A new 8‐12 conversion channel code and its application to high data‐rate video recording
Hirotake Ishii, 益雄 梅本, Hidehiko Sawamura Nonmember, Yoshizumi Eto Member · Electronics and Communications in Japan (Part II Electronics) · 1995
Abstract Short wavelength recording requires a channel code that has a larger minimum magnetic‐transition interval (Tmin) than the data‐bit interval (Tb). An 8‐12 conversion channel code has been developed in whichTminis 1.33 times longer thanTb. In this code, a maximum of four combinations of 12‐bit channel codes are set for each 8‐bit dataword. The proper channel code is selected by referring to the previous channel code and the tentative next channel code. A word‐inversion scheme can be applied to this conversion channel code, drastically reducing the dc component of the code when the code is used in video‐signal recording. As a result, when recording video signals, the dc component and digital sum variation (DSV) characteristics of the new code are superior to those of the (1, 7)RLL code and similar to those of the NRZ‐ASE code. Simulation showed that the 8‐12 conversion code has superior eye‐pattern and error‐rate characteristics compared to the (1, 7)RLL and NRZ‐ASE codes. A video‐signal recording experiment using the 8‐12 conversion code achieved at a recording rate of 198 Mb/s and a recording density of 5.8 μm2/bit indicates that this code will make HDTV digital video cassette recorders feasible. The experimental average error rate was 7 × 10−5, sufficient for HDTV video recording.