Radio Resource Allocation For D2D Communication In Underlaying Cellular Networks

Nowadays everyone wants to have high speed internet,all these services require high bandwidth.The spectrum bandwidth is a limited resource,so the best option is to optimize the use of the spectrum bandwidth.To increase the spectrum bandwidth,we need to consider a technology,which we can implement in the future telecommunication mobile networks.One of the technologies that can improve the throughput,can be achieved by Device-to-Device(D2D)communications in under-laying cellular networks which allows devices to communicate directly with each other in the licensed spectrum band of the cellular network.In this research,we studied D2 D communication in in-band mode where the radio resources of the licensed spectrum are used for communication.The in-band mode is sub divided into the Underlay D2 D and Overlay D2 D communication,In Underlay D2 D communication,the D2 D users reuse the radio resources of a cellular user and the communication will be managed by base station of the cellular networks,this means that the base station will assign radio resources to cellular users and D2 D users.We implement a system model in a single cell environment,where there are cellular links and D2 D links in the same network.We propose a resource allocation scheme where the cellular radio resources are allocated to D2 D links.The transmitter and the receiver of the D2 D user forms the D2 D link.The cellular user and the base station forms the cellular link.So in the system model we have cellular links and D2 D links which are randomly changing the position in the cellular network.Our aim is to proposed an algorithm assign cellular resources to D2 D links to optimize the performance of throughput.The proposed algorithm assigns the cellular radio resources to the D2 D links with minimal interference,when resources of the network are shared the sum rate of the cell can increase.The Signal to Interference Plus Noise Ratio(SINR)is the parameter which is related to Interference.To share a resource with the cellular user,we first check the quality of the SINR of the cellular user,and we also check the SINR quality of the D2 D link.The data of the cellular SINR and D2 D SINR is stored in a matrix.We analyze the data in the matrix and choose based on Quality of Service(QoS)constraints which cellular link can assign their resources to a D2 D link.Finally,the matrix will contain D2 D links that are allowed to use the resources of the cellular links without affecting harmful interference to them.The proposed algorithm is simulated with MATLAB software and the performance of the algorithm is evaluated by analyzing the simulations results and compare it with two scenarios.