ABSTRACT
We report on a new method for translating user information into a
constrained sequence in which prescribed subsequences are forbidden.
The new method, termed sequence replacement technique, recursively removes all
forbidden subsequences and the positions where the forbidden subsequences
are removed are indicated at predefined positions at the beginning of the
constrained sequence.
The sequence replacement technique makes it possible to
translate source words into codewords and vice versa by invoking
an algorithmic procedure rather than performing the translation
with a look-up table.
The new method will be exemplified by constructing
prefix-synchronized codes and maximum run-length-limited codes.
It will be shown that the sequence replacement technique
is efficient as the rate of the code is close to its theoretical maximum.
Key Words: constrained code, recording code, run-length-limited