Patent ID: 7260768

Claim:
A communication device, which uses turbo codes as error-correction codes, comprising: a transmitter that includes a tubo encoding unit which carries out a turbo encoding process on a predetermined number of lower bits in transmission data and outputs information bits corresponding to the lower bits and first and second redundant bits that have been convolutionally encoded in different sequences, wherein the transmitter transmits the output of the turbo encoding unit and upper bits of the transmission data; and a receiver that includes: a first decoding unit which extracts the information bits and the first redundant bit from a received signal, and makes a soft-judgment on the lower bits based upon either the results of the extraction and a previous soft judgment output or only the results of the extraction; a second decoding unit which extracts the information bits and the second redundant bit from the received signal, makes a soft-judgment on the lower bits based upon the results of the extraction and the soft-judgment output from said first decoding unit, and informs said first decoding unit of the result of the soft-judgment as the previous soft-judgment output; a first judging unit which makes a hard-judgment on the lower bits based upon the soft-judgment output of said second decoding unit after the first and a second judging unit execute the soft-judgment repeatedly; and a second judging unit which makes a hard-judgment on the upper bits of the transmission data based upon the received signal.