Partial Interference Cancellation in Heterogeneous LTE-Advanced Networks

Abstract:
In LTE networks, picocells are deployed to take over load from macrocells in areas of high user density or weak coverage. Their support comes at the cost of severe intercell interference if single frequency reuse is implemented. In this paper, a cooperative interference mitigation scheme is presented that combines the theoretical work on rate splitting of Han and Kobayashi with the transmission of MIMO-layers as it is defined in LTE. Two users from different cells form a cooperating pair. A cell-edge user detects a part of the interference such that the effective interference is decreased. Thus, it can be served at a higher data rate. This work focuses on an asymmetric scenario in which a cell-edge user and a cell-center user of neighboring cells form a cooperating pair. Simulations show that the cell-edge user can significantly improve its spectral efficiency compared to treating the whole interference as noise with only small losses for the cell-center user. The proposed scheme uses the tools available in LTE and adds only little overhead for the cooperation.