Digital AM-VSB modulator for compatible PAL systems

Abstract

This paper presents the design of a digital vestigial modulator with the partial suppression of the upper sideband of the composite PAL signal. The choices made during the digital implementation of this device allow to shift the digital-to-analog conversion of the TV signal to intermediate frequency while ensuring the full compatibility with analog transmission systems and the TV receivers currently in use. Particular emphasis is devoted both to the description of the two original schemes proposed for the AM-VSB modulator and to the optimization of the system performance, taking the influence of the most significant parameters of digital filters into account.