Voice encoding system

Abstract

Abstract PURPOSE:To obtain a composite tone having a high quality at a transmission rate of <=10Kb/s by dividing one frame into sub-frames of equal length of unequal length, calculating an interval of a driving pulse and amplitude and a phase of the driving pulse at every sub-frame and generating a driving signal. CONSTITUTION:One frame is divided into sub-frames of equal length or unequal length by executing a processing for calculating an interval and amplitude of a driving pulse by a sub-frame unit. Subsequently, the interval of the driving pulse and amplitude and a phase of the driving pulse are calculated at every sub-frame. A driving signal is generated by a pulse train whose interval is equal in the sub-frame and whose interval is different at every sub-frame, based on information of the interval of the driving pulse and the amplitude and the phase of the driving pulse. In such a way, the pulse interval of the driving signal can be changed at every sub-frame so that it becomes dense in the sub- frame in which important information or many information is contained, and becomes sparse in other sub-frame, therefore, the quality of a composite signal can be improved.

Inventors

• 👤 Masami Akamine
• 👤 政巳 赤嶺

Bibliographic Details