Frame-based subband Kalman filtering method and apparatus for speech enhancement

摘要

A method and apparatus for enhancing a speech signal contaminated by additive noise through Kalman filtering. The speech is decomposed into subband speech signals by a multichannel analysis filter bank including bandpass filters and decimation filters. Each subband speech signal is converted into a sequence of voice frames. A plurality of low-order Kalman filters are respectively applied to filter each of the subband speech signals. The autoregression (AR) parameters which are required for each Kalman filter are estimated frame-by-frame by using a correlation subtraction method to estimate the autocorrelation function and solving the corresponding Yule-Walker equations for each of the subband speech signals, respectively. The filtered subband speech signals are then combined or synthesized by a multichannel synthesis filter bank including interpolation filters and bandpass filters, and the outputs of the multichannel synthesis filter bank are summed in an adder to produce the enhanced fullband speech signal.