Excavating
Patent
1995-05-03
1996-02-13
Knepper, David D.
Excavating
395 238, 371 374, G10L 500
Patent
active
054917727
ABSTRACT:
The quantized parameter bits are grouped into several categories according to their sensitivity to bit errors. More effective error correction codes are used to encode the most sensitive parameter bits, while less effective error correction codes are used to encode the less sensitive parameter bits. This method improves the efficiency of the error correction and improves the performance if the total bit rate is limited. The perceived quality of coded speech is improved. A smoothed spectral envelope is created in the frequency domain. The ratio between the actual spectral envelope and the smoothed spectral envelope is used to enhance the spectral envelope. This reduces distortion which is contained in the spectral envelope.
REFERENCES:
patent: 3982070 (1976-09-01), Flanagan
patent: 4276647 (1981-06-01), Thacker et al.
patent: 4648091 (1987-03-01), Gajjar
patent: 4744086 (1988-05-01), Komly et al.
patent: 4747104 (1988-05-01), Piret
patent: 4802171 (1989-01-01), Rasky
patent: 5007094 (1991-04-01), Hsueh et al.
patent: 5023910 (1991-06-01), Thomson
patent: 5036515 (1991-07-01), Freeburg
patent: 5073940 (1991-12-01), Zinser et al.
patent: 5081681 (1992-01-01), Hardwick
patent: 5097507 (1992-03-01), Zinser et al.
patent: 5105442 (1992-04-01), Wei
patent: 5226084 (1993-07-01), Hardwick et al.
patent: 5247579 (1993-09-01), Hardwick et al.
Campbell et al., "The New 4800 bps Voice Coding Standard," Mil Speech Tech Conference, Nov. 1989.
Chen et al., "Real-Time Vector APC Speech Coding at 4800 bps with Adaptive Postfiltering," Proc. ICASSP 1987, pp. 2185-2188.
Griffin, et al., "Multiband Excitation Vocoder," IEEE TASSP, vol. ASSP36, No. 8, Aug. 1988, pp. 1223-1235.
Hardwick, "A 4.8 kbps Multi-Band Excitation Speech Coder," Proc. ICASSP 85, pp. 945-948, Tampa, FL, Apr. 11-14, 1988.
Jayant et al., "Adaptive Postfiltering of 16 kb/s-ADPCM Speech," Proc. ICASSP 86, pp. 829-832, Tokyo, Japan, Apr. 13-20, 1986.
Makhoul et al., "Vector Quantization in Speech Coding," Proc. IEEE, 1985, pp. 1551-1588.
McAulay et al., "Speech Analysis/Synthesis Based on a Sinusoidal Representation," IEEE TASSP, vol. ASSP34, No. 4, Aug. 1986, pp. 744-754.
Rahikka et al., "CELP Coding for Land Mobile Radio Applications," Proc. ICASSP 90, pp. 465-468, Albequerque, New Mexico, Apr. 3-6, 1990.
Quatieri et al., "Speech Transformations Based on a Sinusoidal Representation," IEEE TASSP, vol. ASSP34, No. 6, Dec. 1986, pp. 1449-1986.
Griffin, "Multiband Excitation Vocoder," Ph.D. Thesis, MIT, 1987.
Griffin, "A New Model-Based Speech Analysis/Synthesis System," Proc. ICASSP 85, pp. 513-516, Tampa, Florida, Mar. 26-29, 1985.
Hardwick, "A 4.8 kbps Multi-Band Excitation Speech Coder," S.M. Thesis, MIT, May 1988.
McAuley et al., "Mid-Rate Coding Based on a Sinusoidal Representation of Speech," Proc. ICASSP 85, pp. 945-948, Tampa, Florida, Mar. 26-29, 1985.
J. L. Flanagan, "Speech Analysis, Synthesis and Perception," Springer-Verlag, 1972, pp. 378-386.
Griffin et all, "A High Quality 9.6 kbps Speech Coding System" Proc. ICASSP 86, pp. 125-128, Tokyo, Japan, Apr. 13-20, 1986.
Jayant et al., Digital Coding of Waveforms, Prentice-Hall, Englewood Cliffs, NJ, 1984.
Levesque et al., Error-Control Techniques for Digital Communication, Wiley, 1985.
Digital Voice Systems, Inc., "INMARSAT-M Voice Coder", Version 1.1 (Dec. 5, 1990).
Hardwick John C.
Lim Jae S.
Digital Voice Systems, Inc.
Knepper David D.
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