5.4.1 Orthogonal signal waveforms For M-ary(M=4) S=E,Wir S2 =E.W2 S=E.Wx s (n Baseband examples "Left"=signals which are completely 4320 overlapped 50 24- "Right"=signals which are completely T/2 non-overlapped T/4 Th T(I In practical, The "Left"is usually generated by a famous procedure called Hardamard/ T/23T/4 Walsh-Hardamard Transform(WHT). The "Right"is often called PPM (Pulse 5() position modulation),which are pulses with diff.position. 3T74T UESTC-Digital transmission through the AWGN channel Prof李晓峰 6