Measuring performance limits of subband adaptive systems

We discuss a method to measure the convergence limits of general subband adaptive systems due to non-ideal filter banks. Aliasing caused in such filter bank presents a distortion to the subband adaptive system which forms a lower limit for the minimum mean squared error. The accuracy of the achievable model is given by the transfer function of the filter bank. To measure both aliasing and filter bank distortions, we employ the measurement technique by Heinle and Schussler (see Proc. IEEE International Conference on Acoustics, Speech and Signal Processing, Atlanta, GA, p.2754-57, 1996). The presented approach is applicable to a wide range of subband adaptive filter systems. Examples for the measured limits are presented.