In this paper

improved greedy algorithm was used to allocate radio resource at one slot based on limited radio resource.User’s priority was confirmed according to user’s quality of service and data queue information.Under the condition of knowing channel state information

subcarriers and bits were dynamically allocated to user according to priority

after searching all subcarrier channels on the basis of minimum transmitted power.Simulation results show that under the condition of two kinds of bit rate

when the same number of users were accessed in system

the proposed algorithm consumed power 3.9622W less than traditional greedy algorithm;the improved algorithm consumed power 1.9858W more than previous algorithm

but two more users were accessed.The average power that was consumed by users was 2.2456W/user less than former algorithm.