Publication

Abstract : Cognitive Radio is an efficient technique to exploit the underutilized electromagnetic spectrum by introducing opportunistic usage of frequency bands that are not occupied by primary users. Spectrum sensing is a fundamental part of Cognitive Radio systems. A common low complexity technique for spectrum sensing is energy detection, however energy detection is known to fail in the presence of noise uncertainty. In this paper a window based energy detection technique that reduces the noise in the spectrum by averaging the power samples in the frequency domain is proposed to identify the presence of primary users. It is clearly shown that this window based technique improves the detection performance. Moreover the existence of primary users in sub bands of the wideband signal is also identified using this modified method. Simulations based on wideband signals in both fading as well as non fading environment are presented to verify the proposed technique.