Research On Design And Construction Of Coded Caching Scheme Based On MDS Codes In Internet Of Vehicles

Coded caching is a novel cache placement and delivery scheme based on network coding proposed in 2014.It designs the data cached in the users,then decides which the data need to be sent according to the users’ needs,and transmits the data to the broadcast channel through network coding.Coded caching can further obtain global cache gain on the basis of local cache gain,which can greatly reduce the amount of data transmission during the peak period of network requests.Considering that in the future,the Internet of Vehicles will require a huge amount of data transmission.At the same time,the Internet of Vehicles channel will change when the vehicle moves.Therefore,this poses a severe challenge to the transmission performance of the system.This article will delve into the design of the coded caching scheme in the Io V system and recover the lost data during transmission.First of all,this paper analyzes the relevant theories of coded caching.Centralized coded caching and decentralized coded caching are given respectively,and their corresponding achievable rates are given.A theoretical proof was carried out.The performance gain of the coded caching compared to the uncoded cache is verified through simulation.Then,this paper proposes a data placement and transmission scheme based on Maximum Distance Separable Code(MDS)code and decentralized coded caching for heterogeneous Io V systems.The data deployment and transmission schemes of macro base stations and roadside units are analyzed respectively,and the corresponding decentralized coded caching transmission schemes and optimal guidelines for roadside unit storage and macro base station transmission are given.At the same time,the amount of data sent by the corresponding caching is derived.The simulation results show that the use of coded caching can greatly reduce the data transmission amount of the Io V system.Finally,this paper gives two recovery schemes for lost data for two communication links in a heterogeneous Io V system.For the link from roadside unit to vehicle,a unit composition matrix is used to construct a flexible fast coding scheme that adapts to channel changes;for the link from the macro base station to the vehicle,a redundant vectors scheme is given to assist the vehicle to recover the lost data.The simulation results show that the two schemes can reduce the amount of data transmission compared to the feedback retransmission scheme.