Recent researches show that inter-session network coding could decrease the number of packets transmission and achieve higher throughput in wireless network compared with traditional forwarding mechanism. In most exis...Recent researches show that inter-session network coding could decrease the number of packets transmission and achieve higher throughput in wireless network compared with traditional forwarding mechanism. In most existing relay mechanisms based on inter-session network such as COPE, relay node demands to collect the messages from its neighbor nodes to get notice of which packets already overheard by them so as to determine whether there exists coding opportunity between or among forwarding packets. However, transmission overhead of this message collection and computing cost of opportunity determination will degrade the performance of these mechanisms. It is observed that coding opportunity at relay node is much more related with the local topology, and the opportunity of encoding three or more packets together is far less than that of encoding two packets together in wireless network with general density. Based on this, a new coding-aware routing mechanism, named TCAR, is proposed. TCAR ignores the oppommity of encoding three or more than three packets together. Each relay node maintains an encoding mapping table being established according to the result of its local topology detection, which can be used to calculate the path cost during routing setup phase, and determine that which two packets can be encoded together during the packets forwarding phase. In TCAR, instead of periodic messages collection, each relay nodes just need once local topology detection, and the encoding determination is much simpler than that of the former mechanisms. Simulation results show that compared with typical inter-session network coding mechanisms COPE and COPE-based routing, TCAR achieves 12% and 7% throughput gains, and keeps the minimum end to end delay.展开更多
To characterize the algebraic structure of wireless network coding, a hypergragh is utilized to model wireless packet networks from network layer. The algebraic description of random convolutional network coding is de...To characterize the algebraic structure of wireless network coding, a hypergragh is utilized to model wireless packet networks from network layer. The algebraic description of random convolutional network coding is deduced, and the coding condition is also presented. Analyses and simulations show that random convolutional coding is capacity-achieving with probability approaching 1.展开更多
Y2000-62073-500 0007985正交频分复接和多载波无线电系统(2)(有7篇论文)=Session S14:OFDM and multi-carrier radio systems Ⅱ[会,英]//1999 IEEE International Conference Com-munications,Vol 1 of 3.—500～538(H)本部分汇编7篇...Y2000-62073-500 0007985正交频分复接和多载波无线电系统(2)(有7篇论文)=Session S14:OFDM and multi-carrier radio systems Ⅱ[会,英]//1999 IEEE International Conference Com-munications,Vol 1 of 3.—500～538(H)本部分汇编7篇论文.内容有:相关正交频分复接(OFDM)系统的符号时间偏差估计,非独立瑞利衰落环境中 MC-CDMA 系统的性能,应用部分传输序列的OFDM 信号的峰值-平均值之比的降低应用速率自适应 OFDM 信令的分组无线网络的通过量分析,无线网络中 OFDM 的低复杂性自适应波束成形和功率分配,基于 OFDM 的无线多媒体通信的新算法同步技术,OFDM展开更多
基金Projects(61173169,61106036)supported by the National Natural Science Foundation of ChinaProject(NCET-10-0798)Program for New Century Excellent Talents in University,China
文摘Recent researches show that inter-session network coding could decrease the number of packets transmission and achieve higher throughput in wireless network compared with traditional forwarding mechanism. In most existing relay mechanisms based on inter-session network such as COPE, relay node demands to collect the messages from its neighbor nodes to get notice of which packets already overheard by them so as to determine whether there exists coding opportunity between or among forwarding packets. However, transmission overhead of this message collection and computing cost of opportunity determination will degrade the performance of these mechanisms. It is observed that coding opportunity at relay node is much more related with the local topology, and the opportunity of encoding three or more packets together is far less than that of encoding two packets together in wireless network with general density. Based on this, a new coding-aware routing mechanism, named TCAR, is proposed. TCAR ignores the oppommity of encoding three or more than three packets together. Each relay node maintains an encoding mapping table being established according to the result of its local topology detection, which can be used to calculate the path cost during routing setup phase, and determine that which two packets can be encoded together during the packets forwarding phase. In TCAR, instead of periodic messages collection, each relay nodes just need once local topology detection, and the encoding determination is much simpler than that of the former mechanisms. Simulation results show that compared with typical inter-session network coding mechanisms COPE and COPE-based routing, TCAR achieves 12% and 7% throughput gains, and keeps the minimum end to end delay.
基金Supported by National Natural Science Foundation of China (No.61271174)Young Teachers' Innovation Foundation of Xidian University(K5051303137)
文摘To characterize the algebraic structure of wireless network coding, a hypergragh is utilized to model wireless packet networks from network layer. The algebraic description of random convolutional network coding is deduced, and the coding condition is also presented. Analyses and simulations show that random convolutional coding is capacity-achieving with probability approaching 1.
文摘Y2000-62073-500 0007985正交频分复接和多载波无线电系统(2)(有7篇论文)=Session S14:OFDM and multi-carrier radio systems Ⅱ[会,英]//1999 IEEE International Conference Com-munications,Vol 1 of 3.—500～538(H)本部分汇编7篇论文.内容有:相关正交频分复接(OFDM)系统的符号时间偏差估计,非独立瑞利衰落环境中 MC-CDMA 系统的性能,应用部分传输序列的OFDM 信号的峰值-平均值之比的降低应用速率自适应 OFDM 信令的分组无线网络的通过量分析,无线网络中 OFDM 的低复杂性自适应波束成形和功率分配,基于 OFDM 的无线多媒体通信的新算法同步技术,OFDM
