多播OFDM系统中比例公平资源分配

Proportional Fairness Resource Allocation in Multicast OFDM Systems

提出了一种多播正交频分复用(OFDM)系统中的比例公平资源分配算法,该算法包括:子载波分配算法和功率分配算法.前者通过修正已有的单播子载波分配算法而得到,后者采用双重二分法迭代分配功率,属于子载波分配给定条件下的最优多播功率分配.仿真结果表明,提出的资源分配算法在保证容量性能的同时能够获得完美的公平性;即使在比例公平的约束下多播仍然比单播获得明显的容量增加,但容量增益的多少与速率比例以及多播组数目直接相关.

A proportional fairness resource allocation algorithm, including both subcarrier assignment and power allocation, is proposed in multicast orthogonal frequency division multiplexing （OFDM） systems. The former is achieved by modifying the existing unicast subcarrier assignment algorithm, whereas the latter is implemented as allocating power via dual-bisection iteration, which is capable of obtaining the optimal allocation results when subcarrier assignment is determined. Simulation results demonstrate that the proposed resource allocation algorithm can achieve perfect fairness among users while maintaining the efficient capacity performance. It is also shown that multicast results have remarkable capacity enhancement comparing to unicast despite proportional fairness constraint. However, the capacity gain has a close relation with rate proportion and the number of multicast group.