单频网多播系统中的开环半动态功率分配算法

摘要

In a wireless single frequency network(SFN) multicast system,the conventional dynamic power allocation(D-PA) algorithm depends on the instantaneous channel state information(CSI) of all users in each slot.The shortcoming of D-PA algorithm is that resource allocation frequency is too fast and the up-link feedback overhead is too much.In order to overcome the drawback,this paper investigates an Open-loop Semi-dynamic Power Allocation(OSD-PA) algorithm with low-complexity for SFN multicast system without any CSI.At first,by introducing the equivalent channel gain(ECG) of cell,under the assumption of equal power distribution for each base station(BS),the OSD-PA algorithm based on topology of SFN is proposed to tackle the issue.Secondly,the power algorithm with rate guarantees for each BS is proposed ac-cording the ECG.Simulation results show that OSD-PA algorithm reduces the uplink feedback overhead and resource allocation frequency greatly compared with the D-PA algorithm at the expense of a small por-tion of performance.Therefore,the OSD-PA algorithm is efficient for practical SFN multicast system.%在单频网多播传输中,传统的全反馈动态功率分配数算法需要根据每个时隙反馈的用户瞬时信道信息进行实时的调整,所以造成了资源分配频率快、上行反馈开销大的缺点.为了克服这个缺点,提出了一个低复杂度、没有用户反馈的单频网多播开环半动态功率分配算法.首先在各小区等功率分配的假设下,根据单频网的形状信息算出各小区等价信道增益,然后再根据这个增益值,实现满足速率需求情况下的各小区功率分配.仿真结果显示,与全反馈的动态功率分配算法相比,该算法以一小部分性能损失为代价,大大减少了单频网的上行反馈和资源分配的开销,因此更适用于实际的单频网多播系统.