摘要: |
针对多入多出正交频分复用(MIMO-OFDM)系统的下行链路,提出一种基于信道状
态信息(CSI)反馈的次优子载波分配算法。算法从寻求容量和公平性之间的平衡出
发,将提高系统容量作为资源分配的优化目标。该算法首先按照比例公平约束进行子载波初
始分配,然后将现行分配给任意两个用户的子载波互换之后计算系统容量,如果系统容量增
加,则将子载波在用户间进行交换,否则保持初始分配不变。将子载波在用户间进行迭代调
整,直到系统总容量不再增加为止。仿真结果表明,该算法能够很好地保证比例公平约束,
有效地提高系统容量,提升效率可以达到贪婪算法的40%左右,对MIMO-OFDM系统中的子
载波分配具有一定的参考价值。 |
关键词: 多入多出 正交频分复用 子载波分配 状态信息反馈 比例公
平 |
DOI: |
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基金项目: |
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An improved sub-carriers allocation algorithm with low complexity for MIMO-OFDM downlink |
WEI Fang-xu,HU Xiao-peng |
() |
Abstract: |
A suboptimal sub-carriers allocation algorithm based on channel state
information (CSI) for the downlink of Multiple Input Multiple Output-Orthogonal
Frequency Division Multiplexing (MIMO-OFDM) system is proposed in this paper. Th
e tradeoff between fairness and capacity is considered and the purpose of the al
gorithm is to maximize the capacity of the system. The algorithm firstly impleme
nts initial allocation according to the proportional fairness constraint, and th
en calculates the variety of the system capacity if the sub-carriers allocated t
o any pair of the users are swapped.〖JP2〗If the system capacity is increased,
the su
b-carriers are swapped, or the initial allocation is kept. The sub-carriers amon
g users are iteratively swapped until the system capacity couldn′t be improv
ed. Simulation result shows that the proposed algorithm can improve sys
tem capacity effectively with proportional fairness among users and the capacity
increment can reach about 40% of the greedy algorithm. The conclusion has refer
ence value for the sub-carriers allocation in the MIMO-OFDM systems. |
Key words: MIMO OFDM sub-carrier allocation CSI feedback proportional fairness |