Cross-tier interference mitigation considering pilot overhead for TDD MIMO heterogeneous networks

Abstract

In a two-tier heterogeneous network, cross-tier interference mitigation between macro-cell (MC) and small-cell (SC) is an important issue, where MC and SC share the same time/frequency resources. In this article, we propose a method to mitigate downlink cross-tier interference between MC and SC, where macro-cell base-station (MBS) and small-cell base-stations have multiple antenna arrays and their precoding weights are optimized to mitigate mutual cross-tier interference under a given pilot overhead. Simulation results show that the proposed scheme improves the downlink sum-rate compared with conventional scheme that coordinates cross-tier interference from MBS to small-cell users under the same pilot overhead condition.