Uplink Interference Management in Massive MIMO Enabled Heterogeneous Cellular Networks

Considering the fact that massive multiple input multiple output (MIMO) macrocells and large number of small cells are deployed in the heterogeneous cellular networks for 5G, more users will be supported for uplink transmissions, which in turn brings more severe uplink interference. As a result, interference management is crucial for enhancing the uplink performance in these networks. In this letter, we exploit uplink power control and cell range expansion for interference coordination. Our results show that the uplink performance in the massive MIMO macrocells can be significantly improved through uplink power control in the small cells, while more uplink transmissions in the macrocells have mild adverse effect on the uplink performance of the small cells. In addition, the uplink performance of the massive MIMO macrocells can be improved by expanding the small cell range when more users are served in the macrocells.