Trellis code detector and decoder
AssigneeSony Corporation
InventorMakoto Noda
Life of this patent
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Abstract
The present invention is to reduce the maximum magnetization reversal interval of a trellis code. A trellis diagram for the trellis code takes into consideration a constraint condition on the DSV of a code and an inter-symbol-interference for three bits. The minimum squared Euclidean distance is 4. When a non-interleaving encoder and a non-de-interleaving code detector are constructed using the trellis diagram, the maximum magnetization reversal interval of a trellis code to be used is reduced to half of that in a known case while having the error rate and circuit size approximately equal to those in the known case. The trellis diagram has a basic repeating unit for two bits. In the actual apparatus, the trellis diagram is repeatedly used. The present invention is applicable to a read/write apparatus.
Claims14
A trellis code detector for performing code detection by using a coding rule for likelihood calculation, comprising:
- means for outputting a digital signal;
- a code detector for performing trellis code detection on the digital signal, wherein the code detector simultaneously applies a plurality of coding rules to detect a code including:
- applying a coding rule on a trellis diagram that there is a spectral null at one of a DC component and a Nyquist component of a code spectrum;
- applying a partial-response class-IV inter-symbol-interference rule;
- and
- applying an inter-symbol-interference rule for three bits on the trellis diagram.
A trellis code detecting method of performing code detection by using a coding rule for likelihood calculation, comprising:
- performing trellis code detection by simultaneously applying a plurality of code detecting rules to detect a code including:
- applying a coding rule on a trellis diagram that there is a spectral null at one of a DC component and a Nyquist component of a code spectrum;
- applying a partial-response class-IV inter-symbol-interference rule;
- and
- applying an inter-symbol-interference rule for three bits on the trellis diagram.
A recording medium having recorded therein a computer-readable program for a trellis code detector for performing code detection by using a coding rule for likelihood calculation, the program comprising:
- computer executable instructions for performing trellis code detection by simultaneously applying a plurality of code detecting rules to detect a code including:
- applying a coding rule on a trellis diagram that there is a spectral null at one of a DC component and a Nyquist component of a code spectrum;
- applying a partial-response class-IV inter-symbol-interference rule;
- and
- applying an inter-symbol-interference rule for three bits on the trellis diagram.
A decoding apparatus for performing code detection by using a coding rule for likelihood calculation, comprising:
- a code detector for performing trellis code detection, wherein the code detector simultaneously applies a plurality of coding rules to detect a code including:
- applying a coding rule on a trellis diagram that there is a spectral null at one of a DC component and a Nyquist component of a code spectrum;
- applying a partial-response class-IV inter-symbol-interference rule;
- applying an inter-symbol-interference rule for three bits on the trellis diagram;
- and
- a decoder for decoding the code detected by the code detector.
A decoding method for a decoding apparatus for performing code detection by using a coding rule for likelihood calculation, comprising:
- performing trellis code detection by simultaneously applying a plurality of code detecting rules to detect a code including:
- applying a coding rule on a trellis diagram that there is a spectral null at one of a DC component and a Nyquist component of a code spectrum;
- applying a partial-response class-IV inter-symbol-interference rule;
- applying an inter-symbol-interference rule for three bits on the trellis diagram;
- and
- a decoding step of decoding the code detected by the code detector.
A recording medium having recorded therein a computer-readable program for a decoding apparatus for performing code detection by using a coding rule for likelihood calculation, the program comprising:
- computer executable instructions for performing trellis code detection by simultaneously applying a plurality of code detecting rules to detect a code including:
- applying a coding rule on a trellis diagram that there is a spectral null at one of a DC component and a Nyquist component of a code spectrum;
- applying a partial-response class-IV inter-symbol-interference rule;
- and
- applying an inter-symbol-interference rule for three bits on the trellis diagram;
- and
- a decoding step of decoding the code detected by the code detector.
Dependencies are inferred from the claim text.