Cognitive network cooperative spectrum sensing method and system based on cyclic characteristics

The invention provides a cognitive network cooperative spectrum sensing method and system based on cyclic characteristics. The method comprises the following steps: receiving and sampling cognitive node data; estimating a cyclic spectral density function; selectively sending soft decision information; calculating a signal power index E and a signal quality index Q according to the cyclic spectral density estimation value of the signal; the cognitive node carries out local judgment according to the signal power index E to obtain a judgment result and judgment credibility, and 2bit soft judgment information is formed; whether judgment information is sent to an information fusion center (FC) is selected according to the signal quality index Q; and finally judging by the information fusion center. According to the method, the spectrum sensing accuracy of the authorization signal under the condition of low signal-to-noise ratio is improved; the whole process is realized by adopting a full-digital ...