Scientific Research

Here the reader can find a short profile of the author in what concerns his research activity in his scientific area of Signal Processing applied to Telecommunication Systems and other scientific activities.

-     After his Ph.D. in recursive adaptive structures for echo cancellation in data transmission, in 1992, the author extended his research activity to Spread Spectrum techniques. Since 1994 he developed Spread Spectrum systems for communication over power lines (PLC).

-     From 1999 to 2001, he participated in the National project “High Processing Gain Spread Spectrum Systems for Selective Noise Channels", financed by program Praxis XXI. In this project, new PN even sequences were developed, which presented low auto/crosscorrelation values, they existed in large numbers and, in limited bandwidth channels, they allowed very high processing gains. This project was continued until 2002, now financed by program POSI.

       Some of the more relevant publications that resulted from this work:

[1]     J. A. L. INÁCIO, J. A. GERALD, M. D. ORTIGUEIRA, “New PN Even Balanced Sequences for Spread Spectrum Systems,” EURASIP Journal on Wireless Communications and Networking – Regular Issue, No. 3, pp. 447-458, August 2005. (PDF)

[2]     J. A. L. INÁCIO, J. A. GERALD, M. D. ORTIGUEIRA, “New PN Even Balanced (PN-EB) Sequences for High Processing Gain DS-SS Systems”, Proc. MWSCAS’99 – 42nd Midwest Symposium on Circuits and Systems, New Mexico State University, Las Cruces, NM, MEXICO, Vol. 2, pp. 891-895, Agosto de 1999. (PDF)

[3]     J. A. L. INÁCIO, J. A. GERALD, M. D. ORTIGUEIRA, “Design of New PN Even Balanced (PN-EB) Sequences Suitable for High Processing Gain DS-SS Systems”, CDROM Proc. 10^th International Conference on Signal Processing Applications & Tecnology - ICSPAT’99, Orlando, FL, USA, November 1999. (PDF)

[4]    J. A. L. INÁCIO, J. A. GERALD, M. D. ORTIGUEIRA, “Communicación Sobre Lineas de Suministro de Energía”,  Information Tecnológica (ISSN 0716-8756), pp. 181-188, Vol. 11, N. 6, Dez. 2000. (PDF).

[5]    CESALTINA N. E. RICARDO, JOSÉ A. L. INÁCIO, JOSÉ A. B. GERALD, MANUEL D. ORTIGUEIRA, “New BCH-Derived Sequences for CDMA Systems”, Proceedings of The 36th IEEE Midwest Symposium on Circuits and Systems – MWSCAS’2003, Cairo, Egypt, December 2003. (PDF).

[6]    CESALTINA N. E. RICARDO, J. A. GERALD, M. D. ORTIGUEIRA, “Analysis of New Quasi-Orthogonal BCH-Derived Sequences for CDMA Applications,” XX Conference on Design of Circuits and Integrated Systems - DCIS´05, Lisbon, Portugal, November 2005. (PDF).

-    Since 2002 till 2005, he participated in the project “Cortical Visual Neuroprosthesis for the Blind - CORTIVIS”, financed by the EC Key Action 6: The Ageing Population and Disabilities. This project aimed at developing prototypes in the field of visual rehabilitation and to demonstrate the feasibility of a cortical neuroprosthesis, interfaced with the visual cortex, through which a limited but useful visual sense may be restored to profoundly blind people. URL: http://cortivis.umh.es/ . Other institutions that have participated in this project: Instituto de Bioingenieria, Facultad de Medicina, Universidad Miguel Hernandez, Dept. Physiology. Med., School University of Vienna; Centre National de la Recherche Scientifique, Unite de Neurosciences integratives et computationnelles, Gif sur Yvette; Departamento de Arquitectura y Tecnologia de Computadores, Facultad de Ciencias, Campus de Fuentenueva Granada; Faculte de Medicine de Montpellier; Biomedical Technologies S.L..

       Some of the more relevant publications that resulted from this work:

[1]     M. PIEDADE, J. GERALD, L. SOUSA, G. TAVARES, P. TOMÁS, “Visual Neuroprosthesis: A Non Invasive System for Stimulating the Cortex”, IEEE Trans. on CAS I – Regular papers, 6(12), pp. 2648-2662, December 2005. (PDF)

[2]     JOSÉ GERALD, GONÇALO TAVARES, MOISÉS PIEDADE, ELÍSIO VARELA, RICARDO RIBEIRO, “RF Link for Cortical Neuroprosthesis,” Proc. ISCAS’05 – 2005 IEEE International Symposium on Circuits and Systems, Kobe, Japan, May 2005. (PDF)

[3]    MOISÉS PIEDADE, JOSÉ GERALD, LEONEL SOUSA, GONÇALO TAVARES, Visual Cortical Neuroprosthesis: A System Approach, Chapter 2 of the book VLSI Circuits for Biomedical Applications, edited by Krzysztof Iniewski, Artech House, 2008. (PDF).

-      Since April 2005, he is the responsible for the project “Adaptive OFDM Communication System for Power Line Communication”, a collaboration between INESC-ID and ESTIG (Escola Superior de Tecnologia e Gestão - Beja),  financed by program POSI. This project aims at developing a simulation system for power line communication (PLC). The first work in this project respects to the power line characterization, confirming the experimental results already obtained by this team, in what respects the line impedance, the observed noise and attenuation. Then, we will develop a simulation system for PLC using adaptive OFDM with precoding, for data rates above 1 Mbps, enough versatile to optionally characterize the line channel, and self sustained in order to be an independent block in the global simulation system. In order to mitigate the adverse effects of the PLC medium, new OFMD transmission schemes will be developed. The effort will be aimed in two directions: on one hand, techniques to deal with the spectral nulls in the channel transfer function and on the other, techniques to address the fading time-dispersive nature of the channel.

      Some of the author's more relevant publications related with this work:

[1]    LUIS SIMÕES, JOSÉ GERALD, “A Communication System for Power Lines,” Proc. 5^th Conference on Telecommunications, Tomar, Portugal, April 2005. (PDF).

[2]     PAULO LOPES, GONÇALO TAVARES, JOSÉ GERALD, “A New Type of Normalyzed LMS Algorithm Based on the Kalman Filter”,  ICASSP’07, April 2007. (PDF).

[3]     PAULO LOPES, JOSÉ GERALD, “New Normalyzed LMS Algorithms Based on the Kalman Filter”, ISCAS’07, May 2007.(PDF).

-     In 2006-2007  the author participated in the project “Mobile Fading Channel Simulator" funded by INESC-ID. The aim of this project was to investigate, assess and demonstrate by means of a prototype, new algorithms for the real-time simulation of mobile-to-fixed and mobile-to-mobile slow-fading channels. Both frequency non-selective (flat fading) and frequency-selective channels were considered. The simulator may also be used to assess performance of information transmission systems over multiple input-multiple output (MIMO) channels and diversity combining scenarios. The work in the initial phase of this project was to establish, assess and validate the required algorithms and solve the relevant implementation problems. Once these difficulties were overcome, work were directed towards the development of a baseband prototype channel simulator (PCS). This prototype was composed of a hardware board interfacing to a personal computer (PC) via a USB interface. The board was developed using state of the art FPGAs and digital signal processors. An application running on the PC  interfaces with the user and allow complete configuration of the channel simulator. The PCS  allows assessment of the simulation algorithms and also demonstrates the validity and usefulness of the new mobile fading channel simulation concepts.

-    Since January 2008 he participates in project ICONS – Intercortical Neuronal Stimulator, funded by FCT. This project aims at implement an IC of the SOC – System on Chip - type, to be implanted in the visual cortex part of the brain in order to provide some useful vision to profound blind people.

-  Since January 2008 to December 2010 he participated in project Noise – Noise Reduction in Power Line Communication Channels, funded by the FCT (Project PTDC/EEA-TEL/67979/2006). This project aims at studying the power line as a physical layer for communications.

[1]  Paulo Alexandre Crisóstomo Lopes, João Pinto and José António Beltran Gerald “Modeling and Optimization of the Access Impedance of Power Line Channels”, International Symposium on Power Line Communications and Its Applications (ISPLC 2010), March 2010.(PDF).

[2] Paulo Alexandre Crisóstomo Lopes, João Pinto, José António Beltran Gerald, “Dealing with Unknown Impedance and Impulsive Noise in the Power Line Communications Channel,” IEEE Transactions on Power Delivery, to appear.

            -   “5^th Conference on Telecommunications – CONFTELE’05, Tomar, Portugal, April, 2005.

            -  "Terceiras Jornadas de Engenharia de Electrónica e Telecomunicações e de Computadores",  ISEL, Lisboa, Portugal, November, 2005.

            -  “2006 IEEE  Internatinal Symposium on Circuits and Systems” – ISCAS 2006, Island of Kos, Greece, May, 2006.

            -  “2011 IEEE  Internatinal Symposium on Circuits and Systems” – ISCAS 2011, Rio de Janeiro, Brasil, May, 2011.

             -   He is a reviewer of the Signal Processing Journal, IEEE Trans. on Wireless Communications, IEEE Signal Processing Letters, in 2006 he was a reviewer of the Australasian Physical and Engineering Sciences in Medicine Journal, and he is an IEEE member.

    -   In 1999-2000 he was the Coordenator of the specialization area of Electronic Systems and Computers of the M.Sc. program in the Electrotechnics and Computers Engineering course (MEEC).

       -   From October 2004 to December 2008 he belonged to the Equivalence Board of IST.

       -   In 2006-2008 he was the Coordenator of the specialization area of Electronics of the M.Sc. program in the Electrotechnics and Computers Engineering course (MEEC).

       -   Since 2007 he belong to the Prize Committee of INESC-ID.

      -   Since March 2012 he belongs to the Equivalence Board of IST.

           - In 2001 he supervised the Ph.D. thesis "New PN Codes for Spread Spectrum Systems" of the Master José António Lobato Inácio.

           - He has been supervising  several M.Sc. theses in the Electrotechnics and Computers Engineering course (MEEC) of IST every year, including more than 10 post-Bologna theses and more than 25 TFCs (final year work for the 5 year course before Bologna, which is equivalent in work to a present M.Sc. thesis).

            - Since 1998 he participated in 4 Ph.D. Juries and more than 10 M.Sc. Juries (besides the Juries of his own supervised students).