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Overlapped OFDMA——新颖的多载波频谱共享传输机制
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作者 宫本康 张朝阳 叶露 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2013年第5期860-866,共7页
针对现有非连续正交频分复用(DOFDM)等系统通常只允许认知用户利用授权用户未使用的频带进行共享传输的问题,提出一种新颖的频谱共享传输机制,即混叠正交频分复用多址接入(Overlapped OFDMA),能够在一定条件下实现认知用户与授权用户的... 针对现有非连续正交频分复用(DOFDM)等系统通常只允许认知用户利用授权用户未使用的频带进行共享传输的问题,提出一种新颖的频谱共享传输机制,即混叠正交频分复用多址接入(Overlapped OFDMA),能够在一定条件下实现认知用户与授权用户的混叠频谱共享.通过对一般OFDM系统的信号结构进行研究发现,当认知用户的子载波带宽采用授权用户子载波带宽的一半进行传输、其频谱和授权用户频谱存在一定混叠时,只要认知用户保持和授权用户时域信号准同步且其子载波分配方案满足一定的限制条件,授权用户将不受干扰.由于各载波上的干扰都包含有其它载波的信息,因此认知用户可以通过适当的恢复算法将信息完整地恢复.仿真和分析结果表明,尽管Overlapped OFDMA会带来一定的复杂度,但授权用户的性能和DOFDM系统相比几乎相同,而认知用户却获得了更加优异的吞吐量性能.该机制为频谱共享传输体制的设计提供了新的可能性. 展开更多
关键词 Overlapped OFDMA 认知无线电 频谱共享传输
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Rayleigh Quotient Based Interference Alignment Spectrum Sharing in MIMO Cognitive Radio Networks 被引量:1
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作者 RONG MEI 《China Communications》 SCIE CSCD 2015年第6期96-105,共10页
An interference alignment(IA)spectrum sharing method based on Rayleigh quotient is proposed for distributed multi-user multi-antenna cognitive radio(CR) networks.The interference from cognitive users(CUs)to the primar... An interference alignment(IA)spectrum sharing method based on Rayleigh quotient is proposed for distributed multi-user multi-antenna cognitive radio(CR) networks.The interference from cognitive users(CUs)to the primary(PR) system is constrained through the Rayleigh quotients of channel matrices to deal with the absence of PR users(PUs) in the IA process.As a result,the IA scheme can be applied in CR networks without harmful interference to PUs.Compared with existing IA based spectrum sharing methods,the proposed method is more general because of breaking the restriction that CUs can only transmit on the idle sub-channels of the PR system.Moreover,in comparison to other four spectrum sharing methods applicable in general scene,the proposed method leads to improved performance of achievable sum rate of the CR system as well as guarantees the transmission of PUs. 展开更多
关键词 cognitive radio spectrum sharing Rayleigh quotient interference alignment MIMO
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Cooperative Anti-Interference Spectrum Sharing with Secondary User Selection
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作者 Peng Hong Zhu Yufei +2 位作者 Lu Weidang Liu Xin Hua Jingyu 《China Communications》 SCIE CSCD 2015年第9期45-52,共8页
In this paper, we propose a cooperative anti-interference spectrum sharing strategy with secondary user selection where the secondary system can gain spectrum access along with the primary system. Specifically, second... In this paper, we propose a cooperative anti-interference spectrum sharing strategy with secondary user selection where the secondary system can gain spectrum access along with the primary system. Specifically, secondary user and are selected to transmit the primary and secondary signal through different bandwidth in the second transmission slot which occupies fraction of the time. Thus, the primary and secondary systems will not interfere with each other. We study the joint optimization of time and bandwidth allocation such that the transmission rate of the secondary system is maximized, while guaranteeing the primary system to achieve its target rate. Simulation results confirm efficiency of the proposed spectrum sharing strategy, and the significant performance improvement of the cognitive system. 展开更多
关键词 cooperative communications spectrum sharing bandwidth allocation user selection
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