SECONDARY CHANNEL USING CODE VIOLATIONS

摘要

A method and an apparatus are disclosed for combining information from two sources and for separating the combined information after transmission over one physical channel. A mask which represents a specified piece of information such as a control command or logic state of an input is exclusively ORed with an encoded input signal, thereby inducing a violation of an error control code. At the receiving end of the system, each of a set of masks is exclusively ORed with the received data stream. One of the masks is the same as the mask initially combined with the encoded input signal. Accordingly, once that mask is combined with the received data stream and so indicated by the favorable outcome of an error control code check, the original encoded input as well as the specified piece of information are recreated and produced.