Very low bit rate voice for packetized mobile applications
- Communication Systems Div., Sandia National Lab., Albuquerque, NM (US)
This paper reports that transmitting digital voice via packetized mobile communications systems that employ relatively short packet lengths and narrow bandwidths often necessitates very low bit rate coding of the voice data. Sandia National Laboratories is currently developing an efficient voice coding system operating at 800 bits per second (bps). The coding scheme is a modified version of the 2400 bps NSA LPC-10e standard. The most significant modification to the LPC-10e scheme is the vector quantization of the line spectrum frequencies associated with the synthesis filters. An outline of a hardware implementation for the 800 bps coder is presented. The speech quality of the coder is generally good, although speaker recognition is not possible. Further research is being conducted to reduce the memory requirements and complexity of the vector quantizer, and to increase the quality of the reconstructed speech. This work may be of use dealing with nuclear materials.
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5663926
- Report Number(s):
- CONF-910774-; CODEN: NUMMB
- Journal Information:
- Nuclear Materials Management. Annual Meeting Proceedings; (United States), Vol. 20; Conference: 32. Institute of Nuclear Materials Management (INMM) annual meeting, New Orleans, LA (United States), 28-31 Jul 1991; ISSN 0362-0034
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
42 ENGINEERING
COMMUNICATIONS
DIGITAL SYSTEMS
NUCLEAR MATERIALS MANAGEMENT
SAFEGUARDS
FILTERS
FREQUENCY RANGE
MODIFICATIONS
PORTABLE EQUIPMENT
QUANTIZATION
RESEARCH PROGRAMS
SANDIA LABORATORIES
SECRECY PROTECTION
VECTORS
EQUIPMENT
MANAGEMENT
NATIONAL ORGANIZATIONS
TENSORS
US AEC
US DOE
US ERDA
US ORGANIZATIONS
055001* - Nuclear Fuels- Safeguards
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& Accountability- Technical Aspects
426000 - Engineering- Components
Electron Devices & Circuits- (1990-)