On a New Speech Coding Technique Using the Nonuniform Sampling and the Separated Bandwidth of Speech Signals
Myung-Jin Bae, WonCheol Lee, Sungbin Im · Information Sciences, Signal Processing and their Applications · 1996
To reduce the redundancy within samples that resulted from uniform sampling method like PCM, nonuniform sampling or nonredundant-sample coding methods can be considered. However, it is well known that when conventional nonuniform sampling methods are applied directly to speech signal the required amount of data is comparable to or more than that of uniform sampling method. To overcome this problem, a new nonuniform sampling method is proposed in which nonuniform sampling is applied to the low-pass filtered speech signal and higher band is compensated by 8 colored Gaussian random noise with various noise levels. By this method, speech signal waveform can be encoded by 1.8 times larger compression ratio than that of the conventional nonuniform sampling method.