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
在满足用户带宽接入需求约束下,针对时分双工OFDM下行链路系统最大化系统加权和速率问题,提出按比例自适应子载波分配算法。在最大信噪比(SNR)子载波分配策略基础上,引入用户权重,提出按比例自适应子载波分配策略,据此给出用户带宽接入...在满足用户带宽接入需求约束下,针对时分双工OFDM下行链路系统最大化系统加权和速率问题,提出按比例自适应子载波分配算法。在最大信噪比(SNR)子载波分配策略基础上,引入用户权重,提出按比例自适应子载波分配策略,据此给出用户带宽接入概率表达式,通过求解具有约束条件的非线性最优化问题,得到满足用户带宽接入需求的用户权重。仿真结果表明:所提算法可自适应地根据用户带宽需求因子和平均SNR给出对应用户权重,并据此按比例地为用户分配所需带宽;随着用户平均SNR的增大,信道估计误差方差减小,当平均SNR达到17.5 d B时,几乎可以达到与理想信道估计下子载波分配算法相同的性能。展开更多
针对异步跳时脉冲无线电超宽带(impulse radio ultra-wide band,IR-UWB)多用户系统中存在多用户干扰,分别推导了当多用户干扰相对于输出噪声能以高概率忽略不计时密集网络和扩展网络所需的IR-UWB信号渐近带宽.理论研究表明所得到的IR-UW...针对异步跳时脉冲无线电超宽带(impulse radio ultra-wide band,IR-UWB)多用户系统中存在多用户干扰,分别推导了当多用户干扰相对于输出噪声能以高概率忽略不计时密集网络和扩展网络所需的IR-UWB信号渐近带宽.理论研究表明所得到的IR-UWB信号渐近带宽与网络内的用户数成正比,而且密集网络所需的IR-UWB信号的渐近带宽远大于扩展网络的.当IR-UWB信号带宽满足理论渐近带宽时,多用户系统的差错概率就简化为单用户系统的差错概率.展开更多
基金supported by China National Science Foundation under Grand No. 61402416Natural Science Foundation of Zhejiang Province under Grant No. LQ14F010003+1 种基金Natural Science Foundation of Jiangsu Province under Grant No. BK20140828the Scientific Foundation for the Returned Overseas Chinese Scholars of State Education Ministry
文摘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.
文摘在满足用户带宽接入需求约束下,针对时分双工OFDM下行链路系统最大化系统加权和速率问题,提出按比例自适应子载波分配算法。在最大信噪比(SNR)子载波分配策略基础上,引入用户权重,提出按比例自适应子载波分配策略,据此给出用户带宽接入概率表达式,通过求解具有约束条件的非线性最优化问题,得到满足用户带宽接入需求的用户权重。仿真结果表明:所提算法可自适应地根据用户带宽需求因子和平均SNR给出对应用户权重,并据此按比例地为用户分配所需带宽;随着用户平均SNR的增大,信道估计误差方差减小,当平均SNR达到17.5 d B时,几乎可以达到与理想信道估计下子载波分配算法相同的性能。
文摘针对异步跳时脉冲无线电超宽带(impulse radio ultra-wide band,IR-UWB)多用户系统中存在多用户干扰,分别推导了当多用户干扰相对于输出噪声能以高概率忽略不计时密集网络和扩展网络所需的IR-UWB信号渐近带宽.理论研究表明所得到的IR-UWB信号渐近带宽与网络内的用户数成正比,而且密集网络所需的IR-UWB信号的渐近带宽远大于扩展网络的.当IR-UWB信号带宽满足理论渐近带宽时,多用户系统的差错概率就简化为单用户系统的差错概率.