Aiming at solving the problems such as time consuming and application limiting presented in the existing synchronous cooperative spectrum sensing schemes,a triggered asynchronous scheme based on Dempster-Shafer(D-S) t...Aiming at solving the problems such as time consuming and application limiting presented in the existing synchronous cooperative spectrum sensing schemes,a triggered asynchronous scheme based on Dempster-Shafer(D-S) theory was proposed.Sensing asynchronously,each cognitive user calculated the confidence measure functions with double threshold spectrum sensing method.When the useful report was received by the fusion center,a fusion process would be triggered.Then the sensing results were fused together based on D-S theory.The analysis and simulation results show that the proposed scheme can improve the spectrum sensing efficiency and reduce the calculation amount of the fusion center compared with the existing schemes.展开更多
We propose and demonstrate a simplified and tunable frequency interval optical frequency comb(OFC) generator based on a dual-drive Mach-Zehnder modulator(DD-MZM) using a single continuous-wave(CW) laser and low-power ...We propose and demonstrate a simplified and tunable frequency interval optical frequency comb(OFC) generator based on a dual-drive Mach-Zehnder modulator(DD-MZM) using a single continuous-wave(CW) laser and low-power radio frequency(RF) driven signal. A mathematical model for the scheme is established. The 21-and 29-mode OFCs with frequency interval ranging from 6 GHz to 40 GHz are obtained under DD-MZM driven by a low-power RF signal within a maximum bandwidth of 1.12 THz. The generated OFCs exhibit spectral flatnesses of less than 0.5 d B and 0.8 d B within bandwidths of 160 GHz and 400 GHz, respectively.展开更多
基金Science and Technology Projects of Xuzhou City,China(No.XX10A001)Jiangsu Provincial National Natural Science Foundation of China(No:BK20130199)
文摘Aiming at solving the problems such as time consuming and application limiting presented in the existing synchronous cooperative spectrum sensing schemes,a triggered asynchronous scheme based on Dempster-Shafer(D-S) theory was proposed.Sensing asynchronously,each cognitive user calculated the confidence measure functions with double threshold spectrum sensing method.When the useful report was received by the fusion center,a fusion process would be triggered.Then the sensing results were fused together based on D-S theory.The analysis and simulation results show that the proposed scheme can improve the spectrum sensing efficiency and reduce the calculation amount of the fusion center compared with the existing schemes.
基金supported by the National Natural Science Foundation of China(No.61571251)the Public Technical Application Research Project of Zhejiang(No.2015C34004)+2 种基金the Discipline Open Fund Project of Zhejiang(No.xkxl1534)the National Education Research of Information Technology(No.146232081)the K.C.Wong Magna Fund in Ningbo University
文摘We propose and demonstrate a simplified and tunable frequency interval optical frequency comb(OFC) generator based on a dual-drive Mach-Zehnder modulator(DD-MZM) using a single continuous-wave(CW) laser and low-power radio frequency(RF) driven signal. A mathematical model for the scheme is established. The 21-and 29-mode OFCs with frequency interval ranging from 6 GHz to 40 GHz are obtained under DD-MZM driven by a low-power RF signal within a maximum bandwidth of 1.12 THz. The generated OFCs exhibit spectral flatnesses of less than 0.5 d B and 0.8 d B within bandwidths of 160 GHz and 400 GHz, respectively.