Study On D2D Communication Technology Based On Network Coding In Cellular Networks

Device-to-Device(D2D)communication is a direct communication technology of device to device.It allows terminal users to communicate directly by sharing cellular spectrum resources under the control of cellular base station.As the key technology in the 3GPP long term evolution(LTE)research project,D2D communication can effectively improve the network capacity and utilization of spectrum.Compared with the traditional cellular communication,D2D communication does not need to be forwarded by base station,two users who are close to directly transmit information,which solve the problem of shortage of spectrum resources in a cellular network.What's more,it can reduce communication delay,save terminal energy consumption,and extend the coverage of cellular communication.However,when D2D communication reuses the spectrum resources of cellular users,there inevitably exists spectrum interference between D2D communication and cellular communication.In this paper,D2D communication in cellular network is studied with network coding technology,and the main research results are as follows:1.D2D relay transmission algorithm based on complex field network coding.In cellular networks,when D2D communication reuse the cellular downlink spectrum resources to communicate,by introducing an appropriate relay node,and in the relay node,the cellular signal and the D2D signal are encoded by the complex field network encoding,and then the complex field network coding signal is forwarded to the cellular user and the D2D receiver.The D2D receiver and the cellular users can correctly recover the desired signal by joint maximum likelihood detection.Theoretical analysis and experimental simulation show that the system achievable rate of the algorithm is much better than that of the traditional D2D transmission algorithm,the outage probability is less than that of the traditional D2D transmission algorithm,and the symbol error probability of the receiver can be reduced.2.D2D interference cancellation and cooperative forwarding scheme based on network coding.When two pairs of D2D users to reuse the same uplink spectrum resource in cellular network,in order to eliminate the interference caused by the cellular users to the D2D users and the interference between the D2D user pairs,in the D2D transmitter,the D2D signal and the cellular signal are encoded with network coding,and allocated the complex field network coding coefficient for each D2D transmitter.Then the coefficient is multiplied with the network coded signal and sent to the two D2D receivers.At the D2D receiver,the D2D signal can be recovered from the received cellular signal and the network coding signal.Performance analysis show that the outage probability of the proposed scheme is lower than that of the traditional D2D communication scheme,and link reachable rate of the scheme is obviously better than the traditional D2D communication scheme.