Journal of South China University of Technology (Natural Science Edition) ›› 2011, Vol. 39 ›› Issue (5): 18-23.doi: 10.3969/j.issn.1000-565X.2011.05.004

• Electronics, Communication & Automation Technology • Previous Articles     Next Articles

Optimal Power Allocation Algorithm for Cognitive Radio Networks

Zhang Guo-bin  Feng Sui-li  Ke Feng   

  1. School of Electronic and Information Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China
  • Received:2010-09-15 Revised:2011-01-05 Online:2011-05-25 Published:2011-04-01
  • Contact: 张国斌(1980-)，女，博士生，主要从事宽带无线通信系统的信号处理与应用研究 E-mail:zhang.gb@mail.scut.edu.cn
  • About author:张国斌(1980-)，女，博士生，主要从事宽带无线通信系统的信号处理与应用研究
  • Supported by:

    国家自然科学基金资助项目(61001113)；华南理工大学中央高校基本科研业务费资助项目(2009ZM0071)；粤港关键领域重点突破项目(20060104-2）

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Abstract:

In order to satisfy the limitation of interference temperature and total transmission power and to maximizeusers' transmission rate,an optimal power allocation algorithm adaptive to uplink cognitive radio OFDM ( OrthogonalFrequency Division Multiplexing) system is proposed. In this algorithm,first,the zero-setting iterative waterfillingalgorithm under the constraints of total power of the cognitive user is applied to the power allocation. Then,the subcarrier power exceeding the interference power limit is set as the new interference power limit. Finally,theresidual power is allocated to the residual subcarriers by the iterative water-filling algorithm until the optimal powerallocation is achieved. Both the mathematical derivation and the simulation results prove that its proposed algorithmis optimal,and that its computation amount reduces by over 50%,as compared with the gradient method even atthe highest iterative times.

Key words: cognitive radio, power allocation, interference temperature, water-filling algorithm