A method and apparatus for reducing the complexity of linear prediction analysis-by-synthesis (LPAS) speech coders. The method and apparatus include product code vector quantization (PCVQ) of multi-tap pitch predictor coefficients, which reduces the search and quantization complexity of an adaptive codebook....http://www.google.de/patents/US6014618?utm_source=gb-gplus-sharePatent US6014618 - LPAS speech coder using vector quantized, multi-codebook, multi-tap pitch predictor and optimized ternary source excitation codebook derivation
