摘要 |
<p>A p-to-q (p<q) code table, and a p-to-q modulation method and system that uses the table and provides a q-bit code stream satisfying a predetermined RLL constraints and the DSV constraint and including no merging bit are provided. The table comprises a plurality of subtables with respective ID's. Each q-bit code in the table is accompanied with a field containing a subtable ID for the modulation of the next code. Codes can be used repeatedly in each subtable such that combinations of appearances of each of the overlapping codes and respective fields are unique in the subtable. The table includes at least one group of a first subtable and at least one second subtable such that the first subtable can be used for the second subtable(s) for the codes of the 2<p> codes that are in a predetermined range and that, for each code in the predetermined range, the number of "1" symbols of two corresponding codes of the first subtable and each of the second subtable(s) is an odd number, which enables DSV control. In modulation, a q-bit code for the current p-bit code is retrieved from a subtable identified by the value of the above-mentioned field that accompanies the q-bit code used for the previous p-bit code. If two subtables are usable, one yielding a smaller DSV absolute value is used. <IMAGE></p> |