Optimized Time-Domain Resource Partitioning for Enhanced Inter-Cell Interference Coordination in Heterogeneous Networks

Heterogeneous networks (HetNets) are expected to be one of the major performance enhancement enablers of LTEAdvanced. Due to significantly challenging interference scenarios, enhanced inter-cell interference coordination (eICIC) based on almost blank subframes (ABS) is the key technology enabler that makes HetNets a reality. The key factor determining the gain of ABS-based eICIC is the configured number of ABS which depends closely on the number of users requesting protection from ABS. In this paper, we study the optimal amount of ABS for synchronous ABS configuration by formulating this optimization as a network-wide utility maximization problem. We firstly propose a distributed method to determine the number of users protected by ABS for any given amount of ABS via dynamic programming, and then find the optimal amount of ABS by evaluating the utility value of each possible amount of ABS. A remarkable feature of the proposed solution is that only limited information exchange via backhaul is required and the optimal amount of ABS could be individually derived at each eNB. Extensive simulations demonstrate that our solution can not only improve the overall system throughput significantly but also provide better user fairness.