Efficient active noise controller using a fixed-point DSP

This paper presents an efficient active noise control (ANC) system using a fixed-point DSP. The proposed controller uses magnitude and phase compensation to eliminate the errors associated with the nonlinear distortion of analog devices in the ANC system, and hence, to improve the noise reduction performance. The quantization and rounding errors associated with the fixed-point DSP are also compensated for. Several ANC experiments reveal that the proposed controller reduces broadband noise by about 20 dB and narrowband noise by about 45 dB. The compensation idea is also useful to other applications of filter design.