采用了一种新的增强干扰协调(eICIC)来管理ABS子帧,该eICIC综合利用时域、频域以及功率调节来提高系统资源利用率.特别地,考虑了一种Pico小区部署在Macro小区中心附近的2层非均匀异构网络,并且每个Pico小区的用户个数各不相同.为了减轻同频信道部署所带来的干扰,Macro小区使用LP-ABS,并将ABS时隙的资源块划分为2部分,一部分只给Macro小区使用,另一部分只给Pico小区使用.允许不同的Macro小区在LP-ABS时隙保留不同比率的频带资源以及不同的发送功率用于传输.综合考虑了用户连接、资源分配、ABS比率、频域划分参数以及Macro小区在LP-ABS时隙的发送功率,其目标为最大化系统比例公平效用,并且提出一种迭代算法求解.仿真结果表明,该算法相比于现有方案在提高系统吞吐量的同时还保证了用户的公平性.
A new enhanced inter-cell interference coordination (elCIC) is adopted for managing almost blank sub-frame (ABS),which jointly exploits the time, frequency and power dimensions to improve the resource utilization. In particular, a non-uniform two tier heterogeneous network ( HetNet) is considered, where the pico cells are located close to the macro cell and the number of users in each pico cell is different. To alleviate the interference caused by the co-channeldeployment,the macro cells employ low power ABS (LP- ABS), and the resource blocks (RBs) are divided into twoparts during an ABS. One is exclusively reserved for macro cell users ad the other is reserved for pico cell users. Themacro cells are allowed to use different percentages of RBs and different powers for their own transmission during the LP- ABS. The user association,resource allocation,ABS proportion,the frequency band partition parameter and the transmission power of macro cells are considered, aiming at maximizing the proportional fairness utility of the system. An iterative algorithm is also proposed and simulation results demonstrate that the proposed algorithm can improve both the system throughput and user fairness compared with the existing schemes.