Sub-channel and power allocation for multiuser OFDM systems with proportional rate constraints based on genetic algorithms

Abstract

This paper considers sub-channel and power allocation based on genetic algorithms to maximize the overall system capacity using proportional rate constraints in multiuser orthogonal frequency division multiplexing (OFDM) systems. The proposed algorithm first performs sub-channel allocation using a rough rate constraint under the premise of equal power allocation among the sub-channels. Then power allocation proceeds based on the subchannel allocation scheme to implement proportional fairness and maintain maximum system capacity. Owing to the separation of sub-channel and power allocation, the computational complexity can be reduced from exponential to linear. Additionally, both the sub-channel allocation and power allocation are based on genetic algorithms, so the computational complexity of the proposed resource allocation algorithm can be further reduced. Simulation results show that the proposed algorithm achieves about 95% of the maximum capacity in an eight-user system and that the ratio of data rates among users can be set freely. © Springer-Verlag Berlin Heidelberg 2013.