Research On Cooperative Retransmission Based On IDNC Coding In D2D Network

In the age of the Internet of Everything,massive amounts of data converge and largescale mobile devices are connected to cellular networks.Access to large-scale devices and massive data convergence at the base station increase the load on the base station and place more stringent requirements on the base station's throughput.Therefore,it is difficult for traditional cellular networks to meet people's demand for bandwidth.When the terminal performs data retransmission,the application of network encryption technology in the wireless network can effectively reduce the number of retransmissions and the transmission power consumption.The D2 D network built by D2 D users(device to device,D2D)is also a type of wireless network.In the cellular network,the combined application of D2 D communication and network coding technology can effectively alleviate the problem of spectrum strain and improve the performance of the communication system.How to combine network encryption and communication technology D2 D in cellular networks has become a research access point in the field of communication.This thesis conducts in-depth research and analysis of current D2 D communication combined with network encryption coordinated transmission with immediate fix.The research and innovation content includes the following three aspects.Firstly,to solve the problem of high average decoding delay during concurrent cooperative retransmission of multiple terminals in a D2 D wireless network,a cooperative retransmission strategy is proposed that sacrifices some receiving terminals.In the retransmission phase,the transmitting terminal uses the INDC(Instantly Decodable Network Coding,IDNC)graph to select the optimal encoding packet from the transmitting terminal according to the quality of the link between the receiving terminal and the transmitting terminal,the weight of the terminal data packet,and connectivity.of the receiver.terminal in the IDNC graph,in order to reduce the performance of the system Average decoding delay.At the same time,the inefficient and unencodable characteristics of some receiving terminals of the optimal encoded packet are used to allow more terminals to participate in the cooperative transmission process.Secondly,in the D2 D network,when the relay terminal has data processing capabilities,a sending terminal selection scheme based on networking weights is proposed,which allows the set of complementary terminals for data packets in the geographical vicinity as the set of sending terminals,increasing the D2 D group The possibility of the network,and then optimize the link quality,so that more user equipment to join the D2 D network,effectively improving the efficiency of transmission.Thirdly,after D2 D networking,when the data packet has a deadline,the weight of the retransmission of lost data and the transmission of new data is measured,and a transmission scheme based on the selection is proposed.of the transmission gain weight.In this solution,the IDNC graph and queue idea is used to build an IDNC graph model based on packet deadlines to measure the transmission gain of relaying lost data and sending new packets,effectively reducing the proportion of overdue packets.and improving the user.experience.At the end of the thesis,a general summary of the full text of the research is carried out and the future direction of the research is detailed.