A method of operating an autocorrelation pitch detector for use in a vocoder overcomes the
pitch doubling and tripling problem using a heuristic rather than an analytic approach. The …

A harmonic speech coding arrangement where vector quantization is used to improve
speech quality. Parame ters are determined at the analyzer of an illustrative coding …

A harmonic coding arrangement where the magnitude spectrum of the input speech is
modeled at the analyzer by a relatively small set of parameters and, significantly, as a …

(57) ABSTRACT A toll quality terrestrial wireless digital multiple access terrestrial
communication system is disclosed having a base station in communication with telephone …

An apparatus, method, and system in which a compressed digital signal is derived from a
digital input signal by compressing the digital input signal in a selected one of plural …

The baseband portion x (t) of a voice signal is first applied to a complex filter which provides
a couple of signal components y and y in quadrature with each other. Each of the …

An orthogonal transform coding system for images which orthogonally transforms image
data to spatial frequencies and divides the domain of the spatial fre quencies into low and …

BACKGROUND Conventional analog telephone systems are being replaced by digital
systems. In digital systems, the ana log signals are sampled at a rate of about twice the …

Speech processing apparatus and methods utilizing a circuit for electronically deriving from
speech over time a series of coordinate values representing positions of points on a path in …

A speech codec operating at low data rates uses an iterative method to jointly optimize pitch
and gain parameter sets. A 26-bit spectrum filter coding scheme may be used, involving …