Greedy Algorithm for Dynamic Resource Allocation in Downlink of OFDMA System

This paper investigates the problem of dynamic multiuser resource allocation in the downlink of OFDMA system. To overcome the users\´ buffer overflow, a greedy algorithm is proposed in order to minimize the total power consumption subject to user\´s traffic requirement. The optimization problem is split into two steps. In the first step, we perform subchannel allocation based on the buffer size and channel condition for every user. In the second step, we optimize power allocation for each user based on a single "water-filling" approach. Simulation results show that the proposed algorithm outperforms classical ones, since it offers a reduced total power consumption. We note a 10 dB gain when the number of users exceeds 4