MTR encoding method, MTR decoding method, MTR encoder, MTR decoder, and magnetic recording device
View Patent ↗An MTR encoder includes convolution units that perform convolution of input data using additional bits, MTR encoding units that MTR-encode data obtained by the convolution units, RDS calculating units and on-bit sequence checking units that calculate RDSs and counts the number of sequential on-bits of the data MTR-encoded by the MTR encoding units, respectively, and a selecting unit that selects optimum data based on the RDSs and the number of sequential on-bits.
1. An MTR encoding method for encoding input data with a maximum transition run (MTR) code, the MTR encoding method comprising:
performing convolution of data in a plurality of patterns obtained by adding additional bits in a plurality of patterns to the input data to obtain a plurality of convolution data;
encoding the convolution data using an MTR code to obtain a plurality of MTR-encoded convolution data;
calculating a running digital sum (RDS) of the MTR-encoded convolution data;
counting number of sequential on-bits of the MTR-encoded convolution data;
selecting MTR-encoded convolution data with an RDS smaller than an RDS threshold and number of sequential on-bits smaller than an on-bits threshold based on calculated RDSs and counted numbers of sequential on-bits; and
outputting selected MTR-encoded convolution data.
2. The MTR encoding method according to claim 1 , wherein the outputting includes outputting the selected MTR-encoded convolution data together with additional bits corresponding thereto.
3. The MTR encoding method according to claim 1 , wherein the selecting includes
first-selecting MTR-encoded convolution data with an RDS not exceeding the RDS threshold as candidates; and
second-selecting MTR-encoded convolution data with minimum number of sequential on-bits from the candidates selected at the first selecting.
4. The MTR encoding method according to claim 1 , wherein the selecting includes
first-selecting MTR-encoded convolution data with number of sequential on-bits not exceeding the on-bits threshold as candidates; and
second-selecting MTR-encoded convolution data with a minimum RDS from the candidates selected at the first selecting.
5. An MTR decoding method for decoding maximum transition run (MTR)-encoded data input together with additional bits which were used in convolution performed for controlling a direct current component of input data in MTR encoding, the MTR decoding method comprising:
decoding the MTR-encoded data using an MTR code to obtain decoded data;
performing inverse convolution of the decoded data using the additional bits; and
outputting inverse-convolution decoded data.
6. An MTR encoder that encodes input data using a maximum transition run (MTR) code, the MTR encoder comprising:
a convolution unit that performs convolution of data in a plurality of patterns obtained by adding additional bits in a plurality of patterns to the input data to obtain a plurality of convolution data;
an MTR encoding unit that encodes the convolution data using an MTR code to obtain a plurality of MTR-encoded convolution data;
an RDS calculating unit that calculates a running digital sum (RDS) of the MTR-encoded convolution data;
a sequential on-bits counting unit that counts number of sequential on-bits of the MTR-encoded convolution data; and
a data selecting unit that selects MTR-encoded convolution data with an RDS smaller than an RDS threshold and number of sequential on-bits smaller than an on-bits threshold based on RDSs calculated by the RDS calculating unit and numbers of sequential on-bits counted by the sequential on-bits counting unit, and outputs selected MTR-encoded convolution data.
7. The MTR encoder according to claim 6 , wherein the data selecting unit outputs the selected MTR-encoded convolution data together with additional bits corresponding thereto.
8. The MTR encoder according to claim 6 , wherein the data selecting unit includes
a first data selecting unit that selects MTR-encoded convolution data with an RDS not exceeding the RDS threshold as candidates; and
a second data selecting unit that selects MTR-encoded convolution data with minimum number of sequential on-bits from the candidates selected by the first data selecting unit.
9. The MTR encoder according to claim 6 , wherein the data selecting unit includes
a first data selecting unit that selects MTR-encoded convolution data with number of sequential on-bits not exceeding the on-bits threshold as candidates; and
a second data selecting unit that selects MTR-encoded convolution data with a minimum RDS from the candidates selected by the first data selecting unit.
10. An MTR decoder that decodes maximum transition run (MTR)-encoded data input together with additional bits which were used in convolution performed for controlling a direct current component of input data in MTR encoding, the MTR decoder comprising:
an MTR decoding unit that decodes the MTR-encoded data using an MTR code to obtain decoded data; and
an inverse convolution unit that performs inverse convolution of the decoded data using the additional bits to obtain inverse-convolution decoded data, and outputs the inverse-convolution decoded data.
11. A magnetic recording device that encodes input data using a maximum transition run (MTR) code, records encoded data on a magnetic recording medium, decodes the encoded data read from the magnetic recording medium using the MTR code, the magnetic recording device comprising:
an MTR encoder including
a convolution unit that performs convolution of data in a plurality of patterns obtained by adding additional bits in a plurality of patterns to the input data to obtain a plurality of convolution data;
an MTR encoding unit that encodes the convolution data using an MTR code to obtain a plurality of MTR-encoded convolution data;
an RDS calculating unit that calculates a running digital sum (RDS) of the MTR-encoded convolution data;
a sequential on-bits counting unit that counts number of sequential on-bits of the MTR-encoded convolution data; and
a data selecting unit that selects MTR-encoded convolution data with an RDS smaller than an RDS threshold and number of sequential on-bits smaller than an on-bits threshold based on RDSs calculated by the RDS calculating unit and numbers of sequential on-bits counted by the sequential on-bits counting unit, and outputs selected MTR-encoded convolution data; and
an MTR decoder including
an MTR decoding unit that decodes the MTR-encoded data using an MTR code to obtain decoded data; and
an inverse convolution unit that performs inverse convolution of the decoded data using the additional bits to obtain inverse-convolution decoded data, and outputs the inverse-convolution decoded data.
12. The magnetic recording device according to claim 11 , wherein the data selecting unit includes
a first data selecting unit that selects MTR-encoded convolution data with an RDS not exceeding the RDS threshold as candidates; and
a second data selecting unit that selects MTR-encoded convolution data with minimum number of sequential on-bits from the candidates selected by the first data selecting unit.
13. The magnetic recording device according to claim 11 , wherein the data selecting unit includes
a first data selecting unit that selects MTR-encoded convolution data with number of sequential on-bits not exceeding the on-bits threshold as candidates; and
a second data selecting unit that selects MTR-encoded convolution data with a minimum RDS from the candidates selected by the first data selecting unit.