Semi-Blind Channel Estimation and Data-Multiplexing for Massive MIMO Network

In this paper, we analyze the performance of massive MIMO network with two-antenna users. We show that increasing the number of antennas at the user side is possible without increasing the channel estimation overhead linearly with the number of extra antennas. We propose a simple data-aided channel estimation method for the extra antenna. The proposed method exploits the asymptotic orthogonality of the channel vectors in very large MIMO system and takes advantage of the pilot-aided channel estimation performed for the first antenna. The extra antenna is used for data multiplexing and therefore increases the user throughput. We obtain achievable rates when matched filtering detection is used in uplink multi-cell MIMO system. The rate bounds are tight even at finite (not very large) number of antennas. The proposed algorithm is applicable for more than two antennas.