The Application of Wave Superposition Algorithm to Identify Cyclostationary Sound Source

The cyclostationary characteristics can not be extracted clearly in reconstruction of the acoustic field radiated from the cyclostationary sources by the conventional near-field acoustic holography procedures. The cyclostationary near-field acoustic holography method uses the cyclic spectrum density function as the reconstruction variance instead of the spectrum or the power spectrum density, which decomposes the carrier wave and modulating wave in the appropriate cyclic frequency. The reconstructed CSD shows the distribution of the modulating wave of cyclostationary sources and supplies more cyclostationary acoustical information than the conventional NAH. In the present work, the theory of the cyclostationary NAH combined with the wave superposition is introduced, which can be used for the arbitrarily shaped cyclostationary sources. A numerical simulation and a speaker experiment are employed to validate this WSA-based cyclostationay NAH method. The results of the simulation show great agreement between the reconstruction and the analytical value. The distribution of the CSD of the cyclostationary acoustical source on the surface coincides with the speaker box accurately.