Time Slot Allocation Based on Region and Time Partitioning for Dynamic TDD-OFDM Systems

TDD mode is considered as a key solution to cope with the asymmetric traffic services. With the TDD mode, however, the inter-BS/inter-MS interference becomes serious in the cross time slot (CTS) region and this interference seriously degrades the system performance. In this paper, we propose a region and time partitioning dynamic TDD (RTP D-TDD) for OFDM systems. To mitigate the inter-BS/inter-MS interference in the CTS region, a cell is divided into several regions and each time slot in the CTS region is split into minislots by the number of regions in the cell. Each minislot is assigned to the users in its corresponding region. We also propose a time slot allocation based on region and time partitioning (TRTP) under the proposed RTP D-TDD system. In the TRTP, the influence of the CCI in the CTS region is further reduced by assigning the minislots closer to the switching point to the users having higher link gains. By the computer simulation, it has been verified that the proposed TRTP outperforms previous time slot allocation schemes in both the outage probability and the bandwidth efficiency.