In
information theory, an
erasure code is a
forward error correction (FEC) code for the
binary erasure channel, which transforms a message of
k symbols into a longer message (code word) with
n symbols such that the original message can be recovered from a subset of the
n symbols. The fraction
r =
k/
n is called the
code rate, the fraction
k’/k, where
k’ denotes the number of symbols required for recovery, is called reception efficiency.