摘要:
An unencoded m-bit data input sequence is divided into a block of n bits and a block of m-n bits. The block of n bits is divided into a first set of n+1 encoded bits, wherein at least one of P1 subblocks of the first set satisfies a G, M and I constraints. The first set of n+1 encoded bits is mapped into a second set of n+1 encoded bits wherein at least one of P2 subblocks of the second set gives rise to at least Q1 transitions after 1/(1+D2) precoding. A second set of n+1 encoded bits is divided into P3 encoded subblocks and the P3 encoded subblocks are interleaved among (m−n)/s unencoded symbols so as to form a (m+1)-bit output sequence codeword which is then stored on a data storage medium.
摘要:
Conventional C2 coding and interleaving for multi-track data tape in LTO-3/4 do not support recording data onto a number of concurrent tracks which is not a power of two. Higher-rate longer C2 codes, which do not degrade error rate performance, are provided. An adjustable format and interleaving scheme accommodates future tape drives in which the number of concurrent tracks is not necessarily a power of two. A data set is segmented into a plurality of unencoded subdata sets and parity bytes are generated for each row and column. The parameters of the C2 code include N2 as the least common multiple of the number of possible tracks to which codeword objects are to be written. COs are formed from N2 C1 codewords, mapped onto a logical data track according to information within headers of the CO and modulation encoded into synchronized COs which are written to the tape.
摘要:
For writing data to multi-track tape, a received data set is received and segmented into unencoded subdata sets, each comprising an array having K2 rows and K1 columns. For each unencoded subdata set, N1-K1 C1-parity bytes are generated for each row and N2-K2 C2-parity bytes are generated for each column. The C1 and C2 parity bytes are appended to the ends of the row and column, respectively, to form encoded C1 and C2 codewords, respectively. All of the C1 codewords per data set are endowed with a specific codeword header to form a plurality of partial codeword objects (PCOs). Each PCO is mapped onto a logical data track according to information within the header. On each logical data track, adjacent PCOs are merged to form COs which are modulation encoded and mapped into synchronized COs. Then T synchronized COs are written simultaneously to the data tape where T is the number of concurrent active tracks on the data tape.
摘要:
An unencoded m-bit data input sequence is divided into a block of n bits and a block of m−n bits. The block of n bits is divided into a first set of n+1 encoded bits, wherein at least one of P1 subblocks of the first set satisfies a G, M and I constraints. The first set of n+1 encoded bits is mapped into a second set of n+1 encoded bits wherein at least one of P2 subblocks of the second set gives rise to at least Q1 transitions after 1/(1+D2) precoding. A second set of n+1 encoded bits is divided into P3 encoded subblocks and the P3 encoded subblocks are interleaved among (m−n)/s unencoded symbols so as to form a (m+1)-bit output sequence codeword which is then stored on a data storage medium.
摘要:
An unencoded m-bit data input sequence is divided into a block of n bits and a block of m−n bits. The block of n bits is divided into a first set of n+1 encoded bits, wherein at least one of P1 subblocks of the first set satisfies a G, M and I constraints. The first set of n+1 encoded bits is mapped into a second set of n+1 encoded bits wherein at least one of P2 subblocks of the second set gives rise to at least Q1 transitions after 1/(1+D2) precoding. A second set of n+1 encoded bits is divided into P3 encoded subblocks and the P3 encoded subblocks are interleaved among (m−n)/s unencoded symbols so as to form a (m+1)-bit output sequence codeword which is then stored on a data storage medium.
摘要:
Conventional C2 coding and interleaving for multi-track data tape in LTO-¾ do not support recording data onto a number of concurrent tracks which is not a power of two. Higher-rate longer C2 codes, which do not degrade error rate performance, are provided. An adjustable format and interleaving scheme accommodates future tape drives in which the number of concurrent tracks is not necessarily a power of two. A data set is segmented into a plurality of unencoded subdata sets and parity bytes are generated for each row and column. The parameters of the C2 code include N2 as the least common multiple of the number of possible tracks to which codeword objects are to be written. COs are formed from N2 C1 codewords, mapped onto a logical data track according to information within headers of the CO and modulation encoded into synchronized COs which are written to the tape.
摘要:
For writing data to multi-track tape, a received data set is received and segmented into unencoded subdata sets, each comprising an array having K2 rows and K1 columns. For each unencoded subdata set, N1−K1 C1-parity bytes are generated for each row and N2−K2 C2-parity bytes are generated for each column. The C1 and C2 parity bytes are appended to the ends of the row and column, respectively, to form encoded C1 and C2 codewords, respectively. All of the C1 codewords per data set are endowed with a specific codeword header to form a plurality of partial codeword objects (PCOs). Each PCO is mapped onto a logical data track according to information within the header. On each logical data track, adjacent PCOs are merged to form COs which are modulation encoded and mapped into synchronized COs. Then T synchronized COs are written simultaneously to the data tape where T is the number of concurrent active tracks on the data tape.
摘要:
An unencoded m-bit data input sequence is divided into a block of n bits and a block of m−n bits. The block of n bits is divided into a first set of n+1 encoded bits, wherein at least one of P1 subblocks of the first set satisfies a G, M and I constraints. The first set of n+1 encoded bits is mapped into a second set of n+1 encoded bits wherein at least one of P2 subblocks of the second set gives rise to at least Q1 transitions after 1/(1+D2) preceding. A second set of n+1 encoded bits is divided into P3 encoded subblocks and the P3 encoded subblocks are interleaved among (m−n)/s unencoded symbols so as to form a (m+1)-bit output sequence codeword which is then stored on a data storage medium.
摘要:
A method and apparatus for providing error correction capability to longitudinal position data are disclosed. Initially, data are encoded via a set of even LPOS words and a set of odd LPOS words. The encoded data are then decoded by generating a set of syndrome bits for each of the LPOS words. A determination is then made as to whether or not there is an error within one of the LPOS words based on its corresponding syndrome bits.
摘要:
A longitudinal position (LPOS) word L(n) is encoded with error correction capability. The LPOS word includes a plurality of LPOS symbols L0(n) through Lk(n) calculated as L ( n ) = ∑ i = 0 5 L i ( n ) 14 i and representing a longitudinal position of a magnetic tape relative to a tape head in a tape storage system. A word type is determined in response to at least one of the plurality of LPOS symbols and, in response to the determined word type, at least one formatted symbol F(n) is generated from the plurality of LPOS symbols L(n). At least one parity symbol P(n) is generated from the formatted symbol F(n). The formatted and parity symbols are communicated to a servo channel of the tape storage system to be recorded onto a servo track of the magnetic tape. Adding redundancy to LPOS words provides the capability of correcting multiple bit errors without increasing the LPOS word length.