Resource Allocation Algorithm Research For Device-to-Device Communication In LTE

With the continuous development of mobile communication technology in our country, the mobile communication system has been gradually moving towards3G era and further development to4G. As a transition of the mobile communication transfers from3G to4G, the LTE system has become a research hotspot.With the increasing demand of the system bandwidth, bandwidth allocation is becoming more and more crowded,furthemore spectrum resources that can be used for mobile communication is also quite limited. So it is necessary to maximize the use of existing spectrum resources of the system and increase the system throughput.In order to solve this problem,D2D(Device-to-Device) communication technology cames into being.D2D communication is a new technology under the control of the LTE system,which allows the terminals to communicate with each other directly through reusing cell resources.It is able to increase the spectral efficiency of cellular communication system and lower terminal transmit power, solve the problem of lacking spectrum resources of the wireless communication system in the certain extent.By reusing cell resources, D2D communication technology can make the spectrum resource utilization improved, but reusing cell resources will increase the intra-cell user interference.In order to reduce such interference and improve utilization of the spectrum, the thesis focuses on two kinds of D2D communication resource allocation algorithms:One is resuing single-user resource based on position information. The algorithm determines the reuse of resources mainly according to cell user’s location information, to reduce interference maximumly which D2D communication users interfere with cellular users and the time complexity of the algorithm;Another is reusing multi-user resources to reach a maximum cell throughput. The algorithm is by reusing a plurality of user resources to achieve the maximum throughput of the system and spectrum utilization, while the interference is within a certain range. This thesis mainly analyzes the two kinds of resource allocation algorithm principle, formula derivation, working process and performance analysis.Simulation results show that the throughput by reusing the single-user resource allocation algorithm based on the location information has achieved approximately equal to greedy algorithm,while reached only fifty percent of the time overhead of the greedy algorithm. Comparing to the reuse of single-user resource allocation algorithm, the reuse of multi-user resource allocation algorithm can achieve higher spectrum efficiency and system throughput, make the minimum interference which D2D users interfere with cellular users, but there is a certain increase on the time overhead of the algorithm.