Abstract
A three-hop AF MIMO relay system with tensor coding at the source and the relays is considered in this paper. The signals received at destination form a fifth-order tensor that satisfies a high-order nested Tucker decomposition, characterized by the concatenation of three Tucker models. We propose a receiver based on an alternating least square algorithm to jointly estimate the symbol matrix and the channels of each hop. Monte Carlo simulation results are provided to illustrate the behavior of the proposed system and of the semi-blind receiver. These simulation results show a performance closest to the one of the zero-forcing receiver, yielding a significant SER improvement due to the relay-assisted link when compared to the direct link.