Signal modulation method, signal modulation device, signal demodulation method and signal demodulation device

Application Number: 00121719
Application Date: 1995.07.07
Publication Number: 1312555
Publication Date: 2001.09.12
Priority Information: 1994/7/8 JP 157175/94
International: G11B20/10;H03M7/00
Applicant(s) Name: Sony Corp.
Address:
Inventor(s) Name: Okazaki Toru;Yoshimura Toshiji
Patent Agency Code: 72001
Patent Agent: ye kaidong
Abstract In the present invention, a partly duplexed conversion table is used as a conversion table for converting an M-bit based data string directly into an N-bit based code string. This conversion table is constituted by first and second sub-tables including plural code groups, respectively. The plural code groups include different codes for the same input data. The second sub-table is a table which is partly duplexed with the first sub-table and is produced by allocating different codes to data from first input data to second input data in the first sub-table. The first and second sub-tables are so designed that code sets of the duplexed portions take variants of digital sum variations which are opposite in sign.