A tap assignment method using MSE and tail taps for sub-band adaptive filters

A new tap assignment method for sub-band adaptive filters is proposed. At the beginning of adaptation, the tap assignment is controlled by the mean-squared error (MSE) of each band. After the residual errors of all the bands become the same, the tap assignment is controlled by both the MSE and the tail tap weights of each sub-band adaptive filter. The new method in contrast to the method which uses only the MSE allows taps to be correctly assigned in the event that the sub-band adaptive filters have substantially different convergence rates. The efficiency of the proposed method has been confirmed through computer simulation. The performance of the proposed method in case of a colored input signal is investigated. It is confirmed that, in the colored input signal case, the total residual error can be minimized even though the unknown system is not exactly identified. Therefore, the proposed method is suitable for applications, such as echo cancellation and noise cancellation.