TIIKOKKTK'AL Fl" NDAM KXTALS OF ITLSK TUAXSMISSIOX 



ion.-) 



For the same bandwidth, the same transmission capacity can be 

 realized with a double sideband sj^stem employing fom- jiulse amplitudes 

 as with a vestigial sideband system Avith two pulse amplitutles. However, 

 the latter type of system will have a greater tolerance to interference 

 from characteristic distortion than the former. This follows when it is 

 considered that in a quaternary system the maximum tolerable inter- 

 ference is ^ the maximum pulse amplitude, as compared to 1^2 the maxi- 

 mum pulse amplitude in a binary system. With )u = ^minMmax = 0, 

 the quadrature component reduces the margin by a factor of 0.5, so that 

 the maximum tolerable interference in relation to the maximum pulse 



PULSE SPACING 

 (1.5 tO.25) cycle 



PULSE SPACING 

 (1.5 +0.25) CYCLE 



PULSE TRANSMITTED IN POSITION n = -1 

 PJLSE TRANSMITTED IN POSITION n = 1 

 RESULTANT ENVELOPE 



Fig. 48 — Impulse exitation of l)aiKl-pass .sA-stem with pulse spacing selected 

 to provide equivalent of vestigial side-band transmission. 



