System Level Performance Evaluation of Dynamic TDD and Interference Coordination in Enhanced Local Area Architecture

The Third Generation Partnership Project (3GPP) has been studying dynamic allocation of sub-frames to uplink or downlink in Time Division Duplex (TDD), since the Long Term Evolution (LTE) Rel. 11 timeframe. At the same time, 3GPP is also standardizing Enhanced Local Area (eLA) small-cell heterogeneous architectures for inclusion in 3GPP Rel. 12 as a solution offering high data rate to user terminals (UEs) along with high spatial reuse of spectrum. In this paper, we focus on a particular eLA architecture proposed by DOCOMO, called the Phantom Cell architecture, that has the option to support dynamic TDD. We evaluate the system performance of dynamic TDD in phantom cells and the corresponding inter-cell interference issues. Then we propose a frequency domain interference coordination technique for dynamic TDD in phantom cells. The superior performance of the proposed scheme over conventional frequency reuse technique and no interference coordination scenario is verified by system level simulations.