**Superimposed Training-Aided Channel Estimation for Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing Systems over High-Mobility Environment**

Han Zhang1, Xianhua Dai2, Daru Pan1 and Shan Gao1

*1School of Physics and Telecommunications Engineering, South China Normal University, Guangzhou 2School of Information Science and Technology, SUN Yat-sen University, Guangzhou China* 
