基于有限反馈的协作多播高效资源分配策略

摘要

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.%提出了协作多播网络中基于有限反馈的联合子载波和功率分配策略,在满足QoS需求的条件下使功率消耗最小化.该策略首先利用有限的反馈信息在等速率分配下将子载波分给不同的多播组,并提出“公平子载波分配”策略,达到了功率消耗和公平性的折中.然后利用提出的“协作功率迭代”策略完成有效的功率分配,该策略利用注水定理确定每个子载波的目标速率后,又通过一个功率迭代过程实现功率最佳化.仿真结果显示,新的协作策略大大降低了上行反馈开销,且所需功率和多播业务中断概率远远小于直传策略.此外,协作功率迭代策略由于有较低的计算复杂度,因此更适合于实际系统.