An efficient resource allocation scheme for OFDMA-based cooperative cognitive radio networks with minimum power constraint

A novel resource allocation algorithm for OFDMA-based cooperative cognitive radio network is proposed. Sum-capacity of Primary Users (PUs) is maximized under minimum power constraint. We design a sub-optimum algorithm with low complexity. In this manner, though sum-capacity does not change significantly, Outage probability of systems decrease considerably. The algorithm is also modified to improve active PUs in the network. Difference between optimum and suboptimum schemes is shown to be negligible in simulation results. These algorithms aim to increase subcarriers of secondary users.