— We address the problem of radio resource allocation in the Downlink (DL) of relay–aided cellular system, based on OFDMA transmission technology. There has been little work on specific resource allocation algorithms for this system in the literature, although these are the key elements for realizing the potential capacity and coverage increase offered by the relay. Therefore, we propose two resource allocation algorithms which improve the overall throughput and coverage compared to a system without relay. The advantage of our algorithms is that they perform well while minimizing the complexity and the required amount of Channel State Information (CSI), making them suitable for practical use.