:its freq band is away from zero, a cos-like waveform, M and widely used in wireless transmission. 4PAM A=1 E UESTC-Digital transmission through the AWGN channel Prof李晓峰 13