Publication date: December 2017
Source:Physical Communication, Volume 25, Part 2
Author(s): Liang Han, Weixia Zou
As one of the most promising candidate technique for the fifth generation (5G) wireless network, massive multiple-input multiple-output (MIMO) has attracted much research interests. However, due to the high path loss and severe shadowing, the cell-edge users may have very poor performance in uplink massive MIMO systems. To overcome this problem, we investigate relay-assisted uplink massive MIMO systems, where single-antenna users communicate with an -antenna base station (BS) through an -antenna relay and is very large. We use amplify-and-forward (AF) relaying schemes which simply forward scaled versions of its received signals. Assuming the BS can obtain perfect channel state information (CSI) of all the user–relay links and relay–BS links, zero-forcing (ZF) receiver is adopted at the BS. Based on these assumptions, we derive the closed-form expressions for the ergodic achievable rate and outage probability. Numerical and simulation results validate our analysis and show that the relay-assisted massive MIMO systems achieve better performance than direct transmission massive MIMO systems when the links from the users to the BS are weak.
Source:Physical Communication, Volume 25, Part 2
Author(s): Liang Han, Weixia Zou