METHOD AND APPARATUS FOR IMPLEMENTING POST-MODULATION ERROR CORRECTION CODING SCHEME

摘要

A method of and apparatus for providing error correction coding for a block of user data is disclosed in which the user data (101) is initially modulated by a first modulator (102) and then the modulated user data (108) is error correction encoded to produce a first plurality of check bits (106). The first plurality of check bits are then modulated by a second modulator (114) whose output is then fed to a second error correction (120) which produces a second plurality of check bits (118). The modulated user data, the first plurality of check bits and the second plurality of check bits are all fed to a shift register (128) where the error correction encoded user data block is formed. The present invention is useful with magnetic and optical storage devices.