1. Centre for Telecommunication Research, School of Engineering, Sri Lanka Technological Campus, Padukka, Sri Lanka
2. Centro de Investigaçä em Tecnologias, Autónoma TechLab, Universidade Autónoma de Lisboa, Lisbon, Portugal
3. DISC/FEMTO-ST, University Bourgogne Franche-Comté, Montbéliard, France