In the field of coding theory
, a coset leader
is a particular codeword for each transmitted word that can be singled out for linear codes
. We call the word of least weight in any particular coset
, the coset leader. Sometimes coset leaders are unambiguously determined however there are cases where there can be two or more words of equal weight.
Coset leaders are used to construct a fast decoding strategy. For each coset leader u we calculate the syndrome uH'. When we receive v we evaluate vH' and find the matching syndrome. The corresponding coset leader is the most likely error pattern and we assume that v+u was the codeword sent.