LTE-A飞蜂窝系统干扰协调智能优化算法

在同频组网的LTE-A飞蜂窝系统中,飞蜂窝基站的密集部署会造成较为严重的同频干扰,导致网络吞吐量和用户的服务质量(Quality of Service,QoS)降低。部分频率复用(Fractional Frequency Reuse,FFR)作为常用的干扰协调方案,可以有效地提高边缘用户的服务质量。在FFR方案的基础上,通过结合遗传算法和基于模拟退火的图着色算法,提出了一种智能优化部分频率复用(Intelligence-FFR,I-FFR)算法。该算法能够动态地调整中心区域所占比例和边缘区域的频率复用因子,以增加宏小区吞吐量,降低小区边缘区域用户的中断概率。仿真结果表明,与FFR-3干扰协调算法相比,提出的I-FFR算法可使宏小区吞吐量提升15%,同时边缘区域平均用户的中断概率从85%降低到40%。

Intelligent Optimization Algorithm for Interference Coordination in LTE-A Femtocell System

In LTE-A femtocell systems,the dense deployment of femtocells may cause strong inter-cell interference(ICI),resulting in the degradation of cell throughput and quality of service(QoS) received by femto user equipments(FUEs).Fractional frequency reuse(FFR) has been widely recognized as an efficient solution to this problem.We proposed an intelligent fractional frequency reuse(I-FFR) algorithm for interference coordination in two-tier LTE-A femtocell systems.In pursuit of high system throughput and low user outage probability,the proposed I-FFR algorithm utilizes a genetic algorithm and a graph-annealing algorithm to achieve adaptive FFR by optimizing proportion of the cell center region(CCR) and clustering of the cell edge region(CER).Simulation results show that,compared to the conventional FFR-3 interference coordination scheme,the proposed I-FFR algorithm improves the system throughput by over 15%,and decreases the outage probability of average CER user from 85% to 40%.