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    DIGITAL SPEECH CODER HAVING IMPROVED LONG-TERM PREDICTOR
    31.
    发明专利
    DIGITAL SPEECH CODER HAVING IMPROVED LONG-TERM PREDICTOR 未知

    公开(公告)号：CA2037899C

    公开(公告)日：1996-09-17

    申请号：CA2037899

    申请日：1990-06-25

    Applicant: MOTOROLA INC

    Inventor： GERSON IRA A ,  JASIUK MARK A

    IPC: G06F17/10 ,  G08B25/10 ,  G10L19/12 ,  G10L5/00

    Abstract: A digital speech coder includes a long-term filter (124) having an improved sub-sample resolution long-term predictor (Figure 5) which allows for subsample resolution for the lag parameter L. A frame of N samples of input speech vector s(n) is applied to an adder (510). The output of the adder (510) produces the output vector b(n) for the long term filter (124). The output vector b(n) is fed back to a delayed vector generator block (530) of the long-term predictor. The nominal long-term predictor lag parameter L is also input to the delayed vector generator block (530). The long-term predictor lag parameter L can take on non-integer values, which may be multiples of one half, one third, one fourth or any other rational fraction. The delayed vector generator (530) includes a memory which holds past samples of b(n). In addition, interpolated samples of b(n) are also calculated by the delayed vector generator (530) and stored in its memory, at least one interpolated sample being calculated and stored between each past sample of b(n). The delayed vector generator (530) provides output vector q(n) to the long-term multiplier block (520), which scales the long-term predictor response by the long-term predictor coefficient .beta.. The scaled output .beta.q(n) is then applied to the adder (510) to complete the feedback loop of the recursive filter (124).

    34.
    发明专利
    未知

    公开(公告)号：DE3750199D1

    公开(公告)日：1994-08-18

    申请号：DE3750199

    申请日：1987-06-01

    Applicant: MOTOROLA INC

    Inventor： GERSON IRA A

    IPC: G10L15/193 ,  G10L5/06

    Abstract: Disclosed is method and arrangement for speech recognition for use in a speech recognition system, wherein a grammar model may be stored in memory, the grammar model being composed of nodes connected by arcs, each arc generally having an associated template prestored in memory and respective originating and terminating grammar nodes, and wherein groups of input frames may be compared to templates to generate similarity measure parameters. The invention includes structuring the grammar model such that arcs may be looped within the structure. For implementing this type of structure, the invention includes providing first parameter storage and second parameter storage for one or more nodes including a terminating node for a selected arc, determining similarity measure parameters for the originating node for the selected arc, determining similarity measure parameters for the arc using a template associated with the arc and the originating node's similarity measure parameters. Further, similarity measure parameters are determined at the terminating node and are stored in the first parameter storage for the terminating node. The first parameter storage contents are transferred to the second parameter storage for the terminating node, and the groups of input frames are recognized using the parameter storage contents associated with the terminating node.

    PROGRAMMABLE MULTIFREQUENCY TONE RECEIVER
    36.
    发明专利
    PROGRAMMABLE MULTIFREQUENCY TONE RECEIVER 未知

    公开(公告)号：CA1150783A

    公开(公告)日：1983-07-26

    申请号：CA365623

    申请日：1980-11-27

    Applicant: MOTOROLA INC

    Inventor： CONGER DAVID R L ,  GERSON IRA A ,  WHITE RICHARD E

    IPC: H04L27/30 ,  H04Q1/457 ,  H03H17/02 ,  G06F15/31

    Abstract: A multifrequency tone receiver is disclosed for detecting simultaneous tone signals in a sampled digital signal. The tone receiver includes a microprogrammed sequence controller, a time-multiplexed digital filter and a signal processing microcomputer. For each sample of the digital signal, the sequence controller is programmed to time multiplex the digital filter for performing three cascaded second order filtering operations (two bandpass filter operations and one low pass filter operation) for each of six tone signals to provide correspond ing energy estimates and one additional filtering operation to provide a total energy estimate. The signal processing microcomputer processes a number of sets of the seven energy estimates and provides an indication when a multifrequency tone pair has been detected. The digital filter, when enabled by a filter start signal from the sequence controller, asynchronously performs a single multiplication like filtering operation to implement each second-order filter, and provides a filter done signal upon completion of the filtering operation. Full-wave rectifying capability is provided during low pass filtering operations by logically complementing the digital filter input signal. Limit cycles may be suppressed in the digital filter output signal by rounding the output signal and clamping positive and negative overflows to the largest allowable positive and negative signals, respectively. The tone receiver may be advantageously utilized in a PCM communication system for detecting multifrequency tone signalling used for dialing and supervisory control. Moreover, the inventive tone receiver may be adapted to receive many different types of tone signalling simply by changing firmware therewithin,

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