Gittercodierte Modulationsvorrichtung

摘要

A 2/3 convolutional encoder includes a first adder 340 for outputting a first output bit 306 by a modulo-two sum of a present input bit 301 and a twice-delayed input bit 304 of an upper stage, a present input bit 302 and a once-delayed input bit 305 of a lower stage, among 3-bit output bits; a second adder 350 for outputting a second output bit 307 by a modulo-two sum of a once-delayed input bit 303 and a twice-delayed input bit 304 of the upper stage and a present input bit 302 of the lower stage; and a third adder 360 for outputting a third output bit 308 by a modulo-two sum of a present input bit 301 of the upper stage and a once-delayed input bit 305 of the lower stage. A trellis-coded modulation system includes such a convolutional coder (210), Fig. 3, (not shown) for receiving and encoding data (202); a mapper (220) for inputting the remaining uncoded bit (201) and the bits (205) coded by the coder and outputting digital valves of components (206), (207), for signal points of a constellation; a modulator (230) for modulating the bit signals output from the mapper; and a synchronization controller (240) for controlling the coder and mapper. An alternative encoder and mappers are described. <IMAGE>