公开(公告)号：AT384374T

公开(公告)日：2008-02-15

申请号：AT04743973

申请日：2004-07-08

Applicant: IBM

Inventor： HIRT WALTER ,  WEISENHORN MARTIN

IPC: H04L12/28 ,  H04B1/69 ,  H04J14/00 ,  H04J99/00

公开(公告)号：DE69920671D1

公开(公告)日：2004-11-04

申请号：DE69920671

申请日：1999-04-21

Applicant: IBM

Inventor： GFELLER FRITZ ,  HIRT WALTER ,  INGHAM R

IPC: H04B10/11 ,  H04L25/02 ,  H04B10/10

Abstract: The present invention provides an apparatus and a method for improved connectivity in wireless optical networks. Therefore at least two or more receiving units are used which receive an infrared signal and convert it to a digital signal. The digital signals represent data in the form of frames whereby each frame comprises at least a data field and a header field containing a preamble. A selector determines a measure related to the signal-to-noise ratio of the preamble and compares the measures in order to select the best suited signal for further processing.

公开(公告)号：DE69723477T2

公开(公告)日：2004-05-27

申请号：DE69723477

申请日：1997-05-15

Applicant: IBM

Inventor： COKER DARREL ,  ELEFTHERIOU STAVROS ,  GALBRAITH LEO ,  HIRT WALTER

IPC: H03M13/41 ,  G11B20/10 ,  H04L25/03 ,  H04L25/497

Abstract: In a maximum likelihood sequence detector for symbol sequences which were equalized in a PR4 equalizer, noise prediction means (35) are provided including infinite impulse response (IIR) filtering, which have noise-whitening capabilities and are imbedded into the maximum likelihood detection process. The resulting INPML detector (10) can be implemented in digital or analog circuit technology. In addition, a DC-notch filter (44a) and a stochastic gradient procedure can be provided for DC offset compensation and for MR head or signal asymmetry compensation.

公开(公告)号：DE69627886D1

公开(公告)日：2003-06-05

申请号：DE69627886

申请日：1996-01-03

Applicant: IBM

Inventor： DE LANGE MARTIN ,  GFELLER RUDOLF ,  HIRT WALTER

IPC: H04B10/114 ,  H04L1/00 ,  H04L7/04 ,  H04L12/28 ,  H04B10/10

Abstract: The communication system includes a robust physical layer header (RPLH) which can be understood by all participating stations. This robust header (50) at least comprises a preamble (52) consisting of frames forming a periodic sequence of pulses, the number of slots per frame and the frame content being known to all participating stations. The preamble serves for relative synchronization and carrier detection of the receiving stations. The robust header further comprises a unique synchronization word (53) which is used for absolute synchronization of the receiving stations. This synchronization word is followed by a control field (59) of fixed length and known structure. The control field informs the receiving stations of which modulation method will be used for the transmission of data. Pref. the control field also includes data for communication link and network control.

公开(公告)号：CZ20003270A3

公开(公告)日：2001-08-15

申请号：CZ20003270

申请日：1999-04-21

Applicant: IBM

Inventor： GRELLER FRITZ ,  HIRT WALTER ,  INGHAM BRIAN R

IPC: H04B10/11 ,  H04L25/02 ,  H04B10/10

Abstract: The present invention provides an apparatus and a method for improved connectivity in wireless optical networks. Therefore at least two or more receiving units are used which receive an infrared signal and convert it to a digital signal. The digital signals represent data in the form of frames whereby each frame comprises at least a data field and a header field containing a preamble. A selector determines a measure related to the signal-to-noise ratio of the preamble and compares the measures in order to select the best suited signal for further processing.

公开(公告)号：CZ20010107A3

公开(公告)日：2001-05-16

申请号：CZ20010107

申请日：1999-07-01

Applicant: IBM

Inventor： HASSNER MARTIN AURELIANO ,  HEISE NYLEST ,  HIRT WALTER ,  TRAGER BARRY MARSHALL

IPC: G11B20/14 ,  H03M5/14

公开(公告)号：DE60143782D1

公开(公告)日：2011-02-17

申请号：DE60143782

申请日：2001-05-14

Applicant: IBM

Inventor： GFELLER FRITZ ,  HIRT WALTER

IPC: H04B14/02 ,  H04L25/49 ,  H04B7/08 ,  H04B10/10 ,  H04B14/04

公开(公告)号：PL195698B1

公开(公告)日：2007-10-31

申请号：PL34546599

申请日：1999-07-01

Applicant: IBM

Inventor： HASSNER MARTIN AURELIANO ,  HEISE NYLES ,  HIRT WALTER ,  TRAGER BARRY MARSHALL

IPC: G11B20/14 ,  G11B20/10 ,  H03M5/14 ,  H03M7/00 ,  H03M7/14 ,  H03M13/00

Abstract: A method and means for reducing high-duty-cycle unconstrained binary signal sequences in storage and communications processes and systems by invertibly mapping such sequences into a (1, k) rate ⅔ RLL codestream constrained to a duty cycle substantially approximating one-third. That is, binary sequences ordinarily mapping into high-duty-cycle RLL-code sequences are either inhibited from repeating indefinitely or excluded.

公开(公告)号：CA2322685C

公开(公告)日：2004-10-26

申请号：CA2322685

申请日：1999-04-21

Applicant: IBM

Inventor： GFELLER FRITZ ,  HIRT WALTER ,  INGHAM BRIAN RICHARD

IPC: H04B10/11 ,  H04L25/02 ,  H04B10/10

Abstract: The present invention provides an apparatus and a method for improved connectivity in wireless optical networks. Therefore at least two or more receiving units are used which receive an infrared signal and convert it to a digital signal. The digital signals represent data in the form of frames whereby each frame comprises at least a data field and a header field containing a preamble. A selector determines a measure related to the signal-to-noise ratio of the preamble and compares the measures in order to select the best suited signal for further processing.

公开(公告)号：DE19717926B4

公开(公告)日：2004-02-05

申请号：DE19717926

申请日：1997-04-28

Applicant: VISHAY SEMICONDUCTOR GMBH ,  IBM

Inventor： SCHAIRER WERNER ,  ANGERSTEIN JOERG ,  GFELLER FRITZ ,  HIRT WALTER

IPC: G08C17/00 ,  H04B10/11 ,  H04B10/10 ,  G08C23/04 ,  H04B10/02 ,  H04B10/24