Adaptive resource allocation in OFDM-based multicast system

In this paper, we consider a resource allocation problem for the downlink in OFDM-based wireless cellular network systems. The objective is to maximize the capacity under the constraint of total transmission power. The problem belongs to the category of nonlinear integer programming, which is NP-hard. Firstly, a subcarrier full search algorithm with perfect bit loading scheme is proposed to solve the problem. To reduce the computational complexity, a subcarrier descending order search scheme is proposed to replace the full search algorithm. Numerical results show that the proposed low computational complexity algorithm outperforms the existing scheme and obtains a significantly performance gain than the conventional scheme.