基于QoS需求的认知无线电资源分配算法

Resource Allocation Algorithm for Cognitive Radio Based on QoS Requirements

在误比特率、总发射功率以及主用户可容忍干扰门限的约束下,提出一种基于正交频分复用的认知无线电系统多目标优化贪婪分配算法。以最小化发射功率、最小化跨频干扰及满足次用户QoS需求为优化目标,线性组合这3个目标函数,把多目标优化问题转化为单目标优化问题,采用贪婪算法实现多目标优化。仿真结果表明,该算法的系统总容量趋近于最优,在降低对主用户跨频干扰的同时,能够有效地满足次用户的QoS需求。

Dynamic spectrum allocation is a key technology of the Cognitive Radio（CR）.Subject to bit error rates,total transmit powers and interference thresholds that primary users can tolerate,a greedy allocation algorithm for multi-objective optimization of Orthogonal Frequency Division Multiplexing（OFDM）-based CR systems is proposed in this paper.The proposed algorithm minimizes the transmit power and the mutual interference,and meets the Quality of Service（QoS） requirements of Secondary User（SU）.The multi-objective optimization problem is converted to a single-objective one through linearly combining the three objective functions,and the greedy algorithm is used to solve the optimization problem.Simulation results show that the total system capacity of the proposed algorithm is close to its maximum,and the mutual interference is reduced as well as the QoS requirements of SU are effectively met.