Abstract:
PROBLEM TO BE SOLVED: To provide a method and apparatus for performing speech coding which improves speech quality. SOLUTION: The method for encoding speech by a speech coding device comprises: a stage for receiving an input signal; a stage for creating an object vector on the basis of the input signal; a stage for creating a plurality of weighted adaptive code book vectors on the basis of a signal sub-sample resolution delay value, an adaptive code book, and a weighted synthesis filter; a stage for creating a weighted fixed code book(FCB) exiting vector on the basis of the object vector and the plurality of weighted adaptive code book vector; a stage for creating a plurality of correlation terms on the basis of the object vector, the plurality of weighted adaptive code book vectors and the weighted FCB exciting vector; and a stage for selecting a gain vector from a table in response to an error minimizing reference. The gain vector comprises at least two adaptive code book gains and one fixed code book gain, and the error minimizing reference is based on the plurality of correlation terms. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a digital voice coding method improving controlls of filters of a voice encoder without increasing the complexity of the voice encoder accordingly. SOLUTION: A single filter providing controls of plural filters without complexity of the plural filters is realized by using an R-order filter for modeling frequency responses of the plural filters. The R-order filter can be used as a spectral noise weight filter (132) or the combination of the short term predictive encoder filter called as a synthesis filter in which noise are spectrally weighted and the spectral noise weighting filter in accordance with which embodiments are to be used. Generally, this method performs the moldeling of frequency responses of L pieces of P-order filters with the single R-order filter and, in this case, the order of R is made to be
Abstract:
A method and system for providing split vector quantization for use in determining constrained ordered set values, such as line spectrum pair parameters to determine spectral parameters in a data compression system, utilizes multiple codebooks (22a-22c) containing delta coded constrained ordered set values that are normalized to an upper and lower bound. An LSP reconstructor (34) reconstructs received spectral parameters to decode data, such as speech, based on the normalized delta quantization data of line spectrum pair parameters obtained from the split vector reconstruction codebooks (22a-22c). The LSP reconstructor (34) dynamically generates line spectrum pair parameters based on the normalized delta quantization data. In another embodiment, instead of storing the absolute value of the line spectrum pair parameters in segmented codebooks, the combination of at least two absolute value vectors and at least one normalized delta quantization vector is used for spectral quantization.
Abstract:
A system or method for modeling a signal, such as a speech signal, wherein harmonic frequencies and amplitudes are identified (106) and the harmonic magnitudes are interpolated (110) to obtain spectral magnitudes at a set of fixed frequencies. An inverse transform is applied (112) to the spectral magnitudes to obtain a pseudo auto-correlation sequence, from which linear prediction coefficients are calculated (114). From the linear prediction coefficients, model harmonic magnitudes are generated by sampling the spectral envelope (118) defined by the linear prediction coefficients. A set of scale factors are then calculated (120) as the ratio of the harmonic magnitudes to the model harmonic magnitudes and interpolated to obtain a second set of scale factors (122) at the set of fixed frequencies. The spectral envelope magnitudes at the set of fixed frequencies (124) are multiplied by the second set of scale factors (126) to obtain new spectral magnitudes and the process is iterated to obtain final linear prediction coefficients.
Abstract:
A speech communication system provides a speech encoder [100] that generates a set of coded parameters representative of the desired speech signal characteristics. The speech communication system also provides a speech decoder [200] that receives the set of coded parameters to generate reconstructed speech. The speech decoder includes an equalizer [204] that computes a matching set of parameters from the reconstructed speech [301] generated by the speech decoder [200], undoes the set of characteristics corresponding to the computed set of parameters, and imposes the set of characteristics corresponding to the coded set of parameters, thereby producing equalized reconstructed speech [306].
Abstract:
A method for characterizing inhalation noise within a pressurized air delivery system, the method including the steps of: generating an inhalation noise model (912, 1012) based on inhalation noise; receiving an input signal (802) that includes inhalation noise comprising at least one inhalation noise burst; comparing (810) the input signal to the noise model to obtain a similarity measure; comparing the similarity measure to at least one threshold (832, 834) to detect the at least one inhalation noise burst; and characterizing (1354, 1356) the at least one detected inhalation noise burst.
Abstract:
A method for equalizing a speech signal generated within a pressurized air delivery system, the method including the steps of: generating an inhalation noise model (1152) based on inhalation noise; receiving an input signal (802) that includes a speech signal; and equalizing the speech signal (1156) based on the noise model.
Abstract:
A method for equalizing a speech signal generated within a pressurized air delivery system, the method including the steps of: generating an inhalation noise model (1152) based on inhalation noise; receiving an input signal (802) that includes a speech signal; and equalizing the speech signal (1156) based on the noise model.
Abstract:
A method for characterizing inhalation noise within a pressurized air delivery system, the method including the steps of: generating an inhalation noise model (912, 1012) based on inhalation noise; receiving an input signal (802) that includes inhalation noise comprising at least one inhalation noise burst; comparing (810) the input signal to the noise model to obtain a similarity measure; comparing the similarity measure to at least one threshold (832, 834) to detect the at least one inhalation noise burst; and characterizing (1354, 1356) the at least one detected inhalation noise burst.
Abstract:
A method for protecting information bits wherein input data bits, at least some of which are to be protected, are sorted based upon information determined from a subset of the input data bits. An error control coding technique is applied to at least some of the sorted bits. In the preferred embodiment, an input data stream of voice coder bits is separated into arrays of bits. A first array (302) comprises voice coder bits needing error protection, with the bits arranged in order of importance determined by voicing mode. The second array (303) comprises bits that will not be error protected. The bits from the first array are provided to the input of an encoder (304), then the encoded bits are combined (305) with the bits from the second array (303) to form a bit stream.