Study Of Radio Resource Allocation In IMT-Advanced System

As the development of wireless broadband communication, researchers have being dedicated to plenty of transmission technologies in order to improve the integrated performance of current wireless telecommunication system. Meanwhile IMT-Advanced system emerges in such an environment, which aims at high data transmission rate and fulfilling the quality-of-service (QoS) of each user in the system. Relaying is one of the proposed technologies for IMT-A system, and this has become a research hotspot due to the capacity advantage and extension of cell coverage area it brings. Based on the relay-aided system architecture and OFDMA technique, two different kinds of downlink resource allocation methods are proposed in this paper. They focus on downlink capacity and fairness respectively. The former applies Lagrange Multiplier Method, iterative algorithm and adjustment to approach the maximum system downlink capacity; the latter employs resource reuse and multiuser diversity, which can not only achieve high subcarrier utilization but also guarantee fairness between users. Simulation results show that compared with traditional algorithm, the former improves the performance of system downlink capacity significantly and the latter increases system fairness factor.