Efficient Channel Estimation for Multi-user MIMO Multi-relay Communication Systems

In this paper, we propose a tensor-based channel estimation method for multi-user multiple input multiple output (MIMO) multi-relay communication systems. Firstly, the proposed method designs each user’s pilot signal and each relay’s coding matrix. Then, we construct the received signal into a tensor model at the receiving end. Finally, the Vector Approximate Message Passing (VAMP) algorithm is developed to fit the resulting tensor model. At the base station (BS), the proposed method can estimate the channels of each user to each relay and the channels of each relay to the BS. Compared with the existing methods, the proposed method does not need to estimate the channel in any relay, and has better channel estimation performance. Simulation analysis shows the effectiveness of the proposed method.