| 摘要 |
A coding/decoding method for high density data recording/reproduction, and an encoder/decoder. In the coding method for encoding an 8-bit binary data symbol Xk (k=1, 2, 3, . . . , 8), received from a storage device or a communications channel, into a 9-bit codeword Yl (l=1, 2, 3, . . . , 9), the number of a maximum transition run (MTR) is limited to a predetermined number, and the number of zero run lengths of the codeword whose MTR is limited is then limited to a predetermined number. Then, a pattern providing a bad effect on detection of a signal is removed from the codeword whose zero run length is limited. In the rate 8/9 modulation code having an MTR of 3, the code rate is high, and the path of the Viterbi detector is reduced as in the rate 2/3 RLL(1,7) code having an MTR of 2, thereby decreasing the delay and complexity of the detector. Also, in order to control the timing and gain control, the k constraint is to 7 such that the signal is easily detected while maintaining self-clocking characteristics of the signal.
|
