公开(公告)号：DE3277248D1

公开(公告)日：1987-10-15

申请号：DE3277248

申请日：1982-06-08

Applicant: IBM

Inventor： ADLER ROY LEE ,  HASSNER MARTIN ,  MOUSSOURIS JOHN PETER

IPC: H03M7/14 ,  G06T9/00 ,  G11B20/14 ,  H04L25/49 ,  G06F5/00

公开(公告)号：DE3269690D1

公开(公告)日：1986-04-10

申请号：DE3269690

申请日：1982-11-05

Applicant: IBM

Inventor： ADLER ROY LEE ,  HASSNER MARTIN

IPC: H03M5/04 ,  G06F5/00 ,  G06T9/00 ,  G11B20/14 ,  H03M7/14 ,  H03M7/40 ,  G11B5/09 ,  H03M7/46

Abstract: An algorithm and the hardware embodiment for producing a run length limited code useful in magnetic recording channels are described. The system described produces sequences which have a minimum of 2 zeros and a maximum of 7 zeros between adjacent 1's. The code is generated by a sequential scheme that maps 1 bit of unconstrained into 2 bits of constrained data. The encoder is a finite state machine whose internal state description requires 3 bits. It possesses the attractive feature of reset data blocks which reset it to a fixed state. The decoder requires a lookahead of three future channel symbols (6 bits) and its operation is channel state independent. The error propagation due to a random error is 3 bits. The hardware implementation is extremely simple and can operate at very high data speeds.

公开(公告)号：DE3586035D1

公开(公告)日：1992-06-17

申请号：DE3586035

申请日：1985-10-23

Applicant: IBM

Inventor： ADLER ROY LEE ,  FRANASZEK PETER ANTHONY ,  HASSNER MARTIN ,  SCHNEIDER RICHARD CRANE

IPC: H03M7/14 ,  G06T9/00 ,  G11B20/14 ,  H03M5/14 ,  H03M13/23 ,  H04L25/497 ,  G11B20/10 ,  H04L25/49

Abstract: The present invention relates to apparatus for encoding and decoding a stream of randomly distributed binary bits representing digital data of the type comprising encoding means (10) for encoding the stream of binary bits, recording means (18) for recording representations of the encoded stream of binary bits and recovery means (20, 25) for recovering timing signals and a stream of data signals from the recorded representations. … The apparatus is characterised in that the encoding means (10) achieves a run length limited, partial response coding of the data stream, and the recovery means comprises a first partial response decoder (20) for recovering a timing signal from the recorded representations, and a second partial response decoder (22) and a constrained decoder (24) means for recovering a stream of data signals from the recorded representations. … The present invention also relates to a method of encoding and decoding a stream of randomly distributed binary bits representing digital data using apparatus as above.