IMPROVED MODEL MULTIDIMENSIONAL TRERIS CODED COMMUNICATION SYSTEM

摘要

PURPOSE: To maintain both alteration invariable and large encoded gain by generating such a new trellis code operating a trellis encoder as is different from a selected subset that corresponds to the shift of the trellis encoder from a current state to the next state. CONSTITUTION: A layout drawing creating device 116 supplies a communication signal point to a modulator 120 by selecting the signal point from a prescribed 12<13> point four-dimensional orthogonal amplitude signal arrangement. That is, the device 116 uses 5 bits that are inputted from a trellis encoder 110 to select a subset of a four-dimensional orthogonal amplitude modulation signal and uses additional eight bits that are inputted from a serial-parallel converter 104 on a line 114 to select a four-dimensional signal point from a selection subset. The selected four-dimensional signal point is supplied to a modulating part 120 through a pulse shaping filter, and the part 120 modulates the permutation of the selected signal point on a communication path 122 to transmit it to a receiving circuit part of a communication system.