A new waterfilling power allocation model in cognitive OFDMA networks

In this paper, the resource allocation problem for the uplink of cognitive orthogonal frequency division multiple access (OFDMA) networks which coexist with primary networks is studied. Specifically, with the objective of maximizing secondary users (SUs) sum-rate, we investigate joint subcarrier and power allocation approaches, in consideration of both transmit power constraints of SUs and interference power limit at primary receivers. Simulation results indicate that the waterfilling algorithm based on the proposed model yields substantial performance gains over the classical waterfilling algorithm for the single SU and multi-PU spectrum sharing case.