Distributed joint subcarrier and discrete power allocation for cognitive radio ad hoc networks
Distributed joint subcarrier and discrete power allocation for cognitive radio ad hoc networks
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DOI：
10.1007/s11235-015-0103-9
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发表时间：
2015-11
影响因子：
2.5
通讯作者：
Fei Wang;Songtao Guo;Yawei Shi;X. Liao
中科院分区：
文献类型：
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作者：
Fei Wang;Songtao Guo;Yawei Shi;X. Liao
正交频分多址（OFDMA）认知无线电（CR）自组织网络的关键问题之一是以分布式方式有效公平地分配子载波和功率。然而，两个可怕的缺点存在于大多数以前的作品。一个是公平性问题没有被充分考虑，使得可能无法保证次级用户（SU）之间的不同类型的公平性。另一种是假设每个SU的发射功率取连续域中的任意值，而对于实际的CR ad hoc网络，功率水平只能量化为离散值。为了克服上述缺点，首先提出了一种优化框架，其中考虑了不同类型的资源分配的公平性，并且每个SU的传输功率仅允许取有限个离散值。特别是，通过将每个SU与每个子载波的效用函数相关联来保证资源分配的公平性，其中效用函数允许是非凹的或不可微的，使得我们的框架可以处理实时应用的资源分配。此外，为了解决所提出的非凸整数优化问题，提出了一种低复杂度的分布式算法，根据该算法，仅需要网络实体之间的有限合作。仿真结果表明，该算法具有很好的收敛性和公平性，可应用于实际的基于OFDMA的CR ad hoc网络。
One of the key problems in orthogonal frequency division multiple-access (OFDMA) cognitive radio (CR) ad hoc networks is to efficiently and fairly allocate subcarriers and powers in a distributed manner. However, two formidable shortcomings exist in most previous works. One is that the fairness issue has not been sufficiently taken into account so that different types of fairness among secondary users (SUs) may not be guaranteed. The other is that the transmission power of each SU is assumed to take any value in a continuous domain, whereas for practical CR ad hoc networks, the power level can only be quantized into discrete values. To overcome the above shortcomings, an optimization framework is first presented, where different types of fairness for resource allocation are considered and the transmission power of each SU is allowed to take only a finite number of discrete values. In particular, the fairness of resource allocation is guaranteed by associating each SU with a utility function for each subcarrier, where the utility function is allowed to be non-concave or non-differentiable so that our framework can deal with resource allocation for real-time applications. Furthermore, to solve the proposed non-convex integer optimization problem, a distributed algorithm with low complexity is proposed, according to which only limited cooperation among network entities is required. At last, simulation results verify that our algorithm has very good convergence and fairness performance, and then it may be applied to practical OFDMA-based CR ad hoc networks.