A Low Complexity Subband Adaptive Filter with Two-Stage Decomposition

The conventional subband adaptive filter (SAF) based on poly-phase decomposition has fast convergence behavior compared by fullband adaptive filter. However, the complexity for one-stage signal decomposition increases significantly, as increasing the number of subband to improve the convergence further. To solve this problem, a new SAF is proposed in this letter, which is constructed with two-stage decomposition. Based on the proposed structure, an adaptive algorithm of updating coefficients is derived based on the principle of minimal disturbance. Compared to the conventional SAF with one-stage decomposition, the proposed one has similar convergence rate with a lower complexity. Theoretical analysis and simulation results validated the superiority of the proposed SAF.