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 LTE-Advanced. 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 UEs 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 victim UEs protected by ABS for any given amount of ABS via dynamic programming, and then find the optimal amount of ABS by evaluating the overall system utility. 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 network-wide fairness.