Gabriel Porto Villardi  received  his  B.E. in Electrical Engineering with emphasis in Telecommunications at the Federal Center for the Technological Education of Rio de Janeiro (CEFET-RJ), Brazil, in 2002. He joined Yokohama National University, Japan, as a Japanese government (Mombukagakusho) scholar where he received M.E. and  Ph.D. in Physics, Electrical and Computer Engineering in 2006 and 2009, respectively. From 1999 until 2000, he was an awardee of the FULBRIGHT/IIE/CAPES scholarship to pursue his studies at Clemson University, South Carolina, USA. He was a visiting research student with the Centre for Wireless Communications (CWC) at University of Oulu, Finland, during the summer of 2006. He joined the National Institute of Information and Communications Technology (NICT), in 2009, where he is now a senior researcher with the Wireless Systems Laboratory at Yokosuka Research Park, Japan. His current research interests span several areas in wireless communications such as massive MIMO beamforming, PHY layer design for white space (WS) cognitive radios, interference modeling of low height antennas systems in the TV bands, coexistence issues in cognitive radio technology, space-time codes and ad-hoc networks. He is senior member of IEEE, member of IEEE-SA, and actively contributed to IEEE 802.22, IEEE 802.11, IEEE 802.15 and IEEE 802.19 standardization working groups. From May 2014, he was the secretary of the IEEE 802.22b Task Group on "Enhancements for Broadband Services and Monitoring Applications in TVWS" until the standard completion in November 2015; and the secretary of the IEEE 802.22 Working Group on "Wireless Regional Area Networks (WRAN) in TVWS" until November 2016. From March 2019 to December 2020, he was a Visiting Scholar with the Qualcomm Institute of Calit2, University of California San Diego, La Jolla, CA, USA.