Dynamic relay selection and channel adaptive uplink for LTE Device-to-Device (D2D) communication

With the advancement of smart phone technologies cellular communication has come to a stage where available bandwidth has surpassed the user demands. Moreover, the well organized yet stubborn architecture of cellular networks sometimes creates hindrance to the optimal usage of the network resources. Due to this, a User Equipment (UE) experiencing a poor channel to the evolved NodeB (eNB) suffers with either low-rates or failed transmissions. However, Device-to-Device (D2D) offload/relay underlying the cellular network provides a unique solution where the poor channel UE can find a close proximity relay UE to relay its data to the eNB. In this paper, we have proposed a joint solution for dynamic selection of an optimal relay UE and then adaptive modulation based D2D scheduling scheme. We have considered the dynamic behavior of random wireless channel and mobility of the UEs. We have validated our proposed model using MATLAB simulations. The simulation based observations show significant improvements in network performance.