ITU-T 8-kbit/s standard speech codec for personal communication services

An 8-kbit/s speech coder (G.729) has been standardized by the ITU-T. This coder will be used for the Future Public Land Mobile Telecommunication Systems and will be suitable for personal communication services. To achieve a short-delay and toll-quality, this coder introduces six new features: adaptive spectral shaping, LSP quantization using interframe prediction, algebraic codebook excitation, VQ gain quantization with backward prediction, an improved postfilter, and frame erasure concealment. Subjective testing indicates that the quality of this coder is equivalent to that of 32-kbit/s adaptive differential pulse code modulation.