[Sheng, Su;Zeng, Xiangjun] Changsha Univ Sci & Technol, Coll Elect & Informat Engn, Changsha 410077, Hunan, Peoples R China.^[Li, K. K.;Chan, W. L.] Hong Kong Polytech Univ, Dept Elect Engn, Kowloon, Hong Kong, Peoples R China.^[Shi, Dongyuan;Duan, Xianzhong] Huazhong Univ Sci & Technol, Coll Elect & Elect Engn, Wuhan 430074, Peoples R China.