【摘要】 随着卫星通信业务量的快速增长,信道如何被最大化的使用已经成为近年来被研究的热点。在有大量业务量接入的情况下,现有算法的信道利用率很难维持正常的通信。基于上述问题在信道中加入认知无线电频谱感知技术,检测主用户空闲信道,次级用户采用扩频时隙多址接入控制方法接入空闲信道,保证了信道被充分利用。因此提出了一种面向认知卫星网络的扩频时隙ALOHA多址接入控制算法。从吞吐量、接入概率和碰撞率等方面测试,评估新算法的性能,并与传统接入算法进行对比。仿真结果表明,改进算法极大提高了信道利用率,有效降低了数据包之间的碰撞率,能够保证大量实时业务的接入。更多还原

【Abstract】 With the rapid growth of satellite communication,how to maximize the use of the channel has become a hot research topic in recent years. In the case of a large amount of traffic accessing,it is difficult for the channel utilization of the existing algorithms to maintain normal communication. Based on this problem,a cognitive radio spectrum sensing technique is added to the channel to detect the idle channel of the primary user,and the secondary users access the idle channel using the spread spectrum time slot multiple access control method to ensure that the channel is fully utilized. Therefore,a spread spectrum S-ALOHA multiple access control algorithm for cognitive satellite networks is proposed. From the aspects of throughput,access probability and collision rate,the performance of the new algorithm was evaluated and compared with the traditional access algorithm. The simulation results show that the improved algorithm greatly can improve the utilization ratio of the channel,effectively reduce the collision rate between the data packets,and guarantee a large number of real-time business access.更多还原