| 摘要 |
PURPOSE:To make it possible to transmit new information by neither modifying nor disturbing a sequence of data by generating a level, which is not generated normally, by inserting the new information at a transmission side, and by supervising and extracting this level at a reception side. CONSTITUTION:At the transmission side, M-scale transmitted data sequence an is coded by pre-coder 11 into information sequence bn, which is further coded into transmission line sequence cn by partial response coder 12. This sequence cn is supplied to new information insertion circuit 13 to detect the positive or negative maximum level of the transmitted signal, and the information is delayed by two data intervals and combined with new information of the current level of the transmitted signal to vary the transmitted signal level, thereby attaining transmission via D/A converter 14. At the reception side, it is inputted to new information detection circuit 18 via A/D converter 16. Circuit 18 detects the positive or negative maximum level of the received signal and the detection signal is delayed and combined with current received signal cn' to decode and output the new information. |
