1. Wired into Nature: The Telegraph and the North American Frontier;James,2018
2. Information from: http://www.360doc.com/content/20/0413/06/66394675_905595439.shtml.
3. Information from: https://www.cnblogs.com/zzl112893/p/13295372.html?utm_source=tuicool.
4. the future development and commercial progress of 5G;Peng;Changjiang Information & Communications,2021
5. OPTIMAL POWER ALLOCATION FOR COGNITIVE RADIO UNDER INTERFERENCE OUTAGE CONSTRAINT1;Lu Luxi,2010