基于OFDM的认知无线电系统最优功率分配算法

Optimal power allocation algorithm in OFDM-based cognitive radio systems

在基于OFDM的认知无线电系统中,授权用户会受到认知用户带内子载波带外旁瓣泄漏功率的干扰。这里引入了功率控制参数来调整授权用户的干扰功率约束值,提出了一种认知用户子载波间的最优功率分配算法,通过求解一个凸优化问题来获得最优的功率分配方案。仿真结果表明:与其他算法相比,采用该方法获得的功率分配方案,在满足授权用户干扰功率约束值的条件下,可以使认知用户的信道容量最大化。

In cognitive radio systems based on orthogonal frequency division multiplexing techniques,the license users suffer from the interference brought by power leaking out with the out-of-band subcarriers′ side-lobes from the in-band subcarrier of cognitive user.This paper introduces power control parameter to adjust the interference power constraint threshold of license user.To get an optimal power allocation scheme,an algorithm is proposed to find out the optimal power allocation scheme for the sub-carriers of cognitive user by means of solving a convex optimization problem.Simulation results show that the proposed power allocation scheme can maximize the capacity of cognitive user under the interference power constraint of license user.