Funding for this research was provided by:
Ministry of Science and Technology of the People's Republic of China (2018ZX03001029-004)
Article History
Received: 11 February 2018
Accepted: 11 April 2018
First Online: 25 April 2018
Authors’ information
: Qian Liu is currently working toward the Ph.D. degree with the School of Information and Communication Engineering, Beijing University of Posts and Telecommunications.
: The authors declare that they have no competing interests.
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