MODULATING/DEMODULATING METHOD, MODULATING APPARATUS AND DEMODULATING APPARATUS

摘要

A modulating/demodulating method that minimizes the error ratio and that is used for a differential calculation the modulus of which is four. There are included a gray-encoding circuit (101) that receives data of (2n + 1) bits, where n is an integer greater than one, and that gray-encodes, as a signal capable of identifying four quadrants, two bits of an input signal of (2n + 1) bits; an encoding circuit (102) that encodes, as a signal indicative of eight subgroups located in the four quadrants, three bits of the input signal of (2n + 1) bits such that the average Hamming distance between the adjacent subgroups in each quadrant is minimized; and a mapping circuit (104) that maps the binary data as encoded by the gray-encoding circuit (101) and encoding circuit (102) onto the four quadrants.