WIDE BAND VOICE SIGNAL RECONSTRUCTION METHOD

摘要

PURPOSE:To reconstruct wide band voice signals (for example 8kHz/band) from narrow band voice signals (for example 300Hz to 3.4kHz) with a good quality. CONSTITUTION:Input narrow band voice signals are LPC analyzed and their spectrum information parameters are obtained (401). These parameters are vector quantized using a narrow band voice signals code book 208 (402). Original voice waveforms corresponding to the code vectors are stored in a representative waveform piece code book 305 equivalent to one pitch for a voiced sound and equivalent to one frame for a voiceless sound for every code number of the code book 208. Using this code book 305 and output code vector numbers of the step 402, voiced sound are waveform synthesized by superimposing pitch synchronization and voiceless sounds are waveform synthesized by randomly using waveforms equivalent to one frame and wide band voice signals are obtained (404). Wide band components other than 300Hz to 3.4kHz are taken out from the wide band voice signals (405), synthesized with the amplified and sampled narrow band signals and wide band voice signals are reconstructed.