Amplitude Optimization and Pitch Prediction in Multipulse Coders

In this paper we discuss the basic multipulse model and describe an algorithm to obtain the excitation pulses with optimally adjusted pulse amplitudes. Within the framework of the algorithm the excitation can be computed with varying degrees of optimization, and with a few modifications the procedure can search for more than one pulse at each stage and use non-exhaustive searches. We show that for high pitched speakers, the pitch dependence of multipulse excitation can be reduced and speech quality improved by including long delay predictors in the multipulse model. Finally we briefly describe the quantization procedure used to simulate a multipulse coder with amplitude optimization and pitch prediction at 9.6 kbits/sec.