Reliable Multicast Schemes For D2D Multicast Cluster In Wireless Cellular Network

With the development of wireless smart devices and the explosive growth of access to cellular network devices,existing mobile communication systems often cause traffic congestion due to simultaneous handling of a large number of traffic service requests.Among these large number of traffic requests,there is a kind of multicast traffic,which is formed by multiple devices requesting the same service data.Because these devices request the same traffic,the base station can send data to them by multicast.However,in the conventional multicast operation,the node that does not correctly receive the data requests the base station to perform the retransmission operation,thereby increasing the burden on the base station.With the development of mobile communication technology,a concept called D2D(Device-to-Device)communication technology has been introduced in the concept of the fifth generation mobile communication system.The D2 D communication technology allows devices in the cellular network to communicate directly without relaying through the base station,greatly eliminating the additional burden of the base station due to relaying.In this way,using D2 D communication technology to assist the base station to perform multicast operation can effectively reduce the load of the base station and increase the network throughput.In this paper,two multicast scenarios based on D2 D are designed for multicast scenarios where multicast nodes are located in a small range(called multicast clusters):1.Design a cluster-based energy efficient D2 D multicast transmission scheme.The scheme performs sub-cluster partitioning on nodes in the multicast group,and optimizes data transmission power of the forwarding nodes in each sub-cluster,thereby minimizing energy consumption of each node.Firstly,a heuristic sub-cluster partitioning algorithm is proposed,which assigns the sub-cluster attribution of all nodes that do not receive the data packet correctly.Then the problem of minimizing the energy consumption of the forwarding node is modeled,the attribute of the problem is analyzed,and the problem is proved to be a convex optimization problem.Then an efficient power allocation algorithm is designed based on the convex optimization theory.This algorithm significantly reduces the energy consumption of the forwarding node.2.Design a high-throughput D2 D multicast transmission scheme based on network coding.The network coding technology can effectively deal with the packet loss problem in multicast,and greatly reduce the number of packet retransmissions.In the design scheme,the base station transmits the data packets to be multicast in units of groups.Regarding the multicast of each group of data packets,the base station multicasts the network-encoded data packets instead of the original data packets,and the node forwards the data packets that re-encode the received packets.This scheme effectively reduces the number of packet retransmissions,thereby increasing the multicast throughput.The above two multicast schemes are optimized with energy efficiency and throughput respectively,and can be applied to different types of multicast scenarios in the cellular network to improve the performance of the cellular network.