1. Xidian University, School of Telecommunications Engineering, No. 2 South Taibai Road, Xi’an 710071, ChinabGuilin University of Electronic Technology, Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing, No. 1 Jinji Road, Guilin
2. Guilin University of Electronic Technology, Guangxi Colleges and Universities Key Laboratory of Satellite Navigation and Position Sensing, No. 1 Jinji Road, Guilin 541004, ChinaeGuangxi Experiment Center of Information Science, No. 1 Jinji Road, Guilin 54