Wideband spectrum sensing using Welch periodogram in cognitive radio

Spectrum sensing is a key function of cognitive radio (CR) to identify the vacant frequency bands (which is also referred to as spectrum holes). The future technology of CRs should be capable to scan wideband frequencies to increase spectrum utilization. This paper investigates a wideband spectrum sensing technique based on energy detection in frequency domain using Welch periodogram. The signal of primary user is modeled as multiband signal with 3 pairs of active band in each simulation. To reduce high sampling rate due to sensing of a wide bandwidth, CR receiver operates at sub-Nyquist sampling rate using Modulated Wideband Converter (MWC). Performance metrics like probability of false alarm (PF), probability of detection (PD) are evaluated by analyzing receiver operating characteristics (ROC) curve. The simulation shows that ROC curve of Welch periodogram gives better result then periodogram.