This paper presents a efficient resource allocation algorithm for the multiuser orthogonal frequency division
multiplexing(OFDM) system based on the network utility maximization framework. In the wireless context, the optimization
problem is nonconvex, which makes the problem difficult to be solved by using the classical optimization theory. Particle
swarm optimization(PSO) algorithm is applied to the design of the optimization problem. To improve the performance of
standard PSO algorithm and avoid trapping to local excellent result, a chaos PSO(CPSO) algorithm is presented, which
embeds logistic chaos into the PSO algorithm. The proposed algorithm can solve the nonconvex optimization problem
efficiently and outforms other algorithms.