Patent ID: 9135923
Filing Date: 2015-09-15
Classification: G10L

Abstract:
1. A method of speech communication from a transmitter to a receiver using a plurality of processors comprising an encoder to compress the speech signal into a digital form and a decoder to recover speech signal from the said compressed digital form comprising: (A) an encoder in the transmitter comprising the following elements: segment the voice-signal into non-overlapping frames, wherein for voiced sections the frames are pitch periods and for unvoiced sections the frame duration is a constant; identify the type of a said frame to generate a type index; identify the pitch period of a said frame from the segmentation process; generate amplitude spectra of a said frame using Fourier analysis; generate an intensity parameter of a said frame from the amplitude spectrum; transform the said amplitude spectrum into timbre vectors using Laguerre functions; apply vector quantization to the said timbre vector using a timbre-vector codebook to generate a timbre index; apply scalar quantization to said intensity parameter using an intensity codebook to generate an intensity index; apply scalar quantization to said pitch period with a pitch codebook to generate a pitch index; transmit the type index, intensity index, pitch index and timbre index to the receiver; (B) a decoder in the receiver comprising the following elements: take the transmitted intensity index, look-up into the intensity codebook to identify the intensity; take the transmitted pitch index, look-up into the pitch codebook to identify the pitch; take the transmitted timbre index, look-up into the timbre-vector codebook to identify the timber vector; inverse transform the said timbre vector into amplitude spectra using Laguerre functions; generate phase spectrum from the amplitude spectrum using Kramers-Knonig relations; use fast Fourier transform to generate an elementary waveform from the said amplitude spectrum, phase spectrum, and intensity; superpose the said elementary waves according to the timing provided by the pitch period to generate an output speech signal.