Reduced-complexity stochastically-excited coder for the low bit-rate coding of speech
Kuldip K. Paliwal · International Journal of Electronics · 1989
Stochastically-excited linear predictive (STLP) coders recently proposed in the literature can produce good quality speech at 4·8 kbits-1. However, these coders suffer from the problem of extremely high computational complexity. As a result, it is not possible to implement these coders on a single digital signal processor (DSP) chip. In the present paper, a new two-stage method is proposed for reducing the computational complexity of the STLP coder. This method can reduce the computational load of the STLP coder by a factor of 25 without sacrificing the quality of the synthetic speech. When this method is used in conjunction with the transform-domain filtering method of Transcoso and Atal, the computational requirement of the STLP coder reduces to 0·35 million multiplications per second, which can easily be met by a present-generation single DSP chip.