Power control based time-domain inter-cell interference coordination scheme in DSCNs

Due to the dense deployment of low-cost small base stations (SBSs), the serious interference among small cells has become a great challenge, which will decrease the system throughput significantly. Most of traditional time-domain inter-cell interference coordination (ICIC) schemes use almost blank subframes (ABS) to completely avoid the inter-cell interference. We observe that users can suffer a certain amount of interference as long as their quality of service (QoS) is satisfied. Therefore, we can improve the system throughput by reducing the transmission power instead of using ABS. Based on the above fact, we propose a power control based time-domain ICIC scheme in dense small cell networks (DSCNs) with the objective to maximize the downlink system throughput as well as guarantee users' QoS. In the proposed scheme, each SBS adopts an adaptive ABS ratio according to its traffic load condition. Then, a Q-learning based algorithm is proposed to get the optimal transmission power of the ABS subframes. Simulation results demonstrate the significant advantages of the proposed scheme over the baseline schemes in the existing literature, in terms of downlink system throughput in DSCNs.