Abstract: We propose a variable step-size affine projection algorithm (APA) with robust-M estimators. The step-size is controlled with an exponential function, based on a criterion of optimal variable step-size performance. The robust-M estimators are applied to the variable step-size APA algorithm using the equivalent error with tri-weights. Theoretical analyses and numerical results show that the proposed algorithm performs well with a low misadjustment error rate and is robust against outliers.

Key words: adaptive filter, variable step-size affine projection algorithm, robust estimation, M-estimators