In
information theory
Information theory is the scientific study of the quantification (science), quantification, computer data storage, storage, and telecommunication, communication of information. The field was originally established by the works of Harry Nyquist a ...
, a soft-decision decoder is a kind of
decoding methods – a class of
algorithm used to decode data that has been encoded with an
error correcting code. Whereas a
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.
Soft-decision decoders are often used in
Viterbi decoder
A Viterbi decoder uses the Viterbi algorithm for decoding a bitstream that has been
encoded using a convolutional code or trellis code.
There are other algorithms for decoding a convolutionally encoded stream (for example, the Fano algorithm). Th ...
s and
turbo code decoders.
References
See also
*
Forward error correction
*
Soft-in soft-out decoder
Error detection and correction
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