Chunk-Based Resource Allocation in OFDMA Systems-Part II: Joint Chunk, Power and Bit Allocation
Chunk-Based Resource Allocation in OFDMA Systems-Part II: Joint Chunk, Power and Bit Allocation
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DOI：
10.1109/tcomm.2011.112811.110036
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发表时间：
2012-02-01
影响因子：
8.3
通讯作者：
Wang, Jiangzhou
中科院分区：
文献类型：
--
作者：
Zhu, Huiling;Wang, Jiangzhou
通过将多个相邻副载波分组为一个块，可以在正交频分多址(OFDMA)系统中逐个块地执行资源分配。在OFDMA系统中，基于块的资源分配是降低资源分配复杂度的有效方法。本文提出并分析了一种基于组块的资源分配方案，即联合组块、功率和比特分配方案，在总发射功率约束下最大化吞吐量。为了实现最优分配，引入了比例因子。考虑到每个副载波(比特/符号/副载波)的每符号比特的数字特性，提出了一种将理论上分配的比特/符号/副载波数字化为整数的数字化过程。引入了功率约束、用户数、相干带宽、子载波数和组块数等系统参数，研究了它们对平均吞吐量的影响。将动态功率分配方案与固定功率分配方案的性能进行了比较。数值结果表明，固定功率分配方案的理论吞吐量与动态功率分配方案的理论吞吐量非常接近。然而，当考虑比特/符号/副载波的数字特性时，动态功率分配的平均吞吐量优于固定功率分配方案。
By grouping a number of adjacent subcarriers into a chunk, resource allocation can be carried out chunk by chunk in orthogonal frequency division multiple access (OFDMA) systems. Chunk-based resource allocation is an effective approach to reduce the complexity of resource allocation in OFDMA systems. In this paper, a chunk-based resource allocation scheme, i.e. joint chunk, power and bit allocation, is proposed and analyzed by maximizing the throughput under a total transmit power constraint. A scaling factor is introduced to achieve optimal allocation. Considering the digital nature of bits per symbol per subcarrier (bits/symbol/subcarrier), a digitization process is proposed to digitize the theoretically allocated bits/symbol/subcarrier to integer. System parameters, such as the power constraint, number of users, coherence bandwidth, number of subcarriers and number of chunks, are introduced and their impacts on the average throughput are studied. The performance of the dynamic power allocation scheme is compared with the fixed power allocation scheme. The numerical results show that the theoretical throughput of the fixed power allocation scheme is quite close to that of the dynamic power allocation scheme. However, when the digital nature of bits/symbol/subcarrier is considered, the average throughput of the dynamic power allocation outperforms the fixed power allocation scheme.