Showing papers on "Enhanced Variable Rate Codec published in 1986"
01 Apr 1986
TL;DR: An effective algorithm based on the TOR (Thinned-Out Residual) method has been developed by modifying the means to thin out and interpolate residuals in voiced and unvoiced frames, and to extract and modify the pitch period.
Abstract: This paper describes the implementation of an 8kbps speech CODEC using a single DSP. First, an effective algorithm based on the TOR (Thinned-Out Residual) method has been developed by modifying the means to thin out and interpolate residuals in voiced and unvoiced frames, and to extract and modify the pitch period. Then, a compact CODEC which consists of one DSP and one MPU each has been developed using the new algorithm. This CODEC supports not only speech coding functions, but also frame synchronization functions and echo suppressing functions. The measured speech quality is quite satisfactory.
2 citations
07 Apr 1986
TL;DR: A 7 kHz-band speech CODEC using an advanced digital signal processor VLSI, "DSSP-1", is developed and arithmetic word-length, arithmetic operation speed, and memory capacity required for this C ODEC is evaluated.
Abstract: A 7 kHz-band speech CODEC using an advanced digital signal processor is developed. The coding algorithm for this CODEC requires greater processing power due to its complexity and high sampling rate. A high-performance digital signal processor VLSI, "DSSP-1", is applied to this CODEC. Arithmetic word-length, arithmetic operation speed, and memory capacity required for this CODEC is evaluated. DSSP-1 can satisfy these requirements; this CODEC has been built with two DSSP-1 chips and several memory chips.