1. Department of Electrical and Electronics Engineering, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
2. Luxembourg Institute of Science and Technology, Esch-sur-Alzette, Luxembourg
3. Instituto Universitario de Investigación y Desarrollo Tecnológico, Universidad Tecnológica Metropolitana, Santiago, Chile
4. Centre for Wireless Communications, University of Oulu, Oulu, Finland