Linjun J Zhou

US Patent:

6754618, Jun 22, 2004

Filed:

Jun 7, 2000

Appl. No.:

09/589612

Inventors:

Konstantinos Konstantinides - San Jose CA
Shaomei Chen - San Jose CA
Linjun Zhou - Santa Clara CA

Assignee:

Cirrus Logic, Inc. - Austin TX

International Classification:

G10L 1900

US Classification:

7042001, 704500

Abstract:

A communication system is disclosed in one embodiment of the present invention to include an encoder circuit responsive to an audio signal for performing compression on the audio signal and adaptive to generate an audio output signal based upon the compressed audio signal, the encoder circuit for sampling the audio signal to generated sampled signals, each sampled signals having a real and an imaginary component associated therewith, each sampled signal having an energy and a phase defined within a current block and each sampled signal being transformed to have a real and an imaginary component, a previous block preceding the current block and a block preceding the previous block, the encoder circuit for calculating the phase of the samples of the current block using the real and the imaginary components of the samples of the previous block and the block preceding the previous block, wherein calculations for determining the unpredictability measure is reduced by avoiding trigonometric calculations of the sampled signals of the current block thereby improving system performance.