Multi-Pulse LPC Using Analytic Signals

Multi-pulse linear predictive coding (MPLPC) is a well-known medium rate speech coding algorithm that provides natural sounding speech at rates in the range of 9.6kbits/s. In this paper, a MPLPC system utilizing an analytic signal representation is presented. The speech signal is processed as a complex signal, with the LPC parameters and multi-pulse excitation being coded as complex quantities. The output synthetic speech is constructed using a Hilbert-transform-type operation. The overall quality of the analytic MPLPC (AMPLPC) system was judged to be superior to that obtained from an equivalent real-signal based system for studio- quality speech, though these differences became minimal for telephone quality speech.