Cell cluster-based dynamic TDD DL/UL reconfiguration in TD-LTE systems

In the previous TD-LTE systems, the semi-static TDD DL/UL configuration can not work effectively under the instantaneous varied DL/UL traffic. Dynamic TDD DL/UL reconfiguration was proposed and discussed as one of the key features in LTE-A to increase the radio resource utilization. However, the freely reconfiguration of each cell TDD DL/UL configuration may result in significant co-channel co-subframe DL-UL interference. In this paper, we propose and evaluate a novel cell clustering scheme for dynamic TDD DL/UL configuration with traffic adaptation in HTN networks where multiple outdoor pico cells and multiple macro cells are deployed on the same carrier frequency. Cells that suffer from serious co-channel co-subframe DL-UL interference are dynamically grouped into different clusters. In order to increase the UL/DL resource utilization with traffic adaptation for clusters, an optimal TDD UL/DL reconfiguration algorithm is proposed to balance the UL/DL buffer status and further increase the transmission performance. Finally, the system level simulation results are provided for the evaluation of our proposed algorithms with non-full buffer traffic under different traffic load levels.