Funding for this research was provided by:
National Natural Science Foundation of China (Nos. 61372076, 61701375)
Shaanxi Key Research and Development Program (No. 2017GY-080)
Guangxi Science Foundation (No. 2017GXNSFBA198231)
Foundation of Science and Technology on Communication Networks Laboratory (KX172600031)
111 Project (No. B08038)
National Natural Science Foundation of China (61705048)
Article History
Received: 29 January 2018
Accepted: 29 March 2018
First Online: 11 April 2018