Fast algorithm for pyramid vector quantization

This paper presents an efficient implementation of a pyramid vector quantization coding/decoding algorithm developed by Filip and Ruf (see Proc. IEEE Conf. GLOBECOM, Orlando, FL, USA, p.240-4, 1992), where the original classical calculation of pyramid numbers V/sub L,K/ is replaced by a sliding calculation. The sliding calculation allows movement in any direction of a lattice so that the calculation of V/sub L,K/ in each algorithm iteration can be continued from the previous pyramid number. These properties can, under certain conditions, significantly (up to 25 times) accelerate the coding/decoding process. The condition under which the sliding calculation is more effective than the original one is also presented. The simulation results confirm the expected improvement over the original algorithm.