认知无线电系统转移接入概率的动态子载波分配

Dynamic Subcarrier Allocation Transferring Access Probability in Cognitive Radio System

针对认知无线电系统可用子载波的动态变化,提出一种基于接入概率的动态子载波分配方法.该方法通过控制认知用户在子载波上的接入概率最大化系统的吞吐量,保证了用户的服务质量需求.为简化求解过程,提出一种基于接入概率转移的启发式算法,该算法可将子载波接入概率在用户间转移,直至所有用户的速率需求都得到满足.仿真结果表明,在瑞利衰落信道环境下启发式算法能得到全局最优解.同时,与现有动态分配方法和载波侦听多路接入方法相比,新方法能有效地提高系统吞吐量性能.

Aimed at dynamic changing of the available subcarriers in cognitive radio system, a dynamic subcarrier allocation method based on access probability is proposed. The method controls access probability of cognitive users on the subcarriers to maximize the system throughput and guarantee the quality of service requirement of the users. To simplify the solution process, a heuristic algorithm is proposed based on the access probability transfer. The algorithm transfers the subcarrier access probability among the users until the rate requirements of all users being satisfied. Simulation shows that the heuristic algorithm can achieve the global optimal solution in Rayleigh channel environment. Also it is shown that the throughput performance of the proposed method is better than current dynamic allocation and carrier sense multiple access method.