1. Department of Electrical and Computer Engineering, University of Victoria, Victoria, BC V8P 5C2, Canada
2. NVIDIA, Santa Clara, CA 95050, USA
3. School of Electronics, Peking University, Beijing 100871, China
4. InterDigital Communications, Inc., London EC2A 3QR, UK
5. Instituto de Telecomunicações, 3810-193 Aveiro, Portugal
6. Department of Electrical and Electronics Engineering, TOBB University of Economics and Technology, Ankara 06510, Turkey
7. Department of Signal Theory and Communications, Universidad Carlos III de Madrid, 28911 Leganés, Spain