Fast vector quantisation using orthogonal codebooks

Vector quantisation techniques are commonly used in the digital transmission of analogue signals such as voice and images. For examples, speech coding using CELP (code excited linear prediction) has already found application in communication systems where high speech quality is required at low bit rates. The paper addresses one of the drawbacks of CELP as originally proposed by Atal and Schroeder (1984) which is its high computational complexity. The authors propose an approach called FVQ-CELP fast vector quantisation CELP which typically reduces the computational load by more than two orders of magnitude compared with conventional schemes, while maintaining high speech quality