Soft-decision decoder

<p>In <a href="/facts/Information_theory/qNLH3U5P">information theory</a>, a soft-decision decoder is a kind of <a href="/facts/Decoding_methods/A0x9Dpgq">decoding method</a> – a class of <a href="/facts/Algorithm/fnl5NmRt">algorithm</a> used to decode data that has been encoded with an <a href="/facts/Error_correcting_code/cLUTUJrA">error correcting code</a>.  Whereas a <a href="/facts/Forward_error_correction/cLUTUJrA">hard-decision decoder</a> operates on data that take on a fixed set of possible values (typically 0 or 1 in a binary code), the inputs to a soft-decision decoder may take on a whole range of values in-between.  This extra information indicates the reliability of each input data point, and is used to form better estimates of the original data.  Therefore, a soft-decision decoder will typically perform better in the presence of corrupted data than its hard-decision counterpart.
</p><p>Soft-decision decoders are often used in <a href="/facts/Viterbi_decoder/7Vu7USwt">Viterbi decoders</a> and <a href="/facts/Turbo_code/F3nmelu0">turbo code</a> decoders.
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Soft-decision decoder open-in-new

Soft-decision decoder