1. College of Communication EngineeringArmy Engineering University of PLANanjing210007People's Republic of China
2. Key Lab of Broadband Wireless Communication and Sensor Network Technology, Ministry of EducationNanjing University of Posts and TelecommunicationsNanjing210016People's Republic of China
3. Nanjing Institute of Telecommunication TechnologyNanjing210007People's Republic of China
4. Department of Electrical and Computer EngineeringConcordia UniversityMontrealQCH3G 1M8Canada