为了提高无线网络中基于网络编码的广播重传方法的编码效率,从而有效地减少重传次数和数据包传输时延,提出一种主动避免编码冗余的高效网络编码广播重传方法(network coding broadcasting retransmission approach based on redundancy ...为了提高无线网络中基于网络编码的广播重传方法的编码效率,从而有效地减少重传次数和数据包传输时延,提出一种主动避免编码冗余的高效网络编码广播重传方法(network coding broadcasting retransmission approach based on redundancy avoiding,NCRA)。NCRA编码时主动避免不能解码的编码组合被重复编码重传,同时优先编码重传对接收节点已缓存的未解码编码包的解码贡献较大的丢失数据包以充分利用编码机会,在对解码贡献相同的条件下优先编码较早丢失的数据包以减小数据包传输时延。理论分析和仿真结果表明,NCRA算法相比于现有算法能有效减小重传次数和降低数据包传输时延,减少网络开销,进一步提高了编码重传的效率。展开更多
为降低无线网络中数据重传时最优异或编码集合的复杂性,并减少数据传输次数、提高算法稳定性,提出一种新的基于可靠重传机制的无线网络数据广播算法(wireless network broadcast data algorithm based on reliable retransmission mecha...为降低无线网络中数据重传时最优异或编码集合的复杂性,并减少数据传输次数、提高算法稳定性,提出一种新的基于可靠重传机制的无线网络数据广播算法(wireless network broadcast data algorithm based on reliable retransmission mechanism,WDRRM)。基于随机线性编码理论,将网络中丢失的数据包进行线性异或编码,以生成新的数据包,并设计可靠的数据重传机制,对其进行重传;引入高斯消元法,在接收节点收到足够数目的编码包后,对其进行解码,获取原始数据包。理论分析与仿真结果显示:WDRRM算法的数据包平均重传次数以及控制开销低于其他对比编码算法。该文算法在一定程度上能够有效降低网络编码复杂性,提高网络性能。展开更多
In DVB-IPDC system, due to the constraints of handheld devices and the broadcast nature of wireless network, packet loss is inevitable. ECDR-NC proposed is a retransmission encoding packet selection algorithm based on...In DVB-IPDC system, due to the constraints of handheld devices and the broadcast nature of wireless network, packet loss is inevitable. ECDR-NC proposed is a retransmission encoding packet selection algorithm based on the dynamic information updating, which can find the current most effective complete decoding packet. ECDR-NC can not only avoid the redundant encoding packets due to the overlapping among encoding packets, but also reduce the computational complexity compared with the traditional encoding schemes. Furthermore, the retransmission upper bound of ECDR-NC is fully controlled. In time-sensitive applications, to maximize the aggregate number of recovery packets while minimizing the total number of discarded packets due to the time limit according to the priority preference, the adaptive priority scheme EPNC is formulized, and the weighted relation graph is constructed to find the maximum-weighted encoding packets sequence according to the decoding gains. In the same network environment, the performances comparisons between PNC and EPNC show that EPNC is more efficient and more rational, and the average discarded packets ratios ofEPNC can be reduced about 18%~27%. The main contributions of this paper are an effective retransmission encoding packet selection algorithm ECDR-NC proposed, and a new adaptive priority recovery scheme EPNC introduced into DVB-IPDC system.展开更多
衰落环境中,自动重传技术是实现错误处理、完成数据传输的有效方法之一。本文提出了一种选择发送的协作网络编码(Cooperative Network Coding based on Selective Transmission,ST-CNC),该技术在数据重传过程中,将空时协同发送与网络编...衰落环境中,自动重传技术是实现错误处理、完成数据传输的有效方法之一。本文提出了一种选择发送的协作网络编码(Cooperative Network Coding based on Selective Transmission,ST-CNC),该技术在数据重传过程中,将空时协同发送与网络编码技术相结合,可以有效减少重传次数,提高网络资源利用率。针对一发两收系统,单个中继节点辅助传输的情形,分析了ST-CNC的中断性能和网络编码增益,结果表明:相对于传统的广播策略,选择发送的协作网络编码可以获得2阶分集增益;此外,在中低信噪比区域,ST-CNC同时可以获得明显的网络编码增益。展开更多
文摘为了提高无线网络中基于网络编码的广播重传方法的编码效率,从而有效地减少重传次数和数据包传输时延,提出一种主动避免编码冗余的高效网络编码广播重传方法(network coding broadcasting retransmission approach based on redundancy avoiding,NCRA)。NCRA编码时主动避免不能解码的编码组合被重复编码重传,同时优先编码重传对接收节点已缓存的未解码编码包的解码贡献较大的丢失数据包以充分利用编码机会,在对解码贡献相同的条件下优先编码较早丢失的数据包以减小数据包传输时延。理论分析和仿真结果表明,NCRA算法相比于现有算法能有效减小重传次数和降低数据包传输时延,减少网络开销,进一步提高了编码重传的效率。
文摘为降低无线网络中数据重传时最优异或编码集合的复杂性,并减少数据传输次数、提高算法稳定性,提出一种新的基于可靠重传机制的无线网络数据广播算法(wireless network broadcast data algorithm based on reliable retransmission mechanism,WDRRM)。基于随机线性编码理论,将网络中丢失的数据包进行线性异或编码,以生成新的数据包,并设计可靠的数据重传机制,对其进行重传;引入高斯消元法,在接收节点收到足够数目的编码包后,对其进行解码,获取原始数据包。理论分析与仿真结果显示:WDRRM算法的数据包平均重传次数以及控制开销低于其他对比编码算法。该文算法在一定程度上能够有效降低网络编码复杂性,提高网络性能。
基金supported by the National High Technology Research and Development Program of China(863 Program )(Grant No: 2015AA01A705)the National Basic Research Program of China (Grant No:2012CB316100)+1 种基金Key Grant Project of Chinese Ministry of Education (Grant No:311031 100)Young Innovative Research Team of Sichuan Province (Grant No:2011JTD0007)
文摘In DVB-IPDC system, due to the constraints of handheld devices and the broadcast nature of wireless network, packet loss is inevitable. ECDR-NC proposed is a retransmission encoding packet selection algorithm based on the dynamic information updating, which can find the current most effective complete decoding packet. ECDR-NC can not only avoid the redundant encoding packets due to the overlapping among encoding packets, but also reduce the computational complexity compared with the traditional encoding schemes. Furthermore, the retransmission upper bound of ECDR-NC is fully controlled. In time-sensitive applications, to maximize the aggregate number of recovery packets while minimizing the total number of discarded packets due to the time limit according to the priority preference, the adaptive priority scheme EPNC is formulized, and the weighted relation graph is constructed to find the maximum-weighted encoding packets sequence according to the decoding gains. In the same network environment, the performances comparisons between PNC and EPNC show that EPNC is more efficient and more rational, and the average discarded packets ratios ofEPNC can be reduced about 18%~27%. The main contributions of this paper are an effective retransmission encoding packet selection algorithm ECDR-NC proposed, and a new adaptive priority recovery scheme EPNC introduced into DVB-IPDC system.
文摘衰落环境中,自动重传技术是实现错误处理、完成数据传输的有效方法之一。本文提出了一种选择发送的协作网络编码(Cooperative Network Coding based on Selective Transmission,ST-CNC),该技术在数据重传过程中,将空时协同发送与网络编码技术相结合,可以有效减少重传次数,提高网络资源利用率。针对一发两收系统,单个中继节点辅助传输的情形,分析了ST-CNC的中断性能和网络编码增益,结果表明:相对于传统的广播策略,选择发送的协作网络编码可以获得2阶分集增益;此外,在中低信噪比区域,ST-CNC同时可以获得明显的网络编码增益。
