The Triple-Interface IDNC Transmission Scheme Based On Space-Air-Ground Integrated Network

The improvement of communication demand is urging the rapid change of network technology.In the future,relying solely on the traditional ground communication mode will be difficult to cope with the explosive growth of network load.The construction of Space-Air-Ground Integrated Network(SAGIN)composed of satellite network,air network and ground network has become the mainstream development trend.However,there are significant differences among the different networks in SAGIN.There are still many challenges in the integration application between space,air and ground networks.Instantly Decodable Network Coding(IDNC),as a technology that can effectively improve network throughput,has been applied in many transmission scenarios.In order to solve the above problems and at the same time obtain the benefits of IDNC in SAGIN,a threeinterface cooperative transmission scheme combining IDNC technology and space-ground integrated network is proposed in this thesis,and the specific work of this thesis is as follows:Part one,propose a triple-interface IDNC method based on SAGIN.Firstly,establish the system model of triple-interface IDNC,analyze the decoding delay and completion time performance of the system according to the model,and give the calculation formulas of them.According to the formula,the decoding delay and completion time minimization problem is transformed into the optimal coding packet scheduling problem,then construct the coding conflict graph of triple-interface IDNC.The optimal coded packet is obtained by the maximum weight coded independent set algorithm based on IDNC graph.Simulation results show that compared with the traditional IDNC,the triple-interface IDNC has lower decoding delay and completion time and has stronger anti-interference performance.Part two,investigate the performance of triple-interface IDNC under lossy feedback.Firstly,analyze the impact of feedback loss on system transmission,and propose a maximum likelihood estimation method to deal with unknown feedback.At the same time,two mathematical expressions of IDNC performance under the maximum likelihood estimation method are given.By setting different weights,the set of coded packets that minimizes the system decoding delay and completion time is obtained.Simulation results show that the proposed scheme can reduce the decoding delay and completion time of the system while ensuring reliability.