Performance comparison between Single-User MIMO and Multi-User MIMO in wireless mesh networks

In this paper, we propose applying to MU-MIMO (Multi-User Multiple-Input Multiple-Output) to wireless mesh networks. If the number of packets which have the same receiving node are not enough, SU-MIMO (Single-User MIMO) cannot take an advantage of the capacity enhancement by the spatial multiplexing. By contrast, MU-MIMO is expected to enlarge the efficiency because it can simultaneously transmit packets to multiple receiving nodes. The hidden node problem is, however, an important problem in wireless mesh networks and causes the performance degradation. In this study, the performances of SU-MIMO and MU-MIMO in wireless mesh networks are analyzed and compared. From results, MU-MIMO is much superior to SU-MIMO if the ratio of the queue size to the number of neighbor nodes is not large. It is also shown that the influence of collisions is the same between MU-MIMO and SU-MIMO.