Transmision Scheme Based On Random Linear Network Coding For Multi-Relay Cooperation Wireless Network

Network Coding combines the technology of encoding and routing.The intermediate nodes is allowed to encode information from different link and then forward.The multiple destinations can benefit from a retransmission based on network coding,the number of retransmissions can be reduced and the transmission efficiency is improved.The relay cooperation technology can effectively overcome the fading of the wireless channel,and improve the transmission efficiency by the cooperation of multiple nodes.Wireless relay cooperation transmission based on network coding combines the advantages of network coding and the relay cooperation transmission,which can effectively improve network throughput.In this paper,the reseach of network coding application in the wireless relay cooperative transmission is developed for single relay and multiple relay cooperative network scenarios respectively.Firstly,to the application of multi-relay cooperative transmission based on random linear network coding and improve the multi-relay cooperative transmission efficiency in wireless networks,a dynamic programming scheduling based on network coding with less feedback(DPNC-LF) is proposed.Taken the effective information of each relay and the transmission reliability of each link into consideration,the multi-relay cooperative forwarding is implemented with the minimum number of retransmissions.In the condition of the state transition path selected adaptively,for the entire transmission process the optimal forwarding node is determined.The efficiency of the proposed scheme is verified by theoretical analysis and experimental simulation.The simulation results show that compared with traditional random or sequential scheduling schemes,the proposed scheme can significantly increase the average throughput and reduce the number of retransmission with the feedback information dependence reduced and the feedback overhead decreased.Secondly,according to the performance analysis of transmission schemes based on network coding with different feedback conditions in single-source and single-relay network scenarios,the complete feedback scheduling algorithm(CFSA),limited feedback scheduling algorithm(LFSA) and no feedback scheduling algorithm(NFSA) are proposed.The transmission performance of the proposed scheduling scheme is analyzed,and the advantages and disadvantages of different scheduling schemes with different feedback modes are analyzed and compared,and the applicable scenarios of each transmission scheme are discussed.Simulation results show that CFSA,LFSA,and NFSA can effectively improve the retransmission performance.The transmission efficiency of CFSA is close to the transmission efficiency of LFSA and are obviously better than NFSA.However,for the feedback overhead and computational complexity,the performance of the NFSA scheme is better.