1. Department of Electronics and Radio EngineeringCollege of Electronics and InformationKyung Hee UniversityGlobal Campus, 1732, Deogyeong‐daero, Giheung‐guGyeonggi‐doYongin‐si17104Republic of Korea
2. Electronics and Telecommunications Research Institute (ETRI)218 Gajeong‐ro, Yuseong‐guDaejeon34129Republic of Korea