62.
    发明专利
    未知

    公开(公告)号:DE3883519D1

    公开(公告)日:1993-09-30

    申请号:DE3883519

    申请日:1988-03-08

    Applicant: IBM

    Abstract: The voice signal s(n) is filtered through a short-term predictive filter (13) tuned with PARCOR derived coefficients computed over a pre-emphasized s(n), said filter (13) providing a short-term residual r(n). Said r(n) signal is then processed through a first Code-Excited/Long-Term Predictive coder providing first couples of table address and gain data (k1, g1)'s. An error signal r min (n) is then derived by subtracting coded/decoded data from uncoded data. Then said error signal is processed through a second Code-Excited/ Long-Term Predictive coder providing second couples of data (k2, g2)'s. Full rate coding is achieved by multiplexing both couples (k1, g1)'s and (k2, g2)'s into a multi-rate frame; while switching to a lower rate is achieved through a mere delation of (g2, k2)'s from the full rate frame.

    63.
    发明专利
    未知

    公开(公告)号:DE3678717D1

    公开(公告)日:1991-05-16

    申请号:DE3678717

    申请日:1986-04-30

    Applicant: IBM

    Abstract: The process is made to detect a received tone including at least one single predetermined frequency, within a signal encoded using block coding and Linear Prediction Coding techniques providing auto-correlation coefficients R(i) and direct form coefficients a(i). The process is based upon Fourier Transform computations over the successive blocks of a(i)'s, with table look up tone identification, further confirmed upon R(i)'s stationarity detecting.

    SPEECH CODING METHOD AND DEVICE FOR IMPLEMENTING THE IMPROVED METHOD

    公开(公告)号:CA1188423A

    公开(公告)日:1985-06-04

    申请号:CA401879

    申请日:1982-04-28

    Applicant: IBM

    Abstract: IMPROVED SPEECH CODING METHOD AND DEVICE FOR IMPLEMENTING THE IMPROVED METHOD Method for coding a speech-originating signal. The spectrum of the initial signal covering a frequency range of 0-4000 Hz is split into 16 subbands, each one containing 12-bit coded samples. The samples of the 16 sub-bands are requantized in BCPCM at dynamically variable bit rates. For this, the sample flow of the sub-bands is divided into blocks of a given duration, then each block is processed for deriving therefrom two scale factors, the difference of which is analyzed to define the sample block as transient or non-transient block. For each non-transient block, only one scale factor is retained, whereas for a transient block, both scale factors are retained. The signal samples of the 16 subbands are then dynamically requantized with an overall number of bits depending on whether the block considered is transient or non-transient.

    66.
    发明专利
    未知

    公开(公告)号:DE2818052A1

    公开(公告)日:1978-11-16

    申请号:DE2818052

    申请日:1978-04-25

    Applicant: IBM

    Abstract: A coding process, given a total number of available bits per unit time, allocates to each of a plurality of signal channels a number of bits proportional to information in the channel. The process is useful for transcoding BCPCM (Block Coded PCM) voice signals for lower bit rate and conserving transmission channel bandwidth.

    67.
    发明专利
    未知

    公开(公告)号:DE69927252D1

    公开(公告)日:2005-10-20

    申请号:DE69927252

    申请日:1999-07-13

    Applicant: IBM

    Abstract: Disclosed herein is a method and a system of network capacity planning for use in a high speed packet switching network. The network comprises a plurality of switching nodes interconnected through a plurality of communication links, each of the switching nodes comprises means for switching packets from at least one input link to at least one output link. Each of the output links is coupled to at least one buffer in the switching node for queuing packets before they are transmitted over the output link. The network capacity planning method of the invention comprises the following steps: In each of the switching nodes and for each of the output links, a time distribution of the occupancy of each buffer during a predetermined monitoring time period is measured, and stored in a centralized memory location. Then, the buffer occupancy time distribution data are retrieved from the centralized memory location in all the switching nodes, gathered and stored in a network dedicated server. These buffer occupancy time distribution data for all the nodes are transmitted from the dedicated network server to a network monitoring center. In the network monitoring center, the buffer occupancy time distribution data are integrated on a larger time scale, and stored. Finally, the integrated buffer occupancy time distribution data are used to apply network capacity planning actions to the network resources.

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