Linear prediction filter coefficient quantizer and filter set

摘要

A simultaneous voice and data (SVD) modem includes a preemphasis filter (175,180,185) for processing an audio source signal, e.g., a voice signal (on 149), before transmission (on 146) to a far-end SVD-capable modem. The preemphasis filter implements a second order linear predictor in which a quantized set of predictor coefficients are selected directly from the normalized autocorrelation coefficients. In addition, an index is associated with the selected set of predictor coefficients. This index is transmitted to an opposite SVD-capable modem, which thereby allows the opposite SVD-capable modem to select the same set of predictor coefficients for use in recovering the voice signal at the opposite endpoint.