Blind identification of complex convolutive MIMO systems with 3 sources and 2 sensors

We address the problem of blind identification of a convolutive Multiple-Input Multiple-Output (MIMO) system with more inputs than outputs, and in particular, the 3-input 2-output case. We assume that the inputs are temporally white, non-Gaussian distributed, spatially independent and that the system impulse response can be complex. In this paper, we look at the problem in the frequency domain, where, for each frequency we construct two tensors based on cross-polyspectra of the output. These tensors lead to the system frequency response within frequency dependent scaling and permutation ambiguities. We propose ways to resolve these ambiguities, and show that it is possible to obtain the system response within a scalar and a linear phase.