Radio Resource Management for Improving the Spectral Efficiency on D2D Underlaying Communications Using A Modified Joint-Greedy Algorithm

Device-to-Device (D2D) underlaying communication system may be the solution to increase system data rate and reduce the workload of eNodeB. This communication system shares the same resources to two types of user, the cellular users and D2D pair. However, by using same resources, D2D underlaying communication system will increase the interference level among users. To overcome this problem, a good allocation algorithm is needed to allocate Resource Blocks (RB) which used by Cellular User Equipment (CUE) and D2D simultaneously. This work assumes all CUEs will use the RB first. The D2D pairs RB allocation take place after all CUEs get the resource. A modified Joint-Greedy algorithm is proposed to improve D2D pairs RB allocation process. The algorithm consist of two main phase. In the first phase, all D2D pairs will choose the best RB on the system, that being used by the CUE, and take that RB as a candidates. In the second phase, the eNodeB (eNB) will decides which of these candidates that will be allocated to D2D pair by searching the minimum impact of each CUE. From the simulation process, system with underlaying D2D communication can increase the system spectral efficiency system by 30%. Modified Joint-Greedy algorithm allocates can improve spectral efficiency of the system by 3.059% compared with mean-greedy allocation algorithm and 4.33% compared with a conventional greedy algorithm.