Novel Method to Improve Control Channel Reliability in LTE-Advanced Heterogeneous Network

Heterogeneous network (HetNet) is considered to be a promising approach to improve spectrum efficiency per area in a Long Term Evolution-Advanced (LTE-A) system and beyond, which allows multiple cells to provide service in an overlaid area. To guarantee stability of the HetNet, one challenge is how to handle inter-cell interference between different cells especially for a control channel that does not support link adaptation or retransmission. In this paper, a novel method is proposed that improves performance of downlink Hybrid Automatic Repeat-request (HARQ) feedback channel in HetNet. In the proposed method, legacy control channel transmission is shifted to another subframe with a lower interference level. Simulation results demonstrate that the downlink HARQ feedback channel performance can be significantly improved in both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) systems.