[1] Yango Univ, Inst Intellectual Finance, Fuzhou 350015, Fujian, Peoples R China
[2] Shandong Univ Sci & Technol, Dept Informat Engn, Tai An 271019, Shandong, Peoples R China
[3] Univ Fed Piaui, Dept Elect Engn, BR-64049550 Teresina, Brazil
[4] Inst Telecomunicacoes, P-1049001 Lisbon, Portugal