Novel method to determine control channel location in LTE-advanced heterogeneous network

Cross subframe scheduling is introduced to improve spectrum efficiency in co-channel heterogeneous network (Het-Net) scenarios. In practical protocol development, the design of control channel signaling, for instance, how to determine the subframe carrying control channel, plays an important role for efficient resource usage. This paper proposes a novel method to determine the subframe carrying the downlink Hybrid Automatic Repeat-request (HARQ) feedback channel in HetNets. In the proposed method, we use a threshold-based iterative algorithm and distribute the HARQ information to all available downlink subframes to reduce the blocking probability. Simulation results show that the proposed method has a large advantage, e.g., more than 50 percent improvement in some cases, from the viewpoints of the Physical Hybrid-ARQ Indicator Channel (PHICH) blocking probability and control channel performance.