Key Laboratory of Knowledge Engineering with Big Data;
Ministry of Education.School of Computer Science and Information Engineering;
Hefei University of Technology;
Hefei 230601;
China;
Anhui Province Key Laboratory of Industry Safety and Emergency Technology;
Hefei 230601;
China;
Key Laboratory of Aerospace Information Security and Trusted Computing;
Ministry of Education.School of Cyber Science and Engineering;
Wuhan University;
Wuhan 430072;
China;
ultra-dense cellular networks(UDCN); cell association(CA); deep Q-learning; proportional fairness; Q-learning;