Abstract:

As a rapid,correct and efficient spectrum detection algorithm is necessary for cognitive radio,this papermainly focuses on the spectrum sensing under ultra- low signal- to- noise ratio (SNR,less than －20dB).In the in-vestigation,first,a Duffing oscillator spectrum sensing model with strong nonlinearity is established based on thetheory of chaotic dynamics and the characteristics of spectrum sensing.Next,by introducing a dimensionless coeffi-cient as the transformation parameter of the system,the equivalence relationship between oscillators with differentdriving forces is derived.Then,a spectrum sensing approach based on the array Duffing oscillator is proposed todetect signals in a frequency band, Finally, the detection performance of the established model is numerically ana-lyzed.The results indicate that,as compared with the conventional spectrum detection methods,the proposed ap-proach is simpler to implement and is of higher detection performance.It is thus more applicable in practice.

Key words: spectrum detection, spectrum sensing, Duffing oscillator, ultra- low SNR, array