Lagrange Multiplier Based Fair Resource Allocation for MIMO-OFDMA Systems

In this paper, we propose a subcarrier and power allocation algorithm for multiple-input-multiple-output orthogonal-frequency-division-multiple-access (MIMO-OFD MA) systems with channel state information available at the transmitter. Fairness constraint is applied to limit the maximum and minimum number of subcarriers for all users. A Lagrange multiplier method is applied to solve the constrained optimization problem. Solving this optimization problem require multi-dimensional searching. A modified searching method is proposed to improve the convergence speed.