Tensor-based channel estimation for non-regenerative two-way relaying networks with multiple relays

In this paper we investigate a two-way relaying network with multiple amplify-and-forward relays where both the user terminals (UTs) and the relays can have multiple antennas. To improve the system performance, the UTs need channel knowledge of all relevant channels. Therefore, we propose block component decomposition based channel estimation (BloCE) algorithms, which use the Tucker decomposition and the CANDECOMP/PARAFAC (CP) decomposition. The proposed methods are analytic, i.e., iterations are not required. We also derive the design criteria for the corresponding relay amplification matrices and the training sequences. Simulation results demonstrate the accuracy of the proposed channel estimation method.