[4] [4] GUPTA M S, KUMAR K. Progression on spectrum sensing for cognitive radio networks:a survey, classification, challenges and future research issues[J]. Journal of Network and Computer Applications, 2019, 143(1):47-76.

[6] [6] KOLEY S, BEPARI D, MITRA D. Predictive multi-user dynamic spectrum allocation using hidden semi-Markov model[J]. Journal of Communications Technology & Electronics, 2018(63):1393-1405.

[8] [8] HABACHI O, HAYEL Y, El-Azouzi R. Optimal energy-delay tradeoff for opportunistic spectrum access in cognitive radio networks[J]. Telecommunications Systems, 2018, 67(4):763-780.

[9] [9] WANG H, WU B, YAO Y C, et al. Wideband spectrum sensing method based on channels clustering and hidden Markov model prediction[J]. Information, 2019, 10(11):331-345.

[10] [10] KUMAR A, SAHA S, BHATTACHARYA R. Wavelet transform based novel edge detection algorithms for wideband spectrum sensing in CRNs[J]. AEU-International Journal of Electronics and Communications, 2018(84):100-110.

[12] [12] CAPTAIN K M, JOSHI M V. SNR wall for cooperative spectrum sensing using generalized energy detector[C]// 2018 10th International Conference on Communication Systems & Networks. Bangalore, India:[s.n.], 2018:1-9.

[13] [13] SASSI I, ANTER S, BEKKHOUCHA A. A new improved Baum-Welch algorithm for unsupervised learning for continuous-time HMM using spark[J]. International Journal of Intelligent Engineering and Systems, 2020, 13(1):214-226.

[14] [14] TEKE O, VAIDYANATHAN P P. Extending classical multirate signal processing theory to graphs-part II:M-channel filter banks[J]. IEEE Transactions on Signal Processing, 2017, 65(2):423-437.

[15] [15] GNU Radio Academy. The GNU Radio Scheduler[EB/OL]. [2018-03-29]. https://wiki.gnuradio.org/index.php/Tutorials/.

[16] [16] RSSDR. Twin RX[EB/OL]. [2018-06-20]. https://www.ettus.com.cn/product/TwinRx.html/.