Patent ID: 6690738
Filing Date: 2004-02-10
Classification: H03M,H04L

Abstract:
A trellis coded modulation system, comprising:a trellis coded modulation encoder comprising a plurality of delay elements and a rate Â½ convolutional encoder for processing k data bits, the rate Â½ convolutional encoder processing the least significant bit to generate two code-bits indicative of a coset of symbols in the transmit symbol constellation, and a look-up table coupled to the delay elements and convolutional encoder that implements a bit-to-symbol map and that outputs a single symbol corresponding to one of the symbols in the transmit constellation; and a trellis coded modulation decoder for processing received symbols comprising an input lookup table for translating locations of a constellation point into a decision region label, a Viterbi decoder coupled to the input lookup table for processing synthesized soft decision data to generate a maximal likelihood estimate of the most likely coset to which a received symbol belongs, a convolutional encoder coupled to the Viterbi decoder for re-encoding the maximal likelihood estimate of the most likely coset to generate a coset label indicative of the coset to which the received symbol most likely belongs, and an output look-up table for processing the decision region label and the coset label to output a maximal likelihood symbol that corresponds to the received symbol.