Abstract: A system and method for determining operating parameters to control a communication rate for an adaptive rate communication system includes a transmitter (101) to transmit a signal (135) through a network (142) to a receiver (103). The receiver (103) determines operating parameters based on, among other things, packet information from a received signal (e.g., packet). The receiver conveys the operating parameters to the transmitter for use in subsequent communications from the transmitter (101) to the receiver (103).

Abstract: System efficiently communicates a perceptually encoded speech spectrum signal from a transmitter to a receiver. The transmitter includes a speech analyzer which accepts a speech signal input and generates a parameterized speech signal. The transmitter also includes a vector quantizer for generating the perceptually encoded speech spectrum signal from the parameterized speech signal. The receiver decodes the perceptually encoded speech spectrum signal to produce decoded spectral parameters to further produce a synthetic speech output. The vector quantizer performs a method for partitioning a vector quantizer (VQ) codebook to produce perceptually organized sub-codebooks. The vector quantizer performs a second method for quantizing a vector based on the perceptually organized sub-codebooks. The second method identifies a vector, from one of the perceptually organized sub-codebooks, to perceptually model the speech signal input.

Abstract: A system and method for determining operating parameters to control a communication rate for an adaptive rate communication system includes a transmitter (101) to transmit a signal (135) through a channel (142) to a receiver (103). The receiver (103) determines operating parameters based on, among other things, an effective bit rate and a percentage of speech in the signal. The receiver conveys the operating parameters to the transmitter for use in subsequent communications from the transmitter (101) to the receiver (103).

Abstract: A vocoder device and corresponding method characterizes and reconstructs speech excitation. An excitation analysis portion performs a cyclic excitation transformation process on a target excitation segment by rotating a peak amplitude to a beginning buffer location. The excitation phase representation is dealiased using multiple dealiasing passes based on the phase slope variance. Both primary and secondary excitation components are characterized, where the secondary excitation is characterized based on a computation of the error between the characterized primary excitation and the original excitation. Alternatively, an excitation pulse compression filter is applied to the target, resulting in a symmetric target. The symmetric target is characterized by normalizing half the symmetric target. The synthesis portion performs reconstruction and synthesis of the characterized excitation based on the characterization method employed by the analysis portion.

Abstract: A speech vocoder device and corresponding method synthesizes speech excitation waveforms. The method entails reconstructing (216) an excitation target from decoded speech data, creating (220) aligned excitation segments by normalizing (296), correlating (298), and aligning (300) a source segment and a target segment, reconstructing normalized intervening segments by ensemble interpolating (318) between the source segment and the target segment, denormalizing (320) the normalized intervening segments, and reconstructing (322) an excitation waveform from the denormalized intervening segments, the source segment, and the target segment.