View source for Soft-decision decoder

In [[Information theory|information theory]], a '''soft-decision decoder''' is a kind of [[Decoding methods|decoding methods]] – a class of [[Algorithm|algorithm]] used to decode data that has been encoded with an error correcting code.  Whereas a [[Forward error correction|hard-decision decoder]] 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.<ref>{{cite book
|last     = Proakis
|first    = John
|title    = Digital communications
|edition  = 4th
|year     = 2001
|publisher = McGraw Hill
|isbn      = 0-07-118183-0
|pages     = 457–460}}</ref>

Soft-decision decoders are often used in [[Viterbi decoder]]s and [[Turbo code|turbo code]] decoders.

== See also ==
* [[Forward error correction]]
* [[Soft-in soft-out decoder]]

== References ==
{{reflist}}

[[Category:Error detection and correction]]



{{Sourceattribution|Soft-decision decoder}}