PARAFAC2 Receivers for Orthogonal Space-Time Block Codes

Space-time block codes can be represented by tensors, like for example the Kathri-Rao space time codes introduced by Sidiropoulos. In this paper, we introduce a parallel factor analysis 2 (PARAFAC2) model for orthogonal space-time block codes (OSTBC). This model, along with a small modification at the transmitter and the use of tensor diagonalisation designed for orthogonal tensors at the receiver, leads us to develop a generic parallel factor analysis (PARAFAC) blind receiver for OSTBC. Unlike most tensor based blind receivers, our channel estimator is based on a data tensor rather than on a cumulant tensor.