基于DF中继的认知OFDM协作系统的资源分配算法  

Resource allocation algorithm in DF relay assisted OFDM cognitive radio systems

作　　者：赵晓晖[1] 沙京祺 

机构地区：[1]吉林大学通信工程学院信息科学实验室,长春130012

出　　处：《吉林大学学报（工学版）》2014年第5期1481-1487,共7页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目(61171079)

摘　　要：针对多中继认知OFDM协作系统的中继和功率分配采用的拉格朗日对偶分解法虽然具有较好的性能,但计算复杂度较高这一问题,提出了一种低复杂度的资源分配算法。该算法放宽了中继选择因子的整数约束条件,综合考虑认知用户各子载波的信道条件和对主用户的干扰进行中继选择。根据系统总功率和干扰约束的特点,提出一种次优功率分配算法对功率进行分步求解,在保证系统容量有所增加的基础上降低了算法的计算复杂度。仿真结果表明:本文提出的算法不仅保证了认知用户对主用户产生的干扰在临界值以内,而且使认知用户的系统容量得到了较大的提升,具有一定的可行性。For resource allocation in multi-relay assisted OFDM radio systems, most current relay and power allocation algorithms use Lagrangian dual decomposition technique to find the optimal solutions. This approach has good performance but the computational complexity is higher. To solve this problem, a resource allocation algorithm with low computational complexity is proposed. The proposed algorithm relaxes the integrality constraint on the relay selection factor. It takes both subcarriers channel conditions and the interference to the primary users introduced by the secondary users into account in the relay selection. A sub-optimal power allocation scheme is given on the basis of the properties of the total system power and interference constraints, in which the power allocation is conducted step by step. The system capacity is guaranteed with lower computational complexity. Simulation results show that the proposed algorithm can ensure that the interference introduced to the primary users is within the threshold, and can also improve the system capacity of the secondary users at the same time. Thus, the feasibility of the proposed algorithm is verified.

关 键 词：通信技术 多中继OFDM系统 认知无线电 中继选择 功率分配 

分 类 号：TN929[电子电信—通信与信息系统]