System and method for resource allocation of OFDM system

The invention relates to a resource allocation system for an OFDM system, comprising subcarrier wave and power allocation module, characterized in that the subcarrier wave and the power allocation module allocate subcarrier wave to each user according to user rates, user channel conditions and user priorities and by a first target function making subcarrier wave capacity maximum and limiting conditions and a second target function making realtime service interrupt probability minimum. And it also provides a resource allocation method. By the two target functions, it assures the maximum subcarrier capacity and simultaneously considers subcarrier waves of realtime service, reducing communication interrupt probability of realtime service.