Spectrum Sensing Analysis Using Water-Fill Algorithm and Energy Detection Using GNU-Radio for Cognitive Radio Users

In this paper, the power spectrum density (PSD) has been considered based on energy detection problem by spectrum sensing for cognitive radios. It is shown that there is an improve in PSD performance of the receiving signal of interest from NI-USRP-2920 using the water-filling algorithm. Further the comparison has been shown using FFT/NFFT conventional periodogram and water-filling algorithm. The constellation pattern has been shown for identification of the multi signal channel (Presence of the primary signals in different bands). The simulation has been performed using real-time signal and QPSK demodulation.