发明名称 |
WORD SYNCHRONIZATION FOR SERVO READ SIGNALS IN TAPE DRIVES |
摘要 |
Methods and apparatus are provided for detecting L-bit sync words occurring at N-bit intervals in PPM-encoded servo pattern read signals read from magnetic tape (3) in tape drives (1). A soft output detector (11) processes the PPM-encoded servo pattern read signal to produce a series of soft output samples corresponding to respective bits encoded in the servo pattern. A sync word detector (12) then produces block correlation values for respective positions of a sliding L-sample block in the soft output sample series. The block correlation values are produced by calculating, at each block position, bit correlation values indicating correlation between respective samples and corresponding bits of the sync word, and summing each bit correlation value minus a predetermined function of the corresponding sample value. The sync word detector (12) then detects a sync word at the block position with the maximum block correlation value in an (N+L-1)-sample sequence of the soft output sample series.
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申请公布号 |
CA2717616(A1) |
申请公布日期 |
2009.12.23 |
申请号 |
CA20092717616 |
申请日期 |
2009.06.09 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
CHERUBINI, GIOVANNI;CIDECIYAN, ROY D.;ELEFTHERIOU, EVANGELOS S.;JELITTO, JENS |
分类号 |
G11B5/584 |
主分类号 |
G11B5/584 |
代理机构 |
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代理人 |
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地址 |
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