Wavelet Supersede FFT in MB-OFDM: an Effective Cognitive Spectrum Sensing

The curiosity of human on wireless devices is expanding exorbitantly, emphasizing high data rates and band width requirements. Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) is the technique that victuals high data rate. Studies manifests that most of the licensed bands are not exercised in an efficient way thereby leading to the progression of cognitive radio which allows the secondary users to access and activate the free band of primary users. Moreover, sensing the free holes is the prior concern in CR cycle. With the existence of diverse spectrum sensing methods each with its own pros and cons, this study is mainly subjected about the enhancement of energy detection method owing to its ease, simplicity and monotony. The Fast Fourier Transform (FFT) block of the above method is replaced with Discrete Wavelet Transform (DWT) as it can operate in both time and frequency domains. Four wavelet families are discussed in this study. The results are perceived from the probability of detection (pd) versus Signal to Noise Ratio (SNR) graph.