Spectrum sensing in cognitive femto base stations using welch periodogram

Reliable spectrum sensing is one of the key technologies for enabling cognitive communications. In this paper, spectrum sensing based on Welch periodogram is applied to a femtocell scenario where cognitive femto base station (FBS) is located in the same frequency band as the surrounding macrocell and neighboring femtocells. Parameters for the femtocell simulations are selected based on 3G Partnership Project (3GPP) contributions to tie this work to on-going femtocell standardization work. Different interference scenarios are also discussed. Spectrum sensing based on Welch periodogram is presented, and two scenarios including a user equipment (UE) located indoor and outdoor are selected for further study. The results, given as receiver operation characteristic (ROC) curves, clarify the practical regions inside of which spectrum sensing is capable of providing reliable results for sensing the presence of the MUE.