基于干扰效率的认知OFDMA网络功率分配算法

Interference efficiency-based power allocation for cognitive OFDMA networks

为了提高认知无线电网络的系统能量效率,同时减小对频谱授权者主用户的干扰,提出了一种新的下行传输干扰效率最大的认知正交频分多址接入(orthogonal frequency division multiplexing access, OFDMA)网络功率分配算法。干扰效率定义为次用户总的传输速率与对主用户总干扰功率的比值。由于原资源分配问题是一个非凸形式的分式规划问题,难以获得功率分配问题的解析解。利用Dinkelbach方法将原问题转换为一个凸优化问题,并利用拉格朗日对偶原理和次梯度更新算法来获得解析解。最后,仿真结果表明,该算法具有较好的收敛性能,并且在干扰效率、对主用户的干扰控制方面都优于传统能效最大的功率分配算法。

In order to improve the energy efficiency of cognitive radio networks and reduce the total interference to the primary users,this paper proposed a new interference efficiency-based maximization power allocation algorithm for downlink cognitive orthogonal frequency division multiplexing access(OFDMA)networks.Interference efficiency is defined as the total rate of secondary users over the total interference to the primary users.Since the original problem is a non-convex fractional programming problem,it is difficult to obtain the analytical solution for power allocation.Based on the Dinkelbach method,the original problem is firstly converted into a convex optimization problem.Then it is solved by using Lagrange dual methods and the subgradient updating methods.Lastly,simulation results show that the proposed algorithm has good convergence,and it outperforms the traditional energy efficiency maximization-based power allocation algorithm in terms of interference efficiency and the protection for primary users.