Space-Time-Frequency Coding for MIMO Relay System Based on Tensor Decomposition

Abstract: Space-time-frequency (STF) coding can obtain the diversity gain from three dimensions (space, time and frequency) to effectively improve the transmission performance of the multi-input multi-output (MIMO) relay system. In this study, a MIMO one-way two-hop amplify-and-forward (AF) relay communication system is presented by means of triple Khatri–Rao space-time-frequency (KRSTF) coding, which forms a five-dimensional tensor at the destination node that satisfies a new multi-dimensional tensor decomposition approach called asymmetric nested PARAFAC decomposition (ANPD). Then based on this model, a semi-blind receiver is derived to perform the joint channel and symbol estimation in terms of three-step alternating least squares (ALS) algorithm. Compared with the existing two-hop symmetry methods, the proposed scheme uses an asymmetric nested model to obtain additional frequency coding diversity, which significantly improves the performance of the system in parameter estimation accuracy as demonstrated by simulation results. © 2020, Pleiades Publishing, Ltd.