Joint Channel Estimation Techniques for Muti-User Massive MIMO Relay Networks

Due to their excellent performance, massive MIMO rely techniques has become more and more popular. In this paper, we develop a joint channel estimation method for a massive MIMO relay system consisting of multi-user and one relay. Firstly, the proposed method transmits interactive orthogonal channel training sequences at each user end. Then the relay amplifies received signals, and forwards the amplified signals to all users. Finally, the Tucker-2 tensor model is constructed at each user end, and the constructed Tucker-2 model is fitted to estimate all the channel matrices. The proposed method has higher channel estimation accuracy. In addition, the analytical expression of the CRB is derived for reference. Simulation results demonstrate the effectiveness of the proposed joint channel estimation method.