Research On Establishment Mechanism And Resource Reuse For Device-to-Device Communication In 5G Cellular Networks

With the increasing availability of massive intelligent terminal equipment and the emerging business that meets the needs of specific users,the contradiction between the explosive growth of data traffic and the shortage of wireless spectrum resources is emerging day by day.It is imperative to increase network capacity,improve spectrum utilization,and enhance Quality of Service(QoS)from richer communication modes.Device-to-Device(D2D)communication technology acts as one of the candidate technologies in 5 G,which will show its advantages based on the ultra-high speed,ultra-large bandwidth,ultra-large scale access and oversized data processing capacity of mobile communication technology in the future.D2D will reuse the resource of cellular network to improve system throughput,which however introduce D2D device discovery,establishment,interference and other issues.The paper focuses on the mechanism of D2D device discovery which meets the specific requirements and the algorithm of resource reuse which can reduce inter-user interference and improve system throughput performance.Based on the introduction of research background,significance and development of D2D communication,D2D device discovery process is proposed to meet the specific requirements of different solutions,and then detailed analysis of the interference that D2D reuse licensed spectrum resource of cellular uplink and downlink.The paper simulated the FFR algorithm,which is compared with other resource allocation algorithms and the results show that the FFR algorithm is superior to others.FFR-based divided sector algorithm and FFR-based divided reuse and communication restricted area algorithm are propsoed and the simulation results show that the two algorithms proposed in this paper can obtain better system throughput compared with FFR algorithm,meanwhile,we find out the optimal ratio of center area to total area that maximizing cell throughput.In addition,considering that data transmission of cellular users will be transferred to the unlicensed spectrum in the future,so we analysis various models of D2D reuse resource after the introduction of unlicensed and simulate user's throughput of four modes.The simulation results show that the throughput of the cell is optimal under the CUE-licensed+CUE-unlicensed+D2D-reuse-licensed mode in the coexistence scenario of the licensed and unlicensed spectrum.