Combined transmission of analogue and digital information as alternating wave, encodes analog signal as amplitudes, digital signal in terms of cycle timings

摘要

Transmission is effected using an alternating current with a frequency and phase, applying PAM modulation on amplitudes of its periods (or half-periods). Digital information is encoded as elements or words, controlling the number or length of the periods (or half-periods). Analog and digital codings are concatenated together to form an alternating signal as an uninterrupted sequence.