| 摘要 |
PROBLEM TO BE SOLVED: To obtain a broad-band speech signal from a narrow-band voice signal by efficiently using an existing telephone system. SOLUTION: This method consists of such processes as a 16kHz sampling processing 101 for 8kHz sampling narrow-band speech signal, a full-wave rectification processing 102 for up-sampled speech signal, a short-time Fourier analysis processing 103 for the full-wave rectification processed speech signal, a band-pass filtering processing 104 for low range of the complex spectra, a processing 106 to obtain a high range complex spectra from the complex spectra obtained by the processing 105, a STFT synthesis processing 109 to synthesize the complex spectra of the high and low ranges, and an addition processing 110 to sum the up-sampled speech signal and the STFT synthesized speech signal. |
