Relay backhaul subframe allocation in LTE-Advanced for TDD

Relay is a key technology in LTE-Advanced (LTE-A) for both FDD and TDD. A major aspect of relay technology is the backhaul subframe allocation. In this paper, we discuss backhaul subframe allocation for TDD-LTE and analyze all seven downlink-uplink configurations for completeness. The discussion is put in context of latest development in 3GPP physical layer and centered on specifications impact and various design constraints. With the subframe allocation as an example, the article provides insights from wireless industry point of view on how to design TDD-LTE relay system to balance the backward compatibility, the operation cost/complexity and technology advancement.