Mutual conversion method of binary data and multilevel signal, its communication method, and its receiving device

摘要

A method for converting binary data into a multilevel signal where the binary data includes m data, or symbols, per group unit which have n bits per data. The multilevel signal includes m time slots, or symbol periods, and m+1 levels per basic period. The m time slots include 0th to m-1 slots. The m+1 levels include 0th to m-1th levels and an upper standard level above the m-1th level. The basic period is alternately and consecutively defined as A type and B type. A type data at a predetermined location is defined as an index data. When the binary data is converted into the multilevel signal, the index data is assigned to the Tth time slot taking the 0th level in the A type basic period and upper standard level in the B type basic period corresponding to a value T of the original index data in binary digit. Other binary data j, or normal data, are allocated to each time slots except the Tth time slot for the index data after converted into the multilevel signal with level values L.sub.j +1 being shifted up by one level in the A type basic period and with level values L.sub.j in the B type basic period without being shifted. As a result, transmission efficiency is improved.