Patent ID: 7219295
Filing Date: 2007-05-15
Classification: G11B,H03M

Abstract:
1. A recording-medium reproducing apparatus for reproducing information data from a recording medium, on which primary channel data and secondary channel data are recorded, the primary channel data having been obtained by performing modulation on the information data to generate primary modulation data and then performing pre-coding on the primary modulation data, and the secondary channel data having been obtained by performing at least systematic error-correcting coding on the primary modulation data to form checking data, then performing at least the modulation on the checking data to generate secondary modulation data, and then performing the pre-coding on the secondary modulation data, comprising: reproducing means reproducing the primary channel data and the secondary channel data recorded on the recording medium and outputting reproduced data; iterative decoding means, based on the reproduced data, iteratively performing a posteriori probability decoding in compliance with a constraint concerning channel data and constraints concerning pre-codes and a recording and reproducing characteristic, and an a posteriori probability decoding in compliance with a constraint concerning systematic error-correcting codes while repeatedly delivering and receiving a priori information regarding the primary modulation data internally, so as to obtain an a posteriori probability of the primary modulation data; and demodulation means binarizing the a posteriori probability of the primary modulation data derived from the iterative decoding means and then performing demodulation corresponding to the modulation so as to reconstruct the information data.