Method for the digital transmission of information, in which the coding is effected by the halfwaves or periods of alternating currents

摘要

The methods for the digital transmission of information items for data, voice or image transmission via cable or radio require elaborate terminals and also considerable bandwidths, particularly due to the transmission code. Although optical waveguides provide more bandwidths, they are expensive and cannot be used for radio. The invention uses a binary code as the transmission code. As code elements, the halfwave or the period of an alternating current with the characteristic states of large amplitude value (large CE in the figure) and small amplitude value (small CE in the figure) are provided which are sent in a direct sequence of positive and negative halfwaves or periods (codeword 9 bit in the figure). The small amplitude value only has half the magnitude of the large one. Apart from a direct transmission via a communications path, a frequency-(figure) or time-division multiplex transmission can also take place. The invention can be used both in baseband and in modem technology and can be used in existing carrier-frequency systems and in PCM systems, in microwave links, radio broadcasting and television. IMAGE