Design of decentralized inter-cell interference coordination scheme in LTE downlink system

Inter-cell interference coordination (ICIC) has become a critical issue in LTE/LTE-A communication system toward efficient radio resource utilization. The basic concept of ICIC is the negotiation of spectrum usage among base stations to prevent interference in cell edge so as to maximize the transmission throughput. In order to achieve effective ICIC, several researches proposed the decision algorithms in centralized manner. However, it is not easy to be implemented in current LTE infrastructure due to the architecture overhead and decision timing constraint. In this paper, we propose a decentralized ICIC algorithms, named relative throughput based resource block coordination (RTRBC) and RTRBC with residual RB (RTRBC_r), to deal with the coordination among eNBs within the existing LTE framework. Through the negotiation for the relative gain and loss in heuristic manner, the proposed scheme negotiates the RB usage between adjacent eNBs to achieve higher throughput. The simulation results show that the proposed scheme performs better than the fractional frequency reuse (FFR) scheme. Additionally, the results indicate that, comparing to the RTRBC scheme, the RTRBC_r scheme can further coordinate the interfered RBs effectively especially when the loads of adjacent cells are unbalanced.