Quality limitations in residual‐excited LP speech coding

High-quality Speech Coding

Kei Kikuiri, Nobuhiko Naka and Shinya Abe The high-quality speech coding is a super-wideband speech coding technique for providing high-quality VoIP services in a high-speed wireless communication environment, and was developed in collaboration with DoCoMo Communications Laboratories USA, Inc. This technology encodes and transmits nearly all of the frequency components of the human voice to all...

Techniques for high-quality ACELP coding of wideband speech

We present in this paper new methods for achieving highquality wideband speech at low rates using the ACELP algorithm. Several innovations are introduced to optimize the quality and minimize the complexity of the coder. A multi-rate wideband speech encoding algorithm based on these techniques was recently selected by 3GPP as the standard for AMR-WB, and is currently one of the candidates for th...

High quality coding of wideband speech at 24 kbit/s

This paper proposes a Wideband-CELP-Coding scheme (bandwidth 7kHz) at 24 kbit/s. The codec introduces a delay of just 10 ms. This fulfills the requirements of a possible codec candidate for wideband speech coding within DECT or video applications [I]. The analysis-by-synthesis structure of the proposed Wideband-CELP-Codec includes an alternative LPC analysis concept, where the autocorrelation f...

Natural quality variable-rate spectral speech coding below 3.0 kbps

We propose new techniques for natural quality variable rate spectral speech coding at an average rate of 2.2 kbps for dialog speech and 2.8 kbps for monolog speech. The coder models the Fourier spectrum of each frame and it builds on recent enhancements to the classical multiband excitation (MBE) approach. New techniques for robust pitch estimation and tracking, for e cient quantization of voic...

High Quality Low - Delay Speech Coding at 12 kb / s