Robust spectrum sensing under noise uncertainty for spectrum sharing

摘要

Spectrum sensing plays an important role in spectrum sharing. Energy detection is generally used because it does not require a priori knowledge of primary user, ( PU ) signals; however, it is sensitive to noise uncertainty. An order statistics ( OS ) detector provides inherent protection against nonhomogeneous background signals. However, no analysis has been conducted yet to apply OS detection to spectrum sensing in a wireless channel to solve noise uncertainty. In this paper, we propose a robust spectrum sensing scheme based on generalized order statistics ( GOS ) and analyze the exact false alarm and detection probabilities under noise uncertainty. From the equation of the exact false alarm probability, the threshold value is calculated to maintain a constant false alarm rate. The detection probability is obtained from the calculated threshold under noise uncertainty. As a fusion rule for cooperative spectrum sensing, we adopt an OR rule, that is, a 1‐out‐of‐N rule, and we call the proposed scheme GOS ‐ OR . The analytical results show that the GOS ‐ OR scheme can achieve optimum performance and maintain the desired false alarm rates if the coefficients of the GOS ‐ OR detector can be correctly selected.