A power allocation scheme maximizing a discrete capacity function of OFDMA system

In this paper, we propose an adaptive power allocation method for an orthogonal frequency division multiple access (OFDMA) system that employs an adaptive modulation and coding(AMC) scheme. Unlike the water-filling scheme that has been aimed to maximize a continuous capacity function, the proposed scheme is to maximize a discrete capacity function that more precisely characterizes the discrete AMC levels. In terms of complexity, numerical results show that the proposed scheme reduces the processing time by more than 80% comparing with greedy adaptive power allocation (APA), and shows as same performance as greedy APA.