Simulation Of Adaptive Resource Allocation Algorithm In LTE-Adavanced Relay System

In order to satisfy the growing requirements on higher service quality, capacity, transmission rate as well as more wireless multimedia service types, relay technologies are introduced into WiMAX, WINNER, and 3 GPP wireless communication standards and conducted in-depth research. As one of the key technologies in next-generation mobile communication systems, relay communication technology plays an important role in reducing operational costs, eliminating coverage blind spots, improving the cell edge users' communication quality, increasing system capacity, expanding the area coverage and easing emergency communication which has become a hot topic in wireless communications.In order to improve the overall system performance, relay stations in multi-hop relay cellular networks (MRCNs) may consume additional radio resource compared with traditional single-hop network. Therefore, how to design optimum relay resource allocation scheme to increase system resource utilization has important research values.Adaptive resource allocation schemes in the context of single-sector single-relay and single-sector two-relay are discussed in the thesis. The main research contents and contributions are as follows:Firstly, the wireless two-hop relay cellular network simulation platform is implemented based on the LTE-A system-level structure, in which the channel, mobile and relay station module are modeled and simulated. Particularly, the simulation of mobile station module is improved by means of grid distribution. Performance involving throughput, spectral efficiency and coverage rate are simulated through the system-level simulation platform and compared with the single-hop network, on the basis of which, performance improvement is analyzed.Secondly, efficient transmission path selection algorithm and frequency reuse between RS (Relay Station) and BS (Base Station) can be effective in alleviating the demand pressure for additional relay resource in MRCN. Taking into account RS's reusability in the time, frequency and space domain, the thesis proposes a method that compares the achievable rate of users to select the appropriate transmission path on the basis of the SINR(Signal to Interference plus Noise Ratio). Moreover, the improved throughput-guaranteed scheduling method based on proportional fair method is presented.Then the resource allocation algorithm of Fixed Time Allocation (FTD) and Adaptive Time Allocation (ATD) for the single-sector single-relay scenario is proposed and evaluated. Meanwhile, RS-RS interference avoiding scheme(RRIAS) and BS-RS interference avoiding Scheme(BRIAS) for the single-sector two-relay scenario are elaborated and compared with full frequency reuse(FFR) algorithm and ATD-BRIAS algorithm.Numerical and simulation results show that the proposed solutions can greatly increase the system spectral efficiency, edge of the user's spectrum efficiency and system coverage in Two-hop Relay Cellular Network.