To whom correspondence should be addressed. E-mail: 07111032 @ bjtu. edu. cn Cao Jianfei, born in 1983. He received his B.S. degree at the Department of Electrical and Information Engineering at Htman University in 2006. He is cun~ntly working toward the Ph. D degree in communication and information system at Beijing Jiaotong University. His re- search interests include MIMO, network information and cooperative communication.