(A) real-time performance evaluation system for speech waveform coders

Abstract

In this thesis, a real-time performance evaluation system for waveform coders is realized. In the first half, various objective measures for the performance of waveform coders are briefly reviewed and the feasibility of hardware realization of these measures is investigated. The system is realized with bit-slice bipolar microprocessors. Three kinds of objective measures are developed in microprogrammed software. In the second half, the performance of a CVSD coder with a sine wave input is evaluated with our evaluation system and with the distortion analyzer, and then the results are compared. Also, the performance of a CVSD coder with real speech input is evaluated with our evaluation system and the result is compared with that obtained in computer simulation. Finally, the use of a sine wave as the input signal in the performance test of a hardware-implemented coder is discussed. It has been found that the performance of a coder with a sine wave input may not correlate with that of a coder with real speech input.