Phase Difference Variance Based Low Complexity Spectrum Sensing Scheme

Considering the dynamics of vacant spectrum in cognitive radio networks, spectrum sensing is one of the most challenging technologies. However, traditional spectrum sensing technologies fail to resolve the contradiction between accuracy and complexity. To solve this paradox, this paper proposes a novel spectrum sensing scheme based on the distribution of phase difference (PD) between noise-perturbed signal and Gaussian noise. By using the variance of PD as the test statistics, the proposed PD variance detection (PDVD) is formulated for efficient spectrum sensing and its performance is analyzed under Rayleigh fading and Gaussian noise, which has a low complexity of O(K) and is immune to the noise uncertainty in contrast to the energy detection scheme. Both simulations and field measurement results show that the proposed PDVD can achieve a performance gain of 2 - 4 dB for SNR requirement compared to the energy detection scheme when the sample length reaches 500.