1. Department of Electrical and Computer Engineering, Rutgers University, New Brunswick, NJ, USA
2. International College of Semiconductor Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
3. Institute of Communications Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
4. Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL, USA
5. Nokia Bell Labs, Murray Hill, NJ, USA