Abstrakt: |
Approximate maximum likelihood and related estimation techniques for source location estimation are investigated. An extended model of the spectral density matrix of the sensor array output for coherent sources (multipath propagation) is introduced. We show that the EM algorithm can be successfully appplied for this special case of practical importance. In contrast to [2], the EM iteration scheme is derived by exploiting that the distribution type of the finite Fourier- transformed sensor outputs belongs to the exponential family. This approach requires neither the additional noise parameters used in [2] nor an alternating step by step optimization of spectral and source location parameters. Finally, we investigate the co-called approximate dual maximum likelihood estimate. |