ENCODING AND DECODING METHODS FOR EXPURGATED CONVOLUTIONAL CODES AND CONVOLUTIONAL TURBO CODES

摘要

A convolutional encoder (50) comprises an expurgation unit (22) and a first component convolutional encoder section (24). A convolutional turbo encoder (20) comprises an expurgation unit (22); a first component convolutional encoder section (24); a second component convolutional encoder section (26); and an interleaver (28). For both the convolutional encoder (50) and the expurgating convolutional turbo encoder (20) the expurgation unit (22) inserts predetermined values at selected bit positions of an input bit sequence and thereby provide an expurgated input bit sequence. A lower rate convolutional code is obtained from a higher rate code via expurgation.