Transmission of speech by adaptive sampling

Abstract

This paper describes a technique for reconstructing a signal which has been sampled at a rate related to its short-term maximum frequency. The method described is based upon a theoretical simulation of active signal recovery filters containing periodically-operated switches. The cut-off frequency of such a filter is a function of the switching duty cycle. It is shown that the optimum filter is one with a sharp cut-off characteristic. The poor transient response usually associated with such filters is not a significant signal distortion factor.