Study of polarization spectrum sensing based on stochastic resonance in partial polarized noise

Abstract

Wireless communications is one of the most rapidly developing segments of the telecommunications industry. A large amount of intelligent terminals occupy the radio spectrum, resulting in the reduction of radio spectrum resources. Cognitive radio, which requires rapid and exact spectrum sensing, is considered the most effective method to resolve this problem. This paper applies bistable stochastic resonance to polarization antenna spectrum sensing. To adhere to its requirements, frequency re-scaling is adopted to degrade high frequency to low frequency. Differential computing is used to wipe the direction current component from the output signal. Three algorithms including differential energy detection, generalized likelihood ratio test, generalized Hadamard ratio test, are then employed for spectrum sensing. The simulation experiment compares the three algorithms above in various channel conditions including additional white Gaussian noise, Rayleigh-fading, and partial polarized noise. The results indicate that bistable stochastic resonance can drastically enhance detection probability in low signal-to-noise-ratio, and partial polarized noise degenerates the accuracy of spectrum sensing.