Orthogonal Frequency Division Multiple Access (OFDMA) is a promising technique which can provide high capacity in future communication systems. The total capacity of OFDMA can be maximized by dynamically allocating subcarriers among users according to channel condition. However, it is quite challenging to properly allocate subcarriers in mobile channels due to the time varying property. Existing approach designed for static users assigned the subcarriers with the best SNR to increase the total capacity but to lose fairness. Fairness can be restored by using max-min criterion or constraint limiting the ratios of user data rates to maintain some balance among users. But when users are mobile, the SNR considered should be replaced by the carrier to interference ratio (CINR) because of the presented inter-carrier interference (ICI) due to Doppler Spread. In this paper we successfully incorporate the ICI into our radio resource allocation algorithm to simultaneously optimize the total capacity and fairness for mobile users. The fairness and priority of user traffic are jointly considered in our adaptive algorithm. The algorithm is demonstrated outperforms the existing algorithm designed for static users, and very robust in realistic operation.
['Feng Seng Chu', 'Kwang-Cheng Chen']
Fair Adaptive Radio Resource Allocation of Mobile OFDMA