Design Of Network Coding Transmission Scheme For 5G Protocol And NS3 Simulation Implementation

With the development of the mobile communication system,the ultra-high speed requirement of the fifth-generation mobile communication system makes the millimeter wave frequency band gradually enter people’s field of vision.There is a large amount of available bandwidth in the millimeter-wave frequency band.However,due to the short wavelength of millimeter waves,the attenuation in transmission is relatively obvious,the diffraction ability is poor,and the path loss is also very serious.The inherent defects of these high frequencies lead to the need for very dense base station deployment,which is unrealistic according to the original 4G optical fiber backhaul scheme,because this will lead to a sharp increase in the cost of communication.Therefore,based on the original LTE relay,3GPP proposes the concept of integrated access backhaul and uses a wireless backhaul solution.In the case of network congestion,the configuration of wireless backhaul deployment has the potential to improve the overall network throughput and reduce communication delay,but at the same time wireless backhaul also poses a great challenge to the reliability and delay of transmission,and the uncertainty of wireless channels Sexuality becomes an urgent problem.At the end of the twentieth century,advances in theoretical research such as information theoretical frameworks,matroids and information theory promoted the development of theoretical research such as distributed coding and information inequalities.As a result,a new research field of ”network coding” was born.The main feature of network coding is that it breaks through the fixed mode of storage and forwarding in traditional data transmission,so that nodes have the ability to process data.On the one hand,the network capacity can be improved by performing network coding at the intermediate nodes,and on the other hand,the network coding at the source node can make the data equivalent,and then reduce the retransmission and reduce the overall network delay by increasing the redundancy of the preceding item.Network coding provides a new solution for wireless backhaul with its unique advantages.By studying the application of network coding in the existing 5G access network transmission protocol,this paper verifies the gain brought by the introduction of network coding in access network data transmission.And for the popular H.264 SVC video transmission scenario,a network coding-based unequal error protection scheme is given,showing the great potential of network coding.The main contributions of this paper are as follows:(1)Considering the existing 5G access network protocol system,design a new protocol stack that couples the network coding layer.This paper proposes a design scheme of the network coding layer,which performs network coding on the original data packets at the source,ensures the reliability of transmission by increasing the coding redundant data packets,and reduces the retransmission,thereby reducing the transmission delay to a certain extent.gain.After the research on the packet loss rate of each layer,the link layer with the most obvious network coding gain effect is selected as the coupling position of the network coding.The design of the header is given,and the overhead is reduced as little as possible.At the same time,for the network coding transmission scheme,a network coding retransmission mechanism is designed to further reduce the retransmission while ensuring the decoding success rate.And the transmission scheme is simulated on the ns-3 platform.The transmission performance of the network coding protocol stack and the traditional protocol stack is compared.The simulation results show that the network coding scheme has obvious gains for data transmission in the access network.(2)For H.264 SVC video transmission,this paper proposes an unequal error protection scheme based on network coding.Without destroying the video frame structure,the special structure of the coding matrix,by optimizing the proportion of the base layer data packets and the enhancement layer data packets in the degree distribution,makes the degree distribution ratio of the base layer better than that of the enhancement layer.In this way,the protection of important data at the base layer is realized.Based on this idea of unequal error protection,several unequal error protection schemes,RLNC-UEP,sparse RLNC-UEP and systematic RLNC-UEP,are proposed.The performance of the scheme is theoretically analyzed,and the upper and lower bounds of the performance of the unequal error protection scheme are given.The simulations and comparisons between the proposed schemes and the EEP scheme are carried out to verify the performance advantage of the network coding UEP scheme in transmitting layered data.