在真实室内环境中,用MICA2节点设计分析影响无线接收信号强度(radio signal strength,RSS)的实验,发现其影响因素不仅包括发送接收方(transmitter-receiver,T-R)之间的距离,且MICA2节点的工作频率和供电电池电压、发送接收方节点差异、...在真实室内环境中,用MICA2节点设计分析影响无线接收信号强度(radio signal strength,RSS)的实验,发现其影响因素不仅包括发送接收方(transmitter-receiver,T-R)之间的距离,且MICA2节点的工作频率和供电电池电压、发送接收方节点差异、天线角度和高度,以及环境中的时空因素和动态环境等都会影响无线接收信号强度.经分别测试这些因素,建议传统无线信号传播模型和信号校准算法应综合考虑各项影响因素.展开更多
Spectrum sharing for efficient reuse of licensed spectrum is an important concept for cognitive radio technologies.In a spectrum-sharing system(SSS),deploying the antennas in a distributed manner can offer a new spati...Spectrum sharing for efficient reuse of licensed spectrum is an important concept for cognitive radio technologies.In a spectrum-sharing system(SSS),deploying the antennas in a distributed manner can offer a new spatial dimension for the efficient reuse of licensed frequency bands.To improve the whole performance of multiple secondary users(SUs),this paper addresses the problem of coordinated multi-SU spectrum sharing in a distributed antenna-based SSS.By adopting the Hungarian method,the primal decomposition method and pricing policy,we propose a coordinated multi-user transmission scheme,so as to maximize the sum-rate of SUs.Simulation results show that the proposed method can significantly enhance the system performance,and the computational complexity is low.展开更多
The signal transceiver of the software radio fuze depends on the front-end radio frequency（ RF） antenna. RF micro-electro-mechanical-system（ MEMS） smart antennas have the capability of flexible beam rapid scanning...The signal transceiver of the software radio fuze depends on the front-end radio frequency（ RF） antenna. RF micro-electro-mechanical-system（ MEMS） smart antennas have the capability of flexible beam rapid scanning,multi-beam forming and so on,which can improve the ability of detecting,sensing and tracking multiple targets of the fuze. The small RF MEMS smart antenna consists of a 2 × 2 aperture coupled antenna array and six 1-bit MEMS phase shifters. Simulated results demonstrate that the antenna can complete beam steering angles of ± 30° in both X and Y plane at 17. 3 GHz. All components can be fabricated and monolithically integrated with MEMS technology which causes the system low cost and small volume. The RF MEMS smart antenna presents a good and important prospect for the development of the software radio fuze antenna.展开更多
基金National Natural Science Foundation of China(61170077,61202377)~~
文摘在真实室内环境中,用MICA2节点设计分析影响无线接收信号强度(radio signal strength,RSS)的实验,发现其影响因素不仅包括发送接收方(transmitter-receiver,T-R)之间的距离,且MICA2节点的工作频率和供电电池电压、发送接收方节点差异、天线角度和高度,以及环境中的时空因素和动态环境等都会影响无线接收信号强度.经分别测试这些因素,建议传统无线信号传播模型和信号校准算法应综合考虑各项影响因素.
基金supported in part by the National Science Foundation of China for Young Scholars under grant No.61201186The National Basic Research Program undergrant No.2012AA01A502+5 种基金National Natural Science Foundation of China under grant No.61201192National S&T Major Project under grant No.2014ZX03003003-002Tsinghua-HUAWEI Joint R&D on Soft Defined Protocol StackTsinghua-HUAWEI Joint Research on 5G Air Interface TechnicalTsinghua-Qualcom joint research programIndependent innovation on Future Virtualization Platform under grant No.015Z02-3
文摘Spectrum sharing for efficient reuse of licensed spectrum is an important concept for cognitive radio technologies.In a spectrum-sharing system(SSS),deploying the antennas in a distributed manner can offer a new spatial dimension for the efficient reuse of licensed frequency bands.To improve the whole performance of multiple secondary users(SUs),this paper addresses the problem of coordinated multi-SU spectrum sharing in a distributed antenna-based SSS.By adopting the Hungarian method,the primal decomposition method and pricing policy,we propose a coordinated multi-user transmission scheme,so as to maximize the sum-rate of SUs.Simulation results show that the proposed method can significantly enhance the system performance,and the computational complexity is low.
文摘The signal transceiver of the software radio fuze depends on the front-end radio frequency（ RF） antenna. RF micro-electro-mechanical-system（ MEMS） smart antennas have the capability of flexible beam rapid scanning,multi-beam forming and so on,which can improve the ability of detecting,sensing and tracking multiple targets of the fuze. The small RF MEMS smart antenna consists of a 2 × 2 aperture coupled antenna array and six 1-bit MEMS phase shifters. Simulated results demonstrate that the antenna can complete beam steering angles of ± 30° in both X and Y plane at 17. 3 GHz. All components can be fabricated and monolithically integrated with MEMS technology which causes the system low cost and small volume. The RF MEMS smart antenna presents a good and important prospect for the development of the software radio fuze antenna.
