The Accuracy of Tensor and Directional Methods for MIMO Channel Modeling

The goal of this paper is to identify MIMO modeling strategies with high accuracy and relatively few parameters. Candidates are existing correlation tensor models (Kronecker, Weichselberger, and maximum entropy), a new generalized tensor model based on the Higher-Order Singular Value Decomposition (HOSVD), and an unstructured diffuse directional model. The performance of the models is investigated by applying them to 8×8 MIMO reference channels generated with a realistic double-directional cluster channel model. It is shown that all of the existing models exhibit high error in the reconstructed spatial spectra (10-30%) and even higher error in the reconstructed full covariance (20-35%).