Constrained EM estimates for harmonic source separation

A constrained iterative method for harmonic source parameter estimation is proposed based on an EM algorithm with intent for harmonic source separation. The problem of coinciding partials and interference among them in general is mitigated by the constraints on the "weak" partials on the stronger ones of the same harmonic source. A useful scheme to determine the weakness of a partial is proposed. The constrained iteration is shown to give more accurate estimates of the sinusoidal parameters, which results in good source separation even in most cases of highly overlapping spectra.