System for the transmission of speech signals

摘要

A speech bandwidth compression system uses a first set of filters to separate the speech signal into baseband (300-800 hz) and highband (800-3200 hz) signals. The baseband (first formant or fundamental pitch frequency) is transmitted directly, and is also rectified to form harmonics which are mixed with the highband signals in a second set of (paired digital) filters which form sine and cosine forms (amplitude and phase information) of the harmonic components, which are then multiplexed for transmission to a receiver which provides the corresponding bandwidth expansion system to reconstruct the original speech signal.