Data communication system with key data bit denoting significance of other data bits

摘要

A communications system includes a transmitter for sending successive composite signals, each of which has successive segments which represent different data. A composite signal can be a pulse group with the segments denoted by individual pulses. A plurality of receivers are connected to receive the successive composite signals and recognize the data in each signal. Part of the transmitted composite signal is encoded by modifying at least one segment of a given composite signal in a predetermined manner. When an addressed receiver detects the encoded data or key in the composite signal, the receiver assigns a different significance to data in the remainder of that composite signal, and/or in at least one other composite signal. If the key is present in the next successive transmission, yet another significance is assigned to the data.