A vectorial generalization of the ADPCM system is introduced. Once the speech signal is grouped in vectors, they are coded using a vector predictor (VP) and a vector quantizer (VQ). Both subsystems are continously adaptive; the VQ is matched the signal power; two algorithms (VLMS and VGAL) are considered to adapt the predictor. At the bit stream corresponding to 2 bits per signal sample, the coding system rends a segmented signal to noise ratio equivalent to other existing coders.
CitacióMasgrau, E., Mariño, J.B. Adaptive vector predictive speech coding with sample by sample update at 16 Kbps. A: European Signal Processing Conference. "EUSIPCO 1986: Signal processing III: theories and applications proceedings of EUSIPCO-86: Third European Signal Processing Conference: The Hague, The Netherlands: September 2-5, 1986". Barcelona: 0, p. 431-434.