Interference alignment based hybrid cooperative transmission strategy with limited backhaul

Abstract

The performance of coordinated multi-point (CoMP) transmission system depends heavily on the quality of information exchange via backhaul links. However, the limited capacity of backhaul leads to quantisation error and delay of shared channel state information. In this study, the authors propose a novel hybrid CoMP transmission strategy to mitigate the impacts of the backhaul delay for data sharing and switch the transmission modes adaptively based on the current arrivals of the shared user data. Furthermore, they present analytical expressions for the average sum rate in an interference alignment network, in which the combining effects of quantisation from limited capacity and connection uncertainty introduced by finite delay are considered. With the analytical results, they evaluate the sum rate performance under limited backhaul for the conventional CoMP transmission modes and the proposed strategy. The simulation results demonstrate that the proposed strategy functions better on overcoming the impacts of capacity limited backhaul than the conventional ones.