A high quality speech coder at 400 bps

A high-quality speech coder at 400 b/s has been developed. This coder is designed to provide reliable communication over an HF channel in a hostile environment. The major techniques utilized for coding include vector quantization, interpolation, and trellis coding. The test results in the presence of speaker variations, background noise, and acoustic impairments are discussed. The three speaker average DRT was 80 for this coder.<
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