| 摘要 |
PROBLEM TO BE SOLVED: To provide a reproduced signal evaluating apparatus in which reproduced signal evaluation value calculating circuits of "(the number of maximum likelihood decoder)-1" can be omitted even if two or more maximum likelihood decoders are provided. SOLUTION: A maximum likelihood decoder 5 based on PR(1, 2, 1) generates two kinds of binary data by NRZ and binary data by NRZI as output, and supplies them to a selection circuit 7. Also, a maximum likelihood decoder 6 based on PR(1, -1) generates two kinds of binary data by NRZ and binary data by NRZI, and supplies them to the selection circuit 7. Also, a decoder 5 and the maximum likelihood decoder 6 generate respectively SAM and supply them to a reproduced signal evaluation value calculating circuit 8. The selection circuit 7 selects binary data by NRZI and supplies it to a demodulation part, while, the circuit 7 selects binary data by NRZ and supplies it to the reproduced signal evaluation value calculating circuit 8. The reproduced signal evaluation value calculating circuit 8 calculates a reproduced signal evaluation value evaluating a reproduced signal based on a SAM value. COPYRIGHT: (C)2007,JPO&INPIT
|
