Abstract
A multiuser Orthogonal Frequency Division Multiplexing (OFDM) system with perfect channel knowledge and limited power at base station is studied to maximize the average system throughput. Data rate and bit error rate (BER) can be adaptively changed with the channel variation. An efficient and low complexity algorithm for subcarrier and power allocation in OFDM systems is proposed in this paper. We consider an OFDM downlink system where each subcarrier is used by only one user. Since our resource allocation problem is non-convex, it is not easy to find an optimal solution. Our approach is to consider a user iterative water filling algorithm (IWF), which is concave, and find a numerical method to approximate the optimal solution for our non convex problem. Our results show that each subcarrier is allocated to a user by taking into account channel gains and interference caused by other users.
