Dynamic TDD interference mitigation by using Soft Reconfiguration

Since uplink (UL) and downlink (DL) traffic loads are time-variant in femtocells, it is essential to adapt dynamic-TDD (D-TDD) to effectively adjust the UL and DL transmission resources. However, due to the cross-link interference of D-TDD, the benefits of dynamically adjusting the UL and DL resources are diminished. The currently used interference mitigation scheme, the clustering scheme, achieves interference mitigation but reduces the ability of DL and UL resource adaptation. In this research, we propose “Soft Reconfiguration” to reduce interference while allowing femtocells to dynamically adjust their UL and DL resources. In Soft Reconfiguration, the femtocells which highly interfere with each other will be categorized in the same interference group, but unlike the clustering scheme, the femtocells in the same group are allowed to choose different subframe configurations. In the simulation, we compared Soft Reconfiguration with two schemes, D-TDD without interference mitigation and the clustering scheme. The results show that the soft reconfiguration scheme outperforms the other two schemes in better throughput and effective resource utilization.