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    1.
    发明专利
    未知

    公开(公告)号：BR9004029A

    公开(公告)日：1991-09-03

    申请号：BR9004029

    申请日：1990-08-15

    Applicant: IBM

    Inventor： CIDECIYAN ROY DARON ,  DOLIVO FRANCOIS BERNARD

    IPC: G11B20/14 ,  H03M5/14 ,  H03M7/14 ,  H04L7/10 ,  H03M7/00

    Abstract: In recording systems using partial-response maximum-likelihood detection (PRML) techniques, data sequences are preceded by a preamble consisting of all ones. Coding schemes are disclosed which allow to keep the number of consecutive ones occuring in the coded data sequences at a minimum, while simultaneously restricting the number of consecutive zeros in full and partial data sequences to a low value which is important for improving receiver operation. The disclosed coding schemes and apparatus enable a faster and more reliable discrimination between timing preambles and data sequences, thus allowing to use shorter timing preambles which results in faster receiver start-up and in a reduction of storage overhead for the preambles.

    IMPROVED SERVICES OF DISTRIBUTION OF QUEUING THE MESSAGES FOR POSTAL SYSTEMS
    3.
    发明专利
    IMPROVED SERVICES OF DISTRIBUTION OF QUEUING THE MESSAGES FOR POSTAL SYSTEMS 未知

    公开(公告)号：PL325903A1

    公开(公告)日：1998-08-17

    申请号：PL32590395

    申请日：1995-08-14

    Applicant: IBM

    Inventor： ANTHIAS TEFCROS ,  DOLIVO FRANCOIS BERNARD ,  HERMANN RETO ,  PAPADOPOULOS CHRISTOS ,  WILLIAMSON ROBIN

    IPC: H04L12/54 ,  H04L12/58 ,  H04Q3/02

    Abstract: The method for transmitting a message involves preparing addressing information for submission of the message from the mail server assigned to the first user over the network to mail servers assigned to the destination users. The addressing information and message are encapsulated in an MQ message. A queue list is created with the MQ addresses of those queue managers through which the mail servers can be reached. The list is used to determine the set of next-hop queue managers and generating associated queue sublists. - The MQ message is routed to each of the next hop queue managers together with a queue list being equal to the queue sublist associated with the respective next-hop queue managers now become acting queue managers. If the queue manager is found to be a queue manager in the queue list it gets the names of local queues from the queue list and delivers the messages to them. The process is repeated until the message has been put in all queues of the list. The MQ messages are retrieved with addressing information from the queues of the queue list. The addressing information is used to determine the set of destination users assigned to the mail server, each of which delivers the message to the destination user if the assigned destination user is local to the mail server. The process is repeated for the subset of destination users that is not local until the message has been delivered to all destination users.

    Method and apparatus for decoding the output signal of a partial-response communication or recording-device channel
    6.
    发明专利
    Method and apparatus for decoding the output signal of a partial-response communication or recording-device channel 未知

    公开(公告)号：SG150594G

    公开(公告)日：1995-03-17

    申请号：SG150594

    申请日：1994-10-17

    Applicant: IBM

    Inventor： DOLIVO FRANCOIS BERNARD ,  UNGERBOECK GOTTFRIED ,  HOWELL THOMAS DAVID

    IPC: H04L25/03 ,  H04L25/08 ,  H04L25/497 ,  G11B11/20

    Abstract: A maximum-likelihood sequence decoder is used with a partial-response signaling system for processing sequences of sampled values from a communication channel or recording device. The partial-response signals can be duobinary, dicode, or partial-response class-IV. The maximum-likelihood decoding for each sequence is based upon a two-state trellis. lnstead of two survivor metrics for the two states, only a difference metric is generated which is simpler but sufficient for the decoding process. The decoder comprises survivor metric determining circuitry (81...99) which, from each input sample (y n ) and a previous difference metric (DJ n - 3 ) determines a new difference metric (DJ n-1 ), two additional binary values (b + , b-) for the two survivor sequences, as well as a binary output value (b) for making a selection among the two survivor sequences.

    7.
    发明专利
    未知

    公开(公告)号：DE3778549D1

    公开(公告)日：1992-05-27

    申请号：DE3778549

    申请日：1987-11-13

    Applicant: IBM

    Inventor： DOLIVO FRANCOIS BERNARD ,  UNGERBOECK GOTTFRIED

    IPC: H04L25/40 ,  G11B20/10 ,  G11B20/14 ,  H04L7/02 ,  H04L7/04 ,  H04L7/10 ,  H04L25/34 ,  H04L25/49 ,  H04L25/497

    Abstract: In a receiver for data having been sent or recorded as partial-response (PR) signals, there is a system for generating a timing gradient value for initially acquiring the sampling phase when a signal resulting from the transmission of a known preamble is received. A common input (55) receives signal samples Yn of a transmitted or recorded PR signal. A delay circuit (67) has a delay stage, for accepting the present received signal sample Yn and provides at least one previous received signal sample Yn-i. A second delay circuit (61) has at least two delay stages, for accepting a present reconstructed data sample Xn and provides at least a first previous reconstructed data sample Xn-j. A reconstruction circuit (43) is connected to the common input and to the second delay circuit for generating the present reconstructed data sample Xn in response to the present received signal sample Yn and the first previous reconstructed data sample Xn-j. A timing gradient generation circuit (41) is connected to the common input and to the delay circuits for generating the timing gradient value.

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