【摘要】 为了降低基于CSMA的频谱接入技术在利用频谱空洞时授权用户和认知用户之间发生冲突的概率,提出了一种基于HMM的动态频谱接入方法。利用HMM预测频谱的状态信息,使认知用户在发现授权用户开始传送数据前退出所占用的频带,避免与授权用户产生冲突,根据预测的信息并利用NC-OFDM调制技术传送数据。仿真结果表明,采用该方法的动态频谱接入系统可以大大地降低用户冲突发生的概率,具有比CSMA系统更好的误码性能。更多还原

【Abstract】 In order to reduce the probability of collision between primary users and cognitive user when spectrum holes were utilized by CSMA-based spectrum access technique,a novel HMM-based dynamic spectrum access method was proposed.Using the spectrum state information by HMM,it made cognitive users leave the band it currently occupied before the start of data transmission,which avoided the collision with primary users.The simulation results indicate that the dynamic spectrum access system based on this method can significantly reduce the probability of collision and performs better than CSMA.更多还原