Network Coding Transmission Scheme Based On Buffer Management In Relay-Assisted Wireless Network

Network coding technology allows the intermediate node to encode the data packets received,and then forward the encoding packet.Network coding can take the data packet requirements of the sinks into consideration comprehensively,and enable the wireless network transmission capacity to the approach theoretical value.The buffer management mechanism optimization in the relay-assisted wireless network can increase encoding and decoding opportunities,reduce the system transmission delay,and improve transmission efficiency.The research work is beginning with the specific network scenario,the buffer management mechanism in the relay-assisted wireless network is studied to analyze the limitation to the system performance,and the impact on the network transmission performance under the delay constraintsFirstly,focusing on the problems of the limited node buffer space and the large overhead of transmitting and buffering data packets in the relay-assisted wireless network,a network coding relay transmission scheme based on buffer management(RTBM)is proposed.This scheme aims at minimizing system overhead,takes the multi-flow comprehensive optimization problem into consideration,and uses Markov chain to model and analyze the buffer queue.The encoding stream rate is combined to increase the encoding opportunity,and the buffer threshold of different streams at the relay is obtained to implement the encoding decision.The relationship among the encoding stream rate,the buffering overhead and the relay node buffer threshold,and the impact of different thresholds on the transmission efficiency are analyzed in the experiment.The simulation results show that the coding opportunities and overhead can be effectively balanced,and the multi-encoded stream can be comprehensively optimized.Under the same conditions,the system overhead can be minimized and the delay can be reduced compared to other schemes,especially in the case of the encoded streams with the different rates.Secondly,for the delay-sensitive network scenario in which the data packets are with delay constraints in the relay-assisted wireless network,a relay transmission scheme based on network coding under delay constraints(RTSDC)is proposed.Taken the delay constraint of data packet and the channel rate of relay transmission data packet into consideration,the encoding packets are generated to improve the success rate of receiving data packet.According to the remaining time slot and the rate graph model of the data packet,the scheduling scheme is selected at the relay,and the encoding packet is transmitted at the optimal channel rate.And the required data packets are achieved at the destination node by decoding the packets encoded.The simulation analyzes the impact of the number of destination nodes and the delay constraint interval on the performance.The experimental results show that the data packet transmission efficiency of this scheme is better relatively,and the delay-sensitive wireless network scenarios suitable.