This paper proposes reduction of mul- tiple narrow-band noise signals from radio signals. The multiple narrow-band noise signals are suppressed one- by-one basis by using sinusoidal signal generators and an adaptive filter. The frequencies are estimated from the amplitude spectrum. Based on the histogram of fre- quency differences, low-power harmonic components can be detected. Fine tuning on frequency is carried out by using the averaged power pattern of three narrow-band- filter outputs. Peak filters are introduced in order to sup- press influence of wide-band signals. The performance are examined by using real measured signals
