Patent ID: 7372376

Claim:
A method of converting a series of m-bit information words to a modulated signal, m being an integer, said method comprising the steps of: converting each received information word into a corresponding n-bit code word, n being an integer exceeding m; and modulating the corresponding code words to form the modulated signal, wherein the converting step converts the series of information words to a series of corresponding code words so that the corresponding modulated signal satisfies a predetermined criterion, and wherein the corresponding code words are spread over at least a group of a first type and at least a group of a second type, while a code word belonging to the group of the first type establishes a coding state of a first type determined by the associated group, and a code word belonging to the group of the second type establishes one of r coding states of a second type determined by the associated group and by the information word ( 1 ) associated to the delivered code word, in which the group of the second type comprises at least one code word being associated with at most r information words among which the respective information word is distinguishable by evaluating a predetermined parameter of the following code word, characterized in that said step of converting each information word comprises the sub-steps: providing each information word with an associated subset of code words comprising at least r code words mutually differing in the value of the predetermined parameter; and selecting the corresponding code word based on an additional criterion from the subset of code words excluding all code words not complying with said predetermined criterion and, in the event that a coding state of the second type has been established by the preceding code word, excluding all code words having a value of the predetermined parameter not corresponding to the established coding state of the second type.