초록 ▼

Speech is encoded into a 90 millisecond frame of bits for transmission across a satellite communication channel. A speech signal is digitized into digital speech samples that are then divided into subframes. Model parameters that include a set of spectral magnitude parameters that represent spectral

Speech is encoded into a 90 millisecond frame of bits for transmission across a satellite communication channel. A speech signal is digitized into digital speech samples that are then divided into subframes. Model parameters that include a set of spectral magnitude parameters that represent spectral information for the subframe are estimated for each subframe. Two consecutive subframes from the sequence of subframes are combined into a block and their spectral magnitude parameters are jointly quantized. The joint quantization includes forming predicted spectral magnitude parameters from the quantized spectral magnitude parameters from the previous block, computing the residual parameters as the difference between the spectral magnitude parameters and the predicted spectral magnitude parameters, combining the residual parameters from both of the subframes within the block, and using vector quantizers to quantize the combined residual parameters into a set of encoded spectral bits. Redundant error control bits may be added to the encoded spectral bits from each block to protect the encoded spectral bits within the block from bit errors. The added redundant error control bits and encoded spectral bits from two consecutive blocks may be combined into a 90 millisecond frame of bits for transmission across a satellite communication channel.

대표청구항 ▼

[ What is claimed is:] [1.] A method of encoding speech into a 90 millisecond frame of bits for transmission across a satellite communication channel, the method comprising the steps of:digitizing a speech signal into a sequence of digital speech samples;dividing the digital speech samples into a se

[ What is claimed is:] [1.] A method of encoding speech into a 90 millisecond frame of bits for transmission across a satellite communication channel, the method comprising the steps of:digitizing a speech signal into a sequence of digital speech samples;dividing the digital speech samples into a sequence of subframes, each of the subframes comprising a plurality of the digital speech samples;estimating a set of model parameters for each of the subframes; wherein the model parameters comprise a set of spectral magnitude parameters that represent spectral information for the subframe;combining two consecutive subframes from the sequence of subframes into a block;jointly quantizing the spectral magnitude parameters from both of the subframes within the block, wherein the joint quantization includes forming predicted spectral magnitude parameters from the quantized spectral magnitude parameters from a previous block, computing residual parameters as the difference between the spectral magnitude parameters and the predicted spectral magnitude parameters, combining the residual parameters from both of the subframes within the block, and using a plurality of vector quantizers to quantize the combined residual parameters into a set of encoded spectral bits;adding redundant error control bits to the encoded spectral bits from each block to protect at least some of the encoded spectral bits within the block from bit errors; andcombining the added redundant error control bits and encoded spectral bits from two consecutive blocks into a 90 millisecond frame of bits for transmission across a satellite communication channel.