Patent ID: 7051270

Claim:
A decoder apparatus adapted to determine a log likelihood that expresses a probability of passing a state in the form of log ratio based on a received value as soft-input for decoding by using the log likelihood, said decoder apparatus comprising: soft-output decoding means housed in the decoder apparatus for performing a decoding operation and for receiving, as input, first probability information and second probability information, the first probability information comprising a channel value divided by a first additive coefficient for regulating an amplitude of the received value, said channel value being produced by multiplying the received value by a predetermined coefficient, said first additive coefficient being adapted to be used for multiplying only the received value, and the second probability information comprising a priori probability information multiplied by a reciprocal of a second additive coefficient, said second additive coefficient being adapted to regulate an amplitude of the a priori probability information by multiplying only the a priori probability information, for soft-output decoding; and said soft-output decoding means generating a log soft-output describing a soft-output in a logarithmic form and extrinsic information by using the first additive coefficient for regulating the amplitude at the time of arithmetic operation of the soft-output decoding means, wherein the soft-output decoding means selects a desired dynamic range and quantization slot accuracy to exchange the extrinsic information via a connection means; and timing means housed in the decoder apparatus for defining a clock time, the clock time representing the duration of the decoding operation.