College of Communications Engineering, Army Engineering University of PLA, Nanjing 210007, China.
College of Telecommunications and Information Engineering, Nangjing University of Posts and Telecommunications, Nanjing 210003, China.
Sensors (Basel). 2018 Nov 12;18(11):3904. doi: 10.3390/s18113904.
With the growing demand, Wireless Multimedia Sensor Networks (WMSNs) play an increasingly important role, which enhances the capacity of typical Wireless Sensor Networks (WSNs). Additionally, integrating satellite systems into WMSNs brings about the beneficial synergy, especially in rural and sparsely populated areas. However, the available spectrum resource is scarce, which contradicts the high-speed content required for multimedia. Cognitive radio is a promising solution to address the conflict. In this context, we propose a novel spectrum-sharing method for the integrated wireless multimedia sensor and cognitive satellite network based on the dynamic frequency allocation. Specifically, the Low Earth Orbit (LEO) satellite system plays the role of the auxiliary to connect sensor nodes and the remote control host, and it shares the same frequency with the Geostationary Earth Orbit (GEO) system in the downlink. Because the altitudes of GEO and LEO satellites differ greatly, the beam size of GEO is much larger than that of LEO, which provides the opportunity for LEO beam to reuse the frequency that was allocated to the GEO beam. A keep-out region is defined to guarantee the spectral coexistence based on the interference analysis in the worst case. In addition, a dynamic frequency allocation algorithm is presented to deal with the dynamic configuration caused by the satellite motion. Numerical results demonstrate that the dynamic spectrum-sharing method can improve the throughput.
随着需求的增长，无线多媒体传感器网络（WMSNs）发挥着越来越重要的作用，增强了典型无线传感器网络（WSNs）的容量。此外，将卫星系统集成到 WMSNs 中带来了有益的协同作用，特别是在农村和人口稀少的地区。然而，可用的频谱资源稀缺，与多媒体所需的高速内容相矛盾。认知无线电是解决这一冲突的一种有前途的解决方案。在这种情况下，我们提出了一种基于动态频率分配的集成无线多媒体传感器和认知卫星网络的新型频谱共享方法。具体来说，低地球轨道（LEO）卫星系统充当辅助，连接传感器节点和远程控制主机，并在下行链路中与地球静止轨道（GEO）系统共享相同的频率。由于 GEO 和 LEO 卫星的高度差异很大，GEO 的波束尺寸比 LEO 的波束尺寸大得多，这为 LEO 波束提供了重用分配给 GEO 波束的频率的机会。基于最坏情况下的干扰分析，定义了一个禁止区域以确保频谱共存。此外，提出了一种动态频率分配算法来处理卫星运动引起的动态配置。数值结果表明，动态频谱共享方法可以提高吞吐量。
