Patents by Inventor Huan Yu

Huan Yu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20020143527
    Abstract: In a coding procedure, coding parameters are selected for coding the speech signal to achieve enhanced perceptual quality of reproduced speech. At least one coding parameter value or preferential coding parameter value is selected to make a spectral response of the speech signal more uniform to compensate for spectral variations that might otherwise be imparted into the speech signal by a communications network associated with the signal processing system.
    Type: Application
    Filed: February 14, 2001
    Publication date: October 3, 2002
    Inventors: Yang Gao, Huan Yu-Su
  • Publication number: 20020116182
    Abstract: A method for preparing a speech signal for encoding comprises determining whether the spectral content of an input speech signal is representative of a defined spectral characteristic (e.g., a defined characteristic slope). A frequency specific filter component of a weighting filter is controlled based on the determination of the spectral content of the speech signal or/and its location in the encoder. A core weighting filter component of the weighting filter may be maintained regardless of the spectral content of the speech signal.
    Type: Application
    Filed: September 13, 2001
    Publication date: August 22, 2002
    Applicant: Conexant System, Inc.
    Inventors: Yang Gao, Huan-Yu Su
  • Patent number: 6397176
    Abstract: A speech encoding comb codebook structure for providing good quality reproduced low bit-rate speech signals in a speech encoding system. The codebook structure requires minimal training, if any, and allows for reduced complexity and memory requirements. The codebook includes a first and at least one additional sub-codebooks, each having a plurality of code-vectors. The codebook may be randomly populated. All even elements may be set to zero in a first codebook, and all odd elements may be set to zero on a second codebook. The resulting comb codebook includes code-vector combination of the code-vectors from the sub-codebooks. In certain embodiments, the code-vectors of the sub-codebooks may contain zero valued elements. In other embodiments where the code-vectors of the sub-codebooks contain only non-zero elements, zero valued elements may be inserted in between the non-zero elements of the sub-codebooks during the forming of the resultant comb codebook.
    Type: Grant
    Filed: October 17, 2001
    Date of Patent: May 28, 2002
    Assignee: Conexant Systems, Inc.
    Inventor: Huan-Yu Su
  • Patent number: 6385573
    Abstract: A multi-rate speech codec supports a plurality of encoding bit rate modes by adaptively selecting encoding bit rate modes to match communication channel restrictions. In higher bit rate encoding modes, an accurate representation of speech through CELP (code excited linear prediction) and other associated modeling parameters are generated for higher quality decoding and reproduction. To achieve high quality in lower bit rate encoding modes, the speech encoder departs from the strict waveform matching criteria of regular CELP coders and strives to identify significant perceptual features of the input signal. To support lower bit rate encoding modes, a variety of techniques are applied many of which involve the classification of the input signal. For each bit rate mode selected, pluralities of fixed or innovation subcodebooks are selected for use in generating innovation vectors.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: May 7, 2002
    Assignee: Conexant Systems, Inc.
    Inventors: Yang Gao, Huan-Yu Su
  • Publication number: 20020049585
    Abstract: In a coding procedure, a spectral content of a speech signal is estimated. A preferential coding algorithm or preferential value of at least one coding parameter is selected based on the estimated spectral content of the speech signal. The speech signal is coded in accordance with the selected coding algorithm or the selected coding parameter to control the operation of one or more of the following: a pre-processing filter, a post-processing filter, a coding control coefficient, a weighting filter, a synthesis filter, and a quantization table.
    Type: Application
    Filed: June 29, 2001
    Publication date: April 25, 2002
    Inventors: Yang Gao, Huan-Yu Su
  • Patent number: 6345248
    Abstract: A pitch lag coding device and method using interframe correlation inherent in pitch lag values to reduce coding bit requirements. A pitch lag value is extracted for a given speech frame, and then refined for each subframe. For every speech frame having N samples of speech, LPC analysis and vector quantization are performed for the whole coding frame. The LPC residual obtained for each frame is then processed such that pitch lag values for all subframes within the coding frame are analyzed concurrently. The remaining coding parameters, i.e., the codebook search, gain parameters, and excitation signal, are then analyzed sequentially according to their respective subframes.
    Type: Grant
    Filed: November 2, 1999
    Date of Patent: February 5, 2002
    Assignee: Conexant Systems, Inc.
    Inventors: Huan-Yu Su, Tom Hong Li
  • Patent number: 6330533
    Abstract: A multi-rate speech codec supports a plurality of encoding bit rate modes by adaptively selecting encoding bit rate modes to match communication channel restrictions. In higher bit rate encoding modes, an accurate representation of speech through CELP (code excited linear prediction) and other associated modeling parameters are generated for higher quality decoding and reproduction. A speech encoder employing various encoding schemes based upon parameters including an available transmission bit rate. In addition, the speech encoder is operable to identify and apply an optimal encoding scheme for a given speech signal. The speech encoder may be applied code-excited linear prediction when the available bit rate is above a predetermined upper threshold. Pitch preprocessing, including continuous warping, may be applied when it is below a predetermined lower threshold.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: December 11, 2001
    Assignee: Conexant Systems, Inc.
    Inventors: Huan-Yu Su, Yang Gao
  • Patent number: 6330531
    Abstract: A speech encoding comb codebook structure for providing good quality reproduced low bit-rate speech signals in a speech encoding system. The codebook structure requires minimal training, if any, and allows for reduced complexity and memory requirements. The codebook includes a first and at least one additional sub-codebooks, each having a plurality of code-vectors. The codebook may be randomly populated. All even elements may be set to zero in a first codebook, and all odd elements may be set to zero on a second codebook. The resulting comb codebook includes code-vector combination of the code-vectors from the sub-codebooks. In certain embodiments, the code-vectors of the sub-codebooks may contain zero valued elements. In other embodiments where the code-vectors of the sub-codebooks contain only non-zero elements, zero valued elements may be inserted in between the non-zero elements of the sub-codebooks during the forming of the resultant comb codebook.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: December 11, 2001
    Assignee: Conexant Systems, Inc.
    Inventor: Huan-Yu Su
  • Publication number: 20010023395
    Abstract: A multi-rate speech codec supports a plurality of encoding bit rate modes by adaptively selecting encoding bit rate modes to match communication channel restrictions. In higher bit rate encoding modes, an accurate representation of speech through CELP (code excited linear prediction) and other associated modeling parameters are generated for higher quality decoding and reproduction. A speech encoder employing various encoding schemes based upon parameters including an available transmission bit rate. In addition, the speech encoder is operable to identify and apply an optimal encoding scheme for a given speech signal. The speech encoder may be applied code-excited linear prediction when the available bit rate is above a predetermined upper threshold. Pitch preprocessing, including continuous warping, may be applied when it is below a predetermined lower threshold.
    Type: Application
    Filed: September 18, 1998
    Publication date: September 20, 2001
    Inventors: HUAN-YU SU, YANG GAO
  • Publication number: 20010016811
    Abstract: Silence description coding for multi-rate speech coding systems that employ discontinued transmission. Speech coding systems include multi-rate speech codecs having an encoder and a decoder. The silence description coding is performed in either the encoder or the decoder of the multi-rate speech codec. It may also be performed in a distributed manner wherein it is performed partially in the encoder and partially in the decoder. The silence description coding is performed on a speech signal having a substantially non-speech-like characteristic. Voice activity detection classifies the speech signal as being either substantially speech-like or substantially non-speech-like. The silence description coding is selected from a plurality of coding modes. In certain embodiments of the invention, the silence description coding is a source coding mode that operates at a bit rate that fits within a bit rate budget as determined by all of the available source coding modes within the plurality of coding modes.
    Type: Application
    Filed: April 24, 2001
    Publication date: August 23, 2001
    Applicant: Conexant Systems, Inc.
    Inventors: Jes Thyssen, Huan-Yu Su, Adil Benyassine, Eyal Shlomot
  • Patent number: 6256606
    Abstract: Silence description coding for multi-rate speech coding systems that employ discontinued transmission. Speech coding systems include multi-rate speech codecs having an encoder and a decoder. The silence description coding is performed in either the encoder or the decoder of the multi-rate speech codec. It may also be performed in a distributed manner wherein it is performed partially in the encoder and partially in the decoder. The silence description coding is performed on a speech signal having a substantially non-speech-like characteristic. Voice activity detection classifies the speech signal as being either substantially speech-like or substantially non-speech-like. The silence description coding is selected from a plurality of coding modes. In certain embodiments of the invention, the silence description coding is a source coding mode that operates at a bit rate that fits within a bit rate budget as determined by all of the available source coding modes within the plurality of coding modes.
    Type: Grant
    Filed: November 30, 1998
    Date of Patent: July 3, 2001
    Assignee: Conexant Systems, Inc.
    Inventors: Jes Thyssen, Huan-yu Su, Adil Benyassine, Eyal Shlomot
  • Patent number: 6240386
    Abstract: A multi-rate speech codec supports a plurality of encoding bit rate modes by adaptively selecting encoding bit rate modes to match communication channel restrictions. In higher bit rate encoding modes, an accurate representation of speech through CELP (code excited linear prediction) and other associated modeling parameters are generated for higher quality decoding and reproduction. For each bit rate mode selected, pluralities of fixed or innovation subcodebooks are selected for use in generating innovation vectors. The speech coder distinguishes various voice signals as a function of their voice content. For example, a Voice Activity Detection (VAD) algorithm selects an appropriate coding scheme depending on whether the speech signal comprises active or inactive speech. The encoder may consider varying characteristics of the speech signal including sharpness, a delay correlation, a zero-crossing rate, and a residual energy.
    Type: Grant
    Filed: November 24, 1998
    Date of Patent: May 29, 2001
    Assignee: Conexant Systems, Inc.
    Inventors: Jes Thyssen, Huan-yu Su, Yang Gao, Adil Benyassine
  • Patent number: 6205423
    Abstract: A method of coding speech under background noise conditions or during noise-like speech periods wherein during active voice speech segments an analysis-by-synthesis method is used. However, when a background noise segment or noise-like speech segment is detected, an adaptive code book (pitch prediction) contribution is used as a source of a pseudo-random sequence in order to provide a better representation of the background noise or the noise-like speech. An improved gain quantization scheme is also employed when a background noise segment is detected, wherein energy of the total excitation with quantized gains is matched to the energy of total excitation with unquantized gains.
    Type: Grant
    Filed: October 19, 1999
    Date of Patent: March 20, 2001
    Assignee: Conexant Systems, Inc.
    Inventors: Huan-Yu Su, Eric Kwok Fung Yuen, Adil Benyassine, Jes Thyssen
  • Patent number: 6122611
    Abstract: A system and method to improve the quality of coded speech coexisting with background noise. For instance, the present invention receives a coded speech signal via a communication network and then decodes and synthesizes the different parameters contained within it to produce a synthesized speech signal. The present invention determines the non-speech periods that are represented within the synthesized speech signal. The determined non-speech periods are then utilized to determine and code LPC parameters needed for background noise synthesis. Because medium or low bit rate LPC-coded speech during voice activity periods has the coexisting background noise attenuated, the decoded signal has audible abrupt changes in the level of the background noise. To improve decoded speech quality, the present invention adds simulated background noise to decoded noisy speech when synthesizing the noisy speech signal during voice activity periods.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: September 19, 2000
    Assignee: Conexant Systems, Inc.
    Inventors: Huan-yu Su, Adil Benyassine
  • Patent number: 6104992
    Abstract: A multi-rate speech codec supports a plurality of encoding bit rate modes by adaptively selecting encoding bit rate modes to match communication channel restrictions. In higher bit rate encoding modes, an accurate representation of speech through CELP (code excited linear prediction) and other associated modeling parameters are generated for higher quality decoding and reproduction. The encoder applies adaptive gain reduction to optimize selection of appropriate gain contributions from the adaptive and fixed codebooks. Specifically, the encoder uses a first target signal to identify a contribution (a best code vector and a gain) from the adaptive codebook. Thereafter, a contribution from the fixed codebook is selected. The gain associated with the adaptive codebook contribution is then reduced by a factor, and the gain contribution from the fixed codebook is searched a second time, permitting fine tuning of the overall contribution.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: August 15, 2000
    Assignee: Conexant Systems, Inc.
    Inventors: Yang Gao, Huan-Yu Su
  • Patent number: 6104994
    Abstract: A method of coding speech under background noise conditions wherein during active voice speech segments an analysis-by-synthesis method is used. However, when a background noise segment is detected, an adaptive code book (pitch prediction) contribution is used as a source of a pseudo-random sequence in order to provide a better representation of the background noise. An improved gain quantization scheme is also employed when a background noise segment is detected, wherein an energy of the total excitation with quantized gains is matched to an energy of total excitation with unquantized gains.
    Type: Grant
    Filed: January 13, 1998
    Date of Patent: August 15, 2000
    Assignee: Conexant Systems, Inc.
    Inventors: Huan-yu Su, Eric Kwok Fung Yuen, Adil Benyassine, Jes Thyssen
  • Patent number: 6014622
    Abstract: A pitch lag coding device and method using interframe correlation inherent in pitch lag values to reduce coding bit requirements. A pitch lag value is extracted for a given speech frame, and then refined for each subframe. For every speech frame having N samples of speech, LPC analysis and vector quantization are performed for the whole coding frame. The LPC residual obtained for each frame is then processed such that pitch lag values for all subframes within the coding frame are analyzed concurrently. The remaining coding parameters, i.e., the codebook search, gain parameters, and excitation signal, are then analyzed sequentially according to their respective subframes.
    Type: Grant
    Filed: September 26, 1996
    Date of Patent: January 11, 2000
    Assignee: Rockwell Semiconductor Systems, Inc.
    Inventors: Huan-Yu Su, Tom Hong Li
  • Patent number: 5920853
    Abstract: A signal compression system includes a coder and a decoder. The coder includes an extract unit for extracting an input feature vector from an input signal, a coder memory unit for storing a predesigned vector quantization (VQ) table for the coder such that the coder memory unit uses a set of primary indices to address entries within the pre-designed VQ table, a coder mapping unit for mapping indices from a set of secondary indices to the first set of indices, and a search unit for searching for one index out of the set of secondary indices, wherein the index from the set of secondary indices corresponds to an entry in the coder memory unit, and the entry best represents the input feature vector according to some predetermined criteria.
    Type: Grant
    Filed: August 23, 1996
    Date of Patent: July 6, 1999
    Assignee: Rockwell International Corporation
    Inventors: Adil Benyassine, Huan-Yu Su, Eyal Shlomot
  • Patent number: 5781880
    Abstract: A pitch estimation device and method utilizing a multi-resolution approach to estimate a pitch lag value of input speech. The system includes determining the LPC residual of the speech and sampling the LPC residual. A discrete Fourier transform is applied and the result is squared. A lowpass filtering step is carried out and a DFT on the squared amplitude is then performed to transform the LPC residual samples into another domain. An initial pitch lag can then be found with lower resolution. After getting the low-resolution pitch lag estimate, a refinement algorithm is applied to get a higher-resolution pitch lag. The refinement algorithm is based on minimizing the prediction error in the time domain. The refined pitch lag then can be used directly in the speech coding.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: July 14, 1998
    Assignee: Rockwell International Corporation
    Inventor: Huan-Yu Su
  • Patent number: 5689615
    Abstract: A method for efficient coding of non-active voice periods is disclosed for a speech communication system with (a) a speech encoder, (b) a communication channel and (c) a speech decoder. The method intermittently sends some information about the background noise when necessary in order to give a better quality of overall speech when non-active voice frames are detected. The coding efficiency of the non-active voice frames can achieved by coding the energy of the frame and its spectrum with as few as 15 bits. These bits are not automatically transmitted whenever there is a non-active voice detection. Rather, the bits are transmitted only when an appreciable change has been detected with respect to the last time a non-active voice frame was sent. To appreciate the benefits of the present invention, a good overall quality can be achieved at rate as low as 4 kb/s on the average during normal speech conversation.
    Type: Grant
    Filed: January 22, 1996
    Date of Patent: November 18, 1997
    Assignee: Rockwell International Corporation
    Inventors: Adil Benyassine, Huan-Yu Su