Research On Resource Allocation Algorithm For OFDMA System

Orthogonal frequency division multiple access (OFDMA) is a typical 4G system, which suffers severe Inter-Cell Interference (ICI) and becomes a challenging problem. Meanwhile, future communication system supports various types of services, which have different QoS requirements, how to use the limited resource effectively is an important issue.Firstly, this paper introduces OFDMA system theory, multiple access schemes, key technologies and radio resource management. Secondly, we introduces traditional resource allocation scheme. Traditional schemes always ignore different QoS requirements of multi-service, which is an essential feature of future system; they usually adopt complex cell edge part separation resource allocation scheme, and allocation of cell inner is too simple. But real coverage of cell is irregular, and ICI relates to electromagnetic wave transmits, so cell separation should take into account electromagnetic wave path loss; as system performance, the allocation of inner part areas is of vital importance. Users have location and service dual factors, if we only consider interference increment, high QoS service would not be guaranteed; if we only consider service QoS requirement, it would lead to severe ICI.Thirdly, we present a novel cell-level associated area location and service allocation (LSA) scheme to solve these problems above. LSA analyzes ICI of area location of inner part quantitatively to define area classification, and it sets area priority associated with services QoS requirements of each area. LSA defines inner part and edge part sub-carrier priority list, and LSA guarantees sub-carrier to optimum match with resource requirement of each area, by which to decrease ICI and meet various service requirements. In fact, LSA associated optimize resource allocation among area location and service requirement as well as sub-carrier priority.Last, this paper designs and completes the OFDMA system level simulation platform. Based on the platform, the novel LSA algorithm performance is evaluated by simulation analysis. The simulation results shows that LSA algorithm can decrease system interference and reduce new call blocking probability, improving resource utilization.