A Novel Tensor-Based Receiver for Joint Symbol and Channel Estimation in Two-Hop Cooperative MIMO Relay Systems

In this letter, we develop a novel tensor-based receiver for two-hop cooperative multiple-input multiple-output (MIMO) relay systems. At the source node, the proposed transmit signal design combines the linear constellation precoding with time-domain spreading. We show that the received signal at the destination node is formulated as a fourth-order tensor satisfying a nested parallel factor (PARAFAC) model, and then a new tensor-based receiver is derived by resorting to the proposed receiver algorithm. Under the assumption that channel state information (CSI) is not available at each node, the proposed receiver jointly estimates the channel parameters and transmitted symbols. Numerical results show that the proposed receiver outperforms some competing tensor-based receivers and operates close to the zero forcing (ZF) receiver with perfect CSI.