针对无线OFDM多播系统,该文提出一种基于子载波合并的多播资源调度算法。该算法通过提前将子载波分组,避免了不必要的子载波配对;自适应地选择子载波合并/非合并,在分集和复用两种模式中选取最优方案;同时根据子载波功率分配的特点,将其解耦为配对子载波集合内功率分配和集合间功率分配两个子问题,进一步优化了算法性能。仿真结果表明,与现有方案相比,所提方案能够在复杂度较低的情况下,较好地提升系统性能。
This paper presents a novel subcarrier combining based multicast resource scheduling algorithm for wireless OFDM multicast systems. By dividing subcarriers into different groups in advance, the algorithm avoids invalid subcarrier pairing, and adaptively chooses the optimal scheme between subcarrier diversity and subcarrier multiplexing by deciding whether to combine subcarriers or not. Moreover, according to the characteristic of subcarrier power allocation, this scheme decouples the problem into two sub-problems of intra-subcarrier-pairing power allocation and inter-subcarrier-pairing power allocation, which further improves the performance of the system. Simulation results show that the proposed scheme properly improves the system performance with lower complexity compared with the existing schemes.