Efficient run-length limited code with short interleave constraints

摘要

An encoder and a method of encoding successive data words into successive code words for transmission through a channel is provided. The encoder divides each successive data word into first and second portions. The first portion of each successive data word is mapped into a corresponding first code pattern and a corresponding state variable according to a selected code. A second portion of each successive data word is mapped into a corresponding second code pattern that is associated with the state variable, according to the selected code. The first and second code patterns are combined to form each of the successive code words. The successive code words are concatenated to form an encoded bit stream having a plurality of bit positions. The encoder imposes a run length constraint on the selected code such that the encoded bit stream has a maximum possible run of seven consecutive same binary symbols in adjacent ones of the plurality of bit positions and imposes an interleave constraint on the selected code such that the encoded bit stream has a maximum possible run of five consecutive same binary symbols in every other one of the plurality of bit positions.