Patent ID: 6018304
Filing Date: 2000-01-25
Classification: H03M

Abstract:
A method for modulating a predefined number of bits of a binary data word X.sub.n with a predetermined set of target constraints into codewords having a predefined number of code bits C.sub.n+1 bits comprising the steps of:a. pad the data word [X.sub.n =x.sub.1 x.sub.2 . . . x.sub.n ] with zeros to the form [0 x.sub.1 x.sub.2 . . . x.sub.n 0],b. process the padded data word with 1.sym.D to form the pre-encoded codeword C'.sub.n+1 such that all C'.sub.n+1 have even weight; andc. choose the pre-encoded codewords C'.sub.n+1 which violate a target constraint and invert in a decodable way an odd number of bits of the codeword to form the odd parity codeword C.sub.n+1 which satisfies the target constraints.