Efficient Beamforming Technique for Cognitive Radio Networks
Zahed Hossain, Ummy Habiba, M. A. Matin · Journal of Advances in Information Technology · 2013
In cognitive radio, it must be ensured that the received signal to interference noise ratio (SINR) of the secondary users (SUs) is at certain level for reliable communication. Therefore, firstly a new beamforming problem has been formulated in this paper considering few new constraints in addition to the only constraint of the conventional minimum variance beamformer and secondly, a solution has been provided using Lagrange multiplier method and complex-matrix calculus to reduce the interference due to the presence of SUs. The simulation results show that our proposed solution put a deeper null towards the direction of the primary users (PUs) than the conventional beamformer. Furthermore, the response of the presented beamformer has been examined with different number of array elements and inter-element spacing.