摘要
分析多播OFDM系统中的资源分配问题,最优的功率子载波分配是NP-hard问题,为此提出三种次优分配算法:算法1对单播情况下的分配方案进行扩展,在初始分配后进行子载波调整,复杂度较高;算法2在等功率的假定条件下进行子载波分配,复杂度最低;算法3首先利用算法2进行子载波分配,然后通过注水进行功率分配,以提高系统性能.分析和仿真证明,所提算法是有效的,且其复杂度低,特别是算法2和算法3,非常适合于实际系统实现.
QoS-guaranteed resource allocation for multicast OFDM systems was studied. The optimal resource allocation is NP-hard, thus three suboptimal algorithms were proposed to solve the problem effectively. The first algorithm performed subcarrier adjusting after the initial allocation, which was extended from the unicast scene. The second algorithm allocated the subcarrier under the assumption that power was loaded equally on each subcarrier and its complexity is the lowest. The third algorithm did the same as the second one in subcarrier allocation and performed water-filling based power loading to further improve system performance. Analysis and simulations were conducted and the results demonstrate the effectiveness of the proposed algorithms and that their low computational complexity, especially for the second and third algorithms, makes them very suitable for implementation in practical systems.
基金
国家重点基础研究发展(973)计划(2007CB310602)资助
