Research On Radio Resource Allocation Of Device-to-device (D2D) Communication Underlaying LTE-advanced Networks

As the rapid development of intelligent terminals, the demands for the multimedia services and high data rates have rapidly grown which means that the development of cellular networks in the future moves towards higher data rates, spectral efficiency and network capacity. D2D(Device-to-Device) communications is a short distance communications from terminal device to another terminal device. D2 D communications can improve the spectral efficiency of LTE-A system(Long Term Evolution Advanced), improve the communication quality between the users on the edge of cell, reduce the offload of the base station and reduce the energy consumption of terminals.The resource allocation problem of D2 D communications underlaying LTE-Advanced system is researched in this thesis. Firstly, the LTE-Advanced system is introduced simply and the key technology is analysed. Then, the fundamental principle, system model and the session establishing process about D2 D are selective introduced, and the interference of non-orthogonal reuse model is simulated and analysed. The resource allocation schemes of D2 D are summarized in the end.After the research of proposed schemes of resource allocation, two schemes are proposed in this thesis for the D2 D communications and D2 D communications with relays to maximize the system thoughtput. Both of them adjust the transmission power and choose the appropriate reuse combination to maximize the system throughtput while guaranteeing the quality-of-service(QoS) requirements for all users. Numerical simulation results show that the two proposed methods can both obtain satisfied performance.Finally, the fisrt resource allocaton scheme is optimized by jointing the resource allocation and interference alignment for the circumstance where multiple D2 D users reuse the same resource. Numerical simulation results shows that it can further improve the system throughtput.