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

Abstract

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.

Keywords

• OFDM;multicast;resource allocation;optimal power allocation