Soft-in soft-out decoder: Difference between revisions

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A '''soft-in soft-out (SISO) decoder''' is a type of decoder used with [[error correcting code]]s. "Soft-in" refers to the fact that the incoming data may take on values other than 0 or 1, in order to indicate reliability. "Soft-out" refers to the fact that each [[bit]] in the decoded output also takes on a value indicating reliability. Typically, the soft output is used as the soft input to forman outer decoder in a system using [[concatenated code]]s, or to modify the input to a further decoding iteration, such as in the decoding of [[turbo code]]s.

Examples include the [[BCJR algorithm]] and the [[soft output Viterbi algorithm]].