Research On Resource Allocation Scheme Of Device-to-Device Communication In LTE Networks

D2D communication underlying cellular network is a novel technology that the adjacent users communicate to each other directly without the base station’s relaying, which shows dominant advantages in improving both spectrum efficiency and system throughput, but also reduces communication latency.In the case that D2 D links have more quantity than cellular links, spectrum efficiency could be raised by reusing the same wireless resource among some D2 D links, which might introduce more complicated interference. To solve the distraction above, three n-to-1 resource reuse schemes are proposed upon graph theory, through which pairs D2 D and cellular users.According to the interference topology created with interference between D2 D links, graphcoloring based uniform clustering scheme clusters D2 D links based on graph coloring theory ensuring the interference of all the D2 D links in the same cluster is tolerable. The reconstruction of the clusters produced is made on different resources to provide the QoS for all users. The allocation of the reconstructed clusters is the last step. The analysis of the simulation shows the first scheme may increase the access rate of D2 D users and improve system throughput.Other than the scheme above, the amount of D2 D links in the cluster is unlimited in improved graph-coloring clustering scheme if only the interference of all the D2 D links is acceptable. After the first allocation, the unassigned D2 D links and the reconstructed clusters should be paired off again. Lastly, the clustering of the unpaired D2 D links is conducted again based on the graph coloring theory. The improvement of the access rate in improved graph-coloring clustering scheme is greater than the first scheme, according to the result of the simulation.The schedule of D2 D users has the higher priority in the D2D-clusters-first scheduling scheme, which means the D2 D users is clustered and scheduled at first. Then cellular users’ resource could be allocated on the account of available wireless spectrum. Simulation results show that, compared with the cellular-users-first scheduling scheme, the proposed method can achieve higher cellular system throughput.