OFDMA毫微微小区双层网络中基于分组的资源分配

摘要

Femtocell is a promising technology to enhance indoor coverage and system capacity. However, the co-tier and cross-tier interference impair greatly the network performance for spectrum-sharing OFDMA femtocell networks. To mitigate the co-tier/cross-tier interference, a cluster-based resource allocation algorithm is proposed. The proposed algorithm consists of two parts: In the first part, an improved Hungarian algorithm is first adopted to assign sub-channels to the Macro Users Equipments (MUEs). Then the averagely assigned power is reallocated in linear water-filling fashion in order to ensure the transmission of MUEs. In the other part, Simulated Annealing algorithm is first used to cluster femtocells into disjoint groups. Then under the condition of avoiding causing interference to MUEs, femtocells perform sub-channel and power allocation according to the rate requirements of Femtocell User Equipments (FUEs) to maximize spectrum efficiency. Simulation results show that the proposed algorithm not only guarantees the data rate requirements of users, but also improves the spectrum efficiency.%毫微微小区(Femtocell)网络能够增强室内覆盖，提高系统容量，但是在频谱共享的正交频分多址(OFDMA)毫微微小区网络中，毫微微小区之间的同层干扰以及毫微微小区与宏小区(Macrocell)之间的跨层干扰严重限制了系统的性能。针对这两种干扰，该文提出一种基于分组的资源分配算法。该算法包括两部分：一部分是宏基站先利用改进的匈牙利算法为宏小区用户分配信道，再用注水算法分配功率，保证宏小区用户的正常传输；另一部分是在避免干扰宏小区用户的基础上，先采用模拟退火算法对毫微微小区进行分组，再进行信道和功率分配，满足毫微微小区用户的数据速率需求，最大化频谱效率。仿真结果表明，该算法有效地抑制了这两种干扰，既能保证用户的数据速率需求，又能有效提升网络频谱效率。