In this work, a method that evaluates both sub-carrier and power allocations together for the users of OFDMA systems is proposed. In practical usage, the allocation to users is implemented from existing subcarrier group considering the transmission power of users is limited. The aim of this study is the realization of subcarrier allocation without exceeding power constraint for each user. In order to make subcarrier allocation fair between users, (REHK)-E-2 algorithm has been performed. User outage probability has been utilized so as to measure the performance of proposed method. Owing to the proposed method, transmission power gain has been achieved without compromising on the outage probability performance.