Resource allocation for multiuser cognitive OFDM networks with proportional rate constraints
Resource allocation for multiuser cognitive OFDM networks with proportional rate constraints
复制标题
具有比例速率约束的多用户认知 OFDM 网络的资源分配
DOI：
10.1002/dac.1272
复制
发表时间：
2012-02-01
影响因子：
2.1
通讯作者：
Du, Sidan
中科院分区：
文献类型：
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作者：
Wang, Shaowei;Huang, Fangjiang;Du, Sidan
本文研究了基于多用户正交频分复用（OFDM）的认知无线电（CR）系统在比例速率约束下的资源分配问题。认知无线电系统中主用户（PU）和认知无线电用户（SU）之间的相互干扰使得认知无线电系统的优化问题变得更加复杂。此外，引入到PU的干扰必须保持在给定阈值之下。在本文中，每个OFDM子信道的最高可达速率计算通过联合考虑信道增益和干扰水平。首先，将子信道分配给具有最高可实现速率的SU。剩余的子信道总是被分配给遭受最大不公正性的SU。其次，一个有效的比特分配算法的开发，以最大限度地提高总容量，这是再次基于每个子信道的最高可达速率。最后，调整程序的设计，以保持比例公平。仿真结果表明，该算法在满足比例速率约束的情况下，最大化了总容量。该算法在总容量最大化和比例公平性之间取得了很好的折衷。此外，与其他算法相比，该算法具有较低的复杂度，使其具有良好的实际应用前景。版权所有（C）2011约翰威利父子有限公司
In this paper we study the resource allocation problem for the multiuser orthogonal frequency division multiplexing (OFDM)-based cognitive radio (CR) systems with proportional rate constraints. The mutual interference introduced by primary user (PU) and cognitive radio user (also referred to secondary user, SU) makes the optimization problem of CR systems more complex. Moreover, the interference introduced to PUs must be kept under a given threshold. In this paper, the highest achievable rate of each OFDM subchannel is calculated by jointly considering the channel gain and interference level. First, a subchannel is assigned to the SU with the highest achievable rate. The remaining subchannels are always allocated to the SU that suffers the severest unjustness. Second, an efficient bit allocation algorithm is developed to maximize the sum capacity, which is again based on the highest achievable rate of each subchannel. Finally, an adjustment procedure is designed to maintain proportional fairness. Simulation results show that the proposed algorithm maximizes the sum capacity while keeping the proportional rate constraints satisfied. The algorithm exhibits a good tradeoff between sum capacity maximization and proportional fairness. Furthermore, the proposed algorithm has lower complexity compared with other algorithms, rendering it promising for practical applications. Copyright (C) 2011 John Wiley & Sons, Ltd.