Glenayre Electronics, Inc.

Bhaskar Bhattacharya

Mohammad Aamir Husain

Patricia Fern Kavanagh

A method of encoding signal segments which represent unvoiced plosives. The signal segments to be encoded are contained within a speech signal divided into m&equals;1, . . . , N frames. Each frame is subdivided into l&equals;1, . . . , L subframes. The speech signal has a gain g,(l) within each subframe. An energy measure e,(l) representative of the signal segments' energy content is defined. An energy threshold e,(l) representative of a sudden energy change characteristic of an unvoiced plosive is also defined. For each frame, the energy measure e,(l) and the energy threshold e,(l) are derived for each subframe within that frame. If e,(l)&lE;e,(l) for each subframe within a particular frame, then a plosive locator l,&equals;0 and a plosive index i,&equals;0 are assigned to that frame to indicate absence of a plosive within that frame. If e,(l)>e,(l) for any subframe within the frame, then that frame's plosive locator l,is assigned a non-zero value, with the plosive locator's value indicating location of the plosive at a transition point immediately following that one of the subframes within the frame for which e,(l)&minus;e,(l) is greatest; and, that frame's plosive index i,is assigned a non-zero value representing presence of a plosive within that frame.

Location and coding of unvoiced plosives in linear predictive coding of speech

A method of suppressing noise in an input signal having voice components and noise components is provided. The method is an automatic gain control (,) implemented preferably in software. The noise components and the voice components are identified by a noise detection routine (,). The input signal, having an energy level, is provided for amplifying the input signal when the voice components are detected. The input signal is amplified by a gain value proportional to the energy level of the input signal. A bias signal, having an energy level, is provided for amplifying the input signal when the noise components are detected. The input signal is amplified by a gain value proportional to the energy level of the bias signal.

Method to suppress noise in digital voice processing

A method and apparatus for reducing peak-to-average power ratio in a paging transmitter broadcasting an independent sideband amplitude modulation protocol is disclosed. A digital signal, for example a digital voice signal, is provided to a control gain generator which generates a digital gain sequence. The digital gain sequence is such that during peak values in the digital signal the gain is low and during low values in the digital signal the gain is high. The digital gain sequence is multiplied with the digital signal to compress the dynamic range of the digital signal.

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Coquitlam, Canada

Bhaskar Bhattacharya