Book Chapters:

B.1 TV White Space Spectrum Technologies: Regulations, Standards and Applications

Chin-Sean Sum, Gabriel Porto Villardi, Richard Paine, Alex Reznik and Mark Cummings, "TV White Space Use Cases", in TV White Space Spectrum Technologies, Crc Pr l Llc Publisher, ISBN 9781439848791, Oct. 2011.

Preprints:

Pin-Hsun Lin, Gabriel Porto Villardi, Zhou Lan and Hiroshi Harada, "Practical Design for Multiple-Antenna Cognitive Radio Networks with Coexistence Constraint", arXiv:1307.2430v1.

Journal Articles:

J.28 IEEE Transactions on Wireless Communications  2022

Govind R. Gopal, Elina Nayebi, Gabriel Porto Villardi and Bhaskar D. Rao, "Modified Vector Quantization for Small-Cell Access Point Placement with Inter-Cell Interference", IEEE Transactions on Wireless Communications, vol. 21, issue: 8, pp. 6387 - 6401, Doi: 10.1109/TWC.2022.3148996, Aug. 2022.

J.27 IEEE Open Journal of the Communications Society 2021

Govind R. Gopal, Bhaskar D. Rao and Gabriel Porto Villardi, "Access Point Placement for Hybrid UAV-Terrestrial Small-Cell Networks", IEEE Open Journal of the Communications Society, vol. 2, pp. 1826 - 1841, Doi: 10.1109/OJCOMS.2021.3100060, Jul. 2021.

J.26 IEEE Access 2020

Wei-Shun Liao, Ou Zhao, MIrza Kibria, Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, "Machine Learning Based Signal Detection for CoMP Download in Untra-Dense Small Cell Networks", IEEE Access, vol. 8, pp. 17454 - 17463, Doi: 10.1109/ACCESS.2020.2965631, Jan. 2020.

J.25 IEEE Transactions on Vehicular Technology 2019

Wei-Shun Liao, Mirza Kibria, Gabriel Porto Villardi, Ou Zhao, Kentaro Ishizu and Fumihide Kojima, "Coordinated Multi-point Downlink Transmission for Dense Small Cell Networks", IEEE Transactions on Vehicular Technology, vol. 68, issue: 1, pp. 431 - 441, doi: 10.1109/TVT.2018.2880788, Jan. 2019.

J.24 IEEE Wireless Communications 2018

Mirza Kibria, Kien Nguyen, Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, "Next Generation New Radio Small Cell Enhancement: Architectural Options, Functionality and Performance Aspects", IEEE Wireless Communications, vol. 25, issue: 4, pp. 120 - 128, doi: 10.1109/MWC.2018.1700277, Aug. 2018.

J.23 IEEE Transactions on Vehicular Technology 2018

Mirza Kibria, Kien Nguyen, Gabriel Porto Villardi, Wei-Shun Liao, Kentaro Ishizu and Fumihide Kojima, "A Stochastic Geometry Analysis of Multi-Connectivity in Heterogeneous Wireless Networks", IEEE Transactions on Vehicular Technology, vol. 67, issue: 10, pp. 9734 - 9746, doi: 10.1109/TVT.2018.2863280, Oct. 2018.

J.22 IEEE Transactions on Communications 2019

Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, "Reducing the Codeword Search Complexity of FDD Moderately Large MIMO Beamforming Systems", IEEE Transactions on Communications - vol. 67, issue: 1, pp. 273 - 287, doi: 10.1109/TCOMM.2018.2870862, Jan. 2019.

J.21 IEEE Access 2018 (Within Top 100 Accessed Articles of IEEE Xplore: July 2018 ~ March, 2019)

Mirza Kibria, Kien Nguyen, Gabriel Porto Villardi, Ou Zhao, Kentaro Ishizu and Fumihide Kojima, "Big Data Analytics, Machine Learning, and Artificial Intelligence in Next Generation Wireless Networks", IEEE Access, vol. 6, pp. 32328 - 32338, doi: 10.1109/ACCESS.2018.2837692, May. 2018. 

J.20 KICS Journal on Communication and Networks 2018

Haesik Kim, Gabriel Porto Villardi, Ma Jing, "Energy Efficient Dynamic Resource Allocation for Wireless Systems Using Receiver Puncturing Technique", KICS Journal of Communications and Networks, vol. 20, pp. 366 - 373, doi: 10.1109/JCN.2018.000052, Aug. 2018

J.19 IEEE Transactions on Vehicular Technology 2017

Mirza Kibria, Gabriel Porto Villardi, Wei-Shun Liao, Kien Nguyen, Kentaro Ishizu and Fumihide Kojima, "Outage Analysis of Offloading in Heterogeneous Networks: Composite Fading Channels", IEEE Transactions on Vehicular Technology, vol. 66, issue: 10, pp. 8990 - 9004, doi: 10.1109/TVT.2017.2703874, Oct. 2017.

J.18 IEEE Journal on Selected Areas in Communications 2017

Mirza Kibria, Gabriel Porto Villardi, Kien Nguyen, Wei-Shun Liao, Kentaro Ishizu and Fumihide Kojima, "Shared Spectrum Access Communications: A Neutral Host Micro Operator Approach", Special Issue on Deployment and Performance Challenges in 5G - IEEE Journal on Selected Areas in Communications (JSAC), vol. 35, issue: 8, pp. 1741 - 1753, doi: 10.1109/JSAC.2017.2710021, Aug. 2017.

J.17 IEEE Journal on Selected Areas in Communications 2017

Mirza Kibria, Gabriel Porto Villardi, Kien Nguyen, Kentaro Ishizu and Fumihide Kojima, "Heterogeneous Networks in Shared Spectrum Access Communications", Special Issue on Spectrum Sharing - IEEE Journal on Selected Areas in Communications (JSAC), vol. 35, issue: 1, pp. 145 - 158, doi: 10.1109/JSAC.2016.2633014, Jan. 2017.

J.16 IEEE Transactions on Vehicular Technology 2017

Gabriel Porto Villardi, Hiroshi Harada, Fumihide Kojima and Hiroyuki Yano, "Multi-Level Protection to Broadcaster Contour and its Impact on TV White Space Availability", IEEE Transactions on Vehicular Technology, vol. 66, issue: 2, pp. 1393 - 1407, doi: 10.1109/TVT.2016.2566675, Feb. 2017.

J.15 EURASIP Journal on Advances in Signal Processing 2016

Mirza Kibria, Gabriel Porto Villardi, Kentaro Ishizu, Fumihide Kojima and Hiroyuki Yano, "Resource Allocation in Shared Spectrum Access Communications for Operators with Diverse Service Requirements", EURASIP Journal on Advances in Signal Processing, 2016:83 doi: 10.1186/s13634-016-0381-8, Jul. 2016.

J.14 IEEE Transactions on Antennas and Propagations 2016

Gabriel Porto Villardi, Hiroshi Harada, Fumihide Kojima and Hiroyuki Yano, "Primary Contour Prediction based on Detailed Topographic Data and its Impact on TV White Space Availability", IEEE Transactions on Antennas and Propagations, vol. 64, issue: 8, pp. 3619 - 3631, doi: 10.1109/TAP.2016.2580164, Aug. 2016.

J.13 IEEE Internet of Things Journal 2016

Mirza Kibria, Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, "Throughput Enhancement of Multicarrier Cognitive M2M Networks: Universal-Filtered OFDM Systems", IEEE Internet of Things Journal, vol. 3, issue:5, pp.: 830 - 838, doi: 10.1109/JIOT.2015.2509259.

J.12 EURASIP Journal on Advances in Signal Processing 2015

Fang Yuan, Gabriel Porto Villardi, Fumihide Kojima and Hiroyuki Yano, "Channel Direction Information Probing for Multi-Antenna Radio System", EURASIP Journal on Advances in Signal Processing, 2015:79  doi: 10.1186/s13634-015-0263-5 Aug. 2015.

J.11 IEEE Communications Magazine 2013

Chin-Sean Sum, Gabriel Porto Villardi, Mohammad Azizur Rahman, Tuncer Baykas, Ha Nguyen Tran, Zhou Lan, Chen Sun, Yohannes Demessie Alemseged, Junyi Wang, Chunyi Song, Chang-Woo Pyo, Stanislav Filin and Hiroshi Harada, "Cognitive Communication in TV White Space: An Overview on Regulations, Standards and Technology", IEEE Communications Magazine, Vol. 51, issue: 7, Jul. 2013.

J.10 IEEE Wireless Communications 2012

Gabriel Porto Villardi, Chin-Sean Sum, Chen Sun, Yohannes Demessie Alemseged, Zhou Lan and Hiroshi Harada, "Efficiency of Dynamic Frequency Selection Based Coexistence Mechanisms for TV White Space Enabled Cognitive Wireless Access Points", IEEE Wireless Communications, vol. 19, issue 6, pp. 69 - 75, Dec. 2012.

J.9 IEICE Transactions on Communications 2012

Chin-Sean Sum, Gabriel Porto Villardi, Mohammad Azizur Rahman, Junyi Wang, Zhou Lan, Chunyi Song and Hiroshi Harada, "Hidden Node due to Multiple Transmission Power Level for White Space Radio Operating in the TV Bands", IEICE Transactions on Communications, vol. E95-A, No.10, pp.1749-1758.

J.8 IEEE Transactions on Vehicular Technology 2012

Chen Sun, Gabriel Porto Villardi, Zhou Lan, Yohannes Demessie Alemseged, Ha Nguyen Tran and Hiroshi Harada, "Optimizing Coexistence Performance of Secondary User Networks under Primary User Constraints for Dynamic Spectrum Access", IEEE Transactions on Vehicular Technology, vol. 61, issue 8, pp. 3665 - 3676, Oct. 2012.

J.7 IEEE Vehicular Technology Magazine 2012 (Within Top 25 Accessed Articles of IEEE Vehicular Technology Magazine: July ~ November, 2012)

Gabriel Porto Villardi, Giuseppe Abreu and Hiroshi Harada, "TV White Space Technology - Interference in Portable Cognitive Emergency Network", IEEE

Vehicular Technology Magazine - Special Issue on Applications of Cognitive Radio Networks,  vol. 7, issue 2, pp. 47-53, Jun. 2012 .

J.6 IEEE Wireless Communications 2011

Gabriel Porto Villardi, Yohannes Demessie Alemseged, Chen Sun, Chin-Sean Sum, Tran Ha Nguyen, Tuncer Baykas and Hiroshi Harada, “Enabling Coexistence of Multiple Cognitive Networks in TV White Space,” IEEE Wireless Communications, vol. 18, issue 4, pp. 32-40, Aug. 2011.

J.5 ISRN Communications and Networking 2011

Chin-Sean Sum, Gabriel Porto Villardi, Zhou Lan, Chen Sun, Yohannes Alemseged, Ha Nguyen Tran, Junyi Wang and Hiroshi Harada, "Enabling Technologies for a Practical Wireless Communication System Operating in TV White Space," ISRN Communications and Networking, vol. 2011, 12 pages, 2011.

J.4 IEEE Transactions on Consumer Electronics 2010 

Gabriel Porto Villardi, Giuseppe Abreu, Ryuji Kohno and Hiroshi Harada,“STBCs with Orthogonal Decoder for Highly Time-Selective Channels,” IEEE Transactions on Consumer Electronics, vol. 56, issue 2, pp. 380-387, May 2010. 

J.3 IEEE Transactions on Vehicular Technology 2008 

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “Modified Orthogonal Space-Time Block Codes for Time-Selective Fading Channels,” IEEE Transactions on Vehicular Technology, vol. 57, issue 6, pp. 3921 - 3927, Nov. 2008.

J.2 IEICE Transactions on Communications 2008 (.pdf)

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “Cumulative Decision Feedback Technique for Energy Constrained Wireless Sensor Networks,” IEICE Transactions on Communications, vol.E91-B, No.11, pp. 3768 - 3774, Nov. 2008. 

J.1 IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences 2006 (.pdf)

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “An Adaptive Frame-based Interpolation Method of Channel Estimation for Space-Time Block Codes in Moderate Fading Channels,” IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences - Special Issue on Multidimensional Signal Processing and its Applications, vol.E89-A, No.3, pp.660-669, Mar. 2006.

Conference Articles:

C.55 IEEE VTC -   Florence, Italy 2023

Govind R. Gopal,  Bhaskar D. Rao and Gabriel Porto Villardi, "Load Balancing in Small-Cell Access Point Placement", IEEE 97th Vehicular Technology Conference (VTC Spring 2023), Jun. 20 - 23, 2023.

C.54 IEEE Asilomar -   Pacific Grove, USA 2021 

Govind R. Gopal, Gabriel Porto Villardi and Bhaskar D. Rao, "Is Vector Quantization Good Enough for Access Point Placement?", Fifty-fifth IEEE Asilomar Conference on Signals, Systems and Computers (Asilomar 2021), Oct. 31 - Nov. 3, 2021. 

C.53 IEEE WCNC – Barcelona, Spain 2018

Mirza Golam Kibria, Kien Nguyen, Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, “Shared Resource Access High Capacity Wireless Networks: A Stochastic Geometry Framework”, Wireless Communications and Networks Conference (WCNC 2018), Apr. 15-18, 2018.

C.52 IEICE General Conference – Tokyo, Japan 2018

Mirza Golam Kibria, Kien Nguyen, Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, “Dual Connectivity in Shared Resource Access High Capacity Wireless Networks”, Proceedings of the 2018 IEICE General Conference, Mar. 20-23, 2018.

C.51 WPMC – Yogyakarta, Indonesia 2017

Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, “Reduced Complexity Decoder for FDD MIMO Beamforming Systems with Large Antenna Arrays”, Wireless Personal Multimedia Communications (WPMC 2017), Dec. 17-20, 2017.

C.50 WPMC – Yogyakarta, Indonesia 2017

Wei-Shun Liao, Mirza Golam Kibria, Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, “CoMP Set Formulation for Downlink Transmission in Dense Small Cell Networks”, Wireless Personal Multimedia Communications (WPMC 2017), Dec. 17-20, 2017.

C.49 IEEE VTC – Sydney, Australia 2017

Kim Haesik, Gabriel Porto Villardi and Jing Ma, “Energy Efficient Radio Resource Allocation Scheme Using Receiver Puncturing Technique for 5G Networks”, The IEEE 85th Vehicular Technology Conference  (VTC 2017 - Spring), June 4-7, 2017.

C.48 IEEE CSCN – Berlin, Germany 2016

Mirza Golam Kibria, Gabriel Porto Villardi, Wei-Shun Liao, Kien Nguyen, Kentaro Ishizu and Fumihide Kojima, “Offloading in HetNets Over Shadowed Nakagami-m Fading Channel”, The IEEE Conference on Standards for Communications & Networking (CSCN'16), Oct.31 - Nov.2, 2016.

C.47 IEEE P2MNET – UAE, Dubai 2016

Kien Nguyen, Gabriel Porto Villardi, Mirza Golam Kibria, Kentaro Ishizu and Fumihide Kojima, “An Enhancement of Multipath TCP Performance in Lossy Wireless Networks”, The 12th IEEE International Workshop on Performance and Management of Wireless and Mobile Networks (P2MNET 2016), Nov. 2016.

C.46 IEICE Smart Radio – Nagoya, Japan 2016

Jing Ma, Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, “An Efficient OBSS Coordination MAC Protocol for Dense Deployment WLAN”, IEICE Technical Committee on Smart Radio, Jul. 2016.

C.45 IEICE Smart Radio – Nagasaki, Japan 201

Kien Nguyen, Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, “An Experimental Study of Multipath TCP”, IEICE Technical Committee on Smart Radio, Jan. 2016.

C.44 WPMC - Hyderabad, India 2015 - Best Paper Award

Mirza Golam Kibria, Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, “Coexistence of Systems with Different Multicarrier Waveforms in LSA Communications,” Wireless Personal Multimedia Communications (WPMC 2015), Dec. 13-16, 2015.

C.43 IEICE SRW - Tokyo, Japan 2015

Hirokazu Sawada, Tomoshige Kan, Gabriel Porto Villardi, Kentaro Ishizu and Fumihide Kojima, “A Comparative Analysis of Measured Electric Field Strength of DTV and its Predictions”, IEICE Technical Committee on Short Range Wireless Communications (SRW 2015), Oct. 2015.

C.42 IEICE SRW – Akashi, Hyogo, Japan 2014

Yuan Fang, Gabriel Porto Villardi, Fumihide Kojima and Hiroyuki Yano, “Channel Direction Information Probing for Multi-Antenna Cognitive Radio System”, IEICE Technical Committee on Software Radio, May 2015.

C.41 IEICE SRW - Chiba, Japan 2014

Hirokazu Sawada, Tomoshige Kan,  Gabriel Porto Villardi and Kentaro Ishizu, “Wide Area Field Strength Measurement of DTV Broadcasting for TV White Space Area Estimation”, IEICE Technical Committee on Short Range Wireless Communications (SRW 2014), Oct. 2014.

C.40 IEEE ICC – Budapest, Hungary 2013

Pin-Hsun Lin, Zhou Lan, Gabriel Porto Villardi and Hiroshi Harada, “The Cognitive Radio in TV White Space with Coexistence Constraint”, International Conference on Communications 2013 (ICC 2013), Jun. 2013.

C.39 IEEE WCNC – Shanghai, China 2013

Gabriel Porto Villardi and Hiroshi Harada, “Computer Prediction of Primary Contour and Service Areas for Unlicensed Radio Systems Operating in TV White Space”, Wireless Communications and Networking Conference (WCNC 2013), Apr. 2013.

C.38 IEEE WCNC – Shanghai, China 2013

Zhou Lan, Keiichi Mizutani, Gabriel Porto Villardi and Hiroshi Harada, “Design and Implementation of a Wi-Fi Prototype System in TVWS Based on IEEE 802.11af”, Wireless Communications and Networking Conference (WCNC 2013), Apr. 2013.

C.37 IEICE Software Radio – Tokyo, Japan 2013

Ha Nguyen Tran, Gabriel Porto Villardi, Zhou Lan and Hiroshi Harada, “Utilizing Multi-Location Option for the Coexistence Among TVWS Devices”, IEICE Technical Committee on Software Radio, Feb. 2013.

C.36 IEICE Short Range Wireless – Tokyo, Japan 2012

Zhou Lan, Keiichi Mizutani, Gabriel Porto Villardi, Ha-Nguyen Tran, and Hiroshi Harada "An Overview of Standardization Development of IEEE 802.11af for WiFi in TVWS", SRW2012-11, Aug. 2012.

C.35 IEICE Software Radio – Kagoshima, Japan 2012

Gabriel Porto Villardi and Hiroshi Harada, “Computer Prediction of Broadcaster Contour and Service Areas for VHF/UHF Unlicensed White-Space Radio Systems”, IEICE Technical Committee on Software Radio, Jul. 2012.

C.34 IEEE WCNC – Paris, France 2012

Gabriel Porto Villardi, Chen Sun, Yohannes Demessie Alemseged and Hiroshi Harada, “Coexistence of TV White Space Enabled Cognitive Wireless Access Points,” Wireless Communications and Networking Conference (WCNC 2012), Apr. 2012.

C.33 IEEE WCNC – Paris, France 2012

Yohannes D. Alemseged, Gabriel Porto Villardi, Chen Sun, Ha Nguyen and Hiroshi Harada, “Distributed Decision Making to Improve Link Quality in Coexisting TVWS Secondary Networks,” Wireless Communications and Networking Conference (WCNC 2012), Apr. 2012.

C.32 IEEE WCNC – Paris, France 2012

Chen Sun, Gabriel Porto Villardi, Zhou Lan, Yohannes D. Alemseged, Ha Nguyen and Hiroshi Harada, “Coexistence of Secondary User Networks under Primary User Constraints in TV White Space,” Wireless Communications and Networking Conference (WCNC 2012), Apr. 2012.

C.31 IEICE Software Radio – Yokosuka, Japan 2012

Zhou Lan, Chen Sun, Yohannes Demessie Alemseged, Gabriel Porto Villardi, Ha Nguyen Tran and Hiroshi Harada, “WiFi in TVWS - An Overview of IEEE 802.11af”, IEICE Technical Committee on Software Radio, Mar. 2012.

C.30 IEICE Software Radio – Kagoshima, Japan 2012

Gabriel Porto Villardi and Hiroshi Harada, “Interference Level Modeling of Low-Height Antenna Wireless Devices in TV Bands”, IEICE Technical Committee on Software Radio, Jan. 2012.

C.29 IEICE Software Radio – Kagoshima, Japan 2012

Yohannes Demessie Alemseged, Gabriel Porto Villardi, Chen Sun, Ha Nguyen Tran and Hiroshi Harada, “Coexistence of TVWS Secondary Networks via Optimum and Sub-optimum Power Selection Strategies”, IEICE Technical Committee on Software Radio, Jan. 2012.

C.28 IEICE Software Radio – Kagoshima, Japan 2012

Zhou Lan, Chen Sun, Yohannes Demessie Alemseged, Gabriel Porto Villardi, Ha Nguyen Tran and Hiroshi Harada, “A Resource Allocation Algorithm for WLAN and WRAN System Coexistence in TVWS”, IEICE Technical Committee on Software Radio, Jan. 2012.

C.27 IEICE Software Radio – Kagoshima, Japan 2012

Chen Sun, Gabriel Porto Villardi, Zhou Lan, Yohannes Demessie Alemseged, Ha Nguyen Tran and Hiroshi Harada, “Coexistence of Secondary User Networks Under Primary User Constraints in TV White Space”, IEICE Technical Committee on Software Radio, Jan. 2012.

C.26 ICST Crowncom – Osaka, Japan 2011

Gabriel Porto Villardi, Giuseppe Thadeu Freitas de Abreu and Hiroshi Harada, “Stochastic-Geometric Model of Expected Service Area for Cognitive TV White Space Wireless Networks,” International ICST Conference on Cognitive Radio Oriented Wireless Networks (Crowncom 2011), Jun. 2011.

C.25 ICST Crowncom – Osaka, Japan 2011

Lidia Soraya Contreras Avila, Gabriel Porto Villardi, Ryuhei Funada and Hiroshi Harada, “An Investigation into the Spectrum Occupancy in Japan in the Context of TV White Space Systems,” International ICST Conference on Cognitive Radio Oriented Wireless Networks (Crowncom 2011), Jun., 2011.

C.24 IEICE Software Radio – Matsue, Japan 2011

Gabriel Porto Villardi, Chin-Sean Sum, Chen Sun, Yohannes Demessie Alemseged, Zhou Lan and Hiroshi Harada, “On the Efficiency of Dynamic Frequency Selection Based Coexistence Mechanisms for TV White Space Enabled Cognitive Networks in Japan”, IEICE Technical Committee on Software Radio, Apr. 2011.

C.23 IEICE Software Radio – Matsue, Japan 2011

Yohannes Demessie Alemseged, Chen Sun, Zhou Lan, Chin-Sean Sum, Ha Nguyen Tran, Gabriel Porto Villardi and Hiroshi Harada, “Television White Space Database Access by Personal Portable Devices”, IEICE Technical Committee on Software Radio, Apr. 2011.

C.22 IEICE Software Radio – Matsue, Japan 2011

Chen Sun, Zhou Lan, Yohannes Demessie Alemseged, Ha Nguyen Tran, Chin-Sean Sum, Gabriel Porto Villardi and Hiroshi Harada, “On the Control of Client Devices in TV White Space”, IEICE Technical Committee on Software Radio, Apr. 2011.

C.21 IEICE Software Radio – Matsue, Japan 2011

Chin-Sean Sum, Zhou Lan, Chen Sun, Yohannes Demessie Alemseged, Ha Nguyen Tran, Gabriel Porto Villardi and Hiroshi Harada, “IEEE 802.11af Standardization Activities: TVWS Security Issues”, IEICE Technical Committee on Software Radio, Apr. 2011.

C.20 IEICE Software Radio – Kyushu, Japan 2011

Stanislav Filin, Junyi Wang, Azizur Rahman, TUncer Baykas, Chin-Sean Sum,  Gabriel Porto Villardi and Hiroshi Harada, “Introduction to IEEE SCC41 White Space Radio Group”, IEICE Technical Committee on Software Radio, Jan. 2011.

C.19 1st Brazil-Japan Symposium on Advances in Digital Television - Sao Paulo, Brazil 2010 - Keynote Speech (invited)

Gabriel Porto Villardi, Yohannes Demessie Alemseged, Chen Sun, Chin-Sean Sum and Hiroshi Harada,“Cognitive Radio Technology in TV Bands", 1st Brazil-Japan Symposium on Advances in Digital Television, Dec., 2010.

C.18 IEEE CogCloud - Istanbul, Turkey 2010 

Tuncer Baykas, Junyi Wang, Mohammad Azizur Rahman, Tran Ha Nguyen, Chunyi Song, Stanislav Filin, Yohannes Demessie Alemseged, Chen Sun, Gabriel Porto Villardi, Chin-Sean Sum, Zhou Lan and Hiroshi Harada,“Overview of TV White Spaces: Current Regulations, Standards and Coexistence Between Secondary Users,” IEEE International Workshop on Cognitive Wireless Cloud Networks (CogCloud 2010), Sept., 2010. 

C.17 IEICE Radio Communication Systems - Kagoshima, Japan 2010 

Chin-Sean Sum, Gabriel Porto Villardi, Junyi Wang, Tunce Baykas, Zhou Lan, Mohammad Azizur Rahman, Chunyi Song, Chen Sun, Yohannes Demessie Alemseged, Tran Ha Nguyen, Stanislav Filin and Hiroshi Harada, “Cross Layer Design of a Wireless Communication System in TV White Space", IEICE Technical Conference on Radio Communication Systems (RCS2010-104), pp. 153-158, Aug. 2010.

C.16 IEEE DYSPAN - Singapore 2010 

Hiroshi Harada, Tuncer Baykas, Chin-Sean Sum, Homare Murakami, Kentaro Ishizu, Stanislav Filin, Yohannes Demessie Alemseged, Tran Ha Nguyen, Chen Sun, Mohammad Azizur Rahman, Zhou Lan, Chang-Woo Pyo, Gabriel Porto Villardi, Chunyi Song, Ryuhei Funada and Fumihide Kojima,“Research, Development and Standards Related Activities on Dynamic Spectrum Access and Cognitive Radio,” IEEE Dynamic Spectrum Access Networks (DYSPAN 2010), Apr., 2010. 

C.15 IEEE CCNC - Las Vegas, USA 2010 

Chunyi Song, Yohannes Demessie Alemseged, Tran Ha Nguyen, Gabriel Porto Villardi, Chen Sun, Stanislav Filin and Hiroshi Harada, “Adaptive Two Thresholds Based Energy Detection for Cooperative Spectrum Sensing,” IEEE Consumer Communications and Networking Conference (CCNC 2010), Jan., 2010. 

C.14 ITS - Kumamoto, Japan 2009 

Jian Rong Loh, Gabriel Porto Villardi and Ryuji Kohno, “Analog Network Coding of Spreaded Signals with Packet Combining,” IEICE Technical Conference on Intel ligent Transport Systems (WBS2009-45), pp.49-54, Dec. 2009. 

C.13 RCS - Kyoto, Japan 2009 

Yohannes Demessie Alemseged, Chen Sun, Tran Ha Nguyen, Gabriel Porto Villardi and Hiroshi Harada, “Cross Layer Approach of Distributed Spectrum Sensing,” IEICE Technical Conference on Radio Communication Systems (RCS2009-129), pp. 111-115, Oct. 2009.

C.12 IEEE ICCS - Guangzhou, China 2008 

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “Performance of STBCs with Linear Maximum Likelihood Decoder in Time-Selective Channels,” IEEE International Conference on Communications Systems (ICCS 2008), Nov. 19-21, 2008. 

C.11 SITA - Kinugawa, Tochigi, Japan 2008 

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “Performance of STBCs with Linear Maximum Likelihood Decoder in Time-Selective Channels,” 31th Symposium on Information Theory and Applications (SITA 2008), Oct. 7-10, 2008. 

C.10 WPMC - Jaipur, India 2007 

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “Cumulative Decision Feedback Techniques for Energy Constrained Wireless Sensor Networks,” Wireless Personal Multimedia Communications (WPMC 2007), Dec. 03-06, 2007.

C.9 SITA - Kashiko jima, Mie, Japan 2007 

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “Empirically Optimized Decision Feedback for Wireless Sensor Networks,” 30th Symposium on Information Theory and Applications (SITA 2007), Nov. 27-30, 2007.

C.8 SITA - Hakodate, Hokkaido, Japan 2006 

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “A Hybrid Decision Feedback Forward Error Correction Approach for Energy Constrained Sensor Networks,” 29th Symposium on Information Theory and Applications (SITA 2006), Nov. 28- Dec. 01, 2006. 

C.7 SITA - Hakodate, Hokkaido, Japan 2006 

Vinicius C. de Oliveira, Gabriel Porto Villardi and Ryuji Kohno, “A Cross-Layer Approach for Byzantine Fault-Tolerance in Sensor Networks,” 29th Symposium on Information Theory and Applications (SITA 2006), pp. 125-128 (volume 1), Nov. 28-Dec. 01, 2006. 

C.6 WPMC - San Diego, USA 2006 

Vinicius C. de Oliveira, Gabriel Porto Villardi and Ryuji Kohno, “Algorithms for Byzantine Fault-Tolerance in Sensor Networks and their Optimal Solutions,” Wireless Personal Multimedia Communications (WPMC 2006), Sept. 17-20, 2006.

C.5 SITA - Tancha-Bay, Okinawa, Japan 2005 

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “Performance of Modified Orthogonal Space-Time Block Codes in Nakagami Fading Channels,” 28th Symposium on Information Theory and Applications (SITA 2005), pp. 555-558 (volume 2), Nov. 20-23, 2005. 

C.4 SITA - Tancha-Bay, Okinawa, Japan 2005 

Vinicius C. de Oliveira, Gabriel Porto Villardi and Ryuji Kohno, “A Novel Byzantine Algorithm-Based Scheme for Fault Tolerance in Sensor Networks,” 28th Symposium on Information Theory and Applications (SITA 2005), pp. 621-624 (volume 2), Nov. 20-23, 2005. 

C.3 IEEE Asilomar - Pacific Grove, USA 2005 

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “Modified Orthogonal Space-Time Block Codes for Time-Selective Fading Channels,” Thirty-ninth IEEE Asilomar Conference on Signals, Systems and Computers (Asilomar 2005), Oct. 30 - Nov. 2, 2005. 

C.2 WPMC - Aalborg, Denmark 2005 

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “An Adaptive Frame-based Interpolation Method of Channel Estimation for Space-Time Block Codes in Moderate Fading Channels,” Wireless Personal Multimedia Communications (WPMC 2005), Sept. 17-22, 2005. 

C.1 SITA - Gero, Gifu, Japan 2004 

Gabriel Porto Villardi, Giuseppe Abreu and Ryuji Kohno, “A Lagrangean Method of Channel Estimation for Space-Time Block Codes in Moderate Fading Channels,” 27th Symposium on Information Theory and Applications (SITA 2004), pp. 335-338, Dec. 14-17, 2004.