Space-Time-Frequency (STF) MIMO Relaying System with Receiver Based on Coupled Tensor Decompositions
Résumé
In this work, we present a two-hop OFDM MIMO relaying system with tensor codings at the source and the relay. The transmission scheme is composed of two steps. In the first one, the source sends a data tensor using a tensor space-time (TST) coding with multiplexing of the symbols across space (antennas), time (blocks) and frequency (subcarriers) domains. In the second one, the relay re-encodes the received signals also using a TST coding and forwards them to the destination. The signals received at destination form a fifth-order tensor that satisfies a coupled nested Tucker decomposition (CNTD). This model consists of a coupling of nested Tucker decompositions (NTD) that share a same component, resulting in the concatenation of a Tucker model with a generalized Tucker one. The tensor modeling is exploited to derive a closed-form semi-blind receiver based on a low-rank approximation algorithm for jointly estimating the symbols and channels. Monte Carlo simulation results are provided to illustrate the effectiveness of the proposed system.