1. 双边带信号(DSB-SC) Double Sideband-Suppressed Carrier S(@) 0 ①c tM(@) Wc N 0 -①H @H SM(@) 0 -①c ①c 6 6 1. 双边带信号(DSB-SC) Double Sideband-Suppressed Carrier S(ω) -ωc ωc -ωc M(ω) ωc ω ω ωH -ωH SM(ω) ω