METHOD OF CONVERTING A SEQUENCE OF M-BIT INFORMATION WORDS TO A MODULATED SIGNAL, METHOD OF PRODUCING A RECORD CARRIER, CODING DEVICE, DECODING DEVICE, RECORDING DEVICE, READING DEVICE, SIGNAL, AS WELL AS A RECORD CARRIER

摘要

The application relates to a method of converting a sequence of m-bit information words (1) to a modulated binary signal (7). For each received information word (1) from the sequence is delivered an n-bit code word (4). The delivered code words (4) are converted to the modulated signal (7). When one of the code words (4) is assigned to the information word (1) to be converted, this code word is selected from a set of code words that depends on a coding state which is related to a digital sum value at the end of the part of the modulated signal that corresponds to the delivered code word (4). By at least one of the digital sum values a first (S2, S4, S6, S8, S10, S12) or a second (S3, S5, S7, S9, S11, S13) coding state of a pair of coding states of a first type is determined. Which of the two coding states of the pair is determined depends on the information word (1) that corresponds to the previously delivered code word (4). The sets (V2/V3; V4/V5; V6/V7; V8/V9; V10/V11; V12/V13) of code words belonging to the pairs of coding states of the first type contain no code word whatsoever in common. In this coding method the number of unique bit combinations that can be established by the code words in the sequence is increased. The modulated (7) signal thus obtained may be reconverted to information words (4) by first converting the modulated signal (7) to a sequence of code words (4) and then assigning an information word (1) to each of the code words from the sequence in dependence on the code word to be converted and also in dependence on the logical values of bits in the bit string which are positioned at p predefined positions relative to the code word. Furthermore, amongst other things a recording device and a reading device are disclosed.