Noise robust blind system identification and subband equalization of room transfer functions

Опубликовано 6 сентября 2016, 17:17

Identification and equalization of Room Transfer Functions (RTFs) is an important topic with several applications in acoustic signal processing. RTFs are often modelled as finite impulse response filters characterized by orders of thousands of taps and non-minimum phase. In practice, only approximate estimates of the actual RTFs are available due to measurement noise, limited estimation accuracy and temporal variation of source-receiver position. These issues make equalization a difficult problem. In the first part of this talk, I will present an adaptive method for blind system identification and introduce several constraints that can be used to improve the robustness of this method in noisy environments. Second, I will introduce a multichannel method for the equalization filter design utilizing decimated and oversampled subbands, where the fullband acoustic impulse response is decomposed into equivalent subband filters prior to equalization. This technique is more computationally efficient and more robust to RTF inaccuracies compared with the fullband counterpart.