Adaptive Sub-Carrier Allocation for Orthogonal Frequency Division Multiple Access Systems with Minimum Transmission Rate Request
Zhimeng Zhong · Xi'an Jiaotong Daxue xuebao · 2008
Focusing on the problem that traditional resource allocation algorithms result in low spectrum efficiency,an adaptive sub-carrier allocation algorithm was proposed for orthogonal frequency division multiple access systems with minimum transmission rate request.In the algorithm, the utility value of each sub-carrier that can be achieved by different users is first evaluated based on users' minimum transmission rate request,the channel state and the current sub-carrier allocation state.Then,the sub-carrier is allocated to the user,who can achieve the maximum utility value.As both efficiency and fairness are taken into account in the algorithm,the performances of the system are improved remarkably.Simulation results show that,compared with algorithms which consider efficiency and fairness separately,when the number of users is within the system load,the frequency efficiency of the proposed algorithm increases by 10% and the system load within the same range of outage probability increases by 60%.