CONVERTING METHOD OF VARIABLE LENGTH CODE

摘要

PURPOSE:To obtain effectively a variable length code limited in width of a detection window by providing the limination to the continuous units of 0 and 1 at right and left ends of a channel code word, and selecting properly the channel code words of different bit lengths. CONSTITUTION:In order to obtain a variable length code having a fixed width of a detection window with limited number of both minimum and maximum continuous bits (d) and (k) respectively, the channel code words are selected on the following standard. That is, the number of continuous bits (l) of 1 at the left L of the channel code word must be set within a specified range together with the number of continuous bits (r) of 0 and 1 at the right R of the code word. Then the channel code words CC0 and its CC0' consisting of codes 0 and 1 alternately are selected at a prescribed intermediate part. Then a code word CW0 having the number of bits (l) less than the prescribed value and its CW0' are set in a pair among the above-mentioned words CC0 and set opposite to data words. In the same way, a code CW1 having the number of bits (l) less than the prescribed value and its CW1' are set in a pair among said word CC0 and set opposite to data words.