Multi-carrier ICI coordination in heterogeneous networks based on Han-Kobayashi coding

With rapid growing of wireless data service, heterogeneous network (HetNet) has evolved as an spectrum and energy efficient cellular network architecture. However, the inter-cell interference (ICI) between the macro-cell and small cells is complicated. Due to the transmit power difference between various nodes and the randomness of user locations, the network may work in strong, mixed or weak interference scenarios. To eliminate the severe impact of ICI in HetNet, we propose a Han-Kobayashi (H-K) coding based coordination scheme to address different interference scenarios systematically. For a pair of macro-user and pico-user, each subcarrier may work in different interference scenario due to the frequency-selective fading. With the known achievable rates of H-K coding, we study an optimized power allocation method to coordinate the transmit powers of two users on each subcarrier. The throughput optimization problem of multi-carrier interference network is generally non-convex, we propose an iterative convex approximation (ICA) method to maximize a concave lower bound of the throughput and iteratively approach its optimum. Simulation results show the superiority of the proposed optimization method, and demonstrate that the proposed ICI coordination scheme can provide substantial throughput gain over the orthogonal transmission schemes.