Adaptive rate balancing techniques in cognitive radio networks

We propose an adaptive bit and power allocation technique for an orthogonal frequency division multiple access based cognitive radio network. The resources are allocated such that each secondary user attains equal data rate while ensuring the interference leakage to the primary users is below a specific threshold. Integer linear programming based optimal algorithm and a suboptimal method based on greedy algorithm have been proposed. Integer linear programming based optimal method is of high complexity whilst the suboptimal method has a lower complexity and performs closer to the optimal method. The simulation results are provided to compare the performance of the suboptimal method with that of the optimal method.