Efficient wireless multicast retransmission using network coding  

作　　者：CAO Zhen TANG Bi-hua LIU Yuan-an XIE Gang LIU Fang DENG Pan-liang 

机构地区：[1]School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China [2]Key Laboratory of Universal Wireless Communication, Ministry of Education, Beijing University of Posts and Telecommunications, Beijing 100876, China

出　　处：《The Journal of China Universities of Posts and Telecommunications》2011年第6期59-67,88,共10页中国邮电高校学报（英文版）

基　　金：supported by the Canada-China Scientific and Technological Cooperation (2010DFA11320);the Fundamental Research Funds for the Central Universities (G470209, 2009RC0308);the National Natural Science Foundation of China (60802033, 60873190);the Important National Science and Technology Specific Projects (2010ZX03007-003-04, 2010ZX03005-001-03)

摘　　要：In wireless multicast, network coding has recently attracted attentions as a substantial improvement to packet retransmission schemes. However, the problem of finding the optimal network code which minimizes the retransmissions is hard to solve or approximate. This paper presents two schemes to reduce the number of retransmissions for reliable multicast efficiently. One is retransmission using network coding based on improved Vandermonde matrix （VRNC）, the other is retransmission using network coding based on adaptive improved Vandermonde matrix （AVRNC）. Using VRNC scheme the sender selects the packets all receivers have lost and encodes them with improved Vandermonde matrix; when receivers receive enough encoded retransmission packets, all the lost packets can be recovered. With AVRNC scheme, the sender can obtain the recovery information from all the receivers after sending out per retransmission packet, and then the improved Vandermonde matrix can be updated, thus reducing the complexity of encoding and decoding. Our proposed schemes can achieve the theoretical lower bound assuming retransmission packets lossless, and approach the theoretical lower bound considering retransmission packets loss. Simulation results show that the proposed algorithms can efficiently reduce the number ofretransmissions, thus improving transmission efficiency.In wireless multicast, network coding has recently attracted attentions as a substantial improvement to packet retransmission schemes. However, the problem of finding the optimal network code which minimizes the retransmissions is hard to solve or approximate. This paper presents two schemes to reduce the number of retransmissions for reliable multicast efficiently. One is retransmission using network coding based on improved Vandermonde matrix （VRNC）, the other is retransmission using network coding based on adaptive improved Vandermonde matrix （AVRNC）. Using VRNC scheme the sender selects the packets all receivers have lost and encodes them with improved Vandermonde matrix; when receivers receive enough encoded retransmission packets, all the lost packets can be recovered. With AVRNC scheme, the sender can obtain the recovery information from all the receivers after sending out per retransmission packet, and then the improved Vandermonde matrix can be updated, thus reducing the complexity of encoding and decoding. Our proposed schemes can achieve the theoretical lower bound assuming retransmission packets lossless, and approach the theoretical lower bound considering retransmission packets loss. Simulation results show that the proposed algorithms can efficiently reduce the number ofretransmissions, thus improving transmission efficiency.

关 键 词：reliable multicast network coding （NC） RETRANSMISSION improved Vandermonde matrix 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论] O151.21[自动化与计算机技术—计算机科学与技术]