1. Electronics and Telecommunications Department; University of the State of Rio de Janeiro; Campus F. Negrão de Lima 20559-900 Rio de Janeiro Brazil
2. Electrical Enginnering Program (COPPE) and Polytechnic School (POLI); Federal University of Rio de Janeiro (UFRJ); 21941-901 Rio de Janeiro RJ Brazil
3. Centro Algoritmi; University of Minho; Campus de Azurém 4800-058 Guimarães Portugal