Delay equalisation of vestigialsideband waveform transmission systems

The well known conditions for distortionless transmission through a vestigial-sideband (v.s.b.) system, i.e. that the v.s.b. shaping network should have amplitude and phase characteristics that are skew symmetric about the carrier frequency, form only one set from an infinite number of possible sets of conditions. A practical example shows that use of an alternative set of conditions proposed by Saraga considerably reduces the complexity of delay equalisation necessary when television or similar waveforms are to be transmitted. However, consideration of the effect of phase errors in the demodulating carrier signal and of noise in a practical system shows that, in these respects at least, conventional v.s.b. transmission is superior.