Noise suppression system for AM radio using Hilbert transformation

抄録

In recent years, an interference of artificial noises from an electrical power transfer becomes large and deterioration of a sound quality of an AM radio is worried. In this paper, a novel noise suppression system using quadrature demodulation techniques is proposed to reduce the effect of the interference. The proposed system utilizes the fact that the in-phase signal from the demodulator includes both of the AM signal and the noise, on the other hand, the quadrature signal includes only the noise. Thus, the interference in the in-phase signal can be canceled by using the quadrature signal. Since the sign of the both interferences are different each other, Hilbert transformation is utilized to match the sign of the interferences. Validity of the proposed system is shown through computer simulation and experiments.