Spectrally efficient digital modulation method and apparatus

摘要

A method and apparatus are provided for generating a uniquely shaped prototype digital pulse which is transmitted with minimal frequency spectrum consumption and yet a relatively high bit rate. Such uniquely shaped digital pulse is stored in a memory included in a transmitter until transmission is desired, at which time a positive of the pulse is transmitted to correspond to a first logic level or the negative of the pulse is transmitted to correspond to a second logic level.