Robust power control using iteratively reweighted least square (IRLS) for cognitive radio networks

In the cognitive radio network, the secondary users (SUs) are allowed to access opportunistically the unused portion of the licensed spectrum without significant interference to the primary users (PUs). The power control algorithms ensure less interference to PUs as well as maximum SINRs for SUs meeting the objective of minimizing the total transmitting power of cognitive radio network. In our paper, we have proposed an algorithm based on iteratively reweighted least squares (IRLS) approach for all the secondary users in the network satisfying the interference constraints of PUs and SINR constraints of SUs. The algorithm updates transmission powers so that it converges to optimum power vector. This provides SINR of all the SUs above a threshold value maintaining the total interference to PUs within a tolerable limit. Our simulation results show the convergence behavior of the proposed algorithm.