HARQ Signalling Design for Dynamic TDD System

In order to satisfy the increasing traffic requirement, dynamic Time Division Duplexing (TDD) Downlink/Uplink (DL/UL) time configuration is introduced to provide a more flexible service and improve the system performance. In a dynamic TDD system, the DL/UL time configuration can be changed based on the traffic load. Since Hybrid Automatic Repeat Request (HARQ) timing may become misaligned in dynamic TDD system, HARQ timing and feedback signalling design need to be considered for dynamic TDD system. In this paper, HARQ timing issue in LTE system is investigated and novel HARQ feedback signalling design schemes for dynamic TDD system are proposed. Performance evaluation and numerical analysis are provided to show the effectiveness of the proposed schemes. By using the proposed schemes, the feedback signalling overhead can be reduced and spectrum efficiency can be improved.