Abstract:

A joint subcarrier and power allocation scheme based on limited feedback for cooperative multicast network was proposed to minimize the consumed power under constrain of QoS requirement.The new scheme worked in two steps.Firstly,subcarriers were distributed to different multicast groups with equal rate assumption according to limited feedback information,where fair subcarrier allocation scheme was used to achieve a tradeoff between power and fairness.Then,a cooperative power iterative scheme was adopted to allocate power effectively,where target rate on each subcarrier was computed by water-filling algorithm in the first place and then a power iterate process was implemented to optimize power allocation.Simulation and comparison results show that the new scheme significantly reduces uplink feedback overhear and the required power and the multicast service outage of cooperative scheme is much less than those of the direct scheme.Besides,cooperative power iterative scheme has lower computational complexity and therefore is suitable for practical system.

Key words: multicast, cooperative diversity, resource allocation, limited feedback