[54] SYSTEM AND METHOD FOR GENERATING RE-CONFIGURABLE BAND LIMITED NOISE USING MODULATION
[75] Inventor: Mark A. Ireton, Travis, Tex.
[73] Assignee: Advanced Micro Devices, Inc.
Sunnyvale, Calif.
[21] Appl. No.: 707,700
[22] Filed: Sep. 4, 1996
[51] Int. CI.6 G10L3/02
[52] U.S. CI 704/226; 704/225
[58] Field of Search 704/226. 261,
704/227, 228, 233, 225
[56] References Cited
U.S. PATENT DOCUMENTS
3,909,533 9/1975 Vrtlliman 704/261
4,170,719 10/1979 Fujimura 704/208
4,544,919 10/1985 Gerson 341/75
4,817,157 3/1989 Gerson 704/230
4,896,361 1/1990 Gerson 704/222
4,912,764 3/1990 Hartwell et id 704/207
■■Illllllllllll
US005797120A [ii] Patent Number: 5,797,120 [45] Date of Patent: Aug. 18, 1998
5,574,824 11/1996 Slyhetal 704/226
OTHER PUBLICATIONS
Aldo Cumani. "On A Covariance-Lattice Algorithm For Linear Prediction," ICASSP 82 Proceedings. May 3. 4, 5. 1982, Palais Des Congres, Paris, France, vol. 2 of 3, IEEE International Conference on Acoustics, Speech and Signal Processing, pp. 651-654.
Primary Examiner—-Richemond Dorvil
Attorney, Agent, or Firm—Conley, Rose & Tayon; Jeffrey C.
Hood
[57] ABSTRACT
A vocoder for generating speech from a plurality of stored speech parameters which efficiently computes a band limited noise signal for use in the speech production model. The band limited noise signal generator includes a white Gaussian noise generator coupled to a band-width limiting filter. The resulting band limited white Gaussian noise signal is provided to a bank of modulators, each having predetermined modulation frequency. The outputs of each of the modulators are provided to variable gain units and summed together to produce the band limited noise signal.
35 Claims, 11 Drawing Sheets
