A Study on Layouts of Distributed Antenna Arrays in an Indoor Multi-User Massive MIMO System

For the 5th Generation mobile communication system, a multi-user Multiple-Input Multiple-Output (MIMO) system has been extensively studied in recent years. However, it may be difficult to arrange antenna elements at one place because a very large number of antenna elements are used in a recent massive MIMO system. On the other hand, distributed antenna systems, where a base station antenna array is divided into several subarrays and they are distributedly located, have attracted attention. In this paper, we consider indoor environments and evaluate the sum capacity characteristics for different numbers of subarrays and different layouts of the subarrays. We also evaluate the difference in sum capacity when changing an antenna height, element arrangement of subarrays, and a distance between the elements. As a result, we can say that we need to choose adequately parameters of the layout of subarray, height of subarray, element arrangement of subarray, and element space of subarray.