OFDM系统中考虑信源编码特性的多播资源分配方案

Multicast resource allocation scheme considering source-coding characteristic in OFDM systems

针对OFDM系统单播以及传统多播没有充分发挥无线传播开放性优势的问题,提出了多个多播组保证组间比例公平的资源分配方案。该方案由子载波分配算法及功率分配算法构成,前者通过修正存在的单播子载波分配算法得到;后者基于理论推导的非线性方程组,得到了子载波分配给定条件下的最优功率分配。仿真结果显示,所提方案能够确保完美的多播组间公平性,且和速率容量性能明显优于传统多播方式。结合方案的低复杂度特性,它适合在实际无线系统的音/视频多播中进行应用。

Aiming to solve the problem that unicast or conventional multicast was incapable of make full use of the opening for wireless propagation in orthogonal frequency division multiplexing（OFDM） systems,a resource allocation scheme involving several multicast groups was proposed to maintain proportional fairness among groups.The proposed scheme consisted of subcarrier assignment algorithm and power allocation algorithm.The former was achieved by modi-fying the existing unicast subcarrier assignment algorithm,whilst optimal power allocation on condition that subcarrier assignment was determined was reached by the latter based on theoretically derived non-linear equations.Simulation re-sults show that the proposed scheme can ensure perfect fairness among different multicast groups,and remarkably out-performs conventional multicast in terms of rate-sum capacity.Combined with the low complexity,it is suitable for the application to voice/video multicast in actual wireless systems.