摘要
认知无线电系统中,如何进行有效地频谱感知是关系到次用户系统传输效能的首要问题,也是认知无线电长期的研究热点之一。传统的认知无线电中,频谱感知只发生在特定的感知阶段,而忽略了决策、传输阶段信息对频谱感知的支持作用。提出了一种充分利用传输阶段的信息进行频谱感知的方法,并基于感知结果优化下一阶段的发射功率分配。考虑基于解码信息的频谱感知算法,在传输阶段,次用户接收机在接收到次用户发射机的信息后,对信息进行解码;之后,将次用户信息从接收信号中去除,利用剩余的信号检测主用户的工作状态,并根据状态的不同,优化次用户下一阶段的发射功率。数值仿真结果表明,相对于传统的衬底式认知无线电算法(传输阶段的信息没有被用于频谱感知),在对主用户造成相同的平均干扰情况下,提出的算法能够在一定程度上提升次用户平均信道容量。提出的算法通过对传输阶段信息的二次利用,能够为频谱感知行为提供更多的可用信息,提升检测主用户当前工作状态的正确率,在对主用户造成一定的平均干扰约束下,更加精确地控制次用户自身的传输参数,从系统机制的层面上提高了对通信信道的综合利用率。
A main problem of cognitive radio（CR） is how to optimize the spectrum sensing and power allocation parameters.In the traditional CR,spectrum sensing is only performed in the sensing phase,however,information in the decision-making and transmission phases are also useful for spectrum sensing.In this paper,a decoding information-based spectrum sensing strategy for transmission phase was proposed for CR system and the transmission power for the next phase was optimized correspondingly.In the transmission phase,after receiving the signals from the secondary transmitter,decoding was performed and the secondary transmission signals were removed.Then,the state of the primary user（PU） were detected based on the remainder signals,and the transmission power were optimized correspondingly.The simulation results showed that,on the case of certain average interference power to the PU,the proposed model provided better system performance and made better use of the channel.By fully using the signals in the transmission phase,the transmission parameters of the SU can be optimized and more information for spectrum sensing can be collected,leading to higher detection accuracy of the state of PU.
出处
《工程科学与技术》
EI
CAS
CSCD
北大核心
2018年第1期120-124,共5页
Advanced Engineering Sciences
基金
国家自然科学基金资助项目(61501510
61301160)
关键词
认知无线电
传输阶段
频谱感知
功率分配
cognitive radio
transmission phases
spectrum sensing
power allocation
