The emerging ultra-wideband (UWB) system offers a great potential for the design of high-speed short-range communications.Compared with great progress at physical layer,the corresponding medium access control (MAC) la...The emerging ultra-wideband (UWB) system offers a great potential for the design of high-speed short-range communications.Compared with great progress at physical layer,the corresponding medium access control (MAC) layer designs are naturally placed on the schedules.We focus on the optimal power load scheme,which is an integral part of the MAC layer protocol design,for UWB space-time coded (STC) orthogonal frequency-division multiplexing (OFDM) transmissions.Assumed the transmitter has perfect or partial channel stage information (CSI).Based on the optimization criteria of maximizing capacity,three kinds of power load schemes were presented with different tradeoff among performance,complexity and feedback bandwidth overhead.The proposed schemes are verified and compared under the channel prototype proposed by IEEE 802.15.3a Task Group.展开更多
针对组网导航系统(networked navigation systems,NNSs)中节点高速移动、能量受限及通信时滞的问题,融合了基于移动汇聚节点的交叉路由树构建及链式分簇相结合的路由协议(cross routing tree construction based on mobile sink and cha...针对组网导航系统(networked navigation systems,NNSs)中节点高速移动、能量受限及通信时滞的问题,融合了基于移动汇聚节点的交叉路由树构建及链式分簇相结合的路由协议(cross routing tree construction based on mobile sink and chain clustering,CRTCC),设计了一种基于节点分级的跨层媒介访问控制协议(medium access control protocol based on graded nodes,GN-MAC)。GN-MAC采取了基于竞争的媒介访问方式,结合CRTCC协议特点定义GN-MAC包格式并完成具有多级别节点的自适应虚拟分簇,同时设计了改进型节点移动性检测算法,作出了最优簇间切换决策,提出了基于优先级的竞争机制以及多信道通信机制。最后通过算例仿真,验证了GN-MAC在节点高速移动和多移动节点情况下,时滞和能耗得到了有效的控制。展开更多
基金Supported by National Natural Science Foundation of China(60872009,60602016)Hi-Tech Research and Development Program(863)of China(2007AA01Z428,2009AA01Z148)Natural Science Foundation of Anhui(ZD2008005-2, ZD200904,JK2009A013,JK2009A025)
基金This work was partially supported by NSF under Grant 60496315 and national "863" projects under Grant2003AA12331005
文摘The emerging ultra-wideband (UWB) system offers a great potential for the design of high-speed short-range communications.Compared with great progress at physical layer,the corresponding medium access control (MAC) layer designs are naturally placed on the schedules.We focus on the optimal power load scheme,which is an integral part of the MAC layer protocol design,for UWB space-time coded (STC) orthogonal frequency-division multiplexing (OFDM) transmissions.Assumed the transmitter has perfect or partial channel stage information (CSI).Based on the optimization criteria of maximizing capacity,three kinds of power load schemes were presented with different tradeoff among performance,complexity and feedback bandwidth overhead.The proposed schemes are verified and compared under the channel prototype proposed by IEEE 802.15.3a Task Group.
文摘针对组网导航系统(networked navigation systems,NNSs)中节点高速移动、能量受限及通信时滞的问题,融合了基于移动汇聚节点的交叉路由树构建及链式分簇相结合的路由协议(cross routing tree construction based on mobile sink and chain clustering,CRTCC),设计了一种基于节点分级的跨层媒介访问控制协议(medium access control protocol based on graded nodes,GN-MAC)。GN-MAC采取了基于竞争的媒介访问方式,结合CRTCC协议特点定义GN-MAC包格式并完成具有多级别节点的自适应虚拟分簇,同时设计了改进型节点移动性检测算法,作出了最优簇间切换决策,提出了基于优先级的竞争机制以及多信道通信机制。最后通过算例仿真,验证了GN-MAC在节点高速移动和多移动节点情况下,时滞和能耗得到了有效的控制。
