Spectrum sensing for OFDM systems based on cyclostationary statistical test

As the first step of cognitive radio, spectrum sensing is one of the most important technologies which find the available spectrum for the cognitive users. At present, the promising OFDM techniques are widely used in many wireless communication systems. As a result, sensing the existence of OFDM signals becomes vital for CR system. For this, a cyclostationary statistical test based on spectrum sensing algorithm (CST method) is proposed in this paper. The algorithm takes advantage of the asymptotic properties of the cyclic-covariance to infer the asymptotic distribution. The thresholds of the algorithm are deduced and a simplified method is also derived. Performance of the proposed algorithm is simulated and analyzed. Simulations are carried out in AWGN channel to verify the validation of the proposed method. It is shown that our method can satisfy the detection and requirement with a low false alarm probability, and the simplified method also has good performances.