1. Technology and Intellectual Property Rights Department, Fractus, 08190 Barcelona, Spain
2. Electronics and Communications Department, Universitat Ramon Llull, 08022 Barcelona, Spain
3. Systems and Concept, Sony Mobile, Redwood City, CA 94085, USA
4. Bluetest AB, Lindholmsallén 10, 417 55 Gothenburg, Sweden
5. Department of Signal Theory and Communications , Universitat Politècnica de Catalunya, 08034 Barcelona, Spain