AN INFINITE IMPULSE-RESPONSE ADAPTIVE DIGITAL-FILTER FOR LINE-CANCELER AND ITS POLE-CONTROL ALGORITHM

This paper proposes the parallel construction of the second-order infi nite impulse response (IIR) adaptive digital filter (ADF) as an adapti ve digital filter for eliminating multiple narrowband signals mixed in the broadband signal. Then the pole-control method for the filter is proposed. In the proposed pole-control, the pole radius and the pole a rgument are controlled separately by different algorithms. In this stu dy, the pole argument is corrected by estimating the deviation of the central frequency of the signal to be eliminated from the convergent v alue of the multiplier coefficient that determines the zero. The pole radius is controlled by the method that determines the direction of co rrection, using the parallel-connected three ADFs with the same pole a rgument and a slightly different pole radius. It is verified by a simu lation that those pole-control methods work effectively. It is demonst rated that the pole radius and the pole argument can be controlled sim ultaneously.