The isolation of undistorted sinusoids in real-time

A single-input, multiple-output adaptive filter that takes a multisinusoidal input signal and produces the individual sinusoid at each of the outputs is described. The individual outputs have amplitudes and phases identical to those of the components of the original input signal. The filter can be adapted in real time using approximate Gauss-Newton updates without recourse to any matrix operations or division. The filter is an extension of a cascade adaptive IIR (infinite-impulse-response) notch filter reported previously